Levels of procalcitonin, C-reactive protein and neopterin in patients with advanced HIV-1 infection

Abstract

OBJECTIVES: To compare the value of procalcitonin, C-reactive protein (CRP) and neopterin as indicators of immune deficiency, co-infection, efficacy of treatment, and disease progression, in patients with advanced HIV-1 infection. DESIGN: Cross-sectional, investigating baseline blood measurements and clinical observations in 82 HIV-positive patients divided into an antiretroviral treatment (ART) group and an ART-naïve group. SETTING: Secondary general hospital in Pretoria. RESULTS: Procalcitonin and CRP levels showed no significant differences between the ART and ART-naïve groups, and no correlations with CD4 counts or viral loads. CRP levels were significantly higher with TB co-infection (p<0.05). Neopterin levels were raised above normal in 92% of the ART-naïve group and in 75% of the ART group. The levels were significantly higher (p<0.05) in the ART- naïve group. Negative correlations were found between neopterin and CD4 counts for the total patient group (r=-0.482; p<0.001). Neopterin was significantly (p<0.05) higher in the HIV/TB co-infection group than in those without TB. Higher neopterin levels at baseline were associated with a decline in CD4 counts over the ensuing 6-month period, and patients with higher baseline neopterin levels developed more complications over the 6-month period. CONCLUSIONS: Compared with procalcitonin and CRP, neopterin appears to be associated with the degree of immunodeficiency and of co-infection with TB. Neopterin levels may be investigated further as a measure of disease progression or treatment response.