ET FAQ

Statements contained herein are of a general nature and should not be construed as personal advice in lieu of recommendations by your physician or other relevant professional consultant.

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Essential thrombocythemia is one of the myeloproliferative diseases (MPD). It is the MPD variant which is characterized by platelet counts greater than 400,000. The “big four” MPDs also include polycythemia vera (PV), Agnogenic Myeloid Metaplasia (AMM), secondary myelofibrosis (MF) and chronic myelogenous leukemia (CML). There are also a group of rarer, atypical MPDs: eosinophilic disorders; systemic mastocytosis; 8p11 myeloproliferative syndrome; juvenile myelomonocytic leukemia; neutrophilic leukemia; chronic eosinophilic leukemia, hypereosinophilic syndrome; chronic monomyelocytic leukemia, chronic basophilic leukemia and unclassified MPD. Each of these variants have predominant features which permit classifications which are named for the cell type showing the most marked involvement. There is a great deal of overlap in the features of these various syndromes and transition from one to another is common. This is discussed in greater detail below. Note-this is not to be confused with Thrombocytopenia (low platelets). And finally there are myelodysplastic syndromes.

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"Myelo" is the Greek word for marrow "Proliferative" means growing or reproducing "Disease" is the improper function of a body organ. MPD is literally "Marrow Proliferative Disease" or improper function of the bone marrow organ. Bone marrow is the body's blood-forming (hematopoeitic) organ. It contains blood-forming cells called "hematopoeitic precursor or stem cells" that have two important functions:

1. self-renewal to maintain a pool of stem cells for future proliferation or growth.
2. ability to mature into adult blood cells that will leave the marrow and enter the circulation.. These precursor cells produce several types of blood cells; red blood cells (RBC), some varieties of white blood cells (WBC) and platelets. Because of this versatility, they are called "pluripotential hematopoeitic precursor cells ("PHPC"). Each PHPC is a stem cell that can reproduce itself (clone) as well as produce a number of daughter cells (blasts). Normal bone marrow is composed of a family of hematopoeitic clones all reproducing themselves and forming daughter cells that will, in turn, develop into red blood cells, white blood cells and platelets. The dedicated daughter cells divide over and over again and it is their growth that fills the marrow with the diverse types of immature and developing blood cells that are seen in a normal bone marrow specimen. The normal marrow also balances production of different cell types so they appear in the blood in their proper proportions.

In MPD, one abnormal PHPC clone has a growth advantage that allows it to overgrow at the expense of the normal PHPC clones. While this PHPC clone is "abnormal", it is still able to self-renew and to produce several types of blood cells. The cells produced by the abnormal clone may be difficult to distinguish from those produced by normal cells. But what we do have in the myeloproliferative disorders is abnormal over or under production of a particular cell type. Thus MPD involves the improper balance between production of different blood cell types just as much as it involves abnormality of any given blood cell type.

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Thrombocythemia (or thrombocytosis) is defined as the occurrence of a platelet count in excess of 400,000 per micro liter in the setting of a myeloproliferative disease. When this is the predominant abnormality, the syndrome is classified as essential thrombocythemia. Abnormal megakaryocytic proliferation (platelet precursors) is seen in all variants of MPD and elevated platelet counts is common in PV, CML and the proliferative states of AMM. On the other hand, ET patients can also have elevated white cell count (WBC), but not hematocrit (HCT) and hemoglobin (HG) counts so a careful differential diagnosis is essential. Polycythemia vera is the only MPD where HCT and HG are elevated.

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No one knows why it develops. In all of the myeloproliferative disorders, the stem cell that is capable of producing red cells, certain white cells and platelets somehow goes haywire and no longer keeps the blood elements produced by the marrow in balance. In essential thrombocythemia, the marrow produces too many platelets. Recently, there have been a series of publications in the medical literature identifying a JAK2 tyrosine kinase mutation that is found in the majority of PV patients and in some ET and MF patients. This mutation, like the bcr-abl tyrosine kinase targeted by Gleevec in CML, is allowing researchers to work on finding target therapies for our diseases and to continue searching for other molecular markers that can be targeted for better therapies.

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The diagnosis of essential thrombocythemia is primarily one of exclusion. If platelet counts are elevated with:

1. no identifiable cause of secondary thrombocytosis i.e. from infection, cancer or other disease state);
2. the red cell volume is normal (excludes polycythemia vera);
3. iron is present in the bone marrow or reduced iron stores have been depleted by oral iron administration for one month without inducing an increase in hemoglobin;
4. collagen fibrosis is absent from the bone marrow biopsy(excludes myelofibrosis); and
5. the Philadelphia chromosome is absent from the bone marrow aspirate (excludes chronic myelogenous leukemia).

