Mayumi Ueta

HLA-B locus in Japanese patients with anti-epileptics and allopurinol-related Stevens-Johnson syndrome and toxic epidermal necrolysis.

INTRODUCTION Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life-threatening severe cutaneous adverse reactions. Recently, strong associations of HLA-B*1502 and HLA-B*5801 with carbamazepine- and allopurinol-induced severe cutaneous adverse reactions were found in Han Chinese patients, respectively, but ethnic differences in the associations have been reported. The objective of this study is to clarify the involvement of HLA-B*1502 and HLA-B*5801 in Japanese SJS/TEN patients. METHODS HLA-B genotyping was performed on 58 Japanese SJS/TEN patients between July 2006 and April 2008 from multicenters in Japan. RESULTS There were no HLA-B*1502 carriers among 58 SJS/TEN patients. This patient group included seven carbamazepine-related and 11 aromatic anti-epileptic agent-related SJS/TEN patients. In addition, there were five HLA-B*5801 carriers, which included four allopurinol-related SJS/TEN patients. CONCLUSION While HLA-B*1502 is unlikely to be associated with carbamazepine-related or aromatic anti-epileptic agent-related SJS/TEN, HLA-B*5801 was significantly associated with allopurinol-related SJS/TEN in Japanese.

HLA-B*1511 is a risk factor for carbamazepine-induced Stevens-Johnson syndrome and toxic epidermal necrolysis in Japanese patients

Stevens‐Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare but life‐threatening severe cutaneous adverse reactions. Recently, strong associations of HLA‐B*1502 with carbamazepine‐induced SJS/TEN have been found in Han Chinese patients. These associations have been confirmed in several Asian populations, excluding Japanese. SJS patients carrying HLA‐B*1508, HLA‐B*1511, or HLA‐B*1521, which are members of the HLA‐B75 type along with HLA‐B*1502, were detected in studies in India and Thailand. In the current study, we genotyped the HLA‐B locus from 14 Japanese typical and atypical SJS/TEN patients in whom carbamazepine was considered to be involved in the onset of adverse reactions. Although there were no HLA‐B*1502 carriers, four patients had HLA‐B*1511. Our data suggest that HLA‐B*1511, a member of HLA‐B75, is a risk factor for carbamazepine‐induced SJS/TEN in Japanese.

Intracellularly Expressed TLR2s and TLR4s Contribution to an Immunosilent Environment at the Ocular Mucosal Epithelium

Epithelial cells are key players in the first line of defense offered by the mucosal immune system against invading pathogens. In the present study we sought to determine whether human corneal epithelial cells expressing Toll-like receptors (TLRs) function as pattern-recognition receptors in the innate immune system and, if so, whether these TLRs act as a first line of defense in ocular mucosal immunity. Incubation of human primary corneal epithelial cells and the human corneal epithelial cell line (HCE-T) with peptidoglycan or LPS did not lead to activation, at the level of DNA transcription, of NF-κB or the secretion of inflammation-associated molecules such as IL-6, IL-8, and human β-defensin-2. However, when incubated with IL-1α to activate NF-κB, the production by these cells of such inflammatory mediators was enhanced. Human corneal epithelial cells were observed to express both TLR2- and TLR4-specific mRNA as well as their corresponding proteins intracellularly, but not at the cell surface. However, even when LPS was artificially introduced into the cytoplasm, it did not lead to the activation of epithelial cells. Taken together, our results demonstrate that the intracellular expression of TLR2 and TLR4 in human corneal epithelial cells fails to elicit innate immune responses and therefore, perhaps purposely, contributes to an immunosilent environment at the ocular mucosal epithelium.

