Identical MHC markers in non-Jewish Iranian and Ashkenazi Jewish patients with pemphigus vulgaris: possible common central Asian ancestral origin

HLA class II antigens in Croatian patients with pemphigus vulgaris and their correlation with anti-desmoglein antibodies

Pemphigus vulgaris (PV) is an acquired autoimmune blistering disease characterized by the production of autoantibodies targeting desmosomal cadherins, primarily desmoglein 1 and desmoglein 3, leading to acantholysis. The etiology of PV is multifactorial, including genetic susceptibility. This retrospective study aimed to evaluate the association of HLA class II alleles and PV and to examine the impact of PV-associated HLA class II alleles on the concentration of anti-desmoglein antibodies. The study group included 30 patients in whom the diagnosis of PV was confirmed by histopathological analysis, immunofluorescence findings, and ELISA testing for detecting antibodies against desmoglein 1 and desmoglein 3. HLA class II alleles were typed by polymerase chain reaction with sequence-specific primers (PCR-SSP). The control group consisted of 190 healthy volunteer blood donors. Data analysis revealed a significantly higher frequency of HLA class II alleles in our population of patients with PV, including HLA-DRB1*04:02, HLA-DRB1*14:54, HLA-DQB1*03:02, HLA-DQB1*05:03, HLA- DQA1*03:01, and HLA-DQA1*01:04, as well as a significantly lower frequency of HLA-DQA1*05:01 compared to the control group. We have also investigated the influence of risk alleles for PV, recognized in almost all study populations, HLA-DRB1*04:02 and HLA-DQB1*05:03, on the concentration of antibodies against desmogleins 1 and 3 in relation to the presence of these alleles. The results showed significantly higher levels of antibodies directed against desmoglein 3 among patients with DRB1*04:02 compared to patients without this allele. No difference was found for anti-desmoglein 1 antibodies. Regarding DQB1*05:03 allele, statistical analysis showed no differences in the concentration of anti-desmoglein antibodies in patients carrying this allele versus those without it.

Association of specific HLA alleles and haplotypes with pemphigus vulgaris in the Bulgarian population

Pemphigus vulgaris (PV) is an autoimmune bullous dermatosis with uneven geographic distribution and higher incidence in certain populations. In previous studies, a relatively high incidence of PV was reported in Bulgaria (0.47/100,000/year) comparable to that in other countries. The genetic background was considered responsible for the disease susceptibility, and multiple reports have proven PV to be an HLA-associated condition. The aim of our study was to analyze the role of genetic factors in the development of PV in Bulgaria. HLA genotyping was performed in 56 PV patients, ethnic Bulgarians whose diagnosis was confirmed based on clinical, histological, and immunofluorescent findings. The control group consisted of 204 healthy individuals from the Bulgarian population without evidence for HLA-associated autoimmune diseases. HLA-A,-B,-DRB1,-DQB1 analysis was performed by PCR-SSP. Our results revealed predisposing associations with DRB1*14, DRB1*04:02, and B*38, B*55, while allele DRB1*03:01 and the corresponding haplotypes were significantly decreased in the PV patients. The predisposing role of these alleles has been observed in other populations. All reported predisposing DRB1 alleles have the same amino acids at key positions of the beta chain of the HLA molecules, 26 (Phe), 67 (Leu or Ileu), 70 and 71 (hydrophobic AA: Gln, Arg, Asp, or Glu), and 86 (Val), which is important for the selective presentation of desmoglein 3 peptides. Additionally, specific alleles HLA-A*01 and DRB1*11 were identified with decreased frequencies in the patients’ group, the last one being a common protective allele for autoimmune diseases in the Bulgarian population. The elucidation of the role of genetic factors for the development of pemphigus will help explain its higher incidence and clinical variability in certain populations.

A systematic review and meta-analysis of HLA class II associations in patients with IgG4 autoimmunity

Autoimmune diseases caused by pathogenic IgG4 subclass autoantibodies (IgG4-AID) include diseases like MuSK myasthenia gravis, pemphigus vulgaris or thrombotic thrombocytopenic purpura. Their etiology is still unknown. Polymorphisms in the human leukocyte antigen (HLA) gene locus, particularly in HLA-DRB1, are known genetic susceptibility factors for autoimmune diseases. We hypothesized a similar role for HLA polymorphisms in IgG4-AID and conducted a systematic review and meta-analysis with case-control studies on IgG4-AID based on MOOSE/ HuGENet guidelines. Genotype (G) and allele (A) frequencies of HLA-DQB1*05 (G: OR 3.8; 95% CI 2.44-5.9; p < 0.00001; A: OR 2.54; 95% CI 1.82-3.55; p < 0.00001) and HLA-DRB1*14 (G: OR 4.31; 95% CI 2.82-6.59; p < 0.00001; A: OR 4.78; 95% CI 3.52-6.49; p < 0.00001) and the HLA-DRB1*14-DQB1*05 haplotype (OR 6.3; 95% CI 3.28-12.09; p < 0.00001/OR 4.98; 95% CI 3.8-6.53; p < 0.00001) were increased while HLA-DRB1*13 (G: OR 0.48; 95% CI 0.34-0.68; p < 0.0001; A: OR 0.46; 95% CI 0.34-0.62; p < 0.00001) was decreased in IgG4-AID patients. In conclusion, the HLA-DQB1*05, HLA-DRB1*14 alleles and the HLA-DQB1*05-DRB1*14 haplotype could be genetic risk factors that predispose for the production of pathogenic IgG4 autoantibodies and the HLA-DRB1*13 allele may protect from IgG4 autoimmunity.

An Updated Review of Pemphigus Diseases

Clinicians may encounter a variety of skin conditions that present with vesiculobullous lesions in their everyday practice. Pemphigus vulgaris, pemphigus foliaceus, IgA pemphigus, and paraneoplastic pemphigus represent the spectrum of autoimmune bullous dermatoses of the pemphigus family. The pemphigus family of diseases is characterized by significant morbidity and mortality. Considering the risks associated with a delayed diagnosis or misdiagnosis and the potential for overlap in clinical features and treatment, evaluation for suspected pemphigus disease often requires thorough clinical assessment and laboratory testing. Diagnosis is focused on individual biopsies for histopathology and direct immunofluorescence. Additional laboratory methods used for diagnosis include indirect immunofluorescence and enzyme-linked immunosorbent assay. Recent advancements, including anti-CD20 therapy, have improved the efficacy and reduced the morbidity of pemphigus treatment. This contribution presents updates on the pathophysiology, clinical features, diagnostic work-up, and medical management of pemphigus. Improved strategies for diagnosis and clinical assessment are reviewed, and newer treatment options are discussed.

