Purpose: Androgenetic alopecia (AGA) is the most common cause of hair loss in men. Although medically benign, it has a significant psychosocial impact on patients. The high rate of family history suggests polygenic inheritance. The current study aims to investigate HLA-DR B1 allele positivity in patients with AGA and evaluate the relationship with metabolic and dermatologic diseases that may accompany this disease and vitamin D3 deficiency. Materials and Methods: The medical records of 85 male patients diagnosed with AGA based on clinical history and physical examination were retrospectively reviewed. Patients with stage II or higher AGA according to the Hamilton-Norwood classification were included in the study. Retrospective data were analyzed and recorded through chart review. Demographic characteristics, clinical findings, laboratory results, HLA-DRB1 allele profiles, and serum vitamin D3 levels were evaluated. Additionally, concomitant metabolic and dermatological conditions were assessed in all patients. Results: In the distribution of HLA-DRB1 allele frequencies, HLA-DRB101, HLA-DRB104, and HLA-DRB111 positivity were observed more frequently. When the specific allele subtypes were analyzed, DRB104 11 was positive in 6.4%, DRB111 11 in 11.2%, and DRB111 13 in 6.4% of cases. Vitamin D3 levels were found to be low in 82% of patients with AGA. Conclusion: This study shows that AGA is associated with immunogenetic factors and vitamin D3 deficiency. Screening these parameters may guide clinicians in early diagnosis and treatment.

Periodontitis is an inflammatory disease characterized by the destruction of the periodontal attachment apparatus, which includes alveolar bone, periodontal ligament, and cementum. This destruction is driven by a dysregulated host immune response to pathogenic subgingival biofilm. The present preliminary study aimed to evaluate immune-related gene expression patterns in patients with stage III/IV periodontitis utilizing the NanoString nCounter® platform. Unstimulated saliva samples were collected from twelve individuals: ten with severe periodontitis (stage III/IV) and two periodontally healthy controls. Total RNA was isolated and analyzed using the nCounter® Human Inflammation Panel, which profiles 249 inflammation-associated human genes. Data normalization and differential expression analysis were performed with nSolver™ software. Following quality control, genes with low expression (mean normalized counts < 20) were excluded, resulting in 89 genes available for comparison. Among these, 26 genes (29.2%) met a predefined effect-size threshold (|log2FC| ≥ 1), comprising 23 upregulated and 3 downregulated transcripts in the periodontitis group. Notably, the upregulated genes HLA-DRB1(p = 0.003; FDR = 0.267) and CCR1 (p= 0.007; FDR = 0.312) exhibited relatively large log2fold changes and the lowest unadjusted p-values; however, neither retained significance after FDR correction. These findings underscore the feasibility of salivary gene expression profiling as a method for identifying molecular markers associated with disease severity. Given their roles in immune activation and leukocyte recruitment, HLA-DRB1and CCR1emerge as potential biomarker candidates for detection, risk stratification, and therapeutic monitoring in periodontitis, necessitating validation in larger, well-characterized cohorts.

Exploring the role of genetic variants in susceptibility to autoimmune Diseases: A molecular genetics approach.

Multiple sclerosis (MS) is a complicated neurological disease in which the central nervous system gradually deteriorates. The body’s immune system wrongly targets the protective myelin coating around nerves, treating it as a threat and damaging it. Due to the loss of the myelin sheath, signals cannot be transmitted anymore. While its exact causes remain unknown, previous research suggests that it has genetic and environmental causes. This paper examines the causes and existing treatment options, with a particular focus on the Human Leukocyte Antigen (HLA) system, specifically the HLA-DRB1 gene. As is well known, the HLA-DRB1 gene is one of the candidates for the control of immune system function and has been strongly and constantly associated with the risk of developing multiple sclerosis. This paper shows how HLA-DRB1 variations influence the susceptibility to MS, and what consequences this could have for further research and treatment approaches. It also includes the environmental causes of the disease, along with an overview of the existing treatments for the same. While no experiment was done to observe the effects, through different sources, research has been done to understand the relationship between the HLA gene, the environment, and the increased risk of MS.

