Investigation of the influence of body weight index to the result of therapeutic erythrocytapheresis in patients with polycythemia vera

We investigated the correlation between body weight index (BWI) and the effective power of erythrocytapheresis in patients with polycythemia vera (PV) who received therapeutic erythrocytapheresis (TEA). Furthermore, the risk factors of the adverse events related to erythroapheresis therapy were analyzed. Two hundred and seventeen cycles of therapeutic erythrocytapheresis were carried out in 139 patients with PV (Hct). The correlation between the BWI and the difference of hematocrit before and after therapeutic erythrocytapheresis (ΔHct) was analyzed by the Pearson correlation analysis method. Logistic regression analysis was used to study the risk factors of adverse events for TEA. We observed a positive correlation between the BWI and ΔHct. BWI over 15 ml/kg, inlet velocity of the apheresis procedure over 45 ml/min and an age older than 50 years were the risk factors of adverse events of TEA. The results suggested that BWI was a sensitive index to estimate the effective power and adverse events of TEA. The rate of adverse events of TEA might be reduced by maintaining the BWI below the dangerous threshold of 15 ml/kg and the inlet velocity of the apheresis procedure below 45 ml/min especially in patients older than 50 years of age.