Milestones in Personalized Medicine in Pemphigus and Pemphigoid

Pemphigus and pemphigoid diseases are autoimmune bullous diseases characterized and caused by autoantibodies targeting adhesion molecules in the skin and/or mucous membranes. Personalized medicine is a new medical model that separates patients into different groups and aims to tailor medical decisions, practices, and interventions based on the individual patient`s predicted response or risk factors. An important milestone in personalized medicine in pemphigus and pemphigoid was achieved by verifying the autoimmune pathogenesis underlying these diseases, as well as by identifying and cloning several pemphigus/pemphigoid autoantigens. The latter has become the basis of the current, molecular-based diagnosis that allows the differentiation of about a dozen pemphigus and pemphigoid entities. The importance of autoantigen-identification in pemphigus/pemphigoid is further highlighted by the emergence of autoantigen-specific B cell depleting strategies. To achieve this goal, the chimeric antigen receptor (CAR) T cell technology, which is used for the treatment of certain hematological malignancies, was adopted, by generating chimeric autoantigen receptor (CAAR) T cells. In addition to these more basic science-driven milestones in personalized medicine in pemphigus and pemphigoid, careful clinical observation and epidemiology are again contributing to personalized medicine. The identification of clearly distinct clinical phenotypes in pemphigoid like the non-inflammatory and gliptin-associated bullous pemphigoid embodies a prominent instance of the latter. We here review these exciting developments in basic, translational, clinical, and epidemiological research in pemphigus and pemphigoid. Overall, we hereby aim to attract more researchers and clinicians to this highly interesting and dynamic field of research.

Pemphigus group: overview, epidemiology, mortality, and comorbidities

Pemphigus forms a group of rare autoimmune bullous diseases that affect the skin and mucous membranes. This group has a chronic course leading to high morbidity and mortality. It is characterized by the production of pathogenic autoantibodies directed against different proteins of the desmosome, leading histologically to intraepidermal cleavage, and clinically to vesicles and erosions on the epithelium of the mucous membranes and/or the skin. The diagnosis of the subtype of pemphigus is based on clinical features, the level of histologic cleavage, and the identification of the antigens recognized by circulating autoantibodies by immunoserological analyses. The epidemiological features of pemphigus vary considerably in different regions of the world. Observational studies examining comorbidities and associations among patients with pemphigus are scarce and sometimes inconclusive. The prognosis, mortality, and clinical outcomes in pemphigus have undergone dramatic change throughout the years. This review provides a brief overview about the different subtypes of pemphigus: pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, pemphigus herpetiformis, and IgA pemphigus. In addition, it summarizes the most recent understanding of the epidemiology, mortality data, and comorbidities of this group of organ-specific autoimmune diseases.

An original Eurasian haplotype, HLA-DRB1*14:54-DQB1*05:03, influences the susceptibility to idiopathic achalasia

Idiopathic achalasia is a relatively infrequent esophageal motor disorder for which major histocompatibility complex (MHC) genes are well-identified risk factors. However, no information about HLA-achalasia susceptibility in Mexicans has previously been reported. We studied a group of 91 patients diagnosed with achalasia and 234 healthy controls with Mexican admixed ancestry. HLA alleles and conserved extended haplotypes were analyzed using high-resolution HLA typing based on Sanger and next-generation sequencing technologies. Admixture estimates were determined using HLA-B and short tandem repeats. Results were analyzed by non-parametric statistical analysis and Bonferroni correction. P-values < 0.05 were considered significant. Patients with achalasia had 56.7% Native American genes, 24.7% European genes, 16.5% African genes and 2.0% Asian genes, which was comparable with the estimates in the controls. Significant increases in the frequencies of alleles DRB1*14:54 and DQB1*05:03 and the extended haplotypes DRB1*14:54-DQB1*05:03 and DRB1*11:01-DQB1*03:01, even after Bonferroni correction (pC<0.05), were found in the achalasia group compared to those in the controls. Concluding, the HLA class II alleles HLA-DRB1*14:54:01 and DQB1*05:03:01 and the extended haplotype are risk factors for achalasia in mixed-ancestry Mexican individuals. These results also suggest that the HLA-DRB1*14:54-DQB1*05:03 haplotype was introduced by admixture with European and/or Asian populations.

Association between human leukocyte antigen-DRB1 and human leukocyte antigen-DQB1 alleles and pemphigus vulgaris in Indian patients: A case-control study

BACKGROUND

HLA-DRB1*04, -DRB1*08, -DRB1*14, -DQB1*03 and -DQB1*05 are reported to have significant association with pemphigus vulgaris; however, this is partially dependent on ethnicity. This study was done to determine the HLA-DR and -DQ types prevalent in Indian patients with pemphigus vulgaris.

METHODS

A prospective case-control study was done for a period of 9 months in Christian Medical College Vellore, India. HLA typing was done by PCR-SSOP method in 50 cases and 50 healthy controls. Allele frequencies in cases and controls were compared and odds ratios with 95% confidence interval were calculated.

RESULTS

The mean age of the patients (29 females, 21 males) and that of controls (36 males, 14 females) were 41.3 ± 13.65 and 35.42 ± 11.09 years, respectively. HLA-DRB1*14 was present in 47 patients and 18 controls (OR, 27.85; 95% CI, 7.57-102.42) and HLA-DQB1*05 was seen in 47 patients and 24 controls (OR, 16.97; 95% CI, 4.66-61.80). The haplotype DRB1*14, DQB1*05 was present in 44 patients and 14 controls (OR, 18.86; 95% CI, 6.58-54.05). DRB1*15 was present in 7 cases and 16 controls (OR, 0.35; 95% CI, 0.13-0.94) and DQB1*06 was present in 8 cases and 19 controls (OR, 0.31; 95% CI, 0.12-0.80). HLA-DQB1*03 was associated with significantly higher pemphigus disease area index scores.

LIMITATIONS

The main limitations were that the numbers studied were small as the study was conducted at a single center, and the haplotype analysis was limited only to the proband. PDAI scores could have been influenced by prior treatment.

CONCLUSION

There was a significant association between HLA-DRB1*14 and HLA-DQB1*05 and pemphigus vulgaris in our patients. A negative association was seen with DRB1*15 and DQB1*06.

Association between HLA-DQB1 polymorphisms and pemphigus vulgaris: A meta-analysis

OBJECTIVE

This study was performed to systematically summarize the results on the association of HLA-DQB1 polymorphisms with pemphigus vulgaris (PV) and other related factors.

METHODS

A comprehensive literature search of PubMed, The Cochrane Library, Embase, and Google Scholar database was conducted to identify relevant articles in English, with the last report up to November 1, 2016. Heterogeneity test was performed, and publication bias was evaluated. Stata software 12.0 was used to perform the meta-analysis. Odds ratios (ORs) and 95% confidence intervals (CI) were used to describe the correlation by random-effects model.

