Salivary immunoglobulin A and G subclasses in HIV positive patients

Many of the opportunistic infections in HIV are related to the mucous membranes, but the protection of oral mucosal compartment mediated by IgA and IgG subclasses in saliva is still not well documented. Therefore, the aim of this study was to investigate the status of salivary IgA and IgG subclass in HIV positive patients. Levels of IgG1, IgG2, IgG3 and IgG4 were determined by ELISA and IgA1 and IgA2 by radial immunodiffusion in the resting whole saliva of 33 HIV patients and 21 HIV-seronegative healthy controls and were expressed in mg/L (IgA) and ug/L (IgG) of saliva. Salivary IgA2 was significantly reduced in the HIV positive patients (p<0.0009) when compared to the healthy controls, but no differences in salivary IgA1 level between HIV patients and healthy controls were found. On the other hand, salivary IgG1, IgG2, IgG3 and IgG4 subclasses were increased (p<0.0009) in HIV patients in comparison to the healthy controls. We can conclude that inspite of IgA2 deficiency which was found in studied HIV positive patients, mucosal antibody responses are quite normal and might not predispose development of oral opportunistic infections.