Platelet Thromboplastic Function in Polycythæmia and Thrombocythæmia

Abstract

SUMMARY The platelet thromboplastic function levels in patients with primary disease of the bone marrow (polycythæmia vera and primary thrombocythæmia) were compared with the findings in patients whose polycythæmia or thrombocytosis was due to a definable underlying disorder. Of the patients with untreated polycythæmia vera, irrespective of the platelet count, 71% showed reduced platelet thromboplastic function, compared with only 12% of patients with secondary polycythæmia which was uncomplicated by either renal or liver disease. Similarly, the platelet thromboplastic function level was reduced in 100% of patients with untreated primary thrombocythæmia, compared with 47% of patients with elevated platelet numbers secondary to other associated diseases. The platelet thromboplastic function test was therefore useful in differentiating between primary and secondary polycythæmia. Normal platelet thromboplastic function virtually excluded a myeloproliferative disease (thrombocythæmia) in patients with raised platelet counts, irrespective of other hæmatological changes. The effect of 32P in the two conditions due to primary disease of the bone marrow was to produce a rise towards normal platelet thromboplastic function. It is considered that the platelet defect in primary thrombocythæmia is a qualitative one, and not, as has been reported by others, a quantitative anticoagulant effect of high in‐vitro platelet numbers.

Essential Thrombocythaemia

“…Bone marrow examina tion showed panmyelosis with a striking increase in megakaryocytes which were large and tended to have many lobes, as has been described by others (32,43,55). The NAP scores, serum lysozyme and vitamin Bi2 levels were variably abnormal in our patients, in keeping with the findings of others (13,19,26,29,32,34,43,57).…”

Platelet Defects in the Myeloproliferative Disorders

“…Two cases of CML (No. 10,11) and three cases of PV (No. 20-22) had been treated previously and were in hematological remission during our studies, whereas seven cases of CML (Nos.…”

“…Three patients with CML (No. 7,11,12) and one patient with MMM (No. 19) had also been studied by Tangun in his series.23 All the patients and control subjects had been asked not to take any medication for at least one week.…”

“…Extensive work on platelet function in this syndrome began with the investigation of the platelet factor 3 activity (PF3a) .3,4J3- 11 The results obtained have, however, varied considerably, since the methods used have been widely different and many of them are now known to have been inadequate. Indeed, at one time attempts were made to explain the hemostatic defects in such cases by taking into consideration the fact that high concentrations of the platelets have an anticoagulant effect.…”