High soluble CD163 levels correlate with disease progression and inflammation in Kenyan children with perinatal HIV-infection.

OBJECTIVES: CD163 is a hemoglobin scavenger receptor on monocytes and macrophages, cleaved to soluble CD163 (sCD163) in the plasma following activation. In HIV+ adults, sCD163 is linked to non-AIDS morbidity and predicts mortality, but there is limited data in children. We investigated sCD163 levels in HIV+ children and their correlations with disease progression, immune activation and gut mucosal damage. DESIGN AND METHODS: We quantified sCD163 levels in Kenyan children aged 0-20 years with perinatal HIV infection, including 74 antiretroviral treatment (ART)-naïve (ART-) and 64 virally suppressed on ART (ART+), and 79 HIV unexposed-uninfected controls (HIV-). The cohort was divided into age groups 0-5 (younger) and 5-20 (older) years. Correlations between sCD163 and HIV viral load, %CD8, CD4 : CD8 ratio, markers of T-cell activation and proliferation, and gut mucosal damage were also assessed.
RESULTS: ART- children have higher sCD163 levels compared with HIV- and ART+ children (P ≤ 0.01); ART+ have equivalent sCD163 levels to HIV- children. In a prospective analysis, sCD163 levels decreased in older ART- children after 12 months of treatment (P < 0.0001). Regardless of age, sCD163 levels correlate with clinical disease progression measured by %CD4 T cells, CD4 : CD8 T-cell ratios and HIV viral load. sCD163 levels directly correlate with T-cell activation markers CD38, human leukocyte antigen-DR isotype, and Ki67 (P ≤ 0.01).
CONCLUSION: High plasma sCD163 levels in HIV+ children correlate with advancing disease and T-cell activation. ART initiation normalizes sCD163 levels and may alleviate HIV-related morbidities and improve long-term pediatric outcomes.