RESULTS

18 studies were obtained after searching databases: 10 studies were about Caucasian, and 8 articles were about non-Caucasian. Meta-analysis revealed that the allele and phenotype frequencies of DQB1*05 were markedly higher in PV patients than in controls [P < 0.001, OR: 2.640, 95%CI: 1.570-4.441; P = 0.030, OR 3.688, 95%CI: 1.138-11.946]. In addition, DQB1*03 was significantly increased at the allele level [P < 0.001, OR: 2.080, 95%CI: 1.507-2.869], and DQB1*02 was significantly decreased in PV at the allele and phenotype levels [P = 0.002, OR: 0.450, 95%CI: 0.289-0.702; P = 0.001, OR: 0.293, 95%CI: 0.146-0.587]. When based on each subtype of HLA-DQB1, DQB1*05:03 and DQB1*03:02 may play susceptibility roles in PV, and DQB1*03:03, DQB1*05:01 and DQB1*06:01 are negatively associated with PV.

CONCLUSION

In summary, our study suggests that alleles from the groups DQB1*05 and DQB1*03, concretely DQB1*05:03 and DQB1*03:02, respectively, may be the susceptibility factors for PV at allele and phenotype levels, whereas DQB1*05:01, DQB1*02, DQB1*06:01, and DQB1*03:03 are negatively associated with PV.

Study of the association between human leukocyte antigens (HLA) and pemphigus vulgaris in Brazilian patients

BACKGROUND

Pemphigus vulgaris is a mucocutaneous blistering autoimmune disease that manifests as painful blisters or erosions on the skin and/or mucosal surfaces. IgG autoantibodies target desmoglein, playing a major role in disease pathogenesis. Genetic predisposal to pemphigus vulgaris, especially the HLA DR and DQ alleles, has been known since the 1980s. The unique constitution of the Brazilian population favors exploratory genetic studies.

METHODS

The study group included 51 patients with a confirmed diagnosis of pemphigus vulgaris from a tertiary hospital in Sao Paulo city, Sao Paulo, southeast Brazil. DNA was extracted from peripheral blood, and HLA A, B, C, DR, and DQ typing was performed. The control group was composed of a database of 297 deceased donors from the city of São Paulo typed with the same method. The statistical significance level was adjusted using the Bonferroni correction depending on the phenotypic frequencies evaluated for HLA A, HLA B, HLA C, HLA DRB1, DQA1, and HLA DQB1.

RESULTS

The alleles HLA-B*57, HLA-C*15, HLA-DRB1*04:02, HLA-DRB1*08:04, HLA-DRB1*14:01, DQA1*03:01, DQB1*03:02, and DQB1*05:03 were associated with susceptibility. Alleles HLA DRB1*04:02 and HLA-DRB1*14:01 and their respective haplotypes DRB1*04-DQA1*03:01-DQB1*03:02, and DRB1*14-DQA1*01:01-DQB1*05:03 conferred a risk of the disease.

CONCLUSIONS

The DRB1*04:02 and DQB1*05:03 alleles are associated with pemphigus vulgaris in our study as well as in various populations. The association with HLA-DRB1*08:04 in our study was confirmed to be specific to this allele and not to linkage disequilibrium to any adjacent gene. The association between HLA-B*57 and pemphigus vulgaris is reported for the first time in the present study.

Remarkable differences in the epidemiology of pemphigus among two ethnic populations in the same geographic region

BACKGROUND

The epidemiology of pemphigus in different ethnic populations exposed to similar environments is unknown. Trends in the incidence of pemphigus based on an immunopathologically validated cohort have not been investigated.

OBJECTIVES

We sought to estimate the incidence of pemphigus in Israel and to investigate differences between the 2 major ethnic populations.

METHODS

Pemphigus incidence was retrospectively estimated from January 2000 to December 2015 in 2 Israeli regions with a total population of 1.56 million inhabitants.

RESULTS

One hundred eighty patients with pemphigus (mean age, 54.70 ± 16 years) were identified. The overall estimated incidence was 7.2 per million inhabitants per year (95% confidence interval, 6.2-8.3). The incidence in the Jewish population was threefold higher than that in Arabs (9.6 vs 3.2 cases per million per year, respectively; P < .0001) and higher among women than men (9 vs 5.3 cases per million per year, respectively; P < .0001). The incidence decreased from 8.4 cases per million per year in 2000 to 2005 to 7.0 and 6.0 (95% confidence interval, 4.5-7.9) in 2006 to 2010 and 2011 to 2015, respectively (P = .068).

LIMITATIONS

This study was limited by the retrospective design and the small population.

CONCLUSIONS

The incidence of pemphigus in Israel is among the highest reported worldwide and is significantly more frequent among Jews.

Localizing Ashkenazic Jews to Primeval Villages in the Ancient Iranian Lands of Ashkenaz

The Yiddish language is over 1,000 years old and incorporates German, Slavic, and Hebrew elements. The prevalent view claims Yiddish has a German origin, whereas the opposing view posits a Slavic origin with strong Iranian and weak Turkic substrata. One of the major difficulties in deciding between these hypotheses is the unknown geographical origin of Yiddish speaking Ashkenazic Jews (AJs). An analysis of 393 Ashkenazic, Iranian, and mountain Jews and over 600 non-Jewish genomes demonstrated that Greeks, Romans, Iranians, and Turks exhibit the highest genetic similarity with AJs. The Geographic Population Structure analysis localized most AJs along major primeval trade routes in northeastern Turkey adjacent to primeval villages with names that may be derived from "Ashkenaz." Iranian and mountain Jews were localized along trade routes on the Turkey's eastern border. Loss of maternal haplogroups was evident in non-Yiddish speaking AJs. Our results suggest that AJs originated from a Slavo-Iranian confederation, which the Jews call "Ashkenazic" (i.e., "Scythian"), though these Jews probably spoke Persian and/or Ossete. This is compatible with linguistic evidence suggesting that Yiddish is a Slavic language created by Irano-Turko-Slavic Jewish merchants along the Silk Roads as a cryptic trade language, spoken only by its originators to gain an advantage in trade. Later, in the 9th century, Yiddish underwent relexification by adopting a new vocabulary that consists of a minority of German and Hebrew and a majority of newly coined Germanoid and Hebroid elements that replaced most of the original Eastern Slavic and Sorbian vocabularies, while keeping the original grammars intact.

