Background
Children living with HIV frequently show high plasma levels of fibroblast growth factor-2 (FGF-2/bFGF). FGF-2 accelerates the progression of several experimental kidney diseases; however, the role of circulating FGF-2 in childhood HIV-chronic kidney diseases (HIV-CKDs) is unknown. We carried out this study to determine whether high plasma FGF-2 levels were associated with the development of HIV-CKDs in children.
Conclusions
High plasma FGF-2 levels appear to be an additional risk factor for developing progressive childhood HIV-CKDs.
Methods
The plasma and urine FGF-2 levels were measured in 84 children (< 12 years of age) living with HIV during the pre-modern antiretroviral era, and followed for at least 3 years to determine the prevalence of proteinuria and HIV-CKDs. We also assessed the distribution of the kidney FGF-2 binding sites by autoradiography and Alcian blue staining, and explored potential mechanisms by which circulating FGF-2 may precipitate HIV-CKDs in cultured kidney epithelial and mononuclear cells derived from children with HIV-CKDs.
Results
High plasma FGF-2 levels were associated with a high viral load. Thirteen children (~ 15%) developed HIV-CKDs and showed a large reservoir of FGF-2 low-affinity binding sites in the kidney, which can facilitate the recruitment of circulating FGF-2. Children with high plasma and urine FGF-2 levels had 73-fold increased odds (95% CI 9-791) of having HIV-CKDs relative to those with normal FGF-2 values. FGF-2 induced the proliferation and decreased the expression of APOL-1 mRNA in podocytes, and increased the attachment and survival of infected mononuclear cells cultured from children with HIV-CKDs. Conclusions: High plasma FGF-2 levels appear to be an additional risk factor for developing progressive childhood HIV-CKDs.