| The purposes of this study were to investigate the effect of HIV infection on mucosal IgA immune responses in parotid saliva (PS) and respiratory tract mucosal fluids including bronchial fluid (BF) and bronchoalveolar lavage (BAL) of HIV+ individuals, to investigate the mucosal immunological effects of highly active antiretroviral therapy (HAART) in HIV-infected patients and to detect the presence of HIV-1 in PS, BF, BAL, and plasma of HIV+ individuals. A total of 36 human subjects were recruited for this research, including 16 HIV− subjects, 10 HIV + CD4 < 200 and 10 HIV + CD4 > 200 subjects. Total immunoglobulin levels of IgA, IgA1, IgA2, S-IgA, S-IgA1, S-IgA2, and IgG were assessed by ELISA. ELISA was also used to evaluate specific IgA and IgA subclass reactivity to Streptococcus mutans and Streptococcus pneumoniae in PS, BF, BAL, and plasma. The reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the presence of HIV-1 in all samples. The present study demonstrated an alteration of mucosal immune responses in either the levels of mucosal immunogloblulin concentrations or specific mucosal IgA and IgA subclass reactivity to bacterial pathogens in the oral cavity and respiratory tract of HIV+ individuals. This alteration may reflect the dysregulation of mucosal Ig secreting cells in HIV+ subjects. Therefore, the dysregulation in IgA responses may play a role in predisposing HIV+ subjects to some opportunistic infections at the mucosal sites. There were significantly higher numbers of PS IgA specific responders to S. pneumoniae polysaccharide in HIV− subjects than in HIV+ subjects. The decreased PS IgA antibody against S. pneumoniae may predispose HIV+ patients to the colonization of S. pneumoniae, leading to the development of pneumococcal disease. There were no significant differences in immunoglobulin levels and specific IgA reactivity to bacterial antigens between HIV+ patients with HAART and those patients not receiving HAART. Our results also demonstrated that the presence of HIV-1 RNA in BAL, and less so in PS and BF, might serve as reservoirs of HIV replication and might contribute to increased transmission risks and resistance to antiretroviral therapy. |