Identification of Proteins Secreted via Vibrio parahaemolyticus Type III Secretion System 1

ABSTRACT Vibrio parahaemolyticus, a gram-negative marine bacterium, is an important pathogen causing food-borne gastroenteritis or septicemia. Recent genome sequencing of the RIMD2210633 strain (a Kanagawa phenomenon-positive clinical isolate of serotype O3:K6) revealed that the strain has two sets of gene clusters that encode the type III secretion system (TTSS) apparatus. The first cluster, TTSS1, is located on the large chromosome, and the second, TTSS2, is on the small chromosome. Previously, we reported that TTSS1 is involved in the cytotoxicity of the RIMD2210633 strain against HeLa cells. Here, we analyzed proteins secreted via the TTSS apparatus encoded by TTSS1 by using two-dimensional gel electrophoresis and identified the proteins encoded by genes VP1680, VP1686, and VPA450. To investigate the roles of those secreted proteins, we constructed and analyzed a series of deletion mutants. Flow cytometry analysis using fluorescence-activated cell sorting with fluorescein isothiocyanate-labeled annexin V demonstrated that the TTSS1-dependent cell death was by apoptosis. The cytotoxicity to HeLa cells was related to one of the newly identified secreted proteins encoded by VP1680. Adenylate cyclase fusion protein studies proved that the newly identified secreted proteins were translocated into HeLa cells. Thus, these appear to be the TTSS effector proteins in V. parahaemolyticus.

Diagnosis and Treatment of Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis with Ocular Complications

PURPOSE To present a detailed clarification of the symptoms at disease onset of Stevens-Johnson syndrome (SJS) and its more severe variant, toxic epidermal necrolysis (TEN), with ocular complications and to clarify the relationship between topical steroid use and visual prognosis. DESIGN Cross-sectional study. PARTICIPANTS Ninety-four patients with SJS and TEN with ocular complications. METHODS A structured interview, examination of the patient medical records, or both addressing clinical manifestations at disease onset were conducted for 94 patients seen at Kyoto Prefectural University of Medicine. Any topical steroid use during the first week at the acute stage also was investigated. MAIN OUTCOME MEASURES The incidence and the details of prodromal symptoms and the mucosal involvements and the relationship between topical steroid use and visual outcomes. RESULTS Common cold-like symptoms (general malaise, fever, sore throat, etc.) preceded skin eruptions in 75 cases, and extremely high fever accompanied disease onset in 86 cases. Acute conjunctivitis and oral and nail involvements were reported in all patients who remembered the details. Acute conjunctivitis occurred before the skin eruptions in 42 patients and simultaneously in 21 patients, whereas only 1 patient reported posteruption conjunctivitis. Visual outcomes were significantly better in the group receiving topical steroids compared with those of the no-treatment group (P<0.00001). CONCLUSIONS Acute conjunctivitis occurring before or simultaneously with skin eruptions accompanied by extremely high fever and oral and nail involvement indicate the initiation of SJS or TEN. Topical steroid treatment from disease onset seems to be important for the improvement of visual prognosis.

Toll-like receptor 3 gene polymorphisms in Japanese patients with Stevens–Johnson syndrome

Background and aim: Stevens–Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are acute-onset mucocutaneous diseases induced by infectious agents and/or inciting drugs. Given the association between the onset of SJS/TEN and infections, the possibility that there is an association between SJS/TEN and a disordered innate immune response was considered. The first line of defence against infection is comprised of evolutionarily conserved sets of molecules, the Toll–like receptors (TLRs). TLR3 recognises double-stranded RNA associated with viral infections. Methods: The Japanese single-nucleotide-polymorphism (JSNP) database reports 7 polymorphisms consisting of 7 SNPs in the human TLR3 gene; 3 of the 7 SNPs are coded in exon regions, (ie, 293248A/G, 293391A/G and 299698T/G), and the other 4 are coded in intron regions, (ie, 294440G/C, 294732C/T, 208036T/C and 298054C/T). These 7 SNPs were analysed in 57 Japanese patients with SJS/TEN with ocular surface complications and in 160 Japanese healthy controls. Results: SNP 299698T/G and the genotype patterns of 293248A/A and 299698T/T were strongly associated with SJS/TEN. Conclusion: The results suggest that polymorphisms in the TLR3 gene could be associated with SJS/TEN in the Japanese population.