A single nucleotide polymorphism in the MerTK gene is associated with increased radiological disease activity in patients with multiple sclerosis on natalizumab therapy.

Cerebrovascular diseases (CeVD) and neurodegenerative diseases (NDs) are two major neurological disorders, which are associated with increasing global morbidity and mortality. Population-based studies have indicated a complex link between CeVD and ND. However, the shared genetic etiology between these disease conditions remains less explored. We conducted genome-wide genetic correlation analysis and investigated the shared genetic architecture through pleiotropy analysis between ND and CeVD, like stroke and its subtypes, to understand shared genetic factors and biological mechanisms. Publicly available large-scale genome-wide association studies (GWAS) summary statistics data of cross-ancestry, European, and South Asian (SAS) ancestry were analyzed using methods implemented in the tools linkage disequilibrium score regression (LDSC), PLeiotropic Analysis under COmposite null hypothesis (PLACO), and Bayesian-based method of colocalization (COLOC). We detected 116 shared genetic loci consisting of 770 lead pleiotropic single nucleotide polymorphisms (SNPs) (ND-CeVD P-range: 4.81×10-8 to 4.57×10-16) and 40 shared causal genetic regions (ND-CeVD PP.H4-range: 0.70-0.9, posterior probability of H4 (PP.H4) ⩾ 0.7) between multiple CeVD and ND pairs. The genetic regions near ICA1L, HLA-DQA1, HLA-DRB1, MIR297, and PITX2 genes were identified as highly pleiotropic across multiple CeVD-ND pairs. We report ERGIC1 (5q35.1) for the first time as a shared causal genetic locus between Amyotrophic Lateral Sclerosis and small vessel stroke. The genetic risk score of stroke derived from the SAS population of the GIGASTROKE study was associated with ND (P-range = 2.23×10-28 to 0.02), despite a small sample size compared to other ethnic groups, indicating high penetrance. The shared genetic loci and pathway analysis in this study provide new genes and pathways shared between ND and CeVD, which may help in a better understanding of disease mechanisms in these neurological diseases.

Rheumatoid arthritis (RA) is the most prevalent autoimmune inflammatory joint disorder worldwide. We aimed to identify the genetic variants contributing to RA and investigate the potential influence of related diseases on RA risk. We performed genome-wide association studies (GWAS) on RA using the 2019 UK Biobank pain questionnaire. We conducted a primary GWAS (9,389 RA cases; 132,108 controls) and separate sex-stratified GWAS for females (4,832 cases; 75,184 controls) and males (4,557 cases; 56,924 controls). We incorporated 12 phenotypes from downstream analyses, such as genetic correlation analyses, transcriptome-wide association studies (TWAS), phenome-wide association studies (PheWAS), and Mendelian randomization (MR) studies to determine causal relationships with RA. Two loci reached genome-wide significance in the primary GWAS. The top SNP, rs35139284 (p = 3.67 × 10-25) in the HLA-DRB1 gene on chromosome 6, exhibited a robust replication. Another locus, harboring the top SNP rs539837 (p = 6.26 × 10-9) near the LINC01680 gene on chromosome 1, also showed a significant association. In the female-specific GWAS, rs35139284 (p = 1.91 × 10-22) remained the top signal, whereas the male-specific GWAS revealed a suggestive significance at rs9267989 (p = 5.28 × 10-8) in TSBP1-AS1. TWAS and tissue specificity studies pointed to the spleen, lung, and small intestine as key tissues implicated in RA. PheWAS and MR analyses highlighted asthma and eosinophils associated with RA. Our findings confirmed an RA locus at chromosome 6 and highlighted associations between RA and a spectrum of immune-related and inflammatory phenotypes. Further analyses may provide greater insights into the genetic architecture of RA. Key Points •Leveraging the 2019 UK Biobank pain questionnaire, our genome-wide association studies (GWAS) confirmed a risk locus on chromosome 6 associated with rheumatoid arthritis (RA). •Sex-stratified analyses revealed significant differences in RA susceptibility between males and females, paving the way for personalized therapeutic strategies by demonstrating sex-specific genetic risks. •Mendelian randomization underscored the associations of both asthma and eosinophils with RA while identifying key hub genes, thereby deepening our understanding of RA's underlying molecular mechanisms and suggesting potential targets for future interventions.

