Comparison of the distribution of IgG and IgA antibodies in serum and various mucosal fluids of HIV type 1-infected subjects

We compared IgG and IgA distribution in serum, three different salivary sam ples, two different rectal secretion samples, cervicovaginal secretions, an d seminal secretions from asymptomatic CDC stage II/III HIV-1-infected subj ects (n = 44) and from HIV-1-seronegative volunteers (n = 52). In-house ELI SAs were used to measure total IgG and total IgA levels, as well as HIV-spe cific anti-gp120 MN and anti-p24 LAI IgG and IgA, Human serum albumin was t itrated in parallel to calculate the relative coefficient of excretion (RCE ), In spite of substantial interindividual variability, total IgG concentra tions in all fluids were found to be significantly greater in the HIV-1-inf ected group than in the seronegative subjects, Calculation of RCE values re vealed three different types of mucosal secretion: secretions,vith no local Ig production, such as sperm; secretions with local production of IgA and transudative origin of IgG, such as salivary and rectal samples; and secret ions with local production of both IgG and IgA, such as in cervicovaginal s ecretions, For all mucosal specimens from HIV-1-infected subjects, the resp onse to HIV-1 was predominantly IgG, with highest titers observed in cervic ovaginal secretions (although these were lower than serum levels). In contr ast, the specific IgA response appeared weaker in the mucosa than in serum.