Some characteristics of circulating erythrocytes in polycythaemia vera: Common features with normal young and foetal red blood cells

Abstract

Although it is well established that in polycythaemia vera (PV) both ‘normal’ and ‘abnormal’ erythroid progenitors proliferate, it is less known to what extent the circulating erythrocytes express normal characteristics. We found reduced erythrocyte densities, decreased MCHC, and increased lipid content. These properties, together with increased sialic acid, seem to explain the extremely low sedimentation rate and decreased deformability of polycythaemic blood samples. Other characteristics were high activity of glycolytic enzymes, increased in vitro production of lactate, and a concomitant decline in ATP and 2,3‐diphosphoglycerate. Some of these properties have been described in foetal erythrocytes and are features of normal young red cells. However, they seem to represent true features of PV and not a consequence of younger cell populations. The similarity between mature erythrocytes in PV and in foetal life supports the possibility that the proliferation process in this disease has a mechanism in common with foetal erythropoiesis.

Reflections on the unexpected laboratory finding of hemorheological alterations observed in some haematological disorders

“…We believe that this unexpected finding is related to the metabolic abnormalities described in red blood cells of PV patients. In fact, for the erythrocytes of PV patients, it has been observed respectively: a) a high activity of glycolytic enzymes (Streichman et al, 1986) b) a reduction of ATP and 2.3 DPG associated with an increased synthesis of lactate in vitro (Streichman et al, 1986;Arnaud et al, 1991); c) an increase in erythrocyte membrane lipids associated with increased phosphatidylserine exposure (Streichman et al, 1986;Fujita et al, 2010;Wautier et al, 2011); d) an increment in fetal haemoglobin (Hoffman et al, 1979); e) a higher electrophoretic mobility (Streichman et al, 1981); f) an increase in sialic acid concentration (Streichman et al, 1981) or a reduced variety of membrane sialic acids (Bratosin et al, 2007).…”

Phospholipid determination in platelets, plasma and red cells of patients with chronic myeloproliferative disorders

“…Red cell studies of these patients are interesting since they have an increased risk to develop vascular occlusive episodes (1,25), which correlates with the packed cell volume level (26). Studies performed in patients suffering CMD found red cell abnormalities, such as a high lipid content (27) and a delay in the filtration time (28), suggesting that erythrocytes have a decreased deformability. This property is strongly dependent on the membrane fluidity, which is mainly determined by the cholesterol content and the SMjPC ratio (29).…”