BACKGROUND: In KhMAO-Yugra, every year there is an increase in the number of cases of type 1 diabetes mellitus (DM1) among residents of the district. The preservation of small indigenous peoples is an important demographic problem that requires an integrated approach. HLA-typing makes it possible to identify genetic markers of predisposition to type 1 diabetes mellitus (DM1) in the early stages of the disease and to ensure its prevention.AIM: Identification of the frequency of carriage of polymorphic alleles and haplotypes in the loci of the HLA-DQA1, HLA-DQB1 and HLA-DRB1 genes of the HLA class II system in samples of the indigenous khanty population and the alien population permanently residing in the territory of KhMAO-Yugra.MATERIALS AND METHODS. Low-resolution HLA typing was performed in 60 representatives of the khanty indigenous people, 54 conditionally healthy people of the alien population and 45 patients with type 1 diabetes mellitus (alien population) permanently residing in the territory of the Khanty-Mansiysk Autonomous Okrug.RESULTS: The analysis of the frequency of occurrence of class II HLA alleles in the khanty cohort revealed statistically significant differences in the alleles DQA1*01:02/03; DQB1*02; *03:02; *05:02/04; *06:01; *06:02-8; DRB1*03; *04; *12; *13; *15; *16 in comparison with the cohort of the conditionally healthy alien population. A similar comparison of the frequencies of DQA1, DQB1, DRB1 alleles, haplotypes and their combinations between representatives of the alien population of conditionally healthy and patients with DM1 revealed significant differences in loci DQA1*01:02/03; *03:01; DQB1*06:02-8; DRB1*07, characteristic of Caucasians. When comparing the frequencies of haplotypes in Hunts with a cohort of conditionally healthy newcomers, a statistically significant low frequency of haplotypes associated with a high and moderate risk of developing DM1 (DR4~DQ8, DR3~DQ2) and a high frequency of «protective» haplotypes DQ6~DR15, DQ6~DR13 were noted.CONCLUSION: In the khanty cohort, the frequency of occurrence of three haplotypes predisposing to the development of DM1 was reduced, and two protective haplotypes were increased, in comparison with the cohort of a conditionally healthy alien population. This determines the significant role of genetic factors in the observed low predisposition to the development of type 1 diabetes in the khanty population.