However, in several 1997 publications and meeting lectures, there is work towards an European Consensus on the Diagnostic Criteria of Essential Thrombocythemia (ET). The proposed diagnostic criteria are

See JJ Michiels et al, Proposal for revised diagnostic criteria of essential thrombocythemia and polycythemia vera by the Thrombocythemia Vera Study Group. Sem Thromb Hemostas 1997; 23:339-347; JJ Michiels et al Diagnosis, Pathogenesis and Treatment of Myeloproliferative Disorders Essential Thrombocythemia, Polycythemia Vera and Idiopathic Myelofibrosis*, Good Heart Institute MPD Center Europe, Rotterdam Institute of Pathology, Cologne, Department of Clinical Hematology, Academic Medical Center, Amsterdam and The European Working Group on Myeloproliferative Disorders (EWGMPD) *Proceedings of the Rotterdam MPD-Workshop March 13-14, 1998. In press Netherlands Journal of Medicine.

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By the criteria discussed above. If other disease states such as cancer, infection, etc. have been ruled out and the bone marrow findings are present, then the diagnosis is primary thrombocythemia.

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Essential thrombocytosis, thrombocytosis, primary thrombocytosis, ET.

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This is a chronic condition. The only potential cure at the moment is a matched donor bone marrow transplant. Most ET patients are not eligible for this procedure. Because of its associated risk and expense, bone marrow transplants are generally reserved for life-threatening diseases. ET patients generally do not fall in this category. But a lot can be done to reduce symptoms and risks of complications.

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ET patients have an excellent chance of living out a normal life span if properly monitored and treated as necessary. We had an ET patient in our mpd-net online discussion group who lived to 92 and died of diseases of old age. Forget the old statistics in the medical literature which scared some of us half to death when we were diagnosed in the 80's. Many physicians did not routinely check platelet counts and this condition would be diagnosed after someone had a heart attack or stroke and was already in trouble. It also once was thought to be a disease of the elderly. The youngest in our mpd-net support group was diagnosed at age 6 years old.

Do keep in mind that this is a chronic hematologic malignancy and it is prudent to be monitored regularly by a hematologist, it is important to report any symptoms such as visual disturbances, unexplained pain, numbness, tingling, bruising to your physician, and for those who have had symptoms from their ET, treatment will be required. But it can be controlled, and you can live with it for a long time.

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The published annual incidence for ET ranges from 0.1-2.4/100,000. It is rare and is classified as an orphan disease. Mesa RA, Tefferi A et al, The incidence and Epidemiology of essential thrombocythemia and agnogenic myeloid metaplasia: an Olmstead Country study. Blood 1997; 90 (supp 1): abstract 1547; Chaiter Y et al, High incidences of myeloproliferative disorders is Ashkezi Jews in Northern Israel, Leuk Lymph 1992; 7:251-255; Dougan LE et al, The effect of diagnostic review on the estimated incidence of lymphatic and hematopoeitic neoplasm's in Western Australia. Cancer 1981; 48:866-872.

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In essential thrombocythemia, in addition to elevated platelet counts, platelets generally can be abnormal in size, shape, density and function. Spontaneous aggregation (clumping) can occur putting ET patients at higher risk for clotting events. There can also be an increased risk of bleeding. According to Dr. Gilbert, clinical manifestations are dominated by hemorrhage (bruising, nosebleeds , unexplained gastrointestinal bleeding, and postoperative hemorrhage) and micro vascular occlusions erythema(redness) and burning as well as a host of neurological complaints such as headache, parathesis-numbness and tingling and transient ischemic attacks).

It also is not uncommon for all MPD patients to have other elevated blood counts. For example, in addition to high platelet counts, white cell counts may also be increased. There may also be signs of extramedullary hematopoeisis (growth of blood-producing cells outside the marrow, usually first seen in the spleen as it enlarges. This expansion of blood producing cells outside the marrow is called myeloid metaplasia and it may be accompanied by Myelofibrosis in the marrow. This finding indicates more advanced disease requiring treatment.

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The answer is a definite maybe. Platelet counts alone are not predictors of complications. Elevated platelets can present a risk of thombosis or bleeding (see below for symptoms and complications. Elevated platelets can also cause excessive bleeding during surgery and your physician is likely to want to reduce platelet counts before surgery. But this is not a monolithic, everyone acts in a predictable fashion kind of disease. Go on the principal that risks are increased if platelet counts are elevated and then work with your doctor based on your own disease course and whether or not you are symptomatic or have independent risk factors that can complicate the course of your disease.

Dr. Michiels presented a talk at the October, 1998 San Diego MPD Conference sponsored by the MPD Research Center and chaired by Dr. Harriet S. Gilbert which summarized thrombotic complications in ET patients and there was also a report on this at the March 1998 MPD Rotterdam workshop. In patients ranging from age 28-86 with essential thrombocythemia at platelet counts between 300,000 and 1 million, followed for a median of 45 months, "minor manifestations" of ET included headache, dizziness, tinnitus, visual disturbances, erythromelalgia, parathesias, leg pain, digital cyanosis. Major complications were defined as transient ischemic attacks (TIAs), cerebrovascular accident or stroke, digital gangrene, heart attack, deep vein thrombosis, pulmonary embolism. Bleeding symptoms included ecchymosis, epistaxis and gingival bleeding. 82% of patients had clinical symptoms related to their ET. Of the symptomatic patients, 67% had neurological symptoms, 37% had peripheral vascular thrombotic complications and 7% had hemorrhagic complications.

