Elevated Serum Lipopolysaccharides and Intrinsic Factor Autoantibodies Correlate With Macrocytic Anemia Among People With HIV

Introduction: Human immunodeficiency virus (HIV) infection is associated with various comorbidities, including macrocytic anemia, though the role of the infection is unclear. HIV has been implicated in microbial translocation and altered immune responses. This study aimed to establish the relationship between gut microbial translocation and immune response, and macrocytic anemia among people with HIV (PWH). Materials and Methods: Fifty-five PWH on combination antiretroviral therapy (cART) were age-matched with 55 HIV-negative individuals. Demographic data and blood samples were collected from February to July 2023. Hematological indices, including red blood cell (RBC) count, hemoglobin concentration, and mean corpuscular volume (MCV), were measured. Serum lipopolysaccharides (LPS) and intrinsic factor autoantibodies (IFAA) were measured using ELISA. Results: The prevalence of macrocytic anemia was significantly higher in the HIV cohort (43.6%) compared to HIV-negative individuals (1.8%), (p < 0.0001). PWH exhibited higher microbial translocation, characterized by elevated LPS levels (p < 0.0001). PWH with macrocytic anemia showed significantly increased serum LPS and IFAA levels compared to those without anemia (p < 0.001). Intrinsic factor autoantibodies correlated positively with systolic (r = 0.49, p < 0.001) and diastolic blood pressures (r = 0.31, p < 0.01), as well as LPS (r = 0.60, p < 0.001) and MCV (r = 0.65, p < 0.001). Conclusion: This study reports for the first time elevated lipopolysaccharides and intrinsic factor autoantibodies among PWH, and the lipopolysaccharides and intrinsic factor autoantibodies strongly correlated with mean corpuscular volume in the patients. Targeting serum lipopolysaccharides and intrinsic factor autoantibodies may offer a novel therapeutic strategy.