Genome-wide association study using the ethnicity-specific Japonica array: identification of new susceptibility loci for cold medicine-related Stevens-Johnson syndrome with severe ocular complications

A genome-wide association study identifies distinct variants associated with pulmonary function among European and African ancestries from the UK Biobank

Pulmonary function is an indicator of well-being, and pulmonary pathologies are the third major cause of death worldwide. We analysed the UK Biobank genome-wide association summary statistics of pulmonary function for Europeans and individuals of recent African descent to identify variants associated with the trait in the two ancestries. Here, we show 627 variants in Europeans and 3 in Africans associated with three pulmonary function parameters. In addition to the 110 variants in Europeans previously reported to be associated with phenotypes related to pulmonary function, we identify 279 novel loci, including an ISX intergenic variant rs369476290 on chromosome 22 in Africans. Remarkably, we find no shared variants among Africans and Europeans. Furthermore, enrichment analyses of variants separately for each ancestry background reveal significant enrichment for terms related to pulmonary phenotypes in Europeans but not Africans. Further analysis of studies of pulmonary phenotypes reveals that individuals of European background are disproportionally overrepresented in datasets compared to Africans, with the gap widening over the past five years. Our findings extend our understanding of the different variants that modify the pulmonary function in Africans and Europeans, a promising finding for future GWASs and medical studies.

Susceptibility Genes and HLA for Cold Medicine-Related SJS/TEN with SOC

We investigated the genetic predisposition for the pathogenesis of Stevens–Johnson syndrome/epidermal necrolysis with severe ocular complications (SJS/TEN with SOC). Cold medicines (CMs) including multi-ingredient cold-medications and non-steroidal anti-inflammatory drugs (NSAIDs) were implicated in the development of SJS/TEN with SOC. Studies on the association between HLA genotypes and CM-related SJS/TEN with SOC (CM-SJS/TEN with SOC) revealed an association with HLA-A*02:06 in the Japanese; it may be a marker in Koreans. HLA-B*44:03 was associated with the Japanese, Thais, and Indians; in Brazilians of European ancestry, it may be a positive marker. PTGER3 is a susceptibility gene; HLA-A*02:06 and PTGER3 polymorphisms exerted additive effects in Japanese and Korean patients. A genome-wide association study showed that IKZF1 was associated with the Japanese. A meta-analysis including Japanese, Koreans, Indians, and Brazilians also revealed an association between CM-SJS/TEN with SOC and IKZF1. The upregulation of hsa-miR-628-3p in the plasma of SJS/TEN with SOC patients may suppress the expression of TLR3 and innate immune-related genes. Not only CMs but also the interaction of TLR3, PTGER3, IKZF1, and HLA and maybe some microbial infections are necessary for the onset of SJS/TEN with SOC.

Findings by an International Collaboration on SJS/TEN With Severe Ocular Complications

Stevens-Johnson Syndrome (SJS) is an acute inflammatory vesiculobullous reaction of the skin and mucosa, e.g., the ocular surface, oral cavity, and genitals. In patients with extensive skin detachment and a poor prognosis, the condition is called toxic epidermal necrolysis (TEN). Not all, but some patients with SJS/TEN manifest severe ocular lesions. Approximately 50% of SJS/TEN patients diagnosed by dermatologists and in burn units suffer from severe ocular complications (SOC) such as severe conjunctivitis with pseudomembrane and ocular surface epithelial defects in the acute stage. In the chronic stage, this results in sequelae such as severe dry eye and visual disturbance. Before 2005, our group of Japanese scientists started focusing on ophthalmic SJS/TEN with SOC. We found that cold medicines were the main causative drugs of SJS/TEN with SOC and that in Japanese patients, HLA-A ^* 02:06 and HLA-B ^* 44:03 were significantly associated with cold medicine-related SJS/TEN with SOC (CM-SJS/TEN with SOC). We expanded our studies and joined scientists from Korea, Brazil, India, Taiwan, Thailand, and the United Kingdom in an international collaboration to detect the genetic predisposition for SJS/TEN with SOC. This collaboration suggested that in Japanese patients, cold medicines, including NSAIDs, were the main causative drugs, and that HLA-A ^* 02:06 was implicated in Japanese and Korean patients and HLA-B ^* 44:03 in Japanese-, Indian-, and European ancestry Brazilian patients. Our joint findings reveal that there are ethnic differences in the HLA types associated with SJS/TEN with SOC.

