Background: Emerging evidence suggests that the interleukin (IL) 17/ IL-23 axis may play a role in the pathogenesis of leishmaniasis. Our aim was to investigate whether the IL-23R variant rs11805303 is a risk factor for the development of cutaneous leishmaniasis (CL) in Leishmania guyanensis-infected individuals.

Methods: We genotyped by polymerase chain reaction-restriction fragment length polymorphism the rs11805303 C/T in 828 patients with CL and 806 healthy individuals. Plasma tumor necrosis factor-α, IL-6, interferon-γ, IL-1β, and IL-17 were measured with the Bioplex assay.

Results: The distribution of the genotypes differed between patients with CL and healthy controls with a common odds ratio of 1.78 (P = 2.2 ×ばつ 10-11) for the disease-associated T allele. Leishmania guyanensis-infected individuals homozygous for the T allele show a 200% increased risk of progressing to disease development, with a 95% confidence interval ranging from 81% to 400% (P = 9.9 ×ばつ 10-6) in comparison to individuals homozygous for the C allele. Males homozygous for the T allele have higher plasma levels of IL-17 compared with heterozygous or homozygous CC individuals.

Conclusions: The present association of the IL-23R variant rs11805303 with the development of CL suggests that the IL-17/IL-23 axis may play an important role in the pathogenesis of CL.