The main objective of the study was to determine the association of genes AIRE (rs2075876), CD40 (rs4810485), HLA-DRB1 (rs6457617) and TRAF1/C5 (rs10818488) polymorphisms with rheumatoid arthritis (RA) from the population of Pakistan. Blood samples of 300 RA patients and 300 healthy controls were taken from different hospitals in Pakistan. Extraction of DNA was carried out; a specific region of DNA was amplified using PCR. Polymorphic analysis was performed for genes AIRE (rs2075876), CD40 (rs4810485), HLA-DRB1 (rs6457617) and TRAF1/C5 (rs10818488). The demographic parameters, like age, showed statistically significant association and increased the risk of the disease up to 2-fold (odds ratio [OR]=2.57; 95% confidence interval [CI]=1.60-4.12; p=0.0001). Gender and family history did not show any significant association with arthritis (OR=1.12; 95% CI=0.69-1.81; p=0.6260; OR=0.70; 95% CI=0.44-1.11; p=0.1313, respectively). In the case of smoking status, the difference was statistically significant for both smokers and non-smokers. In smokers, there was a decreased risk of RA (OR=0.45; 95% CI=0.28-0.73; p=0.0011), and in non-smokers, there was an increased risk of disease up to 2-fold (OR=2.17; 95% CI=1.36-3.47; p=0.0011). In AIRE gene, heterozygous (AG) of rs2075876 showed a highly significant association with increased risk of RA up to 3-fold (OR=3.39; 95% CI=2.08-5.54; p=0.0001), whereas homozygous mutant (GG) also showed significant association (OR=0.43; 95% CI=0.26-0.72; p=0.0014) but with decreased risk. In CD40 gene, heterozygous (AG) of rs4810485 showed significant association with a decreased risk of RA (OR=0.59; 95% CI=0.377-0.945; p=0.027), whereas the homozygous mutant (GG) of rs4810485 showed highly significant association by increasing risk of up to 4-fold (OR=4.318; 95% CI=2.553-7.303; p=0.0001). In HLA-DRB1 gene, heterozygous (CT) of rs6457617 showed significant association with a decreased risk of disease (OR=0.52; 95% CI=0.35-0.85; p=0.007), whereas the homozygous mutant (TT) of rs6457617 showed highly significant association by increasing the risk of RA up to 4-fold (OR=4.37; 95% CI=2.55-7.47; p=0.0001). In the TRAF1/C5 gene, heterozygosity (AG) of rs10818488 showed a significant association with an increased risk of disease up to 4-fold (OR=4.06; 95% CI=2.38-6.98; p=0.0001). Highly significant associations of genes AIRE (rs2075876), CD40 (rs4810485), HLA-DRB1 (rs6457617) and TRAF1/C5 (rs10818488) polymorphisms were observed with RA.

Introduction and Objective: Unprovoked A-β+ ketosis-prone type 2 diabetes (KPD) is characterized by DKA with sudden weight reduction in obese subjects and recovery of insulin secretion by insulin therapy. Previously we reported that insulin peptide specific T cell response exists in KPD as well as type 1 diabetes (T1D), and we thought that similar pathophysiology may exist between KPD and T1D. Recently, we realized that exocrine enzyme elevation is observed both in KPD and in T1D. Therefore, we investigated the etiology. Methods: Forty-nine KPD (46 males, 3 females, mean age 42.2 years, mean disease duration 1.2 years) and 62 T1D (26 males, 36 females, mean age 41.5 years, mean disease duration 6.0 years) persons were enrolled with written informed consent, and serum exocrine enzymes (amylase, lipase, elastase), HLA types and antibody against carbonic anhydrase 2 (CA-2) and lactoferrin, well known exocrine pancreatic antigens, were measured. Results: Either of serum exocrine enzyme elevation was observed in 30.6% of KPD whereas 25.8% in T1D persons. Among KPD with exocrine enzyme elevation, HLA DRB1*08:03 was the most frequent HLA type (40%). Therefore, we focused to this HLA in KPD. CA-2 antibody titer was significantly higher in DRB1*08:03 positive group than negative group (p&amp;lt;0.0001), but it was not the case regarding lactoferrin antibody. On the other hand, regarding T1D with exocrine enzyme elevation, HLA DRB1*09:01 was the most frequent HLA type (81.2%). Therefore, we focused to this HLA in T1D. Lactoferrin antibody titer was significantly lower in DRB1*09:01 positive group than negative group (p&amp;lt;0.01), but it was not the case regarding CA-2 antibody. Conclusion: In conclusion, CA-2 might be a target exocrine tissue antigen in KPD with HLA DRB1*08:03 and may explain a part of exocrine tissue enzyme elevation in KPD, whereas lactoferrin might be a target antigen in T1D without DRB1*09:01 and the anti-lactoferrin response might have a regulatory role regarding exocrine tissue infiltration in T1D. Disclosure A. Shimada: Speaker's Bureau; Sanofi. S. Suzuki: None. A. Satomura: None. Y. Oikawa: None. Funding Grants-in-Aid for Scientific Research (22K08678)