Clinical Aspects of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis With Severe Ocular Complications in South Korea

This review describes the current knowledge regarding genetic susceptibilities and treatment strategies for Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN), with ocular complications, in Korea. In a case-control study, the gene frequencies of both HLA-A*0206 (20.0%) and HLA-Cw*0304 (15.0%) increased but the gene frequency of HLA-Cw*0303 (1.3%) decreased with cold medicine (CM)-SJS/TEN with severe ocular complications (SOCs). In a case-series, positive genotyping of HLA-B*5801 was 80.0% in allopurinol-induced SJS/TEN without SOCs. In a genome-wide association study, HLA-A*0206 was substantially related to CM-SJS/TEN with SOCs. Both HLA-A*0206 and prostaglandin-E receptor 3 (PTGER3) single nucleotide polymorphism (SNP) rs1327464 exert a synergistic effect on SOCs in CM-SJS/TEN. In the acute stage, conventional procedures, amniotic membrane transplantation or suture-less amniotic contact lenses are applied. Applications of intravenous Immunoglobulin (IVIG) or mega-dose steroids are attempted in patients with high acute ocular and systemic involvement scores. In the chronic stage, keratolimbal transplantation and penetrating keratoplasty are the standard procedures. Either autologous nasal or oral mucosal grafts, or biomaterial-free cultured oral mucosal epithelial cell sheets are transplanted as alternative therapies. Deep anterior lamellar keratoplasty is attempted. Combined photodynamic therapy with intrastromal bevacizumab injection or intense pulse laser are used to resolve chronic ocular complication. Corneoscleral contact lenses are available for a visual rehabilitation. As a last resort, Seoul-type keratoprosthesis had been transplanted. There are unmet needs to standardize nationwide ocular grading system and to correct tarsal scarring using mucosal grafting. This review provides a perspective on the current practices to treat ocular complications in SJS/TEN.

Mapping of susceptible variants for cold medicine-related Stevens-Johnson syndrome by whole-genome resequencing

Stevens–Johnson syndrome (SJS) and its severe condition with extensive skin detachment and a poor prognosis, toxic epidermal necrolysis (TEN), are immunologically mediated severe cutaneous reactions of the skin and mucous membranes such as the ocular surface. Genetic variations on the HLA-A and other autosomal genes have been identified as risk factors for cold medicine-related SJS/TEN with severe ocular complications (CM-SJS/TEN with SOC). Using a whole-genome sequencing (WGS) approach, we explored other susceptible variants of CM-SJS/TEN with SOC, especially among rare variants and structural variants (SVs). WGS was performed on samples from 133 patients with CM-SJS/TEN with SOC and 418 healthy controls to obtain single nucleotide polymorphisms (SNPs) and SVs. Genome-wide association tests were performed with these variants. Our genome-wide association test reproduced the associations of the common variants of HLA-A and loci on chromosome 16q12.1. We also identified novel associations of SVs on these loci and an aggregation of rare coding variants on the TPRM8 gene. In silico gene expression analysis on the HLA-A locus revealed that the SNP (rs12202296), which was significantly associated with susceptibility to CM-SJS/TEN with SOC, was correlated to an increase in HLA-A expression levels in the whole blood (P = 2.9 × 10⁻¹⁷), from the GTEx database. The majority of variants that were significantly associated with CM-SJS/TEN with SOC were found in non-coding regions, indicating the regulatory role of genetic variations in the pathogenesis of CM-SJS/TEN with SOC.

