Post-transplant erythrocytosis: role of erythropoietin and male sex hormones.

Seventeen patients with post-renal transplant erythrocytosis and 17 non-erythrocytotic controls, matched in age, sex, serum creatinine and source of donor kidney, were studied to determine the role of erythropoietin, male sex hormones (testosterone, FSH, LH), and various patient risk factors in post-transplant erythrocytosis. Serum erythropoietin was significantly greater in erythrocytotic patients (35.6 +/- 5.7 mU/ml) than non-erythrocytotic patients (18.8 +/- 2.6 mU/ml) (P less than 0.05) and normal subjects (22.5 +/- 0.95 mU/ml) P less than 0.05). Serum testosterone was similar between the male study (13.2 +/- 6.2 nmol/l) and control (13.1 +/- 6.0 nmol/l) patients. This might be due to the greater basal LH in the male control subjects (13.9 +/- 11.7 IU/l versus 8.0 +/- 3.3 IU/l in erythrocytotic males, P = 0.084). Basal FSH in the male controls was greater than that in the study group (13.7 +/- 14 IU/l versus 6.8 +/- 2.9 IU/l, P = 0.067). Among the demographic risk factors, only the smoking history was important. There were more smokers among the erythrocytotic patients than controls (P = 0.051).