Pulmonary interstitial lesions in pemphigus mouse model: Verifying pemphigus may not be only limited to skin and mucosa.

Interstitial lung disease (ILD) has been identified as a prevalent complication and significant contributor to mortality in individuals with pemphigus. In this study, a murine model of pemphigus was developed through the subcutaneous administration of serum IgG obtained from pemphigus patients, allowing for an investigation into the association between pemphigus and ILD. Pulmonary interstitial lesions were identified in the lungs of a pemphigus mouse model through histopathology, RT-qPCR and Sircol assay analyses. The severity of these lesions was found to be positively associated with the concentration of IgG in the injected serum. Additionally, DIF staining revealed the deposition of serum IgG in the lung tissue of pemphigus mice, indicating that the subcutaneous administration of human IgG directly impacted the lung tissue of the mice, resulting in damage. This study confirms the presence of pulmonary interstitial lesions in the pemphigus mouse model and establishes a link between pemphigus and ILD.

DNA methylation of ITGB2 contributes to allopurinol hypersensitivity.

BACKGROUNDS: HLA-B*58:01 allele was strongly associated with allopurinol induced severe cutaneous adverse drug reaction (SCAR). However, HLA-B genotype is not sufficient to predict the occurrence of allopurinol-induced SCAR. OBJECTIVE: To discover DNA methylation markers for allopurinol-induced SCAR which may improve the prediction accuracy of genetic testing. STUDY DESIGN: The study was designed as a retrospective case-control clinical study in multicenter hospitals across Taiwan, Mainland China, Malaysia and Canada. 125 cases of allopurinol-induced SCAR patients and 139 cases of allopurinol tolerant controls were enrolled in this study during 2005 to 2021. RESULTS: The results of genome-wide DNA methylation assay of 62 patients revealed that ITGB2 showed strong discriminative ability of allopurinol-induced SCAR in both HLA-B*58:01 positive and negative patients with AUC value of 0.9364 (95% CI 0.8682-1.000). In validation study, significant hypermethylation of ITGB2 were further validated in allopurinol-induced SCAR patients compared to tolerant controls, especially in those without HLA-B*58:01(AUC value of 0.8814 (95% CI 0.7121-1.000)). Additionally, the methylation levels of 2 sites on ITGB2 were associated with SCAR phenotypes. Combination of HLA-B*58:01 genotyping and ITGB2 methylation status could improve the prediction accuracy of allopurinol-induced SCAR with the AUC value up to 0.9387 (95% CI 0.9089-0.9684), while the AUC value of HLA-B*58:01 genotyping alone was 0.8557 (95% CI 0.8030-0.9083). CONCLUSIONS: Our study uncovers differentially methylated genes between allopurinol-induced SCAR patients and tolerant controls with positive or negative HLA-B*58:01 allele and provides the novel epigenetic marker that improves the prediction accuracy of genetic testing for prevention of allopurinol-induced SCAR.

Dupilumab combined with low-dose systemic steroid therapy improves efficacy and safety for bullous pemphigoid.

Routine systemic therapy for bullous pemphigoid (BP) has been challenged due to the inevitably adverse effects. According to the successful applications of dupilumab in BP cases reported, therefore, we investigate the real-life efficacy and safety of dupilumab combined with low-dose oral steroid for BP. A cohort of BP patients who received either dupilumab plus low-dose methylprednisolone (dupilumab group) or merely methylprednisolone (control group) was retrospectively reviewed. The time to disease control was investigated. Additionally, the control dose and cumulative dosage of steroids, Bullous Pemphigoid Disease Area Index (BPDAI) scores, pruritus scores, and adverse events were assessed. A total of 40 patients, with 20 in each group, were retrospectively studied. The time to disease control was shorter in the dupilumab group than the control group (14 days vs. 19 days, p = 0.043). When the disease was controlled, the control dose and cumulative dosage of methylprednisolone in the dupilumab group were substantially lower than those of the control (24.6 mg vs. 48.8 mg, 376.8 mg vs. 985.6 mg, both p < 0.01). Compared with the control, the percentage change from baseline in BPDAI scores and pruritus scores were both significantly reduced, and the adverse events were also less frequent in the dupilumab group. The combination therapy of dupilumab plus low-dose methylprednisolone exhibits superior efficacy and safety in comparison with the current first-line systemic therapy for BP.