The co-infection of tuberculosis (TB) and human immunodeficiency virus (HIV) poses a major global health challenge. Human leukocyte antigen (HLA) plays a significant role in influencing the outcome of the disease. Several studies have revealed that HLA class II genes, specifically HLA-DRB1 and HLA-DQB1, are linked to TB and HIV infections. Only a few studies have investigated the genotype or allelic frequencies of HLA genes in the co-infection of HIV/TB. In this study, the mRNA expression of DRB1*15:01:01, DQB1*06:02:01:01, CD4, and IFNγ was determined in participants with mono-infection of HIV-1 (n = 28), mono-infection of TB (n = 31), and co-infection of HIV-1/TB (n = 21) and compared with healthy controls (n = 20). The relative quantification of the transcripts was determined using an RT2-Profiler PCR array. The findings revealed a significantly higher expression of the HLA-DRB1 gene, with a fold change of 3.7 (p = 0.005), in individuals with TB infection alone. In contrast, expression of the HLA-DQB1 gene was significantly decreased by 1.3-fold change (p = 0.008) in individuals with HIV-1/TB co-infection. Additionally, the mRNA expression of CD4 was elevated (fc: 1.2, p = 0.94) in the TB group, whereas in the HIV-1 and HIV-1/TB groups, there was a decrease in CD4 mRNA expression (HIV: fc −1.3, p = 0.045) (HIV-1/TB: fc −1.15, p = 0.191). In contrast, IFNγ mRNA expression was decreased in TB but relatively higher in individuals with HIV-1 and HIV-1/TB co-infection. We further evaluated the correlation between CD4 and IFNγ mRNA expression in all three groups. We found a significant negative correlation (TB: r = −0.386, HIV-1: r = −0.498, p &lt; 0.05) between CD4 and IFNγ in the TB and HIV-1 groups, while a positive correlation was observed in the HIV-1/TB group (r = 0.330, p &gt; 0.05). A decrease in HLA-DQB1 and CD4 mRNA expression and an increase in IFNγ in HIV/TB co-infection suggests that these markers are involved in the immunopathogenesis and progression of the disease.

The exact pathogenesis of Kawasaki disease (KD) is unknown despite extensive research in the area. Several studies have also implicated CD8+ T lymphocytes in the pathogenesis of KD. However, studies on the activation status of T lymphocytes have shown conflicting results. In this prospective study, early (CD69) and late activation (HLA-DR) markers were assessed in T lymphocytes by flow cytometry. We assessed serum levels of soluble CD25 (sCD25) by enzyme-linked immunosorbent assay. We compared these activation markers between children with KD (n = 10), febrile controls (n = 9), and healthy controls (n = 10). Furthermore, we studied the HLA-DRA and HLA-DRB gene expression in subgroups of KD with or without coronary artery aneurysms (CAAs). A significantly higher percentage of CD69 in CD3+ and CD3 + CD4+ T lymphocytes was noted in KD and febrile controls compared with healthy controls. We found no significant increase in late activation marker HLA-DR in CD3, CD3 + CD4+, and CD3 + CD8+ lymphocytes between KD, febrile, and healthy controls. We observed higher levels of sCD25 in KD and febrile controls than in healthy controls. Longitudinal follow-up in KD showed a decreasing trend of CD69 expression in CD3 + CD8+ lymphocytes and sCD25 levels over time. HLA-DRA and HLABRB expression was comparable between children with CAAs and those without CAAs. Our study showed early but not late activation of T lymphocytes in children with KD. Markers of lymphocyte activation do fall with subsidence of systemic inflammation following intravenous immunoglobulin therapy in KD.

