Objective: To assess the frequency of glomerular and tubular proteinuria in a cohort of HIV-infected patients, and to determine the factors associated with each type of injury.
Design: Cross-sectional study of 1210 consecutive HIV-infected adults followed in HIV outpatient unit (Montpellier/France).
Methods: Spot urine protein to creatinine (uPCR), albumin to creatinine (uACR) and albumin to protein (uAPR) ratios were assessed. Glomerular injury was defined as uACR at least 30 mg/g or uPCR at least 200 mg/g with uAPR at least 0.4. Tubular injury was defined as uPCR 200 mg/g or more with uAPR less than 0.4. Multivariate logistic regression identified independent factors of each type of proteinuria, in the 1158 patients with estimated glomerular filtration rate (eGFR) at least 60 ml/min per 1.73 m, using re-expressed modification of diet in renal disease equation.
Results: Frequency of proteinuria was 18.2% among patients with eGFR at least 60 ml/min per 1.73 m consisting in tubular proteinuria for 50.7% of them. Factors associated with glomerular proteinuria were age [OR 1.34/10-year increment (95%CI: 1.08-1.66)], diabetes [OR 3.37 (95%CI: 1.53-7.44)], and arterial hypertension [OR 2.52 (95%CI: 1.36-4.66)]. Factors associated with tubular proteinuria were age [OR 1.43 (95%CI: 1.14-1.79)], current tenofovir use [OR 3.52 (95%CI: 1.86-6.65)], hepatitis C co-infection [OR 1.62 (95%CI: 1.00-2.65)], AIDS stage [OR 1.83 (95%CI: 1.18-2.82)], CD4 cell count less than 200 per μl [OR 2.48 (95%CI: 1.31-4.70)].
Conclusion: This study distinguished risk factors for tubular injury, mainly related to HIV disease and its treatment (tenofovir), and glomerular injury, linked to non HIV-related variables (age, diabetes, hypertension). Measuring uPCR, uACR and uAPR may help with the detection and specific management of early chronic kidney disease in HIV-infected patients having normal or sub-normal eGFR.