[Polycythemia after kidney transplantation].

Between 1971 and 1990, 251 kidney transplanted patients with a well functioning graft were evaluated to determine the frequency of post-transplant erythrocytosis (PTE). Thirty-one patients (13 percent) developed polycythaemia 10.6 +/- 10 months after transplantation. Thromboembolic complications occurred in 22 percent of the cases. The frequency of PTE was higher in males than in females (sex ratio: 7.2 vs 2.1; P < 0.05). Patients with renal dysplasia had a lower incidence of PTE (3 vs 22 percent; P < 0.05) as did those who had been treated with azathioprine (9.4 vs 19 percent; P < 0.05). None of the patients treated with recombinant erythropoietin before transplantation developed PTE during a mean follow-up of 15.1 +/- 4.5 months. The majority of polycythaemic patients had normal erythropoietin levels. These results show that there is an erythropoietin-independent proliferation due to an increased sensitivity of erythroid progenitors or to an erythroid stem cell stimulation by cytokines.