Although numerous candidate genes have been identified in studies investigating the role of genetics in sarcoidosis, the strongest association has been reported with the Major Histocompatibility Complex/Human Leucocyte Antigen (MHC/HLA) region. This study aimed to evaluate HLA polymorphism and assess its association with cardiac and other extrapulmonary involvement in sarcoidosis patients. The study included 67 patients diagnosed with sarcoidosis. A control group of 100 bone marrow donors, who had undergone HLA genotyping previously, was also included. Blood samples were collected from all participants for HLA gene polymorphism analysis. The differences in HLA genotypes were investigated between patients with and without cardiac and other extrapulmonary involvement, and between these groups and the control group. Cardiac involvement, was present in 17.9% of the patients. The most frequently affected extrapulmonary organ was the skin (23.8%). HLA DQB103 and HLA DQB106 alleles were expressed more frequently in patients with only pulmonary involvement compared to those with extrapulmonary involvement. Conversely, HLA DQA101 was expressed more frequently in patients with extrapulmonary involvement. No statistically significant difference in the expression of HLA DRB1, HLA DQB1, and HLA DQA1 alleles was observed between sarcoidosis patients with and without cardiac involvement. Our findings suggest that HLA DQB103 and HLA DQB106 alleles might be protective against extrapulmonary organ involvement, while HLA DQA101 could be a risk factor. These findings may contribute to the prediction of treatment response and prognosis in sarcoidosis patients.

Multiple sclerosis (MS) is an inflammatory autoimmune disease affecting the central nervous system (CNS). The pathogenesis of MS is characterized by neuronal axonal degeneration and demyelination. Among the genes that raises MS risk are the HLA-class II genes. The goals of this study were to investigate the role of the HLA-DRB1 and HLA-DQB1 genes (for the first time) in Jordanian MS patients and their association with MS disease. The association of these genes with other clinical features, such as optic neuritis, sensory impairment, and brainstem symptoms in MS patients was investigated as well using PCR-SSP techniques. Our findings indicated an association between HLA-DRB1 * 03:01 (Pc = 0.01) and HLA-DRB1 * 04:01 (Pc = 0.004) alleles with Jordanian MS patients. In addition, a significant linkage between HLA-DRB1 * 15:01 and HLA-DQB1 * 06:01 alleles (Pc ≤ 0.001 and Pc = 0.012, respectively) were presented among Jordanian MS patients with optic neuritis compared to Jordanian MS patients without optic neuritis. Moreover, HLA-DQB1 * 05:01 and HLA-DQB1 * 06:02 alleles (Pc ≤ 0.001 and Pc = 0.006, respectively) was found to be related with sensory impairment in MS patients. Additionally, HLA-DRB1 * 07:01 allele indicates a positive correlation in MS patients with brainstem symptoms (Pc < 0.001). Moreover, our results indicated that there is no association on the HLA-DRB1 ~ HLA-DQB1 haplotype level and MS disease. Knowing the genes that are linked to MS, they may facilitate MS diagnosis, prevention, and treatment at earlier stage. Also, these results may serve in the development of more potent therapeutic regimens for MS and its related complications, such as optic neuritis, sensory impairment, and brainstem symptoms.

P1304 High prevalence of HLA DRB1*01:03 in Australian Inflammatory Bowel Disease patients without prediction of refractory disease

Rheumatoid arthritis (RA) is a chronic autoimmune condition that impacts the immune system, especially through changes in the splenic immune cell system. This review provides an overview of the role of splenocytes in T cell signaling and their immune response in RA patients. The spleen acts as a critical site for the activation and differentiation of splenic immune cells like T cells, B cells, macrophages, dendritic cells, and NK cells. In RA, splenomegaly is characterized by increased immune cell infiltration and altered architecture is often observed, contributing to the disease's pathogenesis. Antigen presentation via major histocompatibility complex (MHC) molecules, specifically HLA DRB1, mediates the contact between splenocytes and T cells, resulting in the clonal growth of autoreactive T cells. This study explains how splenocytes, in response to a pro-inflammatory cytokine, affect T cell development into pathogenic subsets including Th1, Th2, and Th17. It also emphasizes how important dendritic cells and macrophages are for digesting antigens and priming T cells and how NK cells influence T cell responses by releasing cytokines. This study highlights the role of the spleen in the immunopathology of RA and offers possible treatment approaches that target immune response modulation and systemic inflammation reduction.

