Humoral Immunological Factors and Nitric Oxide Levels in HIV Patients with Low CD4+ T-Lymphocytes Count

Purpose: This study determined the plasma levels of nitric oxide (effector molecule in intracellular killing by phagocytes), regulators (C3 inactivator and C1 inhibitor) and factors (C4 and C3c) of Complement system and immunoglobulin classes (IgG, IgA and IgM) in HIV patients compared with HIV un-infected controls. The aim is to provide additional explanation for long persistence of human immunodeficiency virus (HIV) in HIV patients. Methods: The plasma levels of Complement regulators (C3 activator and C1 inhibitor), Complement factors (C3c and C4), immunoglobulin classes (IgG, A and M) were estimated using immunoplates in controls, HIV patients with <200 CD4+ T lymphocytes per microliter of blood and HIV patients with 200–499 CD4+ T lymphocytes per microliter blood. Also the level of plasma NO was determined using Griess reagent. Results: The levels of C1 inh, C3 act, C3c, NO, IgG, IgA and IgM were significantly higher in all HIV patients compared to controls. The mean values of C1 inh and C4 were significantly higher in HIV patients with a CD4+ T lymphocytes <200 cells/ μl blood compared with HIV CD4+ T lymphocytes 200–499 cells/ μl blood. Conclusion: It may be concluded that plasma levels of C1 inh and C4 might be used to distinguish HIV severity.