Introduction: Mannose-Binding Lectin (MBL) is a key complement lectin protein that binds to the surface of pathogens and results in activation of the complement lectin cascade. Its deficiency compromises host defense mechanisms and predisposes humans to infectious diseases. Therefore, the purpose of this study was to evaluate MBL protein expression among individuals co-infected with HIV/HHV-8 in the Republic of Congo.

Material and Methods: A case-control study was conducted between September 2023 and June 2024, including 170 plasma samples divided into two groups: 53 individuals co-infected with HIV/HHV-8 and 117 infected with HIV without evidence of HHV-8, HBV, and HCV infections. MBL plasma level was analyzed by ELISA. Statistical analyses were performed by R version 4.5.1, with p˂ 0.05 considered significant.

Results: The median age was 50 years in cases and 47 years in controls. A majority of participants were females, with 75.47% (40/53) and 70% (83/117) in the cases and controls, respectively. The median HIV viral load was at 1.77 log10 copies/ml in cases and 1.69 log10 copies/ml in controls. Most participants were receiving the first-line antiretroviral therapy (TDF+3TC+DTG), comprising 98.11% of cases and 94.02% of controls, while 1.89% of cases and 5.98% of controls were receiving the second-line antiretroviral therapy (AZT+3TC+ATV/r). MBL levels were significantly lower in cases compared with controls (8.36 µg/L, IQR: 5.46-11.28 µg/L, versus 23.83 µg/L, IQR: 16.38 –36.6 µg/L) with p ˂ 0.001. Then, an inverse correlation was observed between HIV viral load and MBL plasma levels.

Conclusion: Overall, MBL plasma levels were deficient, but significantly lower in individuals co-infected with HIV/HHV-8 compared with HIV-infected individuals without evidence of HHV-8, HBV, and HCV infections.