See Stark P et al. Thrombotic Complications in essential thrombocythemia with relatively low platelet counts. Am J Hematol 1997; 56:168-172; Griesshammer M et al, Aspirin in essential thrombocythemia: status quo and quo vadis. Sem Thromb Hemostas 1997; 23:371-356; Ravandi-Kashani F et al, Microvascular disturbances, thrombosis and bleeding in thrombcythemia, current concepts and perspectives Sem Thromb Hemostas 1997; 23:479-488; Cortelazzo S. et al. Incidence and risk factors for thrombotic complications in a historical cohort of 100 patients with essential thrombocythemia. J Clin Oncol 1990; 8:556-562; Van Genderen PJJ et al, Erythromelalgia: a pathognomonic microvascular thrombotic complication in essential thrombocythemia and polycythemia vera. Sem Thromb Hemostas 1997; 23:36555-370; Michiels JJ et al, Erythromelalgia caused by platelet-mediated arteriolar inflammation and thrombosis in thrombocythemia. An Int Med 1995; 102:466-471; Michiels JJ et al, Transient neurologic ischemic attacks and ocular manifestations in primary thrombocythemia. Neurology 1993; 43:1107-1110.

A number of ET patients in our mpd-net support group report that their doctors brush off their symptoms as having nothing to do with their ET or claim their platelet count isn't high enough to run into problems. Not so. Dr. Michiels presented a distribution chart on this point. Clinical symptoms attributable to ET were recorded at platelet counts lower than 600,000 in 56% of patients studied, in 40% of patients with platelet counts lower than 500,000, in 18% of those with platelet counts lower than 400,000 and in 11% of patients with platelet counts of 300,000-350,000.

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This depends upon the patient and whether there have been symptoms or complications, the views of one’s doctor and the patient. The current treatment options include nothing (no treatment) , or baby aspirin, interferon, anagrelide or hydroxyurea alone or in combination.

Views differ on who/when to treat ET patients. Many experts today stratify patients into low risk, intermediate risk and high risk. Low risk patients are those under 60 with a platelet count under 1.5 million who do not have a history of thrombosis and do not have cardiovascular risk factors. One important overlooked criteria is whether or not the patient is symptomatic. Many of us had symptoms such as visual disturbances, dizziness, transient numbness, etc for a period of time before having a major event such as heart attack, stroke, pulmonary embolism, deep vein thrombosis, portal or spleenic vein infarct, etc. Our symptoms were brushed off as not meaning a thing until something really bad happened and we went from “low risk” to “high risk” in a nanosecond. So if you are in the “low risk” category and your doctor doesn’t feel it necessary to treat your high platelets, talk to him/her about at least taking aspirin and if you start experiencing symptoms, report them immediately and consider carefully if you feel comfortable remaining untreated or would feel safer getting your platelets below 400,000.

“High risk” patients don’t have to struggle with whether or not to treat their ET. Those of us who have had thrombotic events need treatment regardless of age. And it doesn’t need to be a “major” thrombotic event. We have a mother of a young woman on mpd-net whose daughter was diagnosed at 16 after having TIAs. The daughter was put on treatment and will need to remain on treatment for life. So for those of us who have experienced thrombotic or hemorrhagic complications, its really a no brainer. We need to be treated.

“Intermediate risk” is somewhere in between but probably includes those under 60 with platelets under 1.5 million who have so called “minor symptoms” A “minor symptom” probably includes things like visual disturbances, headaches, etc. Again, someone can go from a “low risk” or “intermediate risk” patient to “high risk” in a nanosecond so if you are symptomatic and your doctor doesn’t believe in treating unless something really bad happens, consider a consult for a second opinion with one of the experts. Larry Milnes, our mpd-net online support group emeritus list owner developed and maintained a list of doctors who are experts in MPDs and can give you contact information.

