Urinary Transforming Growth Factor-Beta 1 (uTGF-β1) and Prevalent CKD Risk in HIV-Positive Patients in West Africa

Introduction: This study investigated the association of urinary transforming growth factor-β1 (uTGF-β1) with prevalent chronic kidney disease (CKD) in the HIV-infected population. Methods: HIV-positive patients without CKD (HIV⁺CKD⁻, n = 194) and 114 with CKD (HIV⁺CKD⁺) who did not have hypertension, diabetes mellitus, or hepatitis B or C, had their urinary protein-creatinine ratio (uPCR), serum transforming growth factor (TGF)–β1, and uTGF-β1 measured. uTGF-β1-creatinine ratios (uTGF-β1Cr) were calculated. Spearman correlation was used to determine the association between uTGF-β1Cr and various attributes, and the Cuzick trend test was used to assess the presence of a linear trend in median uTGF-β1Cr levels across the stages of CKD. Multivariable robust linear regression models were used to assess independent association with variability in uTGF-β1Cr and estimated glomerular filtration rate (eGFR) levels. Results: The age of the participants was 38.3 ± 10.3 years with 73.4% women. The median uTGF-β1Cr was higher among HIV⁺CKD⁺ (4.85 ng/mmol [25th–75th percentile 1.96–12.35] vs. 2.95 [1.02–5.84]; P = 0.001]). There was significant correlation between uTGF-β1Cr and age (P = 0.02), eGFR (P = 0.001), and uPCR (P < 0.001) in the HIV⁺CKD⁺ group. Among the HIV⁺CKD⁺ patients, there was gradual reduction in the median level of uTGF-β1Cr with CKD severity (P = 0.04). HIV⁺CKD⁺ patients had significantly higher levels of uTGF-β1Cr after controlling for potential confounders. Using eGFR as dependent variable, proteinuria explained the changes associated with uTGF-β1Cr levels. Conclusion: HIV⁺CKD⁺ patients express higher levels of uTGF-β1 especially in the early stages of CKD apparently related to proteinuria levels.