Bronchiolitis obliterans organizing pneumonia associated with Pneumocystis carinii infection in a liver transplant patient receiving tacrolimus.

We report on a case of bronchiolitis obliterans organizing pneumonia (BOOP) associated with Pneumocystis carinii pneumonia (PCP) after liver transplantation and tacrolimus based immunosuppression. Radiologically, bilateral diffuse interstitial shadowing and patchy alveolar infiltrates developed after switching the patient from cyclosporin A to tacrolimus for persistent rejection. Bronchoalveolar lavage (BAL) fluid showed inflammatory cells but no pathogenic organisms. Open lung biopsy revealed BOOP with granulomatous PCP. Thus, even in the case of negative BAL the possibility of an atypical P. carinii infection has to be considered for differential diagnosis of pneumonia in immunocompromised patients after organ transplantation. The combination of BOOP with PCP after liver transplantation and tacrolimus medication has not been reported previously.