Early impairment of gut mucosal immunity in HIV-1-infected children.

This study was performed in 27 HIV-1+ children to characterize the IgA hyperglobulinaemia observed in the serum during the course of HIV-1 infection. By contrast with serum IgG, which increased very early, IgA elevation was related to the decrease of CD4+ cell percentage. It was demonstrated that IgA1 subclass increased selectively. Secretory IgA (SIgA) and IgA and IgG activity to gliadin, bovine serum albumin (BSA) and at a lower level to casein could be detected in the serum at the early stages of HIV infection, but SIgA levels and IgA activity to gliadin further increased during the course of immunodeficiency. By contrast, IgA and IgG activity to tetanus toxoid did not change. These data demonstrate that the hyper IgA, closely related to the degree of immunodeficiency, could be due in part to a disturbance of the gut mucosal immune system. Moreover, impaired intestinal immunity seems to appear very early, and to progress during the course of paediatric HIV-1 infection.