Interleukin-8 Expression Under Highly Effective Host Immunological Control of HIV-1 Disease Progression

Background: Interleukin-8 (IL-8) is a pro-inflammatory chemokine involved in neutrophil recruitment and immune activation and has been implicated in HIV-1–associated inflammation and disease progression. Despite effective highly active antiretroviral therapy (HAART), residual immune activation persists in many people living with HIV, and the role of IL-8 across different stages of infection and treatment remains incompletely understood, particularly in sub-Saharan Africa. Methods: This cross-sectional study enrolled 40 participants in Osogbo, South-Western Nigeria, comprising HIV-negative controls (n=10), HAART-naïve HIV-positive individuals (OFF-HAART, n=10), HAART-treated individuals (ON-HAART, n=10), and AIDS progressors (n=10). Serum IL-8 levels were quantified using enzyme-linked immunosorbent assay, while CD4+ T-cell counts were determined by flow cytometry. Viral load, hematological indices, and selected biochemical parameters were also assessed. Associations between IL-8, immunological markers, and socio-demographic variables were analyzed using correlation and comparative statistics. Results: Interleukin-8 (IL-8) levels showed a downward trend from HIV-negative subjects (175.89 ± 84.58 pg/mL) and OFF-HAART individuals (211.14 ± 64.55 pg/mL) to ON-HAART participants (125.08 ± 39.73 pg/mL), with the lowest levels observed in AIDS progressors (11.40 ± 1.14 pg/mL), although this trend did not reach statistical significance (p = 0.088). CD4⁺ T-cell counts differed significantly across groups (p < 0.001), with marked depletion in OFF-HAART subjects (166.10 ± 41.40 cells/µL) and partial immune reconstitution in ON-HAART individuals (395.20 ± 61.69 cells/µL). Among AIDS progressors, longer infection duration was significantly associated with higher IL-8 expression (χ² = 6.667, p = 0.010). Conclusion: Elevated IL-8 is linked to impaired immune status and disease progression in HIV-1 infection, while reduced IL-8 accompanies immune recovery and advanced disease stages. IL-8 may serve as a useful biomarker of immune dysregulation and progression across HIV disease states, supporting its potential role in monitoring inflammation alongside conventional immunological markers.