Immunohistochemical study of toll-like receptors 2, 4, and 9 expressions in pemphigus and bullous pemphigoid lesions

Toll-like-Receptor Gene Polymorphisms in Tunisian Endemic Pemphigus Foliaceus

Pemphigus foliaceus (PF) is considered to be caused by the combined effects of susceptibility genes and environmental triggers. The polymorphisms of Toll-like receptors (TLRs) genes have been associated with the risk of various autoimmune diseases. The aim of this study was to evaluate the potential association of TLR2-3-4 and 7 gene polymorphisms with Tunisian PF. Fourteen polymorphisms were analyzed in 93 Tunisian PF patients compared to 193 matched healthy controls: rs5743703-rs5743709 and (GT)n repeat (TLR2); rs5743305, rs3775294, and rs3775291 (TLR3), rs4986790 and rs4986791 (TLR4); and rs3853839 (TLR7). Our results showed that the genetic factors varied depending on the epidemiological feature stratification. In fact, in the whole population, no association with the susceptibility to PF was found. The TLR2 GT repeat seems to be closely associated with PF risk in patients originated from the endemic localities (group 3); the GT18 allele and the heterozygous genotype GT18/GT19 seem to confer risk to endemic PF (P = 0.02; OR = 2.3 [1.1-4.9] and P = 0.0002, OR = 20 [2.5-171], respectively). In contrast, the GT23 repeat could be considered as protector allele (P = 0.02, OR = 0.2 [0.06-0.87]). Furthermore, medium GT alleles which induce high promoter activity were also significantly more frequent in patients versus short or long GT repeats (P = 0.0018 with OR = 3.26 [1.5-7]). On the other hand, the TLR3-rs574305 AA genotype and A allele were significantly more frequent in patients whose age of the onset was above 35 years (group 2) (P = 0.038, OR = 1.78 and P = 0.009, OR = 3.92, respectively). Besides, the TLR4>rs3775294 A allele was found to be protector only in patients with sporadic features (groups 2 and 4) (P = 0.03, OR = 0.57 [0.3-0.9] and P = 0.006, OR = 0.24 [0.08-0.74], respectively). No statistically significant difference was observed in the genotypic and allelic frequencies of TLR-4 and TLR-7 gene polymorphisms. The present data suggest that TLR2and TLR3 polymorphisms are significantly associated with increased susceptibility to PF in the Tunisian population.

Histologic characterization of cellular infiltration in autoimmune subepidermal bullous diseases in a tertiary hospital in Saudi Arabia

Background

Autoimmune subepidermal bullous dermatoses have similar clinical features to those of a spectrum of immune reactants at the dermoepidermal junction (DEJ). It is difficult to obtain a precise diagnosis without an immunofluorescence assay because of their similar clinical presentations. The aim of this study was to describe the cellular cutaneous infiltration among autoimmune subepidermal bullous dermatoses.

Materials and methods

This retrospective analysis was conducted at a hospital in Riyadh, Saudi Arabia using biopsy-based data collected from 65 patients.

Results

Spongiotic changes, neutrophils, and lymphocyte infiltrations in the epidermis differed among the subepidermal bullous diseases. The DEJ showed a difference in the extent of neutrophil infiltration. The dermis showed differences in perivascular lymphocytic infiltration, neutrophilic infiltration, eosinophilic infiltration, and dermal edema.

Conclusion

The dermal and DEJ showed most of the histopathologic changes in subepidermal autoimmune bullous dermatoses.