HLA-A*02:01 allele is associated with tanshinone-induced cutaneous drug reactions in Chinese population.

Tanshinone, a widely used Chinese patent medicine, has been confirmed to have various kinds of pharmacological effects although frequently causing cutaneous adverse drug reactions (cADRs). We aim to identify whether human leukocyte antigen (HLA) class I alleles are associated with tanshinone-induced cADRs in Han Chinese. The association study including 18 patients with tanshinone-induced cADRs, 67 tanshinone-tolerant volunteers, and two general population databases consisted of 10,689 and 169,995 healthy subjects was performed. The frequency of tanshinone-induced cADRs patients carrying HLA-A*02:01 was significantly higher when compared with the general control groups (OR = 6.25, Pc = 7.20 × 10-5; OR = 7.14, Pc = 8.00 × 10-6), and with the tolerant group (OR = 5.09, Pc = 0.024). The molecular docking assay confirmed high affinity of the ingredients of tanshinone towards HLA-A*02:01 (≤-7.5 kcal/mol). The result suggested HLA-A*02:01 may work as a promisingly predictive marker for tanshinone personalized therapy in Han Chinese.

HLA-C*12:02 is strongly associated with Xuesaitong-induced cutaneous adverse drug reactions.

Xuesaitong (XST) is mainly used to treat cardiovascular and cerebrovascular diseases, sometimes causing cutaneous adverse drug reactions (cADRs) with unknown mechanisms of pathogenicity or risk factors. We aimed to verify whether human leukocyte antigen (HLA) alleles are associated with XST-related cADRs in Han Chinese population. We carried out an association study including 12 subjects with XST-induced cADRs, 283 controls, and 28 XST-tolerant subjects. Five out of 12 patients with XST-induced cADRs carried HLA-C*12:02, and all of them received XST via intravenous drip. The carrier frequency of HLA-C*12:02 was significantly high compare to that of the control population (Pc = 4.4 × 10-4, odds ratio (OR) = 21.75, 95% CI = 5.78-81.88). Compared with that of the XST-tolerant group, the patients who received XST through intravenous drip presented a higher OR of cADRs (Pc = 0.011, OR = 27.00, 95% CI = 2.58-282.98). The results suggest that HLA-C*12:02 is a potentially predictive marker of XST-induced cADRs in Han Chinese, especially when XST is administered via intravenous drip.

Skin ulcers infected with conditional pathogenic strains treated with local hydrogen water packing in two pemphigus vulgaris patients: Case reports with follow-up for 2 months.

We are the first to report on a new, safe, and effective treatment of infections induced by conditional pathogenic strains with local wet packing with hydrogen water. The new treatment method may also shed light on the therapy of chronic, inflammatory skin ulcers.

Clinical, Viral and Genetic Characteristics of Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) in Shanghai, China.

DRESS is one of the most severe drug reactions. The aim of this retrospective study was to summarize the clinical presentation, genetic predisposition and prognostic factors of DRESS. A total of 52 patients with DRESS, who were inpatients at a medical referral centre in Shanghai, China, from January 2011 to December 2016, were analysed retrospectively. All the patients had skin eruption, 83% had liver involvement, and ≤10% had other organ involvement. Mean cost of hospitalization was US$5,511±3,050. The 3 most common causative agents were allopurinol (18/52; 35%), salazosulphapyridine (11/52; 21%) and carbamazepine (5/52; 10%). HLA-B*5801 and HLA-B*1302 were associated with allopurinol-induced DRESS. HLA-B*1301 was related to salazosulphapyridine-induced DRESS. The mortality rate was 6% (3/52). Epstein-Barr virus DNA was found in 10 patients (19%) and indicated a poor prognosis. Human herpes virus 6 DNA was detected in 17 patients (33%) and was associated with autoimmune sequelae. Due to its high medical cost and sometimes poor prognosis, prevention of DRESS should be a high priority.

