[Selected parameters of blood platelet function in patients with myeloproliferative syndrome]

Symptoms of hemorrhagic diathesis and/or thrombotic complications are observed in patients with myeloproliferative syndrome (m-p.s.). It is emphasized that there is a meaningful direct and indirect share of blood platelets in the mentioned disturbances of hemostasis. Therefore in own investigations an attempt was made to evaluate the morphology and function of blood platelets in patients with various forms of m-p.s., as well as to find an answer to the question: do any differences in morphology and function (activation) of blood platelets appear in patients with m-p.s.?, and is activation of blood platelets always accompanied by the symptom of hemorrhagic diathesis or past thrombotic episodes (the second ones evidenced in the patients anamneses)?, do the blood platelets in idiopathic thrombocytopenia (one of the forms of m-p.s.), differ morphologically and functionally from platelets in other forms of m-p.s. The investigation comprised 45 patients, in whom m-p.s. was diagnosed at Department of Hematology PAM (28 women, 17 men) aged from 36 to 82 years (mean age 58.10 + 10.61). The diagnosis of m-p.s. in each patient was established on the basis of clinical picture and laboratory examinations (blood morphology, hematocrit, FAG score, histopathological examination of bone marrow). In patients the accomplished determination concerned blood platelets count, mean blood platelet volume, platelocrit, volume range of blood platelets, coagulation time by Duke's method. The function of platelets was estimated with the help of the following studies: aggregation of blood platelets under the influence of ADP according to Born's method, concentration of beta-thromboglobulin (beta-TG) and platelet factor--4 (PF-4) in plasma by ELISA method. In order to pay due consideration to the effect of blood platelets count exerted on the concentration of beta-TG and PF-4, a supplementary parameter was introduced, the so-called beta-TG and PF-4 standardized. That allowed for studying the platelets in all patients under the same conditions. The results of own investigations have shown that most of the patients with m-p.s. had disturbances involving the morphology of blood platelets (Tab. 2) and increased activity of platelets, being expressed by a rise in concentrations of beta-TG and PF-4 in plasma (Fig. 1, 2) and by abnormal aggregation of platelets due to ADP influence. Moreover, the determination of beta-TG and PF-4 concentration in plasma in thrombocytopenia states, particularly in patients with idiopathic thrombocytopenia ought to be performed after the standardization of platelets count, the finding being also supported by the results of own investigations (Tab. 3). There may be compliance with the viewpoint expressed in the literature that the results of studying the morphological parameters of blood platelets and their function (activation) in m-p.s. are not a prognostic factor for the appearance of thrombotic complications and/or hemorrhages.