Genetic Polymorphisms and Immune Responses

Lack of Association Between TNF-α, IFN-γ, IL-10 Gene Polymorphisms and Rheumatic Heart Disease in South Indian Population

BACKGROUND

Proinflammatory and anti-inflammatory cytokines play a crucial role in the development and maintenance of immune mediated inflammatory diseases including rheumatic heart disease (RHD). Polymorphisms in tumor necrosis factor (TNF)-α, interferon (IFN)-γ, and interleukin (IL)-10 genes influence the differential cytokine expression as well as the pathogenesis of various inflammatory and autoimmune diseases.

OBJECTIVE

The aim of the study is to investigate the association between TNF-α, IFN-γ, and IL-10 gene polymorphisms and RHD in South Indian population.

MATERIALS AND METHODS

TNF-α (-308, -238), IFN-γ (+874), and IL-10 (-1082, -819, -592) gene polymorphisms were determined in 100 patients with RHD and 127 healthy siblings by PCR.

RESULTS

There was no significant difference in the genotype, allele, and haplotype frequencies of TNF-α, IFN-γ, and IL-10 polymorphisms between RHD patients and healthy siblings.

CONCLUSION

The present study suggests that TNF-α, IFN-γ, and IL-10 gene variants may not be associated with the development of RHD in South Indian population.

Association of IL17 and IL23R gene polymorphisms with rheumatic heart disease in South Indian population

BACKGROUND

IL-23/Th17 signaling pathway plays a crucial role in the cell-mediated immune response against bacterial infections and also in the pathogenesis of inflammatory and autoimmune diseases. Recent studies indicate that Th17 cell-associated cytokines are involved in the progression and maintenance of valvular lesions in rheumatic heart disease (RHD). Variants in the genes of cytokines that are potentially involved in Th17 response may influence interindividual differences in their expression levels, thereby contributing to the pathogenesis of immune-mediated diseases such as RHD.

OBJECTIVE

The aim of the study is to investigate the association of IL17A, IL17F, and IL23R gene variants with the risk perception of RHD.

METHODS

A total of 225 individuals (99 RHD patients and 126 healthy siblings) were recruited for the study. The IL17A (rs2275913), IL17F (rs763780), and IL23R (rs10889677) polymorphisms were determined by polymerase chain reaction restriction fragment length polymorphisms and amplification-refractory mutation system-polymerase chain reaction methods, respectively.

RESULTS

The frequency of IL17A (rs2275913) A/A genotype was significantly high in pooled RHD patients (odds ratio [OR] = 2.76; p_c = 0.021), rheumatic fever (RF) patients (OR = 14.5; p_c = 0.0001), and mitral valvular lesions patients (OR = 2.74; p_c = 0.039) when compared to healthy siblings. However, the IL17F (rs763780) and IL23R (rs10889677) polymorphisms did not show any association with RHD.

CONCLUSIONS

The results suggest that IL17A (rs2275913) polymorphism is associated with the development of RF/RHD in South Indian population. Further studies are required to substantiate the association of these genes with the disease risk.

Clinical events and their relation to the tumor necrosis factor-alpha and interleukin-10 genotypes in Sickle-Cell-Anemia patients

OBJECTIVE/BACKGROUND

Sickle-cell anemia (SCA) is a genetic blood disease characterized by chronic inflammation and a heterogeneous clinical picture. Serum tumor necrosis factor (TNF-alpha) and interleukin 10 (IL-10) levels are associated with the clinical course of SCA. This study aimed to evaluate the association between the frequency of the polymorphisms TNF-alpha-308 G→A, IL-10-1082 G→A, IL-10-819 C→T, and IL-10-592 A→C; serum TNF-alpha; and IL-10 levels, and the incidence of clinical events in SCA patients.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism and enzyme-linked immunosorbent assay were performed on 25 adults with SCA at the steady state; their data were compared with those for 26 healthy individuals.

RESULTS

The most frequent genotype of the TNF-alpha polymorphism was GG (low producer), and the most frequent genotype of the IL-10 polymorphisms was "low producer" (ACC ACC, ACC ATA, ATA ATA). The TNF-alpha levels were significantly higher in SCA in patients with acute chest syndrome (ACS). The IL-10 levels were reduced in polytransfusion and in patients with ACS.

CONCLUSION

The patients presented prevalence of TNF-alpha and IL-10 low-profile producer. The cytokine serum levels presented an association with the presence of polytransfusion and ACS in SCA patients.