Pneumocystis pneumonia in a patient with type 2 diabetes mellitus

A 76-year-old man, who was in the hospital for the treatment of type 2 diabetes mellitus and was receiving gonadotropin-releasing hormone (GnRH) agonist treatment for prostate cancer, developed fever and hypoxemia. Imaging revealed diffuse interstitial shadows, and PCR of the bronchoalveolar lavage fluid was positive for Pneumocystis jirovecii. The patient's absolute CD4-positive lymphocyte count dropped to 145/microl, but the HIV antibody was negative. After trimethoprim-sulfamethoxazole (TMP/SXT) treatment, the absolute CD4 positive lymphocyte count returned to normal. This patient with type 2 diabetes mellitus developed Pneumocystis pneumonia and developed a transient decrease in CD4-positive lymphocytes.