Myeloproliferative and thrombotic burden and treatment outcome of thrombocythemia and polycythemia patients

Core Tip

Core tip: Spontaneous endogenous erythroid colony formation and low serum erythropoietin (EPO) levels are highly specific for JAK2^V617F mutated essential thrombocythemia (ET), prodromal polycythemia vera (PV), masked PV and classical PV. The quantitation of JAK2^V617F mutation allele burden plays a key-role in the diagnostic work-up and staging of ET, PV and MF patients. The JAK2^V617F mutation allele burden in heterozygous mutated ET is low but high in combined heterozygous - homozygous or homozygous mutated PV. The combined use of JAK2^V617F mutation load, spleen size and pretreatment bone marrow biopsy are of major prognostic significance and therapeutic importance in ET and PV patients. Large Prospective Unmet Need studies are warranted to delineate the natural history and outcome of targeted treatment in MPN patients of various molecular etiology during long-term or life long follow-up.