The chronic stage of human immunodeficiency virus (HIV) infection, although clinically asymptomatic, is characterized by activation of the immune system and persistent inflammation. Procalcitonin (PCT) has been studied in HIV infection as a marker of bacterial infection. Our aim was to assess the effect of persistent immune activation on PCT levels in asymptomatic treatment naïve HIV infected subjects.Methods:
This was a cross-sectional study of 68 asymptomatic antiretroviral therapy-naive HIV infected participants and 42 uninfected controls. Stored serum samples were used to measure: PCT, interleukin-6 (IL-6), lipopolysaccharide binding protein (LBP), high sensitivity C-reactive protein (hsCRP), immunoglobulin G (IgG) and albumin. PCT was correlated with markers of: disease progression (CD4 count and viral load), immune activation (CD 38 on CD8+ T cells, IgG and LBP), inflammation (IL-6, hsCRP and albumin).Results:
IL-6, IgG and CD8/38 were all significantly increased while albumin and CD4 counts were significantly lower in the HIV infected group. PCT levels were not significantly different between the two groups. There was no significant difference in LBP and hsCRP; however, their levels were increased in both groups. PCT correlated only with LBP (p=0.0001). IL-6 and LBP correlated positively with hsCRP and IgG. Albumin correlated inversely with IL-6 and viral load. Only IgG and CD8/38 correlated inversely with CD4 counts.Conclusions:
We demonstrated the activation of the innate (raised LBP), humoral (raised IgG) and cellular immune systems (increased CD8/38 T cells). Despite a state of persistent inflammation, PCT levels are not elevated in asymptomatic untreated HIV infection.