A Randomized, Double-Blinded, Placebo-Controlled Trial of Sitagliptin for Reducing Inflammation and Immune Activation in Treated and Suppressed HIV Infection.

Background: Dipeptidyl peptidase-4 (DPP-4) inhibitors have pleotropic anti-inflammatory and immune regulatory effects in addition to their glucoregulatory actions. We evaluated inflammation and immune markers in suppressed HIV infection during treatment with the DPP-4 inhibitor sitagliptin.

Methods: Virologically suppressed adults with HIV without diabetes mellitus on stable ART with ≥100/mm 3 CD4 cells were randomized to 16 weeks of sitagliptin 100 mg/d vs. placebo in a multicenter trial. The primary endpoint was the change in plasma soluble CD14 (sCD14) from baseline to week 15/16. Additional soluble biomarkers, and lymphocyte and monocyte activation were assessed.

Results: Ninety participants were randomized, and 42 from each arm were included in per-protocol analyses. Evaluable participants were 45% non-Hispanic white, 38% non-Hispanic black, 15% Hispanic, median age of 51 years, 83% male, with median CD4 count 602 cells/mm 3. At week 15/16, there was no difference in sCD14 change between the two arms (p=0.69). Relative to placebo, the sitagliptin arm had 47% greater decline in CXCL10 (95% CI:-57,-35) at week 15 (p<0.001). There were no significant between-arm differences in soluble CD163, soluble CD26, interleukin-6, C-reactive protein, soluble tumour necrosis factor receptors I and II, total CD4 and CD8 counts, or markers of lymphocyte or monocyte activation. Sitagliptin was well tolerated.

Conclusions: Sixteen weeks of sitagliptin had no effect on sCD14 levels in virologically suppressed participants with HIV. CXCL10, a chemokine involved in atherogenesis that predicts non-AIDS events during ART, declined markedly with sitagliptin. This suggests that DPP-4 inhibition has the potential to reduce cardiovascular morbidity in treated HIV infection.