What Is Essential Thrombocythemia (Et)?

Maintained By: Joyce Niblack  JNiblack@Aol.com

This FAQ was last updated January 13,2001

1. (c)Copyright 1996-2001 by Joyce Niblack All rights reserved. No part of this document may be used or reproduced in any form or by any means , or stored in a data base or retrieval system, without prior written permission. However, you may make a copy for your personal use or to share with your physician and family members.

1. What Is Essential Thrombocythemia (Et)?
2. What Is Mpd (myeloproliferative Disease)?
3. Where Does Essential Thrombocythemia Fit In?
4. What Causes This Condition?
5. How Is Essential Thrombocythemia Diagnosed?
6. How Do You Differentiate Between Primary And Secondary Thrombocythemia?
7. What Are Some Of The Other Names For This Condition?
8. Can Et Be Cured?
9. What Is My Probable Life Expectancy?
10. How Common / Rare Is Et?
11. Do Patients Just Have Elevated Platelet Counts?
12. Am I At Risk If My Platelets Are Elevated?
13. How Is Et Treated?
14. Will I Need A Bone Marrow Biopsy And What Are These Like?
15. What Symptoms Might I Experience From Et?
16. Will I Be Able To Take Hormone Replacement Therapy When I Reach menopause?
17. What Are The Criteria For Starting Treatment?
18. Can I Pass This On To My Children?
19. What Do People With Et Die Of?
20. Are There Any Symptoms / Occurences That Signal A Change or Progression?
21. Is Essential Thrombocythemia Cancer?
22. Does This Ever Affect Children?
23. Do Children React Any Differently Than Adults?
24. Are Bone Marrow Transplants An Option For Children With Et?
25. What Causes Bruising With Blood Clots?
26. How Does Et Changes One's Life

    Joyce-age 60, Diagnosed 1988.

    Bonnie-40 Diagnosed 1981

    Drew-6, Diagnosed 1996.

27. Where Else Can I Go For Information?

What is Essential Thrombocythemia(ET)?

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 MPDs also include polycythemia vera (PV), Agnogenic Myeloid Metaplasia (AMM), secondary myelofibrosis (MF) and chronic myelogenous leukemia (CML). 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).

What is MPD (Myeloproliferative Disease)?

"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 plalelets. 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 daugher 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.

Where Does Essential Thrombocythemia Fit In?

Thrombocythemia (or thrombocytosis) is defined as the occurence of a platelet count in excess of 400,000 per microliter in the setting of a myeloproliferative disease. When this is the predominant abnormality, the sydrome is classified as essential thrombocythemia. Abnormal megakarocyte 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), hematocrit (HCT) and hemoglobin (HG) counts so a careful differential diagnosis is essential.

What Causes This Condition?

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.

How is Essential Thrombocythemia Diagnosed?

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 repleted by oral iron administration for one month withot 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

A1 Platelet count in excess of 400,000 and no known cause of reactive thrombocytosis

A2 Increase and clusters of mature giant megakarocytes with hyperploid nuclei in bone marrow biopsies

A3 No preceding or allied other subtype of myeloproliferative disorders or myelodysplastic syndrome

Confirmative

B1 Normal or elevated leukocyte alkaline phosphatase(LAP) score,  normal ESR, and no fever

B2 Normal or slighly increased cellularity and no or minimal reticulin fibrosis in bone marrow biopsies

B3 Splenomegaly on palpation or >11 cm on ultrasound scan or on computer tomogram (CT)

B4 Spontaneous endogenous erythroid colony (EEC) and/or spontaneous mekarocyte colony formation

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*,  Goodheart 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.

How Do You Differentiate Between Primary and Secondary Thrombocythemia?

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.

What are Some of the Other Names for This Condition?

Essential thrombocytosis, thrombocytosis, primary thrombocytosis, ET.

Can ET Be Cured?

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.

What is My Probable Life Expectancy?

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 distrubances, 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.

How Common/Rare is ET?

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 epidemology 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 hematopoitic neoplasms in Western Australia.  Cancer 1981; 48:866-872.

