Is there any relationship between polymorphism of Heat Shock Protein 70 genes and Pemphigus foliaceus?

Analysis of the heat shock protein 70 (HSP70) genetic variants in nonsegmental vitiligo patients

BACKGROUND

Vitiligo is an autoimmune disease that courses with skin depigmentation because of the destruction of melanocytes. Vitiliginous melanocyte is prone to damage because of oxidative stress which activates cellular stress response and the release of heat shock proteins such as HSP70 promoting immune activation against the melanocyte. Variants in HSP70 genes (HSPA) might alter their expression and thus modulate vitiligo susceptibility. Therefore, we sought to evaluate the role of the 5' untranslated region HSPA1A G/C (rs1043618) and the exonic HSPA1B A/G (rs1061581) and HSPA1L T/C (rs2227956) gene variants in nonsegmental vitiligo.

METHODS

A total of 200 nonsegmental vitiligo patients and 208 age/gender-matched healthy subjects were genotyped for rs1043618, rs1061581, and rs2227956 variants by PCR-RFLP.

RESULTS

Variants rs1043618 and rs1061581 were not associated with vitiligo susceptibility. On the other hand, the rs2227956 C allele and TC genotype were associated with protection against vitiligo. A similar effect was observed for the GAC haplotype. Any of the aforementioned HSP70 gene variants were associated with the clinical characteristics of vitiligo.

CONCLUSION

Our findings suggest that the HSPA1L rs2227956 gene variant might influence the susceptibility to vitiligo. Being the first study of HSP70 gene variants in vitiligo, further research is encouraged to corroborate these results.

Beyond the HLA polymorphism: A complex pattern of genetic susceptibility to pemphigus

Pemphigus is a group of autoimmune bullous skin diseases that result in significant morbidity. As for other multifactorial autoimmune disorders, environmental factors may trigger the disease in genetically susceptible individuals. The goals of this review are to summarize the state of knowledge about the genetic variation that may affect the susceptibility and pathogenesis of pemphigus vulgaris and pemphigus foliaceus – both the endemic and the sporadic forms –, to compare and discuss the possible meaning of the associations reported, and to propose recommendations for new research initiatives. Understanding how genetic variants translate into pathogenic mechanisms and phenotypes remains a mystery for most of the polymorphisms that contribute to disease susceptibility. However, genetic studies provide a strong foundation for further developments in this field by generating testable hypotheses. Currently, results still have limited influence on disease prevention and prognosis, drug development, and clinical practice, although the perspectives for future applications for the benefit of patients are encouraging. Recommendations for the continued advancement of our understanding as to the impact of genetic variation on pemphigus include these partially overlapping goals: (1) Querying the functional effect of genetic variants on the regulation of gene expression through their impact on the nucleotide sequence of cis regulatory DNA elements such as promoters and enhancers, the splicing of RNA, the structure of regulatory RNAs and proteins, binding of these regulatory molecules to regulatory DNA elements, and alteration of epigenetic marks; (2) identifying key cell types and cell states that are implicated in pemphigus pathogenesis and explore their functional genomes; (3) integrating structural and functional genomics data; (4) performing disease-progression longitudinal studies to disclose the causal relationships between genetic and epigenetic variation and intermediate disease phenotypes; (5) understanding the influence of genetic and epigenetic variation in the response to treatment and the severity of the disease; (6) exploring gene-gene and genotype-environment interactions; (7) developing improved pemphigus-prone and non-prone animal models that are appropriate for research about the mechanisms that link genotypes to pemphigus. Achieving these goals will demand larger samples of patients and controls and multisite collaborations.