Salivary immunoglobulin A antibodies to gp41 in human immunodeficiency virus-seropositive patients: lack of correlation with disease progression

Mucous membranes are the main route of transmission of human immunodeficien cy virus (HIV). Interestingly, some viral inhibitory activities have been f ound in saliva. The purpose of this study was to determine the level of sal ivary immunoglobulin A (IgA) antibodies to gp41 in HIV+ patients at various disease stages to identify whether gp41 was able to induce vigorous humora l responses. Unstimulated saliva samples were obtained from three groups of subjects (n=37): group A (HIV-), group B (HIV+, CD4(+) < 200/mm(3)), and g roup C (HIV+, CD4(+) > 200/mm(3)). IgA antibody levels to purified gp41 wer e determined by enzyme-linked immunosorbent assay (ELISA). Western blot ana lyses were performed using HIV+ saliva to confirm IgA reactivity to gp41. E LISA demonstrated that HIV+ subjects had higher IgA antibody to gp41 than H IV- individuals. No significant differences were noted between HIV+, CD4(+) < 200/mm3 and CD4(+) > 200/mm(3) subjects. High (81.25%) IgA reactivity to gp41 was demonstrated by Western blotting of saliva from all HIV+ individu als. In conclusion, gp41 responses are important in the HIV disease process , as indicated by the high IgA levels and gp41 reactivity in saliva of HIV patients.