مقاله انگلیسی رایگان در مورد الگوریتم درمانی برای ازدیاد پلاکتهای خون ترمبوسیتمی – NCBI 2018

The term myeloproliferative neoplasms (MPN) typically refers to essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF)1 ; in addition, some patients with ET or PV might in time progress into a PMF-like post-ET or post-PV myelofibrosis2 . As a group, ET, PV, and PMF share three mutually exclusive “driver” mutations, including JAK2, CALR, and MPL3 . The most frequent driver mutation is JAK2V617F, found in ~99% of patients with PV, 55% ET, and 65% PMF4 . The driver mutation distributions in ET and PMF are similar with 50–65% of the patients being JAK2V617F mutated, 15–30% being CALR mutated, and 4–8% being MPL mutated4 , while 10–20% of the patients might not express any one of the three mutations (i.e., are triple-negative)4 . World Health Organization (WHO)-consistent diagnosis of ET requires a platelet count of ≥450 × 10(9)/L, presence of one of the three aforementioned driver mutations or in their absence the exclusion of other causes of thrombocytosis (reactive and clonal), and bone marrow morphologic assessment, especially for distinguishing ET from prefibrotic PMF and “masked” PV5,6 . In addition to clonal thrombocytosis, a variable proportion of patients with ET might display mild splenomegaly, leukocytosis, microvascular symptoms, thrombotic and bleeding complications, increased occurrence of first trimester miscarriage, and time-dependent risk of leukemic transformation or fibrotic progression7 . Survival in patients with any one of the three JAK2 mutation-enriched MPN is significantly shorter than that of the sex- and age-adjusted control population, with median estimates of 20 years for ET, 14 years for PV, and 6 years for PMF8 . Causes of death include leukemic transformation, with 15-year estimates of ~2.1–5.3% for ET, 5.5–18.7% for PV, and more than 20% for PMF9 . Fibrotic progression rates in ET and PV, during a similar time interval, are estimated at 4–11% and 6–14%, respectively9 . To date, drug therapy has not been shown to modify the natural history of these diseases, prevent leukemic or fibrotic progression or prolong survival10. Current indication for drug therapy in ET and PV is to prevent thrombotic complications, especially in high-risk patients7 . In the current review, we provide a risk-adapted treatment algorithm in ET that can be used in daily practice.