Usefulness of (1→3)β-D glucan in early diagnosing Pneumocystis jirovecii pneumonia: a case report.

Pneumocystis jirovecii pneumoniae (PJP) may be difficult to diagnose. Since pneumocystis cannot be cultured, the diagnosis of PJP requires microscopic examination to identify pneumocystis from induced sputum or bronchoalveolar lavage (BAL) fluid. In order to evaluate the usefulness of (1→3) beta-D-glucan (BDG) levels in the early diagnosis of PJP, we describe the case of PJP in a 25-year-old male with acute lymphoblastic leukaemia (ALL) admitted to hospital with progressive dyspnea and fever with chills. The patient was not infected with human immunodeficiency virus (HIV). Sputum, blood, and urine cultures were negative; smears for acid-fast bacilli and tests for viral antibodies were both negative. The microbiology study of the BAL with Giemsa and immunofluorescence staining, seven days after admission showed the existence of P. jiroveci in the lungs. Further, one day and five days after admission, (1→3) beta-D-glucan (BDG) levels were very high. The high serum level of BDG considerably decreased after treatment with trimethoprim-sulfamethoxazole (TMP-SMX) and the clinical condition of the patient increasingly improved.