Increased Antifungal Antibodies in Bronchoalveolar Lavage Fluid and Serum in Pulmonary Sarcoidosis

The recent studies suggest a role of fungi in development of sarcoidosis. Moreover, the immune response in sarcoidosis and fungal infection shows a striking similarity. We formulated a hypothesis of the possible increase in antifungal antibodies in bronchoalveolar lavage fluid (BALF) and serum in pulmonary sarcoidosis. BALF and serum levels of IgG-, IgM- and IgA-specific antibodies against the cell wall β-D-glucan and mannan of Candida albicans and Saccharomyces cerevisiae were tested in 47 patients (29 pulmonary sarcoidosis patients and 18 patients with other interstitial lung diseases (ILD – control group)) and 170 healthy controls. Our results proved: (1) an increase in IgG-, IgM- and IgA-specific antifungal antibodies in BALF in pulmonary sarcoidosis compared with the control group (C. albicans: IgG: P = 0.0329, IgM: P = 0.0076, IgA: P = 0.0156; S. cerevisiae: IgG: P = 0.0062, IgM: P = 0.0367, IgA: P = 0.0095) and (2) elevated levels of serum antifungal antibodies in pulmonary sarcoidosis compared with healthy controls (C. albicans: IgG: P = 0.0329, IgM: P = 0.0076, IgA: P = 0.0156; S. cerevisiae: IgG: P > 0.05, IgM: P < 0.05, IgA: P < 0.001). The study showed increased serum and BALF levels of antifungal antibodies in pulmonary sarcoidosis. The hypothesis that fungal infection is one of the possible aetiologic agents of sarcoidosis is interesting and deserves further attention.