Abstract
The present study analyses human immunoglobulin G (IgG) antibodies directed against the Paracoccidioides brasiliensis exoantigen, gp43, as well as the presence of gp43-IgG immune complexes (ICs) in 31 samples of saliva and serum from 19 patients with paracoccidioidomycosis (PCM) and 12 normal donors. Additional analysis of secretory IgA (sIgA) was performed on the same saliva samples. Consistent with previous findings, a significant increased specific IgG level was observed in PCM patients' saliva and serum (P < 0·05). The analysis of serum gp43 and gp43-IgG IC demonstrated a higher level in patients with PCM (P < 0·05); however, this difference was not statistically significant with regard to gp43 and gp43-IgG in saliva when compared to the healthy donors. A high level of sIgA in saliva of PCM patients compared to that of normal donors was also observed (P < 0·05). Patients exhibiting low levels of serum IgG but with high titres of IC were observed, thus strengthening the idea of the necessity to use more than one marker for diagnosis and treatment monitoring of PCM. This is the first report of sIgA in PCM patients' saliva and may be indicative of a protective role in neutralizing antigens on mucosal surfaces.