For examples of low risk and high risk ET patients, our ET patient who lived to 92 years old, Ben, was never particularly bothered by his disease other than a prolonged bleeding episode at 78 after prostate surgery at platelets of 1.1 million and at 91 after a shopper in a hurry ran into him with her grocery cart and removed a serious chunk of skin and flesh at platelets of 2.2 million. . He also periodically complained of skin sensations-tingling, feeling like something is crawling on his skin. He was only been treated with very brief cycles of Hydrea to rapidly reduce platelet counts when he has needed surgery. He was put on baby aspirin for a while but developed nose bleeds. His daughter, Joyce, on the other hand had a stroke and athrombophlebitis which led to her diagnosis at 49, and at times when platelets were not well controlled, experienced visual disturbances including transient vision loss and other symptoms associated with her ET. While Ben tolerated platelet counts in excess of 1 million, his daughter Joyce is symptomatic at platelet counts above 400,000 and is most comfortable at counts of between 200,000-300,000. Her MPD followed a different path that her father’s. Diagnosed with ET at 49 following a stroke at platelets of 980,000, she developed secondary MF in 1990 and moved to PV with secondary fibrosis in 1996. She remains most comfortable and symptom free with platelets between 200,000-300 but now also has to keep her Hct below 42. She will be 67 in Sept, 2005.

Since this is a chronic condition, it requires treatment for life in patients who have had complications.

For simple, uncomplicated ET where the patient does not have an enlarged spleen and elevated plaletet counts are the only concern, until recently, anagrelide was the drug of choice. It is the first agent useful in this disorder other than aspirin which is neither a chemotherapeutic agent nor an immunomodulator. This drug was approved in the US in the spring of 1997 and subsequently approved in Canada and Israel. Additional approvals are expected. Platelet counts will rebound once this drug is stopped and headache and cardiovascular, and gastrointestinal side effects are of concern and often cause patients to discontinue this therapy.

Tefferi A, Silverstein MN, Petitt RM et al, Anagrelide as a new platelet-lowering agent in essential thrombocythemia: mechanism of action, efficacy, toxicity, current indications. Sem Thromb Hemostas 1997; 23:379-383. Petrides PE et al, Anagrelide, a novel platelet lowering option in essential thrombocythemia treatment experience in 48 patients in Germany. Eur J Haematol 1998; 61:71-76. A. Tefferi, M.S. Elliot, L.A. Solberg, M.N. Silverstein, New Drugs in essential thrombocythemia and polycythemia vera, Blood Reviews 1997; 11. 1-7.

However, a British Study comparing hydroxyurea with anagrelide in high-risk essential thrombocythemia patients was stopped early after 39 months because anagrelide plus aspirin was associated with increased rates of arterial thrombosis, serious hemorrhage and transformation to Myelofibrosis. The conclusion was that hydroxyurea plus low-dose aspirin is superior to anagrelide plus low dose-aspirin for patients with essential thrombocythemia at high risk for vascular events. N Engl J Med 353;1 July 7, 2005, pp 33-45. This study did not include interferon which may be more suitable for ET patients with Myelofibrosis and spleen enlargement.

Hydrea (hydroxyurea) has been used for decades. It is a chemotherapeutic agent that depresses marrow function. Some physicians do not like to use it in younger patients because of reported risks of increasing the incidences of secondary acute leukemias after around 8 years of continual treatment. Converting to acute leukemia occurs in a very small percentage of untreated ET patients. Figures vary in the literature but seem to indicate a 5- 10% rate in patients treated with Hydrea. Some doctors feel this risk is minimal and acceptable. Others do not. Some people have no choice as they cannot tolerate other treatment options. This is an issue that each patient has to work out with their own hem-onc. Platelet and other counts will rebound when this drug is stopped. Hydrea may cause leg ulcers in a small percentage of patients. These can be debilitating and life-threatening and should be taken seriously. We have one ET patient in mpd-net who suffered with this problem for 8 years before coming onto the internet and learning that her treatment was the cause. She switched to interferon and the ulcers cleared up within a month or two.

See for example Sterkers et al, Acute myeloid leukemia and myelodysplastic syndrome following essential thrombocythemia treated with hydroxyurea; high proportion of cases with 17p deletion. Blood 1998; 91:616-622.

Interferon is also one of the treatment options. There is a split in the medical community about treating/not treating with interferon. Some doctors will not use interferon for a variety of reasons-they do not want their patients to have to deal with shots when they can swallow a pill. They argue that the long term side effects aren't known (interferon has been used since the mid-80's for this condition). They don't see any particular advantage over cheaper more convenient therapies. However, the literature and patient experience in our mpd-net group indicate the drug is indeed beneficial.

See for example, Harriet S. Gilbert, M.D., Long Term Treatment of Myeloproliferative Disease with Interferon-alpha-2b Feasibility and Efficacy Cancer September 15,1998, Vol 83, No. 6, 1205-1213. A. Tefferi et al, New Drugs in essential thrombocythemia and polycythemia vera, Blood Review 1997, 11, 1-7. Gilbert HS. The Role of alfa interferon in treating myeloproliferative disease MPD):indications and results of long term management (abstract) Proc Am Soc Clin Oncol 1995; 14 429A. Gilbert HS, Persistence of remission of myeloid metaplasia after treatment with recombinant interferon alpha-2b (abstract) Blood 1988; 72:200a. Silver RT, A new treatment for ppolycythemia vera: recombinant interferon (rIFN) alfa-2b (abstract) Blood 1988; 72:227a. (This is by no means a comprehensive list of literature citations)

There is a split among doctors who do treat with interferon. Some believe in cycling as needed. Some believe in keeping their patients on low maintenance dose once their conditions are controlled. Dr. Gilbert (unfortunately she died in 2003) has found that the benefit of interferon therapy, while not a cure, is more lasting than other therapies. One of her patients was able to go three years without needing further treatment. You don't "lose it" immediately when you go off interferon as with Hydrea and Anagrelide. Doctors are also not in agreement as to how much, how long and how frequently. If you feel this may be a good treatment option for you and your doctor has little experience with its use in our disorders, you may want to consider a consultation with one who does use it in his or her practice in our disorders and let him/her guide your local hematologist in treating you.