HLA-A*02 alleles are associated with tetanus antitoxin-induced exanthematous drug eruptions in Chinese patients.

OBJECTIVE: Tetanus antitoxin (TAT) is an effective antitetanus medicine, but may sometimes cause adverse drug reactions such as rapid-onset anaphylactic shock and late-onset cutaneous adverse drug reactions, including exanthematous drug eruptions (EDE). Human leukocyte antigen (HLA) class I alleles are strongly associated with different types of cutaneous adverse drug reactions. This study aimed to assess whether there is an association between TAT-induced EDE and HLA-A, HLA-B, and HLA-C alleles in the Chinese Han population. PATIENTS AND METHODS: We carried out an association study in 15 patients with TAT-induced EDE and two groups of general Han Chinese patients. Allele-level genotypes of the HLA-A, HLA-B, and HLA-C genes of each patient were determined using the PCR-sequence-specific oligonucleotides method. RESULTS: The carrier frequency of HLA serotype A2 was significantly higher in the TAT-induced EDE patients than in the general Han Chinese study participants from the human major histocompatibility complex database [n=283, odds ratio (OR)=6.93; P=0.0061]. Particularly, the carrier frequency of three A2 alleles, including HLA-A*02:01, HLA-A*02:06, and HLA-A*02:07, is significantly higher than that of the control group (OR=14.40; P=2.4×10). Furthermore, HLA-B*39:01 was in complete linkage disequilibrium with HLA-A*02:06 in the case patients. Consequently, the distribution of the HLA-A*02:06/-B*39:01 haplotype was also significantly different in the cases and the controls (OR=105.00; P=0.0024). CONCLUSION: The HLA-A*02:06/-B*39:01 haplotype is a potential genetic marker for the TAT-induced EDE. Furthermore, the HLA-A2 serotype, especially three alleles A*02:01, A*02:06, and A*02:07, was identified to be associated with the TAT-induced EDE in the Han Chinese population for the first time.

The association between HLA-B variants and amoxicillin-induced severe cutaneous adverse reactions in Chinese han population.

Background: Amoxicillin (AMX) is among the most prescribed and the best tolerated antimicrobials worldwide. However, it can occasionally trigger severe cutaneous adverse reactions (SCAR) with a significant morbidity and mortality. The genetic factors that may be relevant to AMX-induced SCAR (AMX-SCAR) remain unclear. Identification of the genetic risk factor may prevent patients from the risk of AMX exposure and resume therapy with other falsely implicated drugs. Methodology: Four patients with AMX-SCAR, 1,000 population control and 100 AMX-tolerant individuals were enrolled in this study. Both exome-wide and HLA-based association studies were conducted. Molecular docking analysis was employed to simulate the interactions between AMX and risk HLA proteins. Results: Compared with AMX-tolerant controls, a significant association of HLA-B*15:01 with AMX-SCAR was validated [odds ratio (OR) = 22.9, 95% confidence interval (CI): 1.68-1275.67; p = 7.34 × 10-3]. Moreover, 75% carriers of HLA-B*15:01 in four patients with AMX-SCAR, and the carrier frequency of 10.7% in 1,000 control individuals and 11.0% in 100 AMX-tolerant controls, respectively. Within HLA-B protein, the S140 present in all cases and demonstrated the strongest association with AMX-SCAR [OR = 53.5, p = 5.18 × 10-4]. Molecular docking results also confirmed the interaction between AMX and S140 of the HLA-B protein, thus eliminating the false-positive results during in association analysis. Conclusion: Our findings suggest that genetic susceptibility may be involved in the development of AMX-SCAR in Han Chinese. However, whether the HLA-B variants observed in this study can be used as an effective genetic marker of AMX-induced SCAR still needs to be further explored in larger cohort studies and other ethnic populations.