Frequency of HLA-DRB1 and HLA-DQB1 Alleles and Haplotype Association in Syrian Population

The study of Human Leukocyte Antigen (HLA) system is very important in health and diseases. As the HLA loci are the most polymorphic in the human genome, it plays a very important role in the immune responses to self and nonself antigens. In the light of the growing importance of typing the HLA alleles in transplantation, autoimmune diseases, cancer, and many other diseases, we studied 225 unrelated healthy Syrian subjects for their HLA class II genotypes in an attempt to reveal the distribution of the HLA (DRB1-DQB1) alleles in the general Syrian population. Our results revealed that the most common alleles for the DRB1 locus were DRB1*11 (26.4%), DRB1*04 (14%), and DRB1*07 (12%). However, the most frequent alleles for the DQB1 locus were DQB1*03 (40.9%) and DQB1*05 (25.1%). The frequent of two-locus haplotypes carry the most frequent alleles at these loci. The most frequently detected class II ''haplotypes'' are DRB1*11-DQB1*03 (8.9%), DRB1*01-DQB1*05 (3.6%), and DRB1*04-DQB1*03 (2.7%). Compared with other populations, our result, deduced from the analysis of genetic distances and the construction of neighbor-joining (NJ) dendrogram, and principal component analysis (PCA) indicates that Syrians are related to Middle Eastern populations. Our data about the Syrian population will aid researchers in studying the relation of HLA class II with different diseases in a Syrian population and will add to the available international literature associated with these loci.

An Overview of Vesicobullous Conditions Affecting the Oral Mucosa

Vesicobullous diseases are characterised by the presence of vesicles or bullae at varying locations in the mucosa. The most common occurring in the oral cavity are mucous membrane pemphigoid (MMP) and pemphigus vulgaris (PV). Both are autoimmune diseases with a peak age onset of over 60 years and females are more commonly affected than men. This paper reviews the structure of the oral mucosa, with specific reference to the basement membrane zone, as well as bullous conditions affecting the mucosa, including PV and pemphigoid, their aetiology, clinical presentation, and management.

High susceptibility to pemphigus vulgaris due to HLA-DRB1*14:54 in the Slovak population

The current work describes an association between pemphigus vulgaris (PV) and class II HLA alleles in the Slovak population, the first such study in Slovakia on the 'high-resolution level'. This work takes into account the new HLA allele nomenclature, officially adopted in 2010. In particular, we have focused on the associations between PV and DRB1*14:54 and DRB1*14:01. This case-control study was performed in a cohort of 43 PV Caucasian patients and 113 Caucasian control subjects from Slovakia. HLA typing was performed using PCR-SSP (polymerase chain reaction with sequence-specific primers). We found significantly positive associations between PV and the HLA alleles DRB1*04:02, DRB1*04:04, DRB1*14:54, DRB1*14:04, DRB1*14:05, DQB1*03:02 and DQB1*05:03. In contrast, HLA-DQB1*06, DRB1*07 and DRB1*13 were negatively associated with PV. Importantly, 93% of PV patients possessed at least one of two HLA haplotypes, DRB1*04-DQB1*03 or HLA-DRB1*14-DQB1*05. We confirmed the previously reported associations between HLA class II alleles and PV and described a new association between PV and DRB1*14:54. This allele was first described in 2005, and there has been only one report of its association with PV to date.

Association between HLA-DRB1 polymorphisms and pemphigus vulgaris: a meta-analysis

Summary

Background Several studies have reported that HLA-DRB1 may be correlated with pemphigus vulgaris (PV), but most have been based on small samples and the results remain inconsistent and unclear.

Objectives To investigate the correlation between DRB1 and PV by a meta-analysis of case–control/nonfamily studies.

Methods PubMed, Wiley Online Library, ScienceDirect, Google Scholar, Cochrane Library, Chinese National Knowledge Infrastructure and Wanfang databases were searched for studies including: (i) ‘pemphigus’; and (ii) ‘human leukocyte antigen’, ‘HLA’, ‘major histocompatibility complex’, ‘MHC’ or ‘DRB1’. Eighteen selected studies were used in meta-analyses to evaluate DRB1 alleles and phenotypes by calculating the respective odds ratios (ORs) and 95% confidence intervals (CIs). Stratified meta-analyses and meta-regression analysis were also conducted.

Results The frequencies of three genotypes (allele and phenotype, respectively) were significantly increased in PV: DRB1*04 [P-value for comparability (Pc) < 0·00001, OR 3·61, 95% CI 2·28–5·71; Pc = 0·0002, OR 4·14, 95% CI 1·98–8·65], DRB1*08 (Pc = 0·03, OR 2·25, 95% CI 1·07–4·70; Pc = 0·0003, OR 2·46, 95% CI 1·51–4·01) and DRB1*14 (Pc < 0·00001, OR 6·47, 95% CI 4·52–9·26; Pc < 0·00001, OR 9·68, 95% CI 4·47–20·98). Three others (allele and phenotype, respectively) were significantly decreased in PV: DRB1*03 (Pc < 0·00001, OR 0·28, 95% CI 0·19–0·41; Pc = 0·0001, OR 0·25, 95% CI 0·12–0·51), DRB1*07 (Pc = 0·004, OR 0·45, 95% CI 0·26–0·78; Pc = 0·0002, OR 0·27, 95% CI 0·14–0·54) and DRB1*15 (Pc = 0·001, OR 0·35, 95% CI 0·18–0·66; Pc = 0·002, OR 0·32, 95% CI 0·16–0·65). Ethnicity partially explained the heterogeneity of DRB1*07, DRB1*08 and DRB1*14 phenotypes.

Conclusions Our findings suggest that DRB1*04, DRB1*08 and DRB1*14 are statistically significant susceptibility factors for PV. Conversely, DRB1*03, DRB1*07 and DRB1*15 may be negatively associated with PV. Specific HLA-DRB1 types may influence the susceptibility or resistance to PV, which needs further investigations.

Implications for health and disease in the genetic signature of the Ashkenazi Jewish population

BACKGROUND

Relatively small, reproductively isolated populations with reduced genetic diversity may have advantages for genomewide association mapping in disease genetics. The Ashkenazi Jewish population represents a unique population for study based on its recent (< 1,000 year) history of a limited number of founders, population bottlenecks and tradition of marriage within the community. We genotyped more than 1,300 Ashkenazi Jewish healthy volunteers from the Hebrew University Genetic Resource with the Illumina HumanOmni1-Quad platform. Comparison of the genotyping data with that of neighboring European and Asian populations enabled the Ashkenazi Jewish-specific component of the variance to be characterized with respect to disease-relevant alleles and pathways.

