Inflammatory Biomarkers in the Pathogenesis of Respiratory Dysfunction in People Living with HIV

Background: Although the association between HIV infection and airways obstruction is well known, its etiopathogenesis is not clear. Objectives: Our aim was to analyze the association between biomarkers of systemic inflammation and bacterial translocation and pulmonary function tests in HIV infected patients and compare it between smokers and non-smokers. Methods: Cross-sectional, observational study. Inclusion criteria: people living with HIV with undetectable plasma viral load. Exclusion criteria: other comorbidities associated with systemic inflammation. Outcome variables: spirometry and diffusing capacity for carbon monoxide; explanatory variables: inflammatory biomarkers (interleukin-6, tumor necrosis factor-alpha), bacterial translocation (soluble CD14 [sCD14] and bacterial 16S rDNA), and variables related to HIV infection. Associations were tested using the Pearson/Spearman correlation tests, the student t test, and multivariable linear regression. Results: We included 71 patients (54.9% smokers). We did not observe significant differences in pulmonary function tests according to biomarkers of inflammation or bacterial translocation. In non-smokers (n=32), sCD14 was negatively correlated with forced expiratory volume in 1 second (R = -0.35, P = 0.048) and forced vital capacity (R= -0.40, P=0.023). Age, time since HIV diagnosis and CD4+ nadir were associated with alterations in PFTs. In smokers, the only association observed was between the pack-years and pulmonary obstruction. Conclusion: In non-smokers HIV patients, lung dysfunction can be, at least partially, related to bacterial translocation (sCD14), CD4+ nadir and time since HIV diagnosis.