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Yes. As one of our senior experts, Dr. Richard T. Silver says, if you don’t look you don’t see. ET and PV patients can develop secondary fibrosis in their marrows and this is easiest to treat if caught early on. But if you don’t have initial and then periodic bone marrow biopsies, this can progress to the point where counts start to drop and doctors have to scramble to try and deal with the situation.

While the very thought of a bone marrow biopsy tends to be frightening, it can be managed. Patient experience varies. Basically, you lie down on your stomach and a special needle is used to drill into the hip bone and extract a core of bone and an aspirate of the marrow contents. Before the procedure, a local anesthetic is injected to numb the bone. But there is no way to numb the interior marrow so there will be momentary sharp pain. This procedure can be made much more comfortable by insisting that the doctor wait until the local has had a chance to take effect. Do not let them inject and start drilling immediately. Taking a mild tranquilizer about an hour before the procedure can reduce anxiety and make the procedure more comfortable. Finally, some doctors will use a combination of intravenous drugs (demerol and versed, demerol and ativan, morphine and valium, etc.) which allows the patient to sleep through the procedure. Either way, this is an outpatient procedure usually performed in your hematologists' office.

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There are any number of symptoms that can go along with this condition. Visual disturbances when platelets are too high are experienced by many. These generally are described as "light shows" or "silent migraines". One patient in our group noted an increase in the frequency shortly before having a mild stroke. Minor symptoms can include bruising, bleeding such as bleeding gums, nose bleeds, heavy menstrual periods, pain, tingling, burning or numbness in fingers and toes, skin sensations-tingling, feeling of something crawling on your arm, headache and fatigue. More serious symptoms can include stroke, heart attack, pulmonary embolism, thrombophlebitis (pain and swelling will be usually be present in the affected leg), hemorrhage. If myeloid metaplasia is present, the patient may have a sense of fullness in the area of the liver or spleen. There may be pain in those areas.

Many doctors seem to be under the impression that young ET patients do not require treatment and any symptoms reported have nothing to do with their ET. From the postings on MPD-NET and responses to the MPD Survey, we know this is not true.

On March 13-14, 1998, a number of experts in the field attended the Rotterdam MPD-Workshop. Four of the attendees were also speakers at the October 1998 MPD Conference in San Diego: J.J. Michiels, M.D., T.C. Pearson, M.D., S.M. Fruchtman, M.D. and R.T. Silver, M.D.) At the Rotterdam MPD Conference, Dr. Stark reported on thrombotic complications in 57 ET patients ranging in ages from 28-86 at platelet counts of between 300,000 to 1,000,000. These patients were followed for a median of 45 months (range 3-172 months). Minor manifestations of ET included headache, dizziness, tinnitus, visual disturbances, erythromelalgia, paresthesis, leg pain, digital cyanosis. Major complications included transient ischemic attack (TIA), cerebrovascular accident (CVA or stroke), digital gangrene and deep vein thrombosis. (Heart attack, pulmonary embolism and portal vein clot have also been reported in our mpd-net group). Bleeding symptoms included those large bruises under the skin, bleeding from the gums and GI bleeding. 82% of patients were symptomatic. Of these, 67% had neurological symptoms and 37% had peripheral vascular thrombotic complications. 7% had hemorrhagic complications.

Some doctors claim that treatment is not necessary until platelets reach 1 million. Those of us who have had serious complications at much lower counts know this is not true for us. What is interesting is figures given at the Rotterdam and San Diego MPD conferences acknowledged that patients may be symptomatic with counts as low as 300,000. Looking at patients with platelet counts lower than 600,000: 56% had symptoms with counts lower than 600,000; 40% were symptomatic with platelet counts lower than 500,000; 18% were symptomatic with platelet counts lower than 400,000; and 11% were symptomatic with platelet counts between 300,000-350,000.

