Objective: To assess serum beta2-microglobulin levels in human immunodeficiency virus (HIV)-infected and uninfected pregnant women, variations of serum beta2-microglobulin levels during pregnancy and postpartum, factors that might influence beta2-microglobulin levels in pregnant women, and the association between beta2-microglobulin and perinatal HIV-1 transmission.
Methods: We assayed 374 stored (-70C) serum samples from pregnant women enrolled in the Newark perinatal HIV-1-transmission study and 18 nonpregnant women for beta2-microglobulin using a microparticulate enzyme immunoassay. The Student t test, Wilcoxon rank test, binomial test, and Spearman correlation coefficient were used for statistical analysis, with P < .05 considered statistically significant. A linear regression model was used to assess the effect of independent variables on serum beta2-microglobulin levels.
Results: There were no significant differences (P = .16) in serum beta2-microglobulin levels between pregnant and nonpregnant HIV-negative women (1.07+/-0.35 versus 0.99+/-0.18 mg/L). Beta2-Microglobulin levels did not vary throughout pregnancy and postpartum, irrespective of HIV serostatus. Substance abuse did not alter beta2-microglobulin levels. Human immunodeficiency virus infection caused significant increases of this surrogate marker, but it could not discriminate among disease stages. Beta2-Microglobulin levels at delivery were lower among women who delivered HIV-infected infants.
Conclusion: Human immunodeficiency virus infection was associated with increased serum beta2-microglobulin levels in pregnant women and was the most significant correlate of increases of that marker. Pregnancy and substance use during pregnancy did not influence levels of serum beta2-microglobulin significantly.