(1->3)beta-D-glucan as a quantitative serological marker for Pneumocystis carinii pneumonia

We detected (1-->3) beta-D-glucan (beta-glucan), which is one of the major components of the cyst wall of Pneumocystis carinii, in sera obtained from patients with P. carinii. pneumonia (PCP), We confirmed that beta-glucan was detectable by a beta-glucan detection kit (G test; Seikagaku Corporation) in bronchoalveolar lavage fluids (BALFs). The mean concentration of beta-glucan in BALFs obtained from specific-pathogen-free nude mice infected with P. carinii (n = 7; mean, 2,631 [range, 1,031 to 9,095] pg/ml) was significantly higher (P < 0.001) than that in uninfected, specific-pathogen-free mice (n = 7; 6.5 [range, 4.0 to 8.3] pg/ml), The mean level of beta-glucan in BALFs from PCP patients was significantly higher (P < 0.05) than that in BALFs from patients with other lung diseases (7,268 [range, 1,355 to 15,500] pg/ml [n = 4] versus 242.5 [17 to 615] pg/ml [n = 4]), In sera from six of seven patients with PCP, significant levels of beta-glucan (494.1 [8.5 to 1,135] pg/ml) were detected, while it was undetectable in patients with other lung diseases and in a control group, In five patients at follow-up, the level of beta-glucan decreased with clinical improvement, These results suggest that beta-glucan is detectable in sera from patients with PCP and it is a practical serological marker for monitoring of the disease during treatment.