Background: A chronic autoimmune disease called rheumatoid arthritis (RA) is impacted by both environmental and genetic factors. This work explores the impact of genetic predisposition in the development of RA, focusing on the HLA-DRB1 common epitope, PTPN22, and STAT4 gene variations. Objectives: In a cohort from Hayatabad Medical Complex (HMC), the research sought to evaluate the relationship between important genetic markers and RA susceptibility as well as investigate the interplay between genetic predisposition and environmental variables, such as smoking. Methods: 132 RA patients participated in a cross-sectional research that ended in August 2024. To determine the existence of HLA-DRB1, PTPN22, and STAT4 gene variations, genetic analysis was done. The strength of relationships was determined by calculating odds ratios, or ORs. Analysis was also done on the relationship between smoking and the common epitope of HLA-DRB1. At p &lt; 0.05, statistical significance was established. Results: The common epitope between HLA-DRB1 and RA was substantially correlated (OR = 3.45, p &lt; 0.001). While STAT4 did not exhibit a significant correlation with RA (OR = 1.29, p = 0.365), PTPN22 was likewise associated with RA (OR = 2.15, p = 0.009). Compared to non-smokers (OR = 2.18, p = 0.021), smokers with the HLA-DRB1 allele had a significantly higher risk of RA (OR = 5.87, p &lt; 0.001). Conclusions: The main genetic indicators for RA susceptibility are HLA-DRB1 and PTPN22, and smoking greatly increases the risk in those who are genetically susceptible to the condition. These results emphasize the value of lifestyle changes and customized risk assessment in the prevention of RA.

Citrullination, a post-translational modification (PTM), plays a critical role in rheumatoid arthritis (RA) by triggering immune responses to citrullinated self-antigens. Some HLA-DRB1 genes encode molecules with the shared epitope (QKRAA/QRRAA) sequence in the peptide-binding groove which preferentially presents citrulline-modified peptides, like vimentin, that intensifies the immune response in RA. In this study, we used computational approaches to evaluate intermolecular interactions between vimentin peptide-ligands (with/without PTM) and HLA-DRB1 alleles associated with a significantly increased risk for RA development. Crystal structures for HLA-DRB1*04:01, *04:04, and *04:05 bound to citrullinated peptides (PDB ID: 4MCY, 4MD5, 6BIR) were retrieved from the Protein Data Bank and non-citrullinated 3D structures were generated by mutating citrulline to arginine. The pHLA complexes were submitted to four rounds (50 ns each) of molecular dynamic simulations (MD) with Gromacs v.2022. Our results show that citrulline strengthens the interaction between vimentin and the HLA-DRB1 molecules, therefore impacting both the peptide affinity to the HLAs and pHLA stability; it also induces more intermolecular hydrogen bond formation during MD in the pHLA. Citrulline prevents repulsion between amino acid 71β and the P4-residue of native vimentin. Thus, vimentin citrullination seems to affect pHLA binding and dynamics, which may influence RA-related immune responses.

Scleroderma (systemic sclerosis), a complex illness, include severe fibrosis, vascular changes, and autoantibodies against several cellular antigens. Incidence rates range from 2.7 cases per million annually during 1947-1968 to 18.7 cases per million annually during 1972-1982. Prevalence estimates in the United States have also fluctuated, ranging from 138 cases per million during 1950-1979 to 286 cases per million in 1985. Though the exact cause of systemic sclerosis is not known, it is widely believed that both hereditary and environmental factors like parvovirus B19, Epstein-Barr, HLA DRB1*1104 and DQB1*0301 virus play a role in its development. The generally accepted classification of scleroderma is divided into two main subgroups: diffuse cutaneous scleroderma and restricted cutaneous scleroderma. Systemic sclerosis was often thought to be a dull fibrotic process, but there is now strong evidence that the pathophysiology of the disease involves an active inflammatory process. The majority of part of systemic sclerosis is determined clinically. When making a differential diagnosis, it is important to take into account a number of different illnesses that can resemble systemic sclerosis. The disease's normal progression cannot be changed by a conclusive treatment or generally accepted disease-modifying substance. Nonetheless, controlling the impacted system or systems has worked well. For better results, early diagnosis is essential. The effectiveness of treatment depends on clinical assessment, organ identification, and disease progression. In order to maximize the quality of life for impacted patients and stop more organ damage.

