Comparison of trimethoprim-sulfamethoxazole and aerosolized pentamidine for primary prophylaxis of Pneumocystis jiroveci pneumonia in immunocompromised patients with connective tissue disease.

To evaluate the efficacy of primary prophylaxis for Pneumocystis jiroveci pneumonia (PCP) in patients with connective tissue disease (CTD) and immunosuppression, we compared trimethoprim-sulfamethoxazole (TMP-SMZ) with aerosolized pentamidine. Forty-eight CTD patients of Kitasato University Hospital whose CD4+ lymphocyte count in the peripheral blood was less than 300 microl(-1) were reviewed from 2002 to 2004. Twenty-seven patients received TMP-SMZ and none of them developed PCP. Among 18 patients receiving aerosolized pentamidine, three patients developed PCP. These data indicate that TMP-SMZ is better for prophylaxis than aerosolized pentamidine.