Dr. Michaels message (tomorrow at 7:00 PM)

[Memo To Me]

http://www.mpdsupport.org In a nutshell, it is good time right now, if you have to have an MPD, to screen for the JAK2V617F mutation as the cause of ET and PV. Curently we have the advantage to diagnose the latent and very early stages of each of the MPDs when using the WHO and European clinical, molecular and pathological (ECMP) criteria for the detection of latent MPD and to differentiate PVSG-defined ET in to 3 types of ET: true ET, early PV, earlt CMF or EMT Moreover: Life expectancy in true ET is normal. Life expectance of early stages PV is normal or near normal Life expectance of those MPD patients who present or develop leukocytosis, splenomegaly in PV and leukocytosis, splenomegaly and a leikoerythroblasosis of the peipheral blood associated with mild secondary fibrosis in a bone marrow biopsy life expectancy is compromised. I think we have effective treatments for: low risk ET: aspirin intermediate risk ET: we do not yet konown whether aspirin plusr anagrelide or Pegasys is superior. in JAK2V617F negative ET anagrelide is the first line treatment of choice for the control of very high platelet counts above 1 million. hihg risk ET is not dependent on age is currently defined by platelet counts above 1250 or a history of major thrombosis. In high riskET platelet reduction with anagrelide or Pegasys is indicated to postpone hydroxyurea as long as possible. In ET or EMT complicated with leukocytosis, significant splenomegaly, leukoerythroblastosis, uncontrollable high plateletcounts but not anemic, treatment with Pegasys or Hydroxyurea is preferred.

ET with increased cellularity due to increased erythropoiesis is consistent with type 2 ET or early PV and are JAK2V617F positive by definition. The prognosis of ET type 1 (true ET) and ET type 2 (early PV features in a BMB) is favorable and to be treated with low aspirin and additional phlebotomy in early PV to maintain ht below 045 in man and below 0.42 in women.

ET with a hypercellular bone marrow, leukocytosis and/or significant splenomegaly is not true ET, but very likely Essential Myeloproliferative Thrombocythemia (EMT, type 3 ET) featured by a prefibrotic hypercellular bone marrow and increased cellularity due to increased granulopoiesis, relative decreased erythropoiesis and compromized survival due to progression into chronic myelofibrosis (CMF). We do not know yet how many of the EMT (Type 3 ET) patients will develop slowly pogressive CMF durig log-term follow-up. As indicated above PVSG defined ET consist of true ET (ET type 1) early PV (ET type 2) and EMT ((ET type 3) and to be treated similarly according to clinical stratification into low, intermediate and high rik for thrombosis and bleeding complications (as indicated above). With the use of the new WHO ECMP criteria you pick up the latent stages of MPD. This comprises about 30 to 40% of newly diagosed MPD (ET, PV and EMT) patients.

I think we have effective treatments for low risk PV: aspirin/phlebotomy without the need of Pegasys

Intermediate PV: symptomatic PV with leukocytosis, mild

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