Stevens-Johnson syndrome/toxic epidermal necrolysis with severe ocular complications

Introduction: Stevens-Johnson syndrome (SJS) and its severe phenotype, toxic epidermal necrolysis (TEN), are acute inflammatory vesiculobullous reactions of the skin and mucosa. Approximately 50% of SJS/TEN patients diagnosed by dermatologists and in burn units suffer from severe ocular complications (SOC) in the acute stage.Areas covered: Earlier studies on patients with SJS/TEN with SOC identified cold medicines including multi-ingredient cold medications and non-steroidal anti-inflammatory drugs as the main eliciting drugs. HLA analyzes showed that genetic predisposition might play a role in the response to these drugs. Our analysis of the association between HLA genotypes and cold medicine-related SJS/TEN (CM-SJS/TEN) with SOC revealed that certain HLA genotypes play a role in the development of SJS/TEN with SOC. Genetic predisposition and other factors contributing to the elicitation of CM-SJS/TEN with SOC and the management of patients in the acute and chronic stage of the disease are discussed.Expert opinion: The main sequelae of SJS/TEN are ocular sequelae with visual disturbance. SJS/TEN with SOC needs ophthalmic treatment in addition to systemic treatment from the onset time to reduce the ophthalmic sequelae. In addition, HLA examination and public awareness of SJS/TEN with SOC due to cold medicine use might contribute to preventing visual disturbance due to SJS/TEN.Abbreviations: SJS: Stevens-Johnson syndrome; TEN: toxic epidermal necrolysis; SOC: severe ocular complications.

Gene expression analysis of conjunctival epithelium of patients with Stevens-Johnson syndrome in the chronic stage

Objective

To investigate the pathology underlying the ocular surface complications of patients with Stevens-Johnson syndrome (SJS) in the chronic stage.

Methods and analysis

Using oligonucleotide microarrays, we performed comprehensive gene expression analysis of the conjunctival epithelium of patients with SJS in the chronic stage (n=3). The controls were patients with conjunctival chalasis (n=3). We confirmed the downregulation and upregulation of transcripts of interest by quantitative real-time PCR (RT-PCR) assay. The expression of ocular surface protein with significantly upregulated transcripts was assessed immunohistochemically.

Results

Compared with the controls, in the conjunctival epithelium of patients with SJS, 50 transcripts were downregulated by less than one-tenth (analysis of variance (ANOVA) p<0.05). Transcripts MUC7, PIGR, HEPACAM2, ADH1C and SMR3A were downregulated by less than one-fiftieth. 65 transcripts were upregulated more than 10- fold; the difference between patients with SJS and the controls was significant (ANOVA p<0.05). There were 14 transcripts that were upregulated more than 50-fold; they were SERPINB4, KRT1, KRTDAP, S100A7, SBSN, KLK6, SERPINB12, PNLIPRP3, CASP14, ODZ2, CA2, CRCT1, CWH43 and FLG. Quantitative RT-PCR of conjunctival epithelium samples from 11 patients with SJS and 26 controls showed that the gene expression of PIGR, HEPACAM2 and ADH1C was significantly downregulated while the gene expression of ODZ2 (teneurin-2) was significantly upregulated in patients with SJS. We document that teneurin-2 protein can be expressed in human conjunctival epithelium.

Conclusion

Our results suggest that the downregulation of PIGR, HEPACAM2 and ADH1C and upregulation of teneurin-2 expression contribute to the pathology of the ocular surface in patients with SJS in the chronic stage.

Results of Detailed Investigations Into Stevens-Johnson Syndrome With Severe Ocular Complications

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute inflammatory vesiculobullous reactions of the mucosa of the ocular surface, oral cavity, and genitals, and of the skin. Severe ocular complications (SOC) are present in about half of SJS/TEN patients diagnosed by dermatologists. We review our group's findings on the genetic predisposition for and the etiology of SJS/TEN with SOC. We suspected that abnormal innate mucosal immunity, resulting in an anomalous response to commensal bacteria that usually do not elicit such a response, contributes to the ocular surface inflammation seen in SJS/TEN with SOC. We found that cold medicines, including multi-ingredient cold medications and nonsteroidal anti-inflammatory drugs, were the main causative drugs especially in patients with SJS/TEN with SOC. Cold medicine-related SJS/TEN (CM-SJS/TEN) with SOC was strongly associated with HLA-A*02:06 in the Japanese populations, and significantly associated with HLA-B*44:03 in the Japanese and in Indian and Brazilian populations. Single nucleotide polymorphism association analysis showed that the Toll-like receptor 3 (TLR3), prostaglandin-E receptor 3 (PTGER3), and IKZF1 gene were significantly associated with CM-SJS/TEN with SOC and that they could regulate mucocutaneous inflammation including that of the ocular surface. As we found several HLA-SNP sets with a high odds ratio, we postulated that they may help to predict the possible development of SJS/TEN with SOC. From our findings we suggest that besides microbial infection and cold medicines, a combination of multiple gene polymorphisms and their interactions contribute strongly to the onset of CM-SJS/TEN with SOC.