There are also a whole gaggle of metabolic abnormalities that go along in patients with myeloproliferative disorders. These include:

1. Elevated uric acid counts are seen in about half of MPD patients during the course of their disease. If untreated, this leads to uric acid stones, uric acid neuropathy, acute gout, and chronic gouty arthritis. Patients may experience joint pain as a result.
2. Low cholesterol levels (hypercholesterolemia), particularly in those with enlarged spleens.
3. Elevated histamine levels. Symptoms of increased histamine release include puritis (itching characteristically produced by bathing or showering), heartburn, acid eructation (gas) , peptic ulcer, small bowel hypermotility, flushing and angioneurotic edema (swelling of skin, mucous membranes or viscera). This occurs in 2/3rds of MPD patients and correlates with presence of elevated basophil count and hyperhistaminemia.
4. Hypermetabolism which commonly manifests as weakness and fatigue in the absence of anemia.

This must be discussed with your own doctor. We have patients in our mpd-net group who ran into trouble after starting hormone replacement therapy. One had a thrombophlebitis in one leg and a mild stroke about 6 weeks after starting on oral ERT. She was been told to avoid HRT other than use of the vaginal cream and has had no further problems. But more recently, in a consultation with an endocrinologist, she was also told to avoid the cream since it is systemically absorbed. The other had a clot of the vein leading to her liver and nearly died while using the patch. She too has been told only to use the vaginal cream. But we have one woman who had a transient loss of the use of both legs after starting use of the vaginal cream. And we have an ETer who has been using the patch for years without difficulty. This is something each woman has to discuss with her hematologist (not gynecologist) because clotting factors differ from patient to patient and your hematologist is in the best position to evaluate your individual situation. The problem is there is no way to know if hormone replacement or birth control pills are safe for a particular patient without trying and seeing what happens. And each patient has to decide if the risk is worth it. If one has already had a thrombotic complication, then bormone replacement therapy or birth control pills are very risky.

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This may vary from physician to physician. Generally, if the patient is not experiencing any problems from their ET, baby aspirin (unless the patient tends to bleed) may be the only treatment suggested along with close monitoring. If a patient presents with a stroke, heart attack, thrombophlebitis, clearly reduction of platelet counts will be deemed necessary to get them out of danger and reduce the risk of further complications and treatment will be started immediately. If a patient shows up with enlarged spleen or liver which means that you have blood production taking place outside the bone marrow, treatment is a very good idea. When symptoms are "minor", treatment may still be appropriate both for comfort and to help slow disease progression. Symptoms-treatment. No problems-probably no treatment. This is discussed above as to “low risk” vs “high risk” patients.

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Yes. There are two reports in the 1998 ASH meeting abstracts about cases of familial ET. Our 92 year old ET member's daughter also has ET. We also have two sisters with ET in our mpd-net group whose father died of complications of undiagnosed ET (stroke followed by heart attack at age 40) and the son of one has ET. There are reports in the literature of as many as 15 family members over 4 generations who were diagnosed with ET or some other variant of the myeloproliferative disorders. It is prudent to let your childrens' physicians know of your history so their blood counts can be periodically checked. While most cases are “sporadic”, that is one affected member in a family, this is a possibility.

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In most cases, if they are properly monitored and treated, diseases of old age. Our 92 year old passed away in August of 1998 following a massive heart attack. He was an insulin dependent diabetic and also had been treated for congestive heart failure for the last 6 years of his life and angina since he was 78. A study of his coronary arteries the day before he died showed complete blockage and calcification of all coronary arteries. But he walked at least 30 minutes a day up to the day he had his heart attack and did well by "listening" to his body and slowing down when it protested. A small percentage may convert to acute leukemia. This is usually associated with prior treatment of a leukemogenic drug. Some progress to the post thrombocythemic myeloid metaplasia stage where blood counts fall and bleeding and infection complications become a problem. Most of our non-mpd peers die of stroke, heart attack, pneumonia or other infection, or cancer. At any age, all of us, mpd and non-mpd are susceptible to accidents. In the old days, when heavy duty chemotherapy was used to treat us, according to an Italian study of over 1200 PV patients followed over a 20 year period, of the 196 who died, 30% died of cancer or acute leukemia secondary to their treatment. For the most part, agents like chorambuciil, P32, etc are no longer used.

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One of the reasons it is important to be monitored and to have periodic bone marrow evaluations is that changes can take place in the bone marrow that are not readily apparent by looking at blood counts or how the patient feels. For example, we have one ET patient in the MPD-NET group who has a tendency to develop mild myelofibrosis (scarring). Both times this has been picked up on bone marrow biopsies. Her May 1996 BMB was prompted by a mild increase in all blood counts including platelets which had been held in check by anagrelide for the past 20 months, headache, a sense of pressure in the spleen area due to spleen enlargement not picked up on manual examination and fatigue.

If there is a sudden change in your blood counts, or a gradual shift in either direction, or you start having symptoms that you weren't there a short while ago-bruising, headache, fatigue, swelling in your legs or abdomen, visual disturbances, headache, unexplained pain, numbness etc., find out what is going on. We also have to remember that having ET does not give us a free pass on other diseases. Some will convert to polycythemia vera for example. In a retrospective study which followed over 1200 polycythemia vera patients over a 20 year period, of the 200 or so who died, 1/3 died of cardiovascular disease and 1/3 of cancers.

