[Secondary erythrocytoses].

The author provides data pertinent to the modern classification of erythrocytosis, which rests on the pathogenetic principle. The difference in the pathogenesis of erythremia and secondary erythrocytoses was proved with the help of an erythroid culture and by examination of erythropoietins, which can be thus used for diagnostic purposes. Analysis of so-called "pure" erythrocytosis has shown that this term implies different patterns of erythrocytosis from the standpoint of the pathogenesis: erythremia, secondary erythrocytoses that are difficult to diagnose, and hereditary erythrocytosis associated with erythropoietin hyperproduction. There is no evidence for the existence of the "pure" erythroid leukemia and thus the author doubts this disease entity. Analysing the different patterns of secondary absolute erythrocytosis the author discusses specific problems of their pathogenesis. Attention is paid to erythrocytosis of a tobacco smoker, to the role of obesity and concomitant action of some factors on the development of hypoxic erythrocytosis. The data are presented on the new types of erythrocytosis, on the post-transplantation one, in particular, which occurs after kidney transplantation, and finally on erythrocytosis that develops occasionally in patients on hemodialysis. Attention is paid as well to relative erythrocytoses, risk factor in the development of thrombotic complications. The problems of etiologically and pathogenetically valid therapy of secondary erythrocytoses are reviewed.