A matched-pair control study of postrenal transplant polycythemia.

Polycythemia developed in 18 of 133 first kidney allograft recipients (13.5%) with onset from the third month to the fifth year posttransplantation. A group of matched nonpolycythemic patients were used as case controls to compare multiple variables in order to identify predisposing factors. In the polycythemia group, there were: (1) significantly more patients who had not undergone pretransplant nephrectomy; (2) significantly more patients who had glomerulonephritis as original disease; (3) significantly more patients who had received pretransplant transfusions; and (4) significantly more patients who were hypertensive posttransplant. Thus, the factors of the presence of native kidneys, original disease, pretransplant transfusions as well as hypertension posttransplant are factors associated with the presence of posttransplant polycythemia. This condition is usually self-limiting and benign.