Physiopathology and Course of Polycythemia Vera as Related to Therapy

The Erythrocyte Count on Top of Bone Marrow Histology Discriminates Essential Thrombocythemia and Polycythemia Vera in JAK2v617f Mutated Prefibrotic Myeloproliferative Neoplasm with No or Minor Splenomegaly

“…The PVSG and WHO investigators have overlooked the observations of Dameshek in 1950 and of Michiels in the present study that iron deficiency in PV on treatment with phlebotomy results in small microcytic erythrocytes and correction of blood volume with haemoglobin and hematocrit levels in the normal ranges but the erythrocyte numbers remained increased (above 6.0×10 12 /L, Figure 4). As the mean corpuscular volume of red cells becomes reduced to levels of 70 cubic micron or even less due to the chronic iron deficiency state, the discrepancy between the high red cell count far above 6×10 12 /L and low hemoglobin level becomes increasingly more striking in classical PV ( Figure 4) [2,24]. Treatment of PV by phlebotomy alone not only corrects blood volume, hemoglobin and hematocrit values (Figure 4), but also decreases the incidence of major thrombotic complications, and relieves hypervolumemic complaints [9,25,26] with persistence of the coumarin-resistent erythromelalgic microvascular syndrome of associated thrombocythemia [4] indicating the need of low dose aspirin [27,28].…”

“…Survival related cerebrovascular accidents were responsible for death at hematocrits between 0.52 and 0.57 in 3 untreated IE patients (12%) within 3 and 4 years follow-up. We recognized in 1979 the huge importance to detect the erythrocythemic stage of PV (IE) with increased RCM by the combined use of and bone marrow histology and increased erythrocyte count above 6×10 12 /L [1,2] obviating the need to measure RCM. The RCP modifications in 1980 of the 1975 PVSG criteria for PV include 4 main changes (Table 1) [1,2].…”

“…We recognized in 1979 the huge importance to detect the erythrocythemic stage of PV (IE) with increased RCM by the combined use of and bone marrow histology and increased erythrocyte count above 6×10 12 /L [1,2] obviating the need to measure RCM. The RCP modifications in 1980 of the 1975 PVSG criteria for PV include 4 main changes (Table 1) [1,2]. First, the major criterion O 2 -saturation of >92% is deleted since a bone biopsy differentiates between PV and erythrocytosis.…”

“…The bone marrow is diagnostic showing a panmyelosis (increased trilinear hematopoiesis) and large megakaryocytes in smears of aspirated bone marrow from the iliac crest or sternum [1,2]. In a doubtful case, the procedure of blood volume estimation may be helpful [1,2].…”

“…The bone marrow is diagnostic showing a panmyelosis (increased trilinear hematopoiesis) and large megakaryocytes in smears of aspirated bone marrow from the iliac crest or sternum [1,2]. In a doubtful case, the procedure of blood volume estimation may be helpful [1,2]. Between 1975 and 1980 we discovered a causal relationship between plateletmediated erythromelalgia and microvascular cerebral transient ischemic attacks as the presenting symptoms in early stage essential thrombocythemia (ET) and PV.…”