A fine mapping of single nucleotide variants and haplotype analysis of gene in patients with -cutaneous leishmaniasis and plasma cytokines IL-4, IL-5, and IL-13.

INTRODUCTION

Leishmaniasis continues to pose a substantial health burden in 97 countries worldwide. The progression and outcome of infection are influenced by various factors, including the cytokine milieu, the skin microbiota at the infection site, the specific species involved, the genetic background of the host, and the parasite load. In endemic regions to leishmaniasis, only a fraction of individuals infected actually develops the disease. Overexpression of IL-13 in naturally resistant C57BL/6 mice renders them susceptible to infection. Haplotypes constructed from several single nucleotide variant (SNV) along a chromosome fragment may provide insight into any SNV near the fragment that may be genuinely associated with a phenotype in genetic association studies.

METHODS

We investigated nine SNVs (SNV1rs1881457A>C, SNV2rs1295687C>G, SNV3rs2069744C>T, SNV4rs2069747C>T, SNV5rs20541A>G, SNV6rs1295685A>G, SNV7rs848A>C, SNV8rs2069750G >C, and SNV9rs847T>C) spanning the entire gene in patients with cutaneous leishmaniasis (-CL).

RESULTS

Our analysis did not reveal any significant association between the SNVs and susceptibility/protection against -CL development. However, haplotype analysis, excluding SNV4rs2069747 and SNV8rs2069750 due to low minor allele frequency, revealed that carriers of the haplotype CCCTAAC had a 93% reduced likelihood developing Lg-CL. Similarly, the haplotypes ACCCGCT (ORadj=0.02 [95% CI 0.00-0.07]; -value, 6.0×10) and AGCTAAC (ORadj=0.00[95% CI 0.00-0.00]; -value 2.7×10) appeared to provide protection against the development of -CL. Conversely, carriers of haplotype ACCTGCC have 190% increased likelihood of developing -CL (ORadj=2.9 [95%CI 1.68-5.2]; -value, 2.5×10). Similarly, haplotype ACCCAAT (ORadj=2.7 [95%CI 1.5-4.7]; -value, 3.2×10) and haplotype AGCCGCC are associated with susceptibility to the development of -CL (ORadj=1.7[95%CI 1.04-2.8]; -value, 0.01). In our investigation, we also found a correlation between the genotypes of rs2069744, rs20541, rs1295685, rs847, and rs848 and plasma IL-5 levels among -Cl patients. Furthermore, rs20541 showed a correlation with plasma IL-13 levels among -Cl patients, while rs2069744 and rs848 showed a correlation with plasma IL-4 levels among the same group.

CONCLUSIONS

Overall, our study identifies three haplotypes of associated with resistance to disease development and three haplotypes linked to susceptibility. These findings suggest the possibility of a variant outside the gene region that may contribute, in conjunction with other genes, to differences in susceptibility and partially to the pathology.