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

The human Heat Shock Proteins (HSP70) family plays a key role in up-regulating stress responses. Some studies reported possible associations of single nucleotide polymorphisms in the HSP70 genes with some autoimmune diseases. However, whether HSP70 polymorphisms represent a risk factor for pemphigus foliaceus (PF) is still unkown. We analyzed by PCR-RFLP polymorphisms of HSP70 genes HSA1A, HSPA1B and HSPA1L in 80 Tunisian patients with PF, 160 matched healthy controls and 147 related healthy subjects. There were significant differences between PF patients and controls in the allelic (pc=5.91×10(-12), pc=1.14×10(-5) and pc=0.0089, respectively) and homozygous genotypic frequencies of HSPA1L>T, HSPA1A>C and HSPA1B>G (p=2.617×10(-12), p=1.017×10(-5) and p=0.0058, respectively). Haplotype analysis showed significant differences between PF patients and controls: the CCA, CGA, CCG and CGG haplotypes were significantly over-represented in controls whereas the TCG haplotype was significantly over-represented in patients. However, the significant LD found between the HSP70 and the HLA class II susceptibility alleles together with the multivariant regression analysis data between the two loci could argue against a direct role of the HSP70 polymorphism in the occurrence of PF.