RESULTS

Using clustering, principal components, and pairwise genetic distance as converging approaches, we identified an Ashkenazi Jewish-specific genetic signature that differentiated these subjects from both European and Middle Eastern samples. Most notably, gene ontology analysis of the Ashkenazi Jewish genetic signature revealed an enrichment of genes functioning in transepithelial chloride transport, such as CFTR, and in equilibrioception, potentially shedding light on cystic fibrosis, Usher syndrome and other diseases over-represented in the Ashkenazi Jewish population. Results also impact risk profiles for autoimmune and metabolic disorders in this population. Finally, residual intra-Ashkenazi population structure was minimal, primarily determined by class 1 MHC alleles, and not related to host country of origin.

CONCLUSIONS

The Ashkenazi Jewish population is of potential utility in disease-mapping studies due to its relative homogeneity and distinct genomic signature. Results suggest that Ashkenazi-associated disease genes may be components of population-specific genomic differences in key functional pathways.

Immunogenetics of pemphigus: An update

Pemphigus are rare but informative models of organ-specific autoimmune diseases, resulting from the interplay of environmental, genetic and stochastic factors. There are many arguments to consider that pemphigus have a genetic basis involving, as many other autoimmune diseases, several different genes with additive or synergistic effects. So far, the unique strategy used to identify the contributive loci has been direct analysis of candidate genes through conventional case-control association studies. The major histocompatibility complex in particular the class II locus was demonstrated to be associated with pemphigus with a high rate of replicability. The progresses in the understanding of pemphigus physiopathology and the development of new molecular tools offer new perspectives to unveiled the genetic basis of this group of autoimmune blistering diseases, as shown by recent studies of candidate genes expressed at different levels of the autoimmune process.

HLA class II (DRB, DQA1 and DQB1) allele and haplotype frequencies in the patients with pemphigus vulgaris

INTRODUCTION

Pemphigus vulgaris (PV), an autoimmune disease affecting the skin and mucous membranes, is associated with some human leukocyte antigen (HLA) class II alleles and haplotypes.

MATERIALS AND METHODS

In order to evaluate the association of HLA-DR and DQ alleles and haplotypes in Iranian non-Jewish patients with PV, 52 patients with PV and 180 normal subjects as control group were investigated in this study.

RESULTS AND DISCUSSION

HLA-DRB1*04, -DRB1*1401, -DRB4, -DQA1*0104, -DQA1*03011, -DQB1*0302, and -DQB1*0502 alleles have been significantly increased in our patients group. Moreover, the haplotypes HLA-DRB1*04/-DQA1*03011/-DQB1*0302 and HLA-DRB1*1401/-DQA1*0104/-DQB1*0502 increased significantly in our patients. In contrast, the following alleles decreased significantly in our patients: HLA-DRB1*15, -DRB1*0301, -DRB1*07, -DRB1*11, -DRB5, -DQA1*0101, -DQA1*0103, -DQA1*201, -DQA1*05, -DQB1*0201, -DQB1*0301, -DQB1*06011, and -DQB1*0602. In addition, HLA-DRB1*15/-DQA1*0103/-DQB1*06011, HLA-DRB1*0301/-DQA1*05011/-DQB1*0201, HLA-DRB1*07/-DQA1*0201/-DQB1*0201, and HLA-DRB1*11/-DQA1*05/-DQB1*03011 decreased significantly in our patients. Genetic factors are involved in the occurrence of PV; HLA-DRB1*04 and -DRB1*1401 alleles and the related haplotypes are suggestive to be two major PV susceptibility factors in our population study.

Immunological hotspots analyzed by docking simulations: evidence for a general mechanism in pemphigus vulgaris pathology and transformation

Background

Pemphigus vulgaris (PV) is an acquired autoimmune blistering disorder in which greater than 80% of active patients produce autoantibodies to the desmosomal protein desmogelin 3 (Dsg3). As the disease progresses, 40–50% of patients may also develop reactivity to a second component of the desmosomal complex, desmogelin 1 (Dsg1). T cells are clearly required for the production of autoantibodies in PV. However, few T-cell specificities within Dsg3 or Dsg1 have been reported to date, and the precise role of T-cells in disease pathogenesis and evolution remains poorly understood. In particular, no studies have addressed the immunological mechanisms that underlie the observed clinical heterogeneity in pemphigus. We report here a structure-based technique for the screening of DRB1*0402-specific immunological (T-cell epitope) hotspots in both Dsg3 and Dsg1 glycoproteins.

Results

High predictivity was obtained for DRB1*0402 (r² = 0.90, s = 1.20 kJ/mol, q² = 0.82, s_press = 1.61 kJ/mol) predictive model, compared to experimental data. In silico mapping of the T-cell epitope repertoires in Dsg3 and Dsg1 glycoproteins revealed that the potential immunological hotspots of both target autoantigens are highly conserved, despite limited sequence identity (54% identical, 72% similar). A similar number of well-conserved (18%) high-affinity binders were predicted to exist within both Dsg3 and Dsg1, with analogous distribution of binding registers.

Conclusion

This study provides interesting new insights into the possible mechanism for PV disease progression. Our data suggests that the potential T-cell epitope repertoires encoded in Dsg1 and Dsg3 is substantially overlapping, and it may be possible to apply a common, antigen-specific therapeutic strategy with efficacy across distinct clinical phases of disease.

HLA-DRB1*0402 haplotypes without DQB1*0302 in Venezuelan patients with pemphigus vulgaris

The two basic forms of autoimmune intraepidermal blistering diseases, pemphigus vulgaris (PV) and pemphigus foliaceus (PF), affect different layers of the skin, have different symptoms and target different antigens. We have defined human leukocyte antigen (HLA)-DRB1-DQB1 alleles and haplotypes in a case-control study of 66 non-Jewish patients attending a public reference Hospital over the past 10 years. The control group consisted of 101 matched individuals tested also by medium to high-resolution polymerase chain reaction-sequence-specific oligonucleotide with primers and probes from the 12th and 13th International Histocompatibility Workshop. Patients and controls were descendants of three-generation individuals born in the country. Among the patients, 49 had PV, 50% showed predominantly mucosal involvement, 50% showed predominantly the cutaneous clinical phenotype and 17 had PF. Statistically significant HLA-DR frequency differences between patients with PV and controls were found only for DRB1*0402 and DRB1*1401 [odds ratio (OR) = 27.22, confidence interval (CI) 94.7-7.82, P= 1.1 x 10(-14) and OR = 46.56, CI 801.4-2.70 P= 7.5 x 10(-6), respectively]. Both alleles were also increased in the patients with PF compared with the controls (OR = 7.0, P= 0.038 and OR = 21.64, P= 0.009, respectively), but the significance of the difference did not resist Bonferroni correction. Haplotype analysis showed that DRB1*0402 was always present with DQB1*0302 and DRB1*1401 with DQB1*0503, but no independent effect of the DQB1*0302 in the former haplotype was evident. Our results support the hypothesis that the DRB1*0402 without DQB1*0302 is the most relevant HLA-DRB1 allele responsible for the pathogenesis of pemphigus in Venezuelan patients with PV and discard the DQB1*0302 influence observed in other populations.

