Severe pulmonary nocardiosis in a kidney allograft recipient with a low immunological response.

A patient with severe pulmonary nocardiosis occurring in the early posttransplant period is presented. Three outstanding features characterized this case: 1) the failure to diagnose this rare opportunitistic pathogen by conventional detection methods necessitated open lung biopsy; 2) the initiation of trimethoprim-sulphamethoxazole therapy resulted in a dramatic clinical response; and 3) an allograft recipient with a low immunological response contracted nocardiosis. His immune status became apparent following pretransplant donor-specific blood transfusion tests, unresponsiveness to third-party transfusion and graft tolerance permitting the permanent withdrawal of azathioprine without graft function impairment.