Abstract
Four patients who had received cadaveric renal allografts developed a profound and sustained leucopenia in association with a trimethoprim-sulphamethoxazole preparation. Ten other cadaveric renal allograft recipients received identical chemotherapy with no adverse effects. Statistical analysis showed that the association of leucopenia and trimethoprim-sulphamethoxazole therapy was dependent on the time after the transplantation procedure and was not related to the dosage of immunosuppressive chemotherapy or renal function.