Serum Adenosine Deaminase and Total Immunoglobulin G Correlate with Markers of Immune Activation and Inversely with CD4 Counts in Asymptomatic, Treatment-Naive HIV Infection

Abstract

HIV-infection is characterized by aberrant immune activation and ongoing inflammation. Markers of inflammation are now recognized to have prognostic value for adverse events, independent of viral loads and CD4 counts. This study aimed to delineate a panel of affordable markers of immune activation in untreated HIV-infection that may have an impact on the management of HIV in resource-limited settings. This was a cross-sectional study of 86 untreated newly diagnosed HIV-infected patients and 54 matched controls attending a voluntary testing clinic in Cape Town, South Africa. Serum levels of adenosine deaminase (ADA), total immunoglobulin G (IgG), soluble CD14 and lipopolysaccharide-binding protein (LBP) were measured and correlated with CD4 counts, viral loads and expression of CD38 on CD8+ T cells. ADA, IgG and LBP were all significantly increased in the HIV infected group (p < 0.0001) compared with uninfected controls. Soluble CD14 was also significantly increased (p = 0.0187). Furthermore, all these parameters correlated inversely with CD4 counts (r = -0.481 p < 0.0001; r = -0.561; p < 0.0001; r = -0.387 p = 0.0007 and r = -0.254 p = 0.0240, respectively). Only ADA correlated with viral load (r = 0.260 p = 0.0172). Importantly, ADA, IgG and LBP correlated directly with %CD38 on CD8+ T cells (r = 0.369 p < 0.0001; r = 0.284 p = 0.001; r = 0.408 p = 0.0006, respectively). Affordable parameters such as serum ADA and IgG correlated significantly with immune activation levels and markers of disease progression in untreated HIV-infection and therefore may add value to the management of these patients in resource-limited settings.