Epidemiological Insights into Autoimmune Bullous Diseases in China: A Comprehensive Analysis.

OBJECTIVE: This study aims to conduct an extensive analysis of autoimmune bullous diseases, particularly pemphigus vulgaris and bullous pemphigoid, in Shanghai, China, from 2016 to 2023. It seeks to understand the demographic profiles, comorbidities, mortality rates, risk factors, and socioeconomic impacts associated with autoimmune bullous disease. METHODS: A cross-sectional study design was employed, enrolling 1,072 patients. Diagnostic measures included clinical manifestations, histopathology, direct immunofluorescence, and serologic tests. The study also involved a detailed socioeconomic analysis and evaluation of occupational risks. RESULTS: The findings highlight a significant occupational risk in industries requiring enhanced safety measures, with a notable prevalence of autoimmune bullous disease among workers in these sectors. A considerable portion of the patients were from low-income backgrounds with limited literacy, indicating the economic burden of autoimmune bullous disease. A key discovery of the study is the potential pathological link between autoimmune bullous disease and interstitial lung disease. CONCLUSION: This research, one of the first comprehensive studies on autoimmune bullous disease in China, underscores the need for targeted healthcare strategies and further investigation into autoimmune bullous disease, particularly its relationship with interstitial lung disease.

Efficacy and Safety of Hydrogen Therapy in Patients with Early-Stage Interstitial Lung Disease: A Single-Center, Randomized, Parallel-Group Controlled Trial.

Purpose: Several in vivo experiments have shown that molecular hydrogen is a promising therapeutic agent for interstitial lung diseases (ILD). In this study, hydrogen therapy was investigated to determine whether it is superior to N-Acetylcysteine (NAC) for the treatment of patients with early-stage ILD. Patients and Methods: A prospective, single-center, randomized, controlled clinical trial was conducted in 87 patients with early-stage ILD. Hydrogen or NAC therapy was randomly assigned (1:1 ratio) to the eligible patients. The primary endpoint was the change in the high-resolution computed tomography (HRCT) and composite physiologic index (CPI) scores from baseline to week 48. Pulmonary function was evaluated as a secondary endpoint, and adverse events were recorded for safety analysis. Results: The rate of HRCT image improvement from the baseline in the HW group (63.6%) was higher than that in the NAC group (39.5%). A significant decrease in CPI and improvement in DLCO-sb were observed in the hydrogen group compared with those in the control group. Changes in other pulmonary function parameters, including FVC, FEV1, FEV1/FVC%, and TLC, were not significantly different between the two groups. Adverse events were reported in 7 (15.9%) patients in the HW group and 10 (23.3%) patients in the NAC group, but the difference was not significant (P=0.706). Conclusion: Hydrogen therapy exhibits superior efficacy and acceptable safety compared with NAC therapy in patients with early-stage ILD.

An association study of HLA with levofloxacin-induced severe cutaneous adverse drug reactions in Han Chinese.

Levofloxacin-induced severe cutaneous adverse drug reactions (LEV-SCARs) remain unexplored. An association study of human leukocyte antigen (HLA) alleles with LEV-SCARs among 12 patients, 806 healthy subjects, and 100 levofloxacin-tolerant individuals was performed. The carrier frequencies of HLA-B∗13:01 (odds ratio [OR]: 4.50; 95% confidence interval [CI]: 1.15-17.65; p = 0.043), HLA-B∗13:02 (OR: 6.14; 95% CI: 1.73-21.76; p = 0.0072), and serotype B13 (OR: 17.73; 95% CI: 3.61-86.95; p = 4.85 × 10-5) in patients with LEV-SCARs were significantly higher than those of levofloxacin-tolerant individuals. Molecular docking analysis suggested that levofloxacin formed more stable binding models with HLA-B∗13:01 and HLA-B∗13:02 than with non-risk HLA-B∗46:01. Mass spectrometry revealed that nonapeptides bound to HLA-B∗13:02 shifted at several positions after exposure to levofloxacin. Prospective screening for serotype B13 (sensitivity: 83%, specificity: 78%) and alternative drug treatment for carriers may significantly decrease the incidence of LEV-SCARs.