Oseltamivir induced Stevens-Johnson syndrome/toxic epidermal necrolysis-case report

RATIONALE

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are 2 rare but life-threatening diseases characterized by detachment of epidermis, bullous skin lesions, and mucous membrane erosions. Drugs are highly suspected to be the causative agents. We report a case of SJS/TEN induced by oseltamivir, which is a very rare event.

PATIENT CONCERNS

A 9-year-old girl with upper respiratory tract infections presented with generalized maculopapular rash the second day after taking oseltamivir.

DIAGNOSIS

The diagnosis of SJS/TEN was made based on cytotoxic skin lesions and mucous membrane involvement.

INTERVENTIONS

After discontinuing of the drug and combination therapy of corticosteroid and human immunoglobulin initiation, the lesions were improved. Human leukocyte antigen (HLA) gene sequencing was done.

OUTCOMES

The girl was followed-up for 1 year. The skin and mucous membranes symptoms were relieved.

LESSONS

We report this case to attract attention to the rare but serious side effect of this antiviral drug.

Genome analyses for the Tohoku Medical Megabank Project towards establishment of personalized healthcare

Personalized healthcare (PHC) based on an individual's genetic make-up is one of the most advanced, yet feasible, forms of medical care. The Tohoku Medical Megabank (TMM) Project aims to combine population genomics, medical genetics and prospective cohort studies to develop a critical infrastructure for the establishment of PHC. To date, a TMM CommCohort (adult general population) and a TMM BirThree Cohort (birth+three-generation families) have conducted recruitments and baseline surveys. Genome analyses as part of the TMM Project will aid in the development of a high-fidelity whole-genome Japanese reference panel, in designing custom single-nucleotide polymorphism (SNP) arrays specific to Japanese, and in estimation of the biological significance of genetic variations through linked investigations of the cohorts. Whole-genome sequencing from >3,500 unrelated Japanese and establishment of a Japanese reference genome sequence from long-read data have been done. We next aim to obtain genotype data for all TMM cohort participants (>150,000) using our custom SNP arrays. These data will help identify disease-associated genomic signatures in the Japanese population, while genomic data from TMM BirThree Cohort participants will be used to improve the reference genome panel. Follow-up of the cohort participants will allow us to test the genetic markers and, consequently, contribute to the realization of PHC.

Current Perspectives on Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered a delayed-type hypersensitivity reaction to drugs. They represent true medical emergencies and an early recognition and appropriate management is decisive for the survival. SJS/TEN manifest with an "influenza-like" prodromal phase (malaise, fever), followed by painful cutaneous and mucous membrane (ocular, oral, and genital) lesions, and other systemic symptoms. The difference between SJS, SJS/TEN overlap, and TEN is defined by the degree of skin detachment: SJS is defined as skin involvement of < 10%, TEN is defined as skin involvement of > 30%, and SJS/TEN overlap as 10-30% skin involvement. The diagnosis of different degrees of epidermal necrolysis is based on the clinical assessment in conjunction with the corresponding histopathology. The mortality rates for SJS and TEN have decreased in the last decades. Today, the severity-of-illness score for toxic epidermal necrolysis (SCORTEN) is available for SJS/TEN severity assessment. Drugs with a high risk of causing SJS/TEN are anti-infective sulfonamides, anti-epileptic drugs, non-steroidal anti-inflammatory drugs of the oxicam type, allopurinol, nevirapine, and chlormezanone. Besides conventional drugs, herbal remedies and new biologicals should be considered as causative agents. The increased risk of hypersensitivity reactions to certain drugs may be linked to specific HLA antigens. Our understanding of the pathogenesis of SJS/TEN has improved: drug-specific T cell-mediated cytotoxicity, genetic linkage with HLA- and non-HLA-genes, TCR restriction, and cytotoxicity mechanisms were clarified. However, many factors contributing to epidermal necrolysis still have to be identified, especially in virus-induced and autoimmune forms of epidermal necrolysis not related to drugs. In SJS/TEN, the most common complications are ocular, cutaneous, or renal. Nasopharyngeal, esophageal, and genital mucosal involvement with blisters, erosions as well as secondary development of strictures also play a role. However, in the acute phase, septicemia is a leading cause of morbidity and fatality. Pulmonary and hepatic involvement is frequent. The acute management of SJS/TEN requires a multidisciplinary approach. Immediate withdrawal of potentially causative drugs is mandatory. Prompt referral to an appropriate medical center for specific supportive treatment is of utmost importance. The most frequently used treatments for SJS/TEN are systemic corticosteroids, immunoglobulins, and cyclosporine A.

