Does HAART improve renal function? An association between serum cystatin C concentration, HIV viral load and HAART duration.

AIM: The prevalence of renal disease in human HIV-infected individuals varies between 2% and 10%. Many reports have demonstrated the beneficial effect of antiretroviral (ARV) therapy on slowing the progression of renal diseases. The aim of our cross-sectional study was to determine serum cystatin C concentration in different stages of HIV infection and the relationship between cystatin C concentration and ARV treatment.
METHODS: Cystatin C concentration was measured in the sera of 77 HIV-1-infected individuals and 18 HIV-seronegative volunteers. The glomerular filtration rate (GFR) was estimated using the Modification of Diet in Renal Disease Study formula.
RESULTS: HIV infection resulted in a significant increase in serum cystatin C concentration compared with healthy individuals (933.4 +/- 32.1 vs 621.1 +/- 56.8 ng/ml, P < 0.001). There were no significant differences in urea, creatinine and GFR between those groups. On multivariate analyses serum cystatin C was independently associated with highly active antiretroviral therapy (HAART) duration (beta = -0.34, P = 0.04) and HIV viral load (beta = 0.33, P = 0.04), whereas there were no significant relationships with age, body mass index, HIV duration, CD4+ and CD8+ T-cell counts and serum high sensitivity C-reactive protein concentration.
CONCLUSIONS: Our initial observations indicate that serum cystatin C, which may reflect mild renal dysfunction, is increased during HIV-infection and is associated with HIV viral load. Long-lasting HAART seems to decrease cystatin C concentration, thus potentially improves renal function.