Serum immunoglobulins in children perinatally exposed to human immunodeficiency virus

Abstract

OBJECTIVE: Hypergammaglobulinemia is an early manifestation of perinatal HIV infection. Our objective was to analyze the differences in serum immunoglobulin levels between infected and seroreverter children and their association with clinical outcome. METHODS: We carried out a historical prospective study with 107 infected and 90 seroreverter children. We compared the IgA, IgG, and IgM levels between infected and seroreverters in the first 18 months of life; IgA, IgG, and IgM as surrogate markers of infection; and IgA, IgG, and IgM levels in the first 5 years in infected children, according to clinical outcome. The Mann-Whitney test was used for comparison between groups. Surrogate markers were assessed according to sensitivity, specificity, positive and negative predictive values, and J index. RESULTS: Infected children, when compared to seroreverters, showed significantly higher levels of: IgM from the 1st to the 5th trimester; IgA and IgG from the 2nd to the 6th trimester (P </= 0.05). Levels of IgA >/= 90 mg/dl in the 2nd trimester and IgG >/= 1,700 mg/ dl or 1,200 mg/dl in the 2nd and 3rd trimesters were associated with HIV infection with J indexes of 0.97, 0.92, and 0.93, respectively. Infected children in the B and C categories, compared to those in the N and A, showed higher levels of IgM from the 2nd to the 4th year, and IgA from the 3rd to the 5th year (P </= 0.05). CONCLUSIONS: The temporal progression of IgA, IgG, and IgM levels showed an early and intense stimulation to the synthesis of immunoglobulin in infected children. Clinical and epidemiological indicators showed that such levels may be surrogate markers of infection. Higher IgM and IgA levels from the 2nd to the 5th year in more severely infected children suggest a dysfunction in immune regulation secondary to persistent antigenic stimulation.