Circulating (1 → 3)-ß-D-Glucan as an immune activation marker decreased after ART in people living with HIV.

Background: Plasma level of polysaccharide (1 → 3)-ß-D-Glucan (ßDG), as a diagnostic marker of invasive fungal infection has been reported to be elevated in people living with HIV (PLWH). We assessed the association of circulating ßDG to inflammation and systemic immune activation and the effect of antiretroviral therapy (ART) on ßDG in PLWH. Method: Plasma and peripheral blood monocular cell samples from 120 PLWH naive to ART and after 1 year's ART were collected. Plasma levels of ßDG, markers of bacterial translocation, gut damage, and cellular immune activation were quantified. Result: The plasma ßDG levels were negatively correlated with CD4+ T cells count (r = -0.25, p = 0.005) and positively with HIV viral load (r = 0.28, p = 0.002) before ART. It was also positively correlated with immune activation markers, including PD-1 expression on CD4+ T cell (r = 0.40, p = 0.01) and CD8+ T cell (r = 0.47, p = 0.002), as well as HLADR+CD38+ co-expression on CD8+ T cell (r = 0.56, p = 0.0002), but not with the plasma levels of LPS (r = 0.02, p = 0.84), LPS binding protein (LBP, r = 0.11, p = 0.36), soluble LPS receptor sCD14 (r = 0.04, p = 0.68), intestinal fatty acid binding protein (IFABP, r = -0.12, p = 0.18), and regenerating islet-derived protein 3α (REG3α, r = 0.18, p = 0.06). After 1 year's ART, the levels of ßDG were significantly decreased compared to that in pre-ART (1.31 ± 0.24 Log10 pg/ml vs. 1.39 ± 0.18 Log10 pg/ml, p < 0.001). Conclusion: The level of plasma ßDG was associated with cellular immune activation and decreased after ART in PLWH, suggesting it could serve as a biomarker of immune activation and efficacy monitoring.