Specific association of the rs6500265 and rs9933632 single-nucleotide polymorphisms in Japanese patients with antipyretic analgesic-related Stevens-Johnson syndrome and toxic epidermal necrolysis with severe ocular involvements

A recent study using the microarray for single-nucleotide polymorphisms (SNPs) genotyping specifically designed for the Japanese population in combination with genome-wide imputation showed the association of several SNPs with cold medicine-related Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) with severe ocular complications. However, it remains to be determined whether these polymorphisms are associated with the onset of antipyretic analgesic (AA)-related SJS/TEN, the progression of severe ocular involvements (SOIs), or both AA-related SJS/TEN and SOI phenotypes. To gain a better understanding of the features of these genetic markers, we compared the allele and carrier frequencies of these SNPs among our original SJS/TEN patient groups: (a) AA-related SJS/TEN with SOIs, (b) AA-related SJS/TEN without SOIs, and (c) AA-unrelated SJS/TEN with SOIs. AA-related SJS/TEN with SOIs were found to be associated significantly with both rs6500265 [allele frequency: odds ratio (OR): 2.18; 95% confidence interval (CI): 1.30-3.65; P=0.0052; carrier frequency: OR: 2.52; 95% CI: 1.33-4.78; P=0.058] and rs9933632 (allele frequency: OR: 2.28: 95% CI: 1.37-3.79; P=0.0032; carrier frequency: OR: 2.76; 95% CI: 1.46-5.22; P=0.0031). In contrast, allele and carrier frequencies of these SNPs in patients with AA-related SJS/TEN without SOIs or with SOIs not treated with any AAs were comparable with those in healthy Japanese controls. Collectively, our findings indicate that the rs6500265 and rs9933632 SNPs could be specific markers for AA-related SJS/TEN with SOIs, suggesting that certain genetic backgrounds contribute toward the etiology of this complex syndrome.

Association of Human Leukocyte Antigen Class 1 genes with Stevens Johnson Syndrome with severe ocular complications in an Indian population

Stevens Johnson syndrome (SJS) is part of a spectrum of adverse drug reactions resulting in the destruction of skin, mucous membranes, and the ocular surface. A similar, more severe form of the disorder included in this spectrum is toxic epidermal necrolysis (TEN). Approximately 35% of patients suffer chronic sequelae such as vascularization, corneal scarring, conjunctival inversion to the cornea, keratinization, symblepharon, scarring of the palpebral conjunctiva, trichiasis, and severe dry eye. We focused on 80 Indian patients with SJS/TEN with severe ocular complications (SOC) and investigated the association of alleles at HLA -A, HLA-B and HLA-C loci; the controls were 50 healthy Indian volunteers. Genotyping at HLA-A, HLA-B, and HLA-C loci showed a significant positive association with HLA-A*33:03, HLA-B*44:03, and HLA-C*07:01 alleles, and a significant negative association with HLA-B*57:01 and HLA-C*06:02. This indicates that HLA-A*33:03, HLA-B*44:03 and HLA-C*07:01 are risk alleles, and HLA-B*57:01 and HLA-C*06:02 are protective alleles in this population. We also found that the haplotypes consisting of HLA-B*44:03 and HLA-C*07:01 were strongly associated with SJS/TEN with SOC in our Indian population (p = 1.1 × 10⁻⁷, odds ratio = 11.0). Describing the association of the haplotype could facilitate the understanding of increased risk factors for developing SJS/TEN with SOC.