Plasma C-reactive protein levels were found to be higher in patients with American cutaneous leishmaniasis (ACL −16.45 ± 7.35 mg/L), patients with type 2 diabetes mellitus (T2DM-28.55 ± 14.19 mg/L), and patients with both diseases (17.79 ± 7.41 mg/L) compared to the control group (5.94 ± 3.76 mg/L). This evidence concerns the gene CRP and diabetes mellitus.