[Therapeutic thrombocytapheresis--effect on hemorheologic parameters]

Common features of all myeloproliferative diseases (CMPE) are a markedly increased number of platelets and restrictions in the subjective feeling of the patients, comprising symptoms like nausea, headache, sensory deficits and transient paresis. Meanwhile, it has been shown that platelet pheresis (mTD) does not only reduce platelet counts sufficiently but also results in an impressive relief of the subjective complaints. To test the part that rheological mechanisms play hereby, relevant rheological parameters in the blood of 22 CMPE patients and of 8 healthy platelet donors as controls were analyzed before and after treatment with an AS-104 cell separator. Concerning the viscosity of whole blood und the filterability of erythrocytes, there was seen neither a difference between the patients and the controls, nor before and after mTD. As a result of treatment of patients, the moderately raised plasma viscosity was normalized, whereas the aggregation of erythrocytes was significantly lowered. It is concluded that there is an influence of hemorheological conditions on the patient's subjective feeling. These would originate in neurological dysfunctions caused by CMPE-induced restrictions in cortical microcirculation. The erythrocyte aggregation, lowered by mTD, would cause an improvement of microcirculatory fluidity and would, in consequence, abolish the neurological symptoms.