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The relationship of anemia and thrombocytosis.

1974; National Institutes of Health; Volume: 84; Issue: 3 Linguagem: Inglês

Carl W. Jackson, Joseph V. Simone, Carol C. Edwards,

Myeloproliferative Neoplasms: Diagnosis and Treatment

Abstract An inverse correlation between hematocrit and platelet count is often encountered clinically, but the controlling factors in this relationship have not been identified. To examine this problem, we studied thrombopoiesis in anemic rats with or without simultaneously inhibited erythropoiesis. This approach allows specific alteration of hematocrit without alteration of the platelet count. Lowering the hematocrit to 35 per cent with anti-erythrocyte antiserum or to 26 per cent by exchange transfusion with erythrocyte-poor, platelet-rich plasma caused little change in the platelet count unless erythroid differentiation was selectively inhibited with small daily doses of actinomycin D. With erythroid inhibition the platelet count increased to 178 per cent of baseline. A nearly identical increase in platelet count was obtained without erythroid inhibition when the hematocrit was reduced to 22 per cent. A study of megakaryocytopoiesis in rats with acute anemia induced by exchange transfusion alone revealed little change in megakaryocyte concentration compared to control values. However, both the proportion of inmature megakaryocytes and the 24-hour megakaryocyte 3 HTdr labeling index were increased, suggesting that increased platelet production was the result of a shortened megakaryocyte transit time. Bilateral nephrectomy prevented increases in the 3 HTdr labeling index and the proportion of immature megakaryocytes. We conclude that a substance elaborated by the kidney in response to acute anemia accelerates marrow transit time of megakaryocytes resulting in increased platelet production.