Extensive cutaneous iatrogenic Kaposi's sarcoma after bullous pemphigoid treatment with oral methylprednisolone: a rare Chinese case report.

Bullous pemphigoid (BP) is an autoimmune disease that requires immunosuppressive therapy. Systemic corticosteroids are considered the standard treatment for moderate-to-severe BP. Kaposi's sarcoma (KS) is a rare multifocal endothelial tumour that affects the skin, mucosa and viscera. As an angioproliferative disease of obscure aetiopathogenesis and histogenesis, KS is associated with human herpesvirus 8 (HHV-8). This current case report describes a rare occurrence of extensive cutaneous KS in a 60-year-old Chinese male patient after oral methylprednisolone treatment for BP with an emphasis on its pathological characterization. A total of more than 40 nodules were found on his trunk and lower limbs covering more than 20% of his body surface area. Immunohistochemical staining of biopsy samples from the lesion showed the patient was positive for HHV-8, CD31, CD34, XIIIa, ERG and Ki-67. The Epstein-Barr virus test showed the patient tested negative for immunoglobulin (Ig)A and IgM, but was positive for IgG. Immunosuppression associated with the treatment for BP may activate a latent HHV-8 infection and induce the development of KS.

Clinical profile of cutaneous adverse drug reactions: a retrospective study of 1883 hospitalized patients from 2007 to 2016 in Shanghai, China.

BACKGROUND: Cutaneous adverse drug reactions (CADRs) are drug-induced skin reactions with or without systemic involvement, ranging from mild maculopapular exanthema (MPE) to life-threatening severe CADRs (S-CADRs). Due to their unpredictability and severity, early recognition of suspected causative drugs is highly recommended. However, the profile of CADRs remains unknown in China. OBJECTIVES: To assess the clinical profile, predominant causative drugs, and cost associated with CADRs in Shanghai, China. MATERIALS AND METHODS: Clinical records of inpatients admitted with a diagnosis of CADRs to the dermatology ward of Huashan Hospital from January 2007 to December 2016 were retrospectively studied. RESULTS: A total of 1,883 patients (1,231 female and 652 male), admitted with a diagnosis of CADR, were investigated. S-CADRs made up 21.99% of all cases (n=414), and urticaria (27.19%) was the most frequent reaction. Of the patients, 53.43% suffered from multiple drug-induced drug eruptions and the rest (45.83%) from single drug-induced drug eruptions. Overall, antimicrobials (28.85%) was the main drug group involved, and for S-CADRs, this was antiepileptic drugs (36.15%). The total cost for CADRs was RMB23,718,788.83 ($3,588,319.04). Both age and sex were related to admission cost (p=0.005 and p=7.84E-8, respectively). Antimicrobials were the most common treatment causing CADRs. CONCLUSION: The management of CADRs requires considerable medical cost. CADRs are not only a health problem but also a significant financial burden for affected individuals.

HLA-A*24:02 is associated with metronidazole-induced cutaneous adverse drug reactions in Han Chinese individuals: A pilot case-control study with both HLA gene and T cell receptor repertoire analysis.

Metronidazole, a widely used drug for the treatment of infections with anaerobic and facultative anaerobic bacteria and protozoa, can frequently cause metronidazole-induced cutaneous adverse reactions (McADRs). The aim of the present study was to investigate the association between human leucocyte antigen (HLA) alleles and McADRs in a Chinese Han population. The frequency of HLA-B*24:02 carriers among the McADR patients was 73.3%, which was significantly higher than that of the population controls (32.16%, OR = 5.80, 95% CI = [1.80-18.72], Pc = 0.004) and of the metronidazole-tolerant patients (26.67%, OR = 7.56, 95% CI = [2.02-28.35], Pc = 0.004). Molecular docking showed that metronidazole and one of its major metabolites had the potential to bind in the HLA groove and that there was a relatively stable binding state of the HLA-B*24:02-metronidazole/the metabolite complex. The CDR3 repertoires of both T cell receptor (TCR)Vα and Vß of the patients showed a significantly skewed or an oligoclonal distribution. The TCRVß CDR3 of the patients shared a similar motif, "CASSxxxxxxQxF." The current study demonstrated that both the HLA-A*24:02 allele and TCR are involved in the pathogenesis of McADRs.