Literature data suggest that HLA alleles may be associated with the development of Sjögren's syndrome (SS) and the production of autoantibodies against the Ro/SSA and La/SSB antigens. However, such studies have not been conducted in Russia.Objective: to study the association between alleles of the HLA-A, HLA-B, HLA-C and HLA-DRB1 genes and the risk of developing SS and the production of autoantibodies.Material and methods. The study included 80 patients with SS or Sjögren's disease (SD). All patients met the ACR/EULAR criteria, 2016. AntiRo/SSA and anti-La/SSB autoantibodies were detected in 67 patients (83.8%), 37 patients had the combination anti-Ro/SSA/anti-La/SSB, 30 patients had only anti-Ro/SSA, and 13 patients did not have these antibodies. The control group consisted of 160 healthy blood donors without autoimmune diseases and without a family history of autoimmune diseases, who were comparable in gender and age to the patient group. High-throughput sequencing of the alleles of the HLA-A, HLA-B, HLA-C and HLA-DRB1 genes was performed on the Illumina MiSeq platform using the MiSeq Reagent Kit v3. To amplify the exons of the HLA-A, HLA-B, HLA-C and HLA-DRB1 genes, 56 specially designed primers containing Illumina adapters at the 5’ ends for subsequent indexing were used. Statistical data processing, including comparison of the frequencies of HLA alleles in the group of patients with SS/SD and in the control group, was performed in the Python software environment using the Numpy, Pandas and scikit-learn libraries.Results and discussion. In the group of patients compared to the control group we observed an increase in frequency for the alleles HLA-A*01:01:01 (OR=3.28, 95% CI [1.90–5.67], p &lt;0.001), B*08:01:01 (OR=5.41, 95% CI [3.00–9.82], p&lt;0.001), C*07:01:01 (OR=5.12, 95% CI [2.57– 10.19], p&lt;0.001). In addition, all 2-, 3- and 4-allele combinations were significantly more frequent in the patient group compared to the controls. The most significant combinations of alleles as risk markers for the development of SS were the 2-allele haplotype B*08:01:01-DRB1*03:01:01 (OR=6.65, 95% CI [3.37–13.14], p&lt;0.001) and the 4-allele haplotype A*01:01- B*08:01-C*07:01-DRB1*03:01 (OR=6.05, 95% CI [2.71–13.51], p &lt;0.001). The most significant correlation between the production of two autoantibodies anti-Ro/SSA/anti-La/SSB was found for the haplotypes B*08:01:01-DRB1*03:01:01 (OR=9.50, 95% CI [4.16–21.70], p&lt;0.001) and A*01:01:01-B*08:01:01-C*07:01:01-DRB1*03:01:01 (OR=7.20, 95% CI [2.81–18.43], p &lt;0.001). In the group of 30 patients who only produced anti-Ro/SSA, the association with the above-mentioned haplotypes was less pronounced, although it remained high. Small sample of patients without anti-Ro/SSA and anti-La/SSB (13 patients), did not allow to determine statistically significant associations with HLA alleles/haplotypes.Conclusion. A statistically significant association was found between several HLA alleles/haplotypes belonging to ancestral haplotype 8.1 (AH 8.1) as markers of susceptibility to SS and the production of Ro/SSA and La/SSB autoantibodies.