SOURCE:

Faculty: Health Sciences And Technology
Department: Medical Laboratory Science

CONTRIBUTORS:

Ewenighi, O.C;
Onyenekwe, C.C;

ABSTRACT:

Human immunodeficiency virus (HIV) infection weakens the immunity of an individual; reduces lymphocyte population, alters cytokine secretion and impairs B and T cell function. The physiological status of pregnant women predisposes them to HIV progression hence the use of HAART for suppressing HIV replication, multiplication and restoration of the immune system. One of the ways to access the immune system is by invitro stimulation assay which specifically determines lymphocyte function without interference from other immune cells. This study evaluated impact of maternal HIV infection and HAART on plasma immunoglobulins and cytokine secretion by B and T lymphocyte. A total of 207 pregnant women aged (30 ± 4) years were recruited for the study using simple random sampling technique. The subjects were divided into HIV infected HAART treated (n = 122), HIV infected HAART naïve (n = 13) and HIV uninfected (n = 72) pregnant women as control. The study design was a case controlled study. Invitro stimulation of harvested B and T lymphocytes were performed using mitogens: concanavalin A (con A), phytohemaglutinin (PHA) and pokeweed (PW). Cytokine levels (interleukin 2- IL2, tissue necrosis factor alpha-TNF-α, interferon gamma-IFN- γ, interleukin 4 -IL4, interleukin 10- IL10) were measured in the supernatant of B and T lymphocyte using cytokine magnetic bead panel. However, plasma concentrations of Immunoglobulin A (IgA), Immunoglobulin M (IgM), Immunoglobulin G (IgG) were also analyzed using enzyme linked immunosorbent assay (ELISA). Column analysis (t-test, one-way ANOVA- Bonferroni's Multiple Comparison Test) and Mann-Whitney test were done using Graph Pad Prison 5. Significant values were set at P < 0.05. HIV infected HAART treated pregnant women showed significantly low levels of IFN-γ, IL-10 by con A, PW and PHA stimulation; and IL-4 by con A stimulation. Secretions of TNF-α and IL-2 using con A, PW and PHA stimulation were similar in supernatants of B and T lymphocyte culture of HIV infected HAART treated and control pregnant mothers. Trimester categorization revealed significantly low IL-10 secretions throughout 1st, 2nd and 3rd trimester in HIV infected HAART treated pregnant mothers. Secretions of TNF-α, IL-2 and IL-4 were similar in both normal and HIV infected HAART treated pregnant mothers at 1st. 2nd and 3rd trimester. There was significantly low IFN-γ secretion by PW and PHA stimulations in HIV infected HAART treated pregnant mothers at 1st trimester. TNF- α showed significantly (P = 0.02; 0.03) low level by PHA stimulation as pregnancy progressed to 3rd trimester. HAART treated pregnant women showed significantly (P < 0.0001) higher IgG but significantly (P < 0.0001) low IgM levels compared to control pregnant women. There was no significant difference in plasma IgA amongst the groups (P˃0.05). Plasma IgG was significantly higher (P˂0.0005) in 1st and 3rd trimesters in HAART treated pregnant women compared to control pregnant women. The findings in this study showed that the low secretions of IFN-γ, IL-4, IL-10 observed among HIV infected HAART treated pregnant mothers were normalized as pregnancy progressed to term but for IL-10 which remained significantly low throughout 1st, 2nd and 3rd trimester. The consistently lowered IL-10 level throughout the trimesters is an indication of possible role of this regulatory cytokine in HIV infection.