Comprehensive assessment of T cell receptor ß repertoire in Stevens-Johnson syndrome/toxic epidermal necrolysis patients using high-throughput sequencing.

Stevens-Johnson syndrome (SJS) /toxic epidermal necrolysis (TEN) are life-threatening severe cutaneous adverse drug reactions characterized by widespread epidermal necrosis. Recent studies have indicated that SJS/TEN is a specific immune reaction regulated by T cells. Certain drug serves as foreign antigens that are presented by major histocompatibility complex (MHC) and recognized by T cell receptors (TCRs), inducing adaptive immune responses. However, few studies have performed detailed characterization of TCR repertoire in SJS/TEN, and it remains unclear whether the particular types of TCRs expanded clonally are drug-specific, which would provide a potential underlying mechanism of SJS/TEN. In this study, using high-throughput sequencing, we comprehensively assessed the diversity, composition and molecular characteristics of the TCRß repertoires in 17 SJS/TEN patients associated with three different causative drugs including methazolamide (MZ), carbamazepine (CBZ) and allopurinol (ALP). Systematic analysis of the TCRß sequences revealed that SJS/TEN patients had more highly expanded clones and less TCR repertoire diversity, and the TCR repertoire diversity of these patients showed certain associations with the clinical severity of disease. Similar predominant clonotypes, shared-usage TRBV/TRBJ subtypes and combinations thereof were observed among different subjects with the same causative agent. Our observations provide enhanced understanding of the role of T lymphocytes in the pathogenesis of SJS/TEN and enumerate potential therapeutic targets.

Overexpression of cytotoxic proteins correlates with liver function impairment in patients with drug reaction with eosinophilia and systemic symptoms (DRESS).

Drug reaction with eosinophilia and systemic symptoms (DRESS) is characterised by skin rash and multivisceral involvement. The liver is the organ most frequently affected and the degree of liver function impairment often correlates with the mortality rate of DRESS. We aimed to examine the expression of cytotoxic proteins, including soluble Fas ligand (sFasL), TNF-α, granulysin, perforin, and granzyme B in the sera and skin lesions of patients with DRESS and evaluate their clinical significance. Our cohort consisted of 21 patients with DRESS and control groups including 39 patients with Stevens-Johnson syndrome/toxic epidermal necrolysis, 21 patients with maculopapular eruption, and 29 normal controls. Concentrations of cytotoxic proteins in the sera were measured using enzyme-linked immunosorbent assays. Tissue samples were also obtained from typical skin lesions, and immunohistochemical staining was conducted to assess the local expression of cytotoxic proteins. We found that sFasL and granzyme B were significantly overexpressed in the sera of DRESS patients compared to normal controls. Furthermore, the levels of sFasL, perforin, and granzyme B significantly correlated with the serum level of liver enzymes in DRESS patients. Immunohistochemical examination also showed overexpressed cytotoxic proteins in cutaneous DRESS lesions. Cytotoxic proteins may play a vital role in the pathogenesis of DRESS, and serum sFasL, perforin, and granzyme B may also be involved in liver function impairment in DRESS patients.

HLA-A*02:07 Allele Associates with Clarithromycin-Induced Cutaneous Adverse Drug Reactions in Chinese Patients.