Epidemiologic survey of pemphigus vulgaris with oral manifestations in northern Greece: retrospective study of 129 patients

OBJECTIVE

To evaluate the epidemiology of pemphigus vulgaris (PV) in a Greek population and to compare it with other countries.

MATERIALS AND METHODS

A retrospective study was conducted based on the records of 129 patients (41 males and 88 females) with PV who visited the Department of the Oral Medicine and Maxillofacial Pathology, Aristotle University of Thessaloniki, Greece and the State Hospital for Skin and Venereal Diseases of Thessaloniki, Greece, between 1985 and 2004. A group of 73 individuals was used as controls.

RESULTS

The average annual incidence was found to be eight patients per year. The male to female ratio was 1 : 2.25. The difference in the age of onset between the two genders was statistically significant in marginal levels (P = 0.05). In addition, 86.1% of the patients showed oral lesions only, 13.3% oral and skin lesions and 1.3% manifested oral, skin, and ocular lesions. Twenty-eight of the 88 females were in the premenopausal period-of-life. Additionally, 19 males were farmers who had daily contact with organophosphoric pesticides. Co-existing pathologic conditions were present in 75 of the 129 patients, and of these 75 patients six (8%) were diabetics, 15 (20%) presented with hypertension, two (2.6%) faced problems from their thyroid gland, and 10 (13.3%) of the patients complained of allergic reactions.

CONCLUSIONS

The results of this study demonstrated a relatively high incidence of PV in northern Greece compared with that in other countries. The disease most frequently occurred in the sixth decade-of-life and the majority of the patients manifested oral lesions. Further epidemiological studies are needed to elucidate whether this region is constituted from population groups with high susceptibility to PV.

Pemphigus vulgaris is associated with the transporter associated with antigen processing (TAP) system

Pemphigus vulgaris (PV) is a human leukocute antigen (HLA) class II-associated autoimmune disease of the skin of unknown etiology. We recently described the association of pemphigus vulgaris with two clusters of microsatellite loci within the major histocompatibility complex region. One cluster includes the microsatellite marker TAP1CA, located in proximity to the transporter associated with antigen processing (TAP) genes. These genes are essential for class I antigen processing machinery and could be an additional set of genes involved in susceptibility to PV. The aim of this study was to investigate a possible association between TAP gene polymorphisms and PV. For this purpose we examined 37 unrelated Jewish Israeli patients with PV and compared them with 37 healthy Israeli Jewish HLA-matched controls. Significant differences were detected in TAP2 amino acid residues (p=0.001). Two PV TAP2 risk alleles were identified (TAP2*C and TAP2*D), the frequency of which was estimated to be 37.8% in the patients and 5.3 % in the controls. This association was found to be independent of HLA-DR. It is therefore likely that TAP2 genes are involved in susceptibility to development of PV.

Disease relevant HLA class II alleles isolated by genotypic, haplotypic, and sequence analysis in North American Caucasians with pemphigus vulgaris

Early studies of genetic susceptibility to pemphigus vulgaris (PV) showed associations between human leukocyte antigen (HLA) DR4 and DR6 and disease. The emergence of DNA sequencing techniques has implicated numerous DRB1 and DQB1 loci in various populations, leading to confusion regarding which exact alleles confer susceptibility. The strong linkage disequilibrium among DR and DQ HLA alleles further complicates the investigation of the true susceptibility loci. In this study, we report genotyping data for the largest sampling of North American Caucasian non-Jewish and Ashkenazi Jewish PV patients studied to date and compare our data with other population studies. To pinpoint true susceptibility, alleles among overrepresented sequences, we applied a step-wise reductionist analysis through (1) determination of the degree of linkage disequilibrium (LD) between purportedly associated alleles, (2) haplotype frequencies comparisons, and (3) primary sequence comparisons of disease-associated versus non-disease-associated alleles to identify crucial differences in amino acid residues in putative peptide binding pockets. Collectively, our data provide extended support for the hypothesis that the HLA associations in Caucasian PV patients map to DRB1*0402 and DQB1*0503 alone. Further structure-function studies will be required to define the exact mechanisms of HLA-mediated control of susceptibility and resistance to disease.

Genetic factors in pemphigus

Epidemiological studies performed in different ethnic populations and family studies, notably based on a partial phenotype of the autoimmune process, indicate that genetic factors are involved in the occurrence of pemphigus. However, the precise heritability remains uncertain in the absence of twin concordance rate studies. Among the different strategies available to identify genetic factors participating in autoimmune disease susceptibility, only population studies based on case-control design have been performed in pemphigus. These studies consistently showed that MHC locus, in particular HLA class II alleles, are associated with pemphigus vulgaris and pemphigus foliaceus. Other genes of the MHC locus may also participate in disease susceptibility as shown by studies using microsatellite markers across different regions of the MHC. It is likely that other non-MHC genes are involved in the pathogenesis of pemphigus. In particular, involvement of a polymorphic variant of desmoglein 1 gene was shown to be associated with pemphigus foliaceus and to interact in an epistatic manner with MHC class II genes to contribute to the autoimmune process. Other candidate genes to which a role can be assigned in the disease pathogenesis should be considered to design case-control or family-based association studies. Genome scan studies which require a large number of multiplex families to reach statistical power, should also be considered in the endemic form of pemphigus foliaceus because of the high number of familial cases.

Number II Pemphigus vulgaris

Pemphigus is a group of potentially life-threatening autoimmune diseases characterized by cutaneous and/or mucosal blistering. Pemphigus vulgaris (PV), the most common variant, is characterized by circulating IgG antibodies directed against desmoglein 3 (Dsg3), with about half the patients also having Dsg1 autoantibodies. There is a fairly strong genetic background to pemphigus with linkage to HLA class II alleles and ethnic groups such as Ashkenazi Jews and those of Mediterranean and Indian origin, are especially liable. Oral lesions are initially vesiculobullous but readily rupture, new bullae developing as the older ones rupture and ulcerate. Biopsy of perilesional tissue, with histological and immunostaining examination are essential to the diagnosis. Serum autoantibodies to either Dsg1 or Dsg3 are best detected using both normal human skin and monkey oesophagus or by enzyme-linked immunosorbent assay. Before the introduction of corticosteroids, PV was typically fatal mainly from dehydration or secondary systemic infections. Current treatment is largely based on systemic immunosuppression using corticosteroids, with azathioprine or other adjuvants or alternatives but newer therapies with potentially fewer adverse effects, also appear promising.

