Evaluation of the pathogenicity of anti-desmoglein antibodies of pemphigus vulgaris patients using human organ culture assay

Anti-desmoglein (anti-Dsg) antibodies are key players in the pathogenesis of pemphigus vulgaris (PV) disease. We aimed to evaluate the pathogenicity of anti-Dsg antibodies of PV patients using human organ culture assay and to assess the correlation between the pathogenicity and the disease score. In this cross-sectional study, sera from 37 PV patients were included. The organ culture acantholysis index (OCAI) was calculated as (width of blister/total width of the specimen) × 100. The sera were analyzed using Dsg ELISAs and ethylenediaminetetraacetic acid (EDTA) treated ELISAs. OCAI ranged from 0 to 100%, median = 50%. There was a moderate significant correlation between OCAI and the disease severity, r = 0.503, p = 0.002. There was a moderate significant correlation between OCAI and non-Ca²⁺-dependent anti-Dsg3 and anti-Dsg1 antibodies, p values were 0.01 and 0.021, respectively. The OCAI was assessed along the disease time course of four patients. The OCAI fluctuated parallel to the disease severity along the time course of the four patients. Human organ culture assay is an objective tool that detects the pathogenicity of anti-desmoglein antibodies. It can be used before stopping systemic steroids especially in patients in remission with high titer or if the Dsg ELISA is not available.

Family study of monozygotic twins affected by pemphigus vulgaris

Rare are the family studies that include siblings affected by pemphigus vulgaris (PV) and in whom HLA class II alleles are related. HLA-DR and -DQ genotyping and profiling of antibodies against desmogleins (Dsg) 1 and Dsg3 were performed in ten members of a family including monozygotic twins affected by PV. The twin sisters were heterozygotes; they presented the haplotypes most commonly associated with increased susceptibility to PV (DRB1∗04:02-DQA1∗03:01-DQB1∗03:02 and DRB1∗14:04-DQA1∗01:01-DQB1∗05:03). Their parents and five siblings had only one or none of these two haplotypes in combination with the alleles or haplotypes associated with resistance to PV (DRB1∗07:01-DQA1∗02:01-DQB1∗02:02 and DRB1∗13:01-DQA1∗01:03-DQB1∗06:03). Only the monozygotic twins presented IgG antibodies against both Dsg1 and Dsg3. According to our knowledge based on a review of published literature on the topic, this is the first report of PV affecting monozygotic twins.