Genetic risk factors could cause cutaneous adverse drug reactions (cADRs) in patients after treatment with clarithromycin. This study explored the association of HLA class I genes with clarithromycin-cADRs in Han Chinese patients. A total of 12 clarithromycin-cADR patients and 34 clarithromycin-tolerant controls were recruited for the high-resolution genotyping of HLA class I genes (HLA-A, HLA-B and HLA-C). The population controls consisted of 283 Han Chinese retrieved from the MHC database for validated comparison. A molecular docking analysis of HLA-A*02:07 protein and clarithromycin was conducted using glide module with Schrödinger Suite. Among all tested HLA alleles, the carrier frequencies of HLA-A*02:07 (58% versus 5.9%, OR = 22.40, 95% CI = 3.58-139.98, p = 8.20 × 10E-5, pc = 1.1 × 10E-3) and HLA-B*46:01 (50% versus 5.9%, OR = 16.00, 95% CI = 2.59-98.99, p = 0.002, pc = 0.03) were significantly higher in clarithromycin-cADRs than in clarithromycin-tolerant controls. However, when compared to population controls, only HLA-A*02:07, and not HLA-B*46:01, reached statistical significance (58% versus 15.5%, OR = 7.61, 95% CI = 2.31-25.04, p = 1.2 × 10E-4, pc = 1.7 × 10E-3). Furthermore, molecular docking data revealed that clarithromycin could bind to and interact with HLA-A*02:07 in two possible binding situations. These data suggest that HLA-A*02:07 might be a genetic risk factor for developing clarithromycin-cADRs in Han Chinese and serve as a useful biomarker for personalized medicine to prevent clarithromycin-cADRs.

Association Study and Fine-Mapping Major Histocompatibility Complex Analysis of Pemphigus Vulgaris in a Han Chinese Population.

To identify possible additional genetic susceptibility loci for pemphigus vulgaris (PV), we performed a genome-wide association study of 240 PV patients and 1,031 control individuals, and we selected the top single nucleotide polymorphisms for replication in independent samples, with 252 patient samples and 1,852 control samples. We identified rs11218708 (P = 3.1 × 10-8, odds ratio = 1.54) at chromosome locus 11q24.1 as significantly associated with PV. A fine-mapping analysis of PV risk in the major histocompatibility complex region showed three independent variants predisposed to PV using stepwise analysis: HLA-DRB1*14:04 (P = 2.47 × 10-38, odds ratio = 6.28), rs7454108 at the TAP2 gene (P = 2.78 × 10-12, odds ratio = 3.25), and rs1051336 at the HLA-DRA gene (P = 3.06 × 10-6, odds ratio = 0.33). A systematic evaluation using gene- and pathway-based analyses showed a high tendency for PV susceptibility genes to be associated with autoimmunity. Our study highlights the involvement of immune-mediated processes in the pathophysiology of PV and illustrates the value of imputation to identify variants in the major histocompatibility complex region.

HLA-B*13:01 is associated with salazosulfapyridine-induced drug rash with eosinophilia and systemic symptoms in Chinese Han population.

AIM: Salazosulfapyridine (SASP) frequently causes several adverse reactions, such as drug rash with eosinophilia and systemic symptoms (DRESS). This study aims to assess whether there is an association between SASP-induced DRESS and HLA-A, -B and -C alleles in the Chinese Han population. SUBJECTS & METHODS: We performed an association study of six subjects with SASP-induced DRESS, 30 SASP-tolerant patients and 283 general subjects from the human MHC database, all of whom are Han Chinese. RESULTS: The frequency of the SASP-induced DRESS patients carrying the HLA-B*13:01 allele is 66.67% (4/6). It is significantly higher compared with the general Chinese Han population (15.19%, 43/283; odds ratio: 11.16; p = 0.007) or with the SASP-tolerant patients (13.33%, 4/30; odds ratio: 13.00; p = 0.004). CONCLUSION: These findings show for the first time that in the Chinese Han population, HLA-B*13:01 is associated with SASP-induced DRESS. HLA-B*13:01 might serve as a potential genetic marker for reducing the prevalence of SASP-induced DRESS.