HLA class II profile and distribution of HLA-DRB1 and HLA-DQB1 alleles and haplotypes among Lebanese and Bahraini Arabs

The gene frequencies of HLA class II alleles were studied in 95 healthy Lebanese Arab and 72 healthy Bahraini Arab subjects. Our aim was to establish the genetic relationship between Bahraini and Lebanese Arabs in terms of HLA class II gene and haplotype frequencies and to compare these results with frequencies for other countries with populations of Caucasian and non-Caucasian descent. Subjects were unrelated and of both sexes, and HLA-DRB1 and -DQB1 genotyping was done by the PCR sequence-specific primer technique. Comparative analysis of the HLA-DR and -DQ alleles revealed differences in the allelic distribution among Bahraini and Lebanese subjects. Analysis of the 25 HLA-DRB1 alleles that have been investigated showed that the DRB1*040101 and DRB1*110101 alleles were more frequent among Lebanese, whereas DRB1*030101 and DRB1*160101 alleles were more frequent among Bahrainis. Similarly, of the seven HLA-DQB1 alleles analyzed, the presence of DQB1*0201 was more frequent among Bahrainis, whereas DQB1*030101 was more frequent among Lebanese. The DRB1*160101-DQB1*050101 (0.1318 versus 0.0379%) and DRB1*030101-DQB1*0201 (0.1202 versus 0.0321%) haplotypes were more frequent among Bahrainis, while the DRB1*110101-DQB1*030101 (0.3142 versus 0.1198%) and DRB1*040101-DQB1*0302 (0.1416 versus 0.0278%) haplotypes were more frequent in Lebanese subjects. Furthermore, a high prevalence of the DRB1*040101-DRB1*110101-DQB1*0302-DQB1*030101 (12.63 versus 1.35%, P = 0.015) and the homozygous DRB1*110101-DRB1*110101-DQB1*030101-DQB1*030101 (7.37 versus 0.00%, P = 0.046) genotypes was seen among Lebanese, and DRB1*070101-DRB1*160101-DQB1*0201-DQB1*050101 (6.76 versus 0.00%, P = 0.034) was seen more frequently among Bahraini subjects. Our results underline significant differences between these two populations in HLA class II distribution, provide basic information for further studies of major histocompatibility complex heterogeneity among Arabic-speaking countries, and serve as a reference for further anthropological studies.

Common ancestral origin of pemphigus vulgaris in Jews and Spaniards: a study using microsatellite markers

Pemphigus is a group of autoimmune blistering diseases of the skin and mucous membranes. The association of pemphigus with human leukocyte antigen (HLA) is widely accepted. It was described in many ethnic groups and in most countries of the world. Studies showed that the associated HLA haplotype in Jewish pemphigus vulgaris (PV) patients is HLA-B38, DRB1*0402, and DQB1*0302; or HLA-B35, DRB1*0402, and DQB1*0302. Similar associations with class II genes were found in Spanish non-Jewish PV patients. As Jews lived in Spain for hundreds of years and many converted to Christianity, the presence of the same HLA haplotype in the Jewish and Spanish PV suggests that they may share the same founder. Microsatellite markers which span the entire major histocompatibility complex (MHC) locus were used as genetic probes. They were utilized to dissect the MHC region in the search for possible common haplotypes, besides HLA, which may provide an answer to this question. It was found that in both cohorts, in addition to HLA class II genes, there are probably genes in the class I region which are associated with PV. Alleles belonging to the associated markers were used to construct haplotypes and to estimate genetic distances. The distance between the two PV cohorts is relatively short, but the distance between the Jewish patients and the Jewish controls is greater compared to the distance between Spanish patients and Spanish controls. In both PV populations, the same microsatellite haplotypes in addition to a common class II haplotype were found, suggesting that both patient populations originated from the same genetic stock and, therefore, share the same ancestral disease gene.

HLA-G is associated with pemphigus vulgaris in Jewish patients

Pemphigus is a group of life-threatening autoimmune blistering diseases of the skin and mucous membranes. The etiology and pathogenesis of this destructive autoimmune process remains unknown, but significant association with human leukocyte antigen (HLA) factors have been described in pemphigus vulgaris (PV) patient cohorts worldwide. We have recently analyzed DNA samples obtained from pemphigus patients and matched controls with a set of microsatellite markers, and found that markers mapped to HLA class I region are significantly associated with the disease. In order to narrow the region that is associated with the disease single nucleotide polymorphism (SNP) technology was used. In this study, a set of 26 SNP markers, which span a chromosomal region of about 600,000 bp, were used to screen DNA samples of the patients and their matched controls. Of the 26 SNPs, four markers were found informative, all mapped to HLA-G. Typing patients and controls for HLA-G polymorphism revealed significant differences in the exon 8 deletion/insertion variant. The latter is probably associated with the efficiency of transcription of this gene. Taken together, the results suggest that HLA-G is associated with PV in Jewish patients.

Pemphigus vulgaris: update on etiopathogenesis, oral manifestations, and management

Pemphigus is a group of potentially life-threatening diseases characterized by cutaneous and mucosal blistering. There is a fairly strong genetic background to pemphigus with linkage to HLA class II alleles. Certain ethnic groups, such as Ashkenazi Jews and those of Mediterranean origin, are especially liable to pemphigus. Pemphigus vulgaris (PV), the most common and important variant, is an autoimmune blistering disease characterized by circulating pathogenic IgG antibodies against desmoglein 3 (Dsg3), about half the patients also having Dsg1 autoantibodies. Oral lesions are initially vesiculobullous but readily rupture, new bullae developing as the older ones rupture and ulcerate. Biopsy of perilesional tissue, with histological and immunostaining examinations, is essential to the diagnosis. Serum autoantibodies to either Dsg1 or Dsg3 are best detected by both normal human skin and monkey esophagus or by enzyme-linked immunosorbent assay (ELISA). Before the introduction of corticosteroids, pemphigus vulgaris was typically fatal mainly from dehydration or secondary systemic infections. Current treatment is largely based on systemic immunosuppression using systemic corticosteroids, with azathioprine, dapsone, methotrexate, cyclophosphamide, and gold as adjuvants or alternatives, but mycophenolate mofetil and intravenous immunoglobulins also appear promising.

A study of desmoglein 1 autoantibodies in pemphigus vulgaris: racial differences in frequency and the association with a more severe phenotype

BACKGROUND

Pemphigus vulgaris (PV) is characterized by pathogenic autoantibodies to desmoglein (Dsg) 3, but additional antibodies to Dsg1, the pemphigus foliaceus antigen, are detectable in some cases.

