Imunoglobulinas séricas em crianças com exposição perinatal ao vírus da imunodeficiência humana

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 seroreverting children and their association with clinical outcome. METHODS: We carried out a historical prospective study with 107 infected and 90 seroreverting children. We compared the IgA, IgG, and IgM levels between infected and seroreverting patients within the first 18 months of life; IgA, IgG, and IgM as surrogate markers of infection; and IgA, IgG, and IgM levels within 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 Youden's index. RESULTS: Infected children, when compared to seroreverters, showed significantly higher levels of IgM between the 1st and 5th trimesters; IgA and IgG between the 2nd and 6th trimesters (P less than or equal to 0.05). Levels of IgA greater than or equal to 90 mg/dl in the 2nd trimester and IgG greater than or equal to 1,700 mg/dl or 1,200 mg/dl in the 2nd and 3rd trimesters were associated with HIV infection, with Youden's 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 between the 2nd and 4th years, and IgA between the 3rd and 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 between the 2nd and 5th years in more severely infected children suggest a dysfunction in immune regulation secondary to persistent antigenic stimulation.