The dipeptidyl peptidase-4 inhibitor vildagliptin does not affect ex vivo cytokine response and lymphocyte function in patients with type 2 diabetes mellitus

AimsThe enzyme dipeptidyl peptidase-4 (DPP-4) is a key player in the degradation of incretin hormones that are involved in glucose metabolism. DPP-4 is also expressed on immune cells and is associated with several immunological functions. Some studies have reported increased rates of infections in patients treated with DPP-4 inhibitors. We therefore assessed whether treatment with the DPP-4 inhibitor vildagliptin affected cytokine production and T-cell differentiation.MethodsPatients with type 2 diabetes were treated with vildagliptin or an active comparator, acarbose, for four weeks, in a randomized cross-over trial. Blood was sampled at the end of each treatment period and peripheral blood mononuclear cells were isolated and stimulated with a broad spectrum of pattern recognition receptor agonists.ResultsSerum cytokine concentrations and ex vivo cytokine production (both monocyte and T-cell derived) did not differ during treatment with vildagliptin compared to acarbose. Similarly, ex vivo relative upregulation of mRNA transcription of T-cell lineage specific transcription factors was unaffected by vildagliptin treatment.ConclusionsThese data show that a four-week treatment with vildagliptin in patients with type 2 diabetes mellitus does not result in a significant modulation of cytokine responses. This observation suggests that inhibition of DDP-4 does not lead to an increased risk of infection by diminishing cytokine production.