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Experts differ in what they call ET. There are no cancerous cells in the sense of cells that can spread and invade other organs. But it is considered a chronic hematological malignancy because of the wild, disordered growth of bone cells in our marrows. And blood producing cells that were active in the fetus but inactive in healthy adults can reactivate when the bone marrow isn’t functioning properly. So various organs can be affected. And some experts consider it a cancer. This can be confusing, and insurance companies take varying views. It really doesn’t matter what you call it. The issues are the same. The treatments are the same. The life expectancy is the same. Its just more soothing on the nervous system to think of it as not cancer.

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Unfortunately yes. The youngest child we have had in our support group is 22 months (or rather his mother is in the group. Our next youngest was diagnosed at 6, is presently 16. Dr. Murali Chintagumpala, of Texas Children's Cancer Center/ Baylor university, treated this child with anagrelide.

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This was originally thought of as a disease of old age and symptoms were largely ignored in younger patients until the last decade or so. So there isn't much in the literature about childhood ET and most of it simply reports treatment with anagrelide. We have heard of the mother of a teenager whose daughter had a number of serious complications but her ET was discovered accidentally after her spleen was removed. Her symptoms had been ignored for a number of years and this will cause problems in adults and children alike. A second teenager whose mother's participates in our MPD-NET group had experienced TIA's and is being treated with interferon. We had a new member on MPD-NET whose then 22 month old son was diagnosed at 8 months old, is symptomatic and Drew, (story below) was 6 at diagnosis and was symptomatic. Both children are treated with anagrelide.

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This is something that that would have to be discussed with one's hematologist. We have one parent in our group with a 3 year old child with PV that we understand underwent a bone marrow transplant with the father as the matched donor. In adults, bone marrow transplants are reserved for those whose disease has progressed to the point where there is a high risk of dying without a transplant so the risk/reward of transplant are better than if someone healthy wants one just so they don’t have to think about their disease again (it isn’t that simple). The issues may be different in children and this is something that has to be discussed carefully with one’s doctor and potential transplant team.

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Bruising is caused by bleeding under the skin. Blood clots may form within the bruises if there is excessive bleeding and the body is trying to stop it. Clotting is the normal body reaction to bleeding.

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This is a common question among newly diagnosed ET patients. So we asked the original FAQ team, all ET patients, for their input. Joyce-Age 66+, Diagnosed 1988 at age 49.

The quality of my life improved significantly after diagnosis. I went through a long period where I suffered/complained of any number of symptoms-headache, visual disturbances, gastric problems, numbness and tingling, pain in fingers and toes, headaches. Then I started feeling a sense of pressure in the area of the spleen and would get sharp, excruciating pains if I turned the wrong way. Twisting to put on a seatbelt brought tears to my eyes. Then for nearly a year, I started having a series of increasingly severe bronchial infections and my white cell count kept steadily climbing despite repeated courses of antibiotic. I was sent to an infectious disease specialist who poked around, looked at blood counts, called a hematologist and said you have PV, you'll be dead in 5 years but let's do a red cell mass study to make sure. It was normal, I was back to square one. My husband commented physicians were treating me like a psycho ceramic (crackpot) case. I had a medicine cabinet full of prescription drugs for all of the symptoms. Finally they decided this was all due to menopause and put me on hormone replacement therapy. Silent migraines increased, I had a mild stroke and then a thrombophlebitis and finally was referred to a hematologist and properly diagnosed. Once my platelet counts were brought under control and the enlarged spleen returned to a more normal size, I started feeling much better.

Now these are chronic and at the moment incurable conditions. So I've required constant medical attention. I originally was treated with Hydrea. The concern was to rapidly knock down platelet counts and get me out of danger. That it did but it also seriously depressed my marrow and it took 6 months for it to recover. Interferon has been the best treatment option for me. It has reversed mild myelofibrosis twice. It reduced cellularity significantly each time I've needed treatment. It normalized myeloid/erthyroid ratio, etc. Best of all, the effect was lasting and the first time I stopped, I was able to go 3 years without further treatment. I only needed anagrelide for the next 20 months and went back on interferon for 31 months because of return of mild myelofibrosis which has again been reversed . 6 weeks since I stopped, platelet counts were holding at 266,000 but a short time later they started to rise and I needed treatment. I’ve been on anagrelide but my Myelofibrosis returned, spleen enlarged to 28 cm and hct increased to 48 at which time my diagnosis changed to PV and I went back on interferon. I’m currently on an IFN break and taking Hydrea.

I do have to pace myself more carefully when I am on interferon and I am more alert about reporting changes to my doctor. Apart from more frequent medical monitoring and knowing that I have a chronic condition that will require treatment for the rest of my life, I have gotten on with things. The hardest thing for me was to learn to slow down when my body said enough already. I also found that meditation, relaxation and exercise have been a significant help.