OBJECTIVES

To investigate the clinical significance of the presence of both Dsg 1 and 3 antibodies.

METHODS

In 79 subjects with PV, enzyme-linked immunosorbent assays were used to detect IgG autoantibodies reactive with the ectodomain of Dsg1 and Dsg3.

RESULTS

There was a clear association between the clinical phenotype and the Dsg antibody profile. All subjects had Dsg3 autoantibodies and 61% had coexisting Dsg1 antibodies (Dsg3+/Dsg1+). PV limited entirely to the mucosal surfaces was seen only in Dsg3+/Dsg1- patients, while additional Dsg1 antibodies (Dsg3+/Dsg1+) predicted cutaneous in addition to mucosal involvement. Although minor cutaneous involvement was observed in most Dsg3+/Dsg1- patients, severe cutaneous involvement was seen only in Dsg3+/Dsg1+ patients. Dsg1 antibodies were detectable early in the course of disease and their appearance did not relate to the use of systemic therapy. The proportion of Dsg1+ patients was higher in those of Indian origin compared with white northern Europeans (P < 0.05).

CONCLUSIONS

These data suggest that the presence of Dsg1 antibodies is predictive of a potentially more severe disease and that genetic factors may determine the Dsg antibody profile.

HLA class II polymorphism contributes to specify desmoglein derived peptides in pemphigus vulgaris and pemphigus foliaceus

Susceptibility to Pemphigus, an autoimmune disease of the skin, has been previously linked to DRB1*0402, 1401/04 and DQB1*0503 in pemphigus vulgaris (PV), to DRB1*0102, 0404, 1402/06 in endemic pemphigus foliaceus in Brazil and to DRB1*04 in Italian patients suffering from pemphigus foliaceus (PF). The disease is caused by autoantibodies against desmoglein (Dsg1 in PF, Dsg3 in PV). Molecular typing of 57 French patients suffering from PV (37) and from PF (20) confirmed previous results concerning PV and showed that DRB1*0102 and 0404 are susceptible molecules to PF in France. We have analysed the characteristics of the 'pockets' of the susceptibility-associated molecules to PV and PF and we showed that (i) in PV, two kinds of Dsg3 derived peptides may be presented by HLA-DR according to HLA polymorphism (DRB1*0402 or DRB1*14/0406), (ii) the same Dsg1 peptides may be presented by DRB1*0102, DQB1*0404 or DRB1*14 in PF, (iii) the DRB1*14/0406 PV-related molecules may be able to present Dsg1 and Dsg3 peptides thereby providing an explanation for the cases of PV with combined responses to Dsg1 and to Dsg3 which are typified by a muco-cutaneous clinical phenotype.

Jewish and Middle Eastern non-Jewish populations share a common pool of Y-chromosome biallelic haplotypes

Haplotypes constructed from Y-chromosome markers were used to trace the paternal origins of the Jewish Diaspora. A set of 18 biallelic polymorphisms was genotyped in 1,371 males from 29 populations, including 7 Jewish (Ashkenazi, Roman, North African, Kurdish, Near Eastern, Yemenite, and Ethiopian) and 16 non-Jewish groups from similar geographic locations. The Jewish populations were characterized by a diverse set of 13 haplotypes that were also present in non-Jewish populations from Africa, Asia, and Europe. A series of analyses was performed to address whether modern Jewish Y-chromosome diversity derives mainly from a common Middle Eastern source population or from admixture with neighboring non-Jewish populations during and after the Diaspora. Despite their long-term residence in different countries and isolation from one another, most Jewish populations were not significantly different from one another at the genetic level. Admixture estimates suggested low levels of European Y-chromosome gene flow into Ashkenazi and Roman Jewish communities. A multidimensional scaling plot placed six of the seven Jewish populations in a relatively tight cluster that was interspersed with Middle Eastern non-Jewish populations, including Palestinians and Syrians. Pairwise differentiation tests further indicated that these Jewish and Middle Eastern non-Jewish populations were not statistically different. The results support the hypothesis that the paternal gene pools of Jewish communities from Europe, North Africa, and the Middle East descended from a common Middle Eastern ancestral population, and suggest that most Jewish communities have remained relatively isolated from neighboring non-Jewish communities during and after the Diaspora.

Polymorphisms of HLA class II genes in Japanese patients with pemphigus vulgaris

Pemphigus vulgaris (PV) is an autoimmune disease mediated by autoantibodies that bind to a keratinocyte adhesion molecule, desmoglein-3. The purpose of this study was to identify critical amino acid residues of PV-associated HLA class II genes. Haplotype and allele distributions, along with molecular polymorphisms, of HLA class II genes were analyzed based on the polymerase chain reaction-restriction fragment length polymorphism in 17 Japanese PV patients. Each patient had one or two alleles of DRB1*04 (*0403, *0404, *0406) or DRB1*14 (*1401, *1405, *1406) subtypes. All DRB1*04 and DRB1*14 alleles carried by PV patients with different ethnic backgrounds reported to date, including DRB1*0402, which confers strong susceptibility to PV among Jewish populations, have amino acid residues Phe26, Leu67 or Ile67, and Val86, as well as hydrophilic amino acid residues at positions 70 and 71 of the DRB1 beta chain.

Pemphigus vulgaris autoantibody response is linked to HLA-DQB1*0503 in Pakistani patients

Pemphigus vulgaris (PV) is an autoimmune disease of the skin and mucous membranes characterized by an autoantibody response against an epidermal cadherin. We performed high resolution HLA class II typing in 19 patients with PV from Rawalpindi, Pakistan and 19 non-Jewish European PV patients from Boston by sequence-specific oligonucleotide probe hybridization. The results were compared with two separate ethnically matched control populations. WE found that PV patients from Pakistan had significantly increased frequencies of DRB1*1404 (p = 0.01), DQA1*0101 (p = 0.02), and DQB1*0503 (p = 0.01). Among the patients of non-Jewish European ancestry, DRB1*1401 (p < 10(-6)), DQA1*0101 (p < 10(-5)) and DQB1*0503 (p < 10(-6)), were increased in PV patients. Formal linkage analysis between the major histocompatibility complex and the PV antibody was performed in 67 relatives of the 19 Pakistani patients. The results showed strong evidence for linkage of HLA-DRB1*1404, DQA1*0101, DQB1*0503, with the presence of PV antibody in relatives' families with a significant logarithm of the odds score of 6.06. Based on the three dimensional structure of class II molecules, we propose that HLA-DQA1*0101 and DQB1*0503, encode a negatively charged P9 peptide binding pocket of the DQ molecule and are significantly associated with susceptibility to PV in non-Jewish populations.