Background & objectives: Visceral leishmaniasis or kala-azar is a fatal protozoan disease caused by an obligate intracellular parasite, Leishmania donovani. Susceptibility, establishment of infection and severity of this disease depend upon many factors, but it is the host immune system that plays decisive role in disease progression. Keeping this view into consideration, we investigated the probable relationship between polymorphisms rs2275913 and rs8193036 in IL-17 gene, and its association as a risk factor for kala-azar in an endemic population of Assam, India.
Methods: A total of 209 subjects, 76 kala-azar cases (male: 46, female: 30, mean age ± SD: 34.60 ± 12.61) and 133 controls (male: 66, female: 67, mean age ± SD: 33.35 ± 14.48) were included in this study. We analysed the polymorphisms, rs2275913 and rs8193036 by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. The data were analysed using logistic regression analysis and SPSS software.
Results: The results revealed that the mutant rs8193036 TT genotype conferred 4.7-fold higher risk for kala-azar (p = 0.00991, OR = 4.72, 95% CI = 1.330–16.911). A significant difference was found between the allele frequencies of rs8193036 (p = 0.029, OR = 1.64, 95% CI = 1.04–2.57) when comparisons were done using the genetic models of association. When stratification analysis was done on the basis of active and past cases we found that during active infection rs2275913 A allele was significantly associated with increased risk of kala-azar (p = 0.016, OR = 3.95, 95% CI = 1.21–12.87).
Interpretation & conclusion: The findings revealed that IL-17 genetic variant, rs8193036 is an independent risk factor for kala-azar infection and may contribute in pathogenesis of the disease. Further, rs2275913 polymorphism of IL-17 gene is associated with kala-azar during active infection.

中文翻译：

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IL-17 基因多态性在印度黑热病中的作用

背景和目的：内脏利什曼病或黑热病是由专性细胞内寄生虫多诺瓦利什曼原虫引起的一种致命的原生动物疾病。这种疾病的易感性、感染的建立和严重程度取决于许多因素，但宿主免疫系统在疾病进展中起决定性作用。考虑到这一观点，我们研究了 IL-17 基因中 rs2275913 和 rs8193036 多态性之间的可能关系，及其作为印度阿萨姆邦地方性人群黑热病危险因素的关联。
方法：共有 209 名受试者，76 例黑热病病例（男性：46，女性：30，平均年龄 ± SD：34.60 ± 12.61）和 133 名对照（男性：66，女性：67，平均年龄 ± SD：33.35 ± 14.48）被纳入这项研究。我们通过聚合酶链反应限制性片段长度多态性 (PCR-RFLP) 技术分析了多态性 rs2275913 和 rs8193036。数据采用逻辑回归分析和SPSS软件进行分析。
结果：结果显示突变体 rs8193036 TT 基因型赋予黑热病风险高 4.7 倍（p = 0.00991，OR = 4.72，95% CI = 1.330–16.911）。当使用关联遗传模型进行比较时，发现 rs8193036 的等位基因频率之间存在显着差异（p = 0.029，OR = 1.64，95% CI = 1.04–2.57）。当基于活动病例和既往病例进行分层分析时，我们发现在活动感染期间 rs2275913 A 等位基因与黑热病风险增加显着相关（p = 0.016，OR = 3.95，95% CI = 1.21–12.87）。
解读与结论：研究结果表明，IL-17 遗传变异 rs8193036 是黑热病感染的独立危险因素，可能参与该疾病的发病机制。此外，IL-17 基因的 rs2275913 多态性与活动性感染期间的黑热病有关。