Ben-92, Diagnosed 1988.

I am Joyce's father. I am not on this FAQ team but Joyce asked me to comment. My platelets have run between 1.2 and 2.3 million for decades but I wasn't diagnosed with ET until I started having significant back and leg pain, and right leg weakness and a cat scan revealed a fractured vertebrae (having nothing to do with ET). I was also severely anemic. My wife had just died of cancer and I was told I probably had cancer as well. The same hem-onc who diagnosed my wife's cancer, Joyce's ET also diagnosed me. He went back in the hospital records and found no one had paid any attention to my elevated platelet counts when blood was drawn for major surgery over the years. I don't know how long I've had the condition but at least since the early 70's. Unlike my daughter, I've never had any particular problems. I was treated briefly with Hydrea when platelet counts went over 2 million to reduce risks of complications. I have been treated with short bursts of Hydrea to reduce platelet counts prior to surgery. I was told to take a baby aspirin a day but developed nose bleeds and stopped. The one symptom that seems consistent is a sense of skin sensations-sort of like something crawling on my skin and occasional numbness or tingling. My hands and feet get cold easily. I have some slow days but who knows if that is from my heart condition, diabetes, ET or old age. I am in fairly constant pain from a bad back. But I refuse to let it get me down. I walk 30-60 minutes a day. I read. I enjoy life and my motto when something goes wrong is "well, if that's the worst thing that ever happens." (Note-Ben passed away August 9, 1998)

Bonnie-38 Diagnosed 1981

When I was 21, I broke out in hives all over my body. I had joint pains and was easily fatigued. Despite taking Atarax, benadryl, medrol dose packs when the hives would invade my trachea, I managed to graduate as a respiratory therapist with high honors. Those hives stayed with me for 3 years continuously. I only took aspirin for the platelets, and was told something dreadful would develop health wise within 5 years. They were wrong about that. I had 2 healthy children,with one dramatic delivery that was not connected with the ET. I worked part time at a local hospital,then began my own home care respiratory care business.

About 2 years ago, I couldn't seem to keep up with anything anymore-moving in slow motion it seemed. My platelet counts were staying at around 750K with an aspirin daily. I took a position with a home care company, working less hours, but progressively feeling more and more fatigued. I experienced those silent migraines("it must be a sinus infection "I was told) continued nausea, fatigue,several bouts of bronchitis, and general malaise. In January of this year, I developed right-sided numbness and tingling,and felt awful. A trip to the ER revealed platelets of 1.5 million. The next day I started Hydrea. It has taken 8 months to "stabilize my counts". Initially I did not respond at all to the Hydrea, but when I did-Wham! I slept for about 12-14 hours daily, my WBC's would dip to 4K,and the dosage was changed weekly. I have just graduated to bimonthly blood work, from weekly . My energy level has not increased;I haven't worked since Jan.1996.What has changed is my attitude . I got more than a little depressed when I had to start Hydrea. I was not offered anything else, and thought I was going to die. If I did not have young children, I don't think I would take anything at this point. But the idea of not watching them grow scares me too much, so for now, Hydrea seems to be the least invasive.

I have been up to Brigham and Woman's in Boston for a third opinion. They all seem to agree Hydrea is for me .A poet! I can't imagine going back to work yet, and am trying to get disability. It takes all my energy to take care of myself, and cook one meal daily. I am beginning to enjoy this slower pace, and can appreciate it . I walk 2 miles every morning, and nap daily. I am happy to be able to spend all my time with the kids and my husband, and am going to take up quilting and do pottery again. I am learning to live with this every day.

Drew-16, diagnosed 1996 at 6.

Drew's mother Dawn asked Drew how his ET has affected him shortly after he was diagnosed. His reply was the ickiest thing about it is they give me too many shot blood outs (his term for having blood drawn three times a week) and the headaches. He asks how come I have lights in my eyes. I do not like to stay outside at school if I get hot. Then he told his Mom I will have to think about it. I don't like ET.

Drew's mother Dawn.

Since Drew's diagnosis, I don't take life for granted anymore. You never know what is around the corner. I found myself taking more time to spend with both of my children. I find myself reading more to the boys and the other night we went to zoo safari and that was a fun night. I also have learned to be an advocate for Drew. When I had problems with the first three doctors, I did not accept that. Now we have a wonderful doctor, Dr. Murali Chintagumpala, who really cares. He is with Texas Children's Cancer Center/ Baylor university. His Nurse's name is Laura Kennedy and she is very understanding and answers all my questions and doesn't push us aside. I like having my doctor's and nurse's email address and I am able to communicate with them anytime I want to. I know that the mpd-net group has been a source of knowledge and information and am glad to be able to discuss it with Drew's doctors. Keeping informed about this disease is very important. One day when Drew is able to do this for himself, I will let him do it. Drew is now an active teenager. He’s a straight A student and excels in sport.

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