Do Patients Just Have Elevated Platelet Counts?

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 microvascular 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 increase.

Am I At Risk If My Platelets Are Elevated?

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),  cerabrovascular accident (CVA or stroke),  digital gangrene,  heart attack,  deep vein thrombosis,   pulmonary emoblism.  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. 

How Is ET Treated?

This depends upon the patient and whether there have been symptoms or complications. The current treatment options include nothing, baby aspirin, interferon, anagrelide or hydroxyurea alone or in combination.

Our 92 year old ET patient, Ben,  was never been bothered by his disease other than a recent prolonged bleeding episode after a shopper in a hurry ran into him with her grocery cart and removed a serious chunk of skin and flesh. He also periodically complained of skin sensations-tingling, feeling like something is crawing 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 thrombophlebitis which led to her diagnosis 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, Joyce is symptomatic at platelet counts above 500,000 and is most comfortable at counts of between 200,000-300,000.

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, anagrelide may be 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 side effects are of some concern.

Tefferi A,  Silverstein MN,  Petitt RM et al, Anagrelide as a new platelet-lowering agent in essential thrombocythemia: mechanism of action,  efficacy,  toxicty,  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.

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 percentagage 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 debilating 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 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.

Will I Need a Bone Marrow Biopsy and What Are These Like?

Yes. 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) which allows the patient to sleep through the procedure. Either way, this is an outpatient procedure usually performed in your hematologists' office.

What Symptoms Might I Experience From the ET?

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), hemorrage. 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 emoblism 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 (hypocholestoremia), 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.

Will I Be Able to Take Hormone Replacement Therapy When I Reach Menopause?

This must be discussed with your own doctor. We have three 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 usin 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.

What Are the Criteria For Starting Treatment?

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.

Can I Pass This on to My Children?

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 themyeloproliferative disorders.  It is prudent to let your childrens' physicians know of your history so their blood counts can be periodically checked. 

What Do People with ET Die of?

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 heart attack.  He was an insulin dependent diabetic and also had been treated for congestive heart failure and angina for the last 6 years of his life.  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.

Are There Any Symptoms/Occurences That Signal a Change or Progression?

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.

Is Essential Thrombocythemia Cancer?

No. There are no cancerous cells. But it is considered a chronic hematologic malignancy. This can be confusing, and insurance companies take varying views.

Does This Ever Affect Children?

Unfortunately yes. The youngest child we have in our support group is 22 months (or rather his mother is inthe group. Our next youngest was diagnosed at 6,  is presently 9.  Dr. Murali Chintagumpala, of Texas Children's Cancer Center/ Baylor university, is treating this child with anagrelide. Due to the development of myelodysplasia,  this child is schedule for a bone marrow transplant.

Do Children React Any Differently Than Adults?

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 have a new member on MPD-NET whose 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.  Drew has progressed to MDS and is awaiting a bone marrow transplant.

Are Bone Marrow Transplants an Option for Children with ET?

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. Drew,   whose story appears below,  will be undergoing a bone marrow biopsy shortly.   Treated with anagrelide since his diagnosis,  he is now showing signs of myelodysplasia.  So perhaps the medical community is more willing to use this procedure in a very young child who otherwise will face a very long treatment course.

What Causes Bruising with Blood Clots?

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.

HOW DOES ET CHANGES ONE'S LIFE

This is a common question among newly diagnosed ET patients. So we asked the FAQ team, all ET patients, for their input.

Joyce-Age 60, 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, excrutiating 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 psychoceramic (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.  It has only been 6 weeks since I stopped but so far,  counts are remaining within normal limits with platelets at 266,000 at last check.

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.

Update-My condition has changed to PV and I had my first phlebtomy on February 13, 1999.  For details,  see my story under patient stories on our web page.

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 occassional 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 continuosly. I only took aspirin for the platelets, and was told something dreadful would develop healthwise 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 homecare 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 homecare company, working less hours, but progressively feeling more and more fatigued. I experienced those silent migranes("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 bloodwork, 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-9, 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 ickkiest 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.

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