Cystatin C in addition to creatinine for better assessment of glomerular renal function decline in people with HIV receiving antiretroviral therapy.

Objective: To compare the estimated glomerular filtration rate (eGFR) using the creatinine equation (eGFRcreat) or the cystatin C equation (eGFRcys) in people with HIV (PWH) under antiretroviral drugs. We specifically included patients with an eGFRcreat around 60 ml/min per 1.73 m2 to evaluate agreement on stage 2 and 3 chronic kidney disease (CKD) classification.

Design: eGFRcreat, eGFRcys and resulting CKD staging were determined in 262 consecutive patients with HIV-1 (PWH) with a suppressed viral load (<200 copies/ml) under antiretroviral drugs and having impaired renal function (eGFRcreat between 45 and 80 ml/min per 1.73 m2). Antiretroviral drugs regimens were classified into eight groups: cobicistat (COBI)+elvitegravir (EVG), ritonavir (RTV)+protease inhibitor, dolutegravir (DTG), DTG+rilpivirine (RPV), RPV, raltegravir (RAL), bictegravir (BIC), and other antiretroviral drugs.

Results: Mean eGFRcys was higher than mean eGFRcreat (77.7 ± 0.5 vs. 67.9  ± 7.9 ml/min per 1.73 m2, P < 0.0001). The differences were significant in five treatment groups with COBI/EVG; DTG; DTG+RPV; RPV; RAL. CKD classification was modified for 51% of patients when using eGFRcys instead of eGFRcreat, with reclassification to less severe stages in 37% and worse stages in 14%.

Conclusion: This study highlighted significant differences in eGFR depending on the renal marker used in PWH, having a significant impact on CKD classification. eGFRcys should be an additive tool for patients having eGFRcreat around 60 ml/min per 1.73 m2 for better identification of renal impairment.