Humoral immune response within the lung in HIV-1 infection

Abstract

In order to study the humoral immune defences in the respiratory tract during HIV‐1 infection, we measured the levels, local productions and anti‐HIV and antibacterial activities of IgG and IgA in the bronchoalveolar lavage fluid (BALF) and serum of 61 adult patients with severe HIV infection and of 56 HIV− controls. Albumin was used as the serum transudation factor. The increase of immunoglobulin levels in the serum of HIV‐infected patients was confirmed. The IgG level was also increased in epithelial lining fluid (ELF), whereas the total IgA level was unchanged and secretory IgA (SIgA) level was decreased. The ELF/serum immunoglobulin ratios suggested that the IgG present in ELF resulted mainly from transudation, in contrast to SIgA, which was synthesized locally in controls but greatly diminished in HIV‐infected patients. IgG to HIV‐1 could be detected in BALF of all the patients, but IgA to HIV‐1 only in 30% of patients. BAL IgG reacted more consistently and with a broader array of HIV‐1 antigens than did IgA. BAL IgA, when present in samples, reacted primarily with viral envelope antigens. Because IgA specificities to some HIV‐1 antigens were detected more intensively by BAL than by serum immunoglobulins, we conclude that the mucosal immune response is distinct from that in serum. IgG antibody activity to Streptococcus pneumoniae was decreased in HIV‐infected patients' sera, and IgA antibody activities to S. pneumoniae and to Pseudomonas aeruginosa were decreased in ELF in HIV‐infected patients.

Immunity in the Female Lower Genital Tract and the Impact of HIV Infection

“…Increased levels of IgG have also been identified in blood [59] of HIV1 women compared to low-risk subjects. Similar patterns of Ig appear in the lung [59] and the female LGT [58], with increased IgG compared to static or reduced sIgA levels.…”

“…Increased levels of IgG have also been identified in blood [59] of HIV1 women compared to low-risk subjects. Similar patterns of Ig appear in the lung [59] and the female LGT [58], with increased IgG compared to static or reduced sIgA levels. Studies on intestinal mucosa have suggested that this unexpected predominance of IgG over IgA may result from abnormal Ig production in the mucosa rather than from serum leakage [60].…”

Decreased Production of Local Immunoglobulin A toPneumocystis cariniiin Bronchoalveolar Lavage Fluid from Human Immunodeficiency Virus-Positive Patients

“…An immediate freezing of sampled BAL was performed to avoid urea splitting by organisms potentially present in BAL. Using this approach, we were able to determine the initial concentration of Igs in the ELF recovered by bronchoalveolar lavage (24,30). To determine the concentration of urea recovered from BAL and serum samples, a commercially available kit (Biomerieux, Marcy l'Etoile, France) was used.…”

Community-acquired pneumonia in Ugandan adults: short-term parenteral ampicillin therapy for bacterial pneumonia.

“…6 A substantial dysfunction of humoral immunity associated with HIV infection appears to predispose to bacterial pneumonia in these patients. 7 Previous investigators have demonstrated that penicillin is cost-effective in the treatment of lobar pneumonia before the outbreak of HIV infection in Africa. 8,9 A recent paper from India also emphasized the need for a cost-effective approach to treatment of CAP, for example with the use of parenteral penicillin in developing countries.…”