Successful Treatment of Stevens-Johnson Syndrome with Steroid Pulse Therapy at Disease Onset

PURPOSE To evaluate the visual prognosis of patients with Stevens-Johnson syndrome (SJS) and its severe variant, toxic epidermal necrolysis (TEN), followed by general and topical high-dose corticosteroids administration from disease onset. DESIGN Prospective, observational case series. METHODS Between May 1, 2003 and June 30, 2005, we enrolled 5 patients with SJS or TEN with ocular complications at the acute stage. Intravenous pulse therapy with methylprednisolone (steroid pulse therapy; 500 or 1000 mg/day for 3 to 4 days) was initiated within 4 days from disease onset. Topically, 0.1% betamethasone was applied over 5 times daily for at least 2 weeks. Visual acuity (VA) and slit-lamp microscopic appearance 1 year from disease onset were evaluated. RESULTS At the first examination, corneal or conjunctival epithelial defects and pseudomembranous conjunctivitis were present in all cases. Skin eruptions dramatically improved after steroid pulse therapy. Although ocular inflammation increased for several days, pseudomembranes disappeared and corneal and conjunctival epithelium regenerated within 6 weeks. At the chronic stage, all eyes had clear corneas with the palisades of Vogt (POV), implying the presence of corneal epithelial stem cells. Best-corrected VA was 20/20 or better in all eyes. Five eyes showed superficial punctate keratopathy. No eye had cicatricial changes except for 1 with slight fornix shortening. No significant adverse effects of steroid occurred during all clinical courses. CONCLUSIONS Steroid pulse therapy at disease onset is of great therapeutic importance in preventing ocular complications. Topical betamethasone also shows great promise for preventing corneal epithelial stem cell loss in the limbal region and cicatricial changes.

Visual Improvement after Cultivated Oral Mucosal Epithelial Transplantation

PURPOSE To report the effectiveness, disease-specific outcomes, and safety of cultivated oral mucosal epithelial sheet transplantation (COMET), with the primary objective of visual improvement. DESIGN Noncomparative, retrospective, interventional case series. PARTICIPANTS This study involved 46 eyes in 40 patients with complete limbal stem cell deficiency (LSCD) who underwent COMET for visual improvement. These LSCD disorders fell into the following 4 categories: Stevens-Johnson syndrome (SJS; 21 eyes), ocular cicatricial pemphigoid (OCP; 10 eyes), thermal or chemical injury (7 eyes), or other diseases (8 eyes). METHODS Best-corrected visual acuity (BCVA) and ocular surface grading score were examined before surgery; at the 4th, 12th, and 24th postoperative week; and at the last follow-up. Data on COMET-related adverse events and postoperative management were collected. The outcomes in each disease category were evaluated separately. MAIN OUTCOME MEASURES The primary outcome was the change in median logarithm of the minimum angle of resolution (logMAR) BCVA at the 24th postoperative week. The secondary outcome was the ocular surface grading score. RESULTS Median logMAR BCVA at baseline was 2.40 (range, 1.10 to 3.00). In SJS, logMAR BCVA improved significantly during the 24 weeks after surgery. In contrast, the BCVA in OCP was improved significantly only at the 4th postoperative week. In 6 of the 7 thermal or chemical injury cases, logMAR BCVA improved after planned penetrating keratoplasty or deep lamellar keratoplasty. Grading scores of ocular surface abnormalities improved in all categories. Of 31 patients with vision loss (logMAR BCVA, >2) at baseline, COMET produced improvement (logMAR BCVA, ≤2) in 15 patients (48%). Visual improvement was maintained with long-term follow-up (median, 28.7 months). Multivariate stepwise logistic regression analysis showed that corneal neovascularization and symblepharon were correlated significantly with logMAR BCVA improvement at the 24th postoperative week (P=0.0023 and P=0.0173, respectively). Although postoperative persistent epithelial defects and slight to moderate corneal infection occurred in the eyes of 16 and 2 patients, respectively, all were treated successfully with no eye perforation. CONCLUSIONS Long-term visual improvement was achievable in cases of complete LSCD. Cultivated oral mucosal epithelial sheet transplantation offered substantial visual improvement even for patients with end-stage severe ocular surface disorders accompanying severe tear deficiency. Patients with corneal blindness such as SJS benefited from critical improvement of visual acuity. FINANCIAL DISCLOSURE(S) The author(s) have no proprietary or commercial interest in anymaterials discussed in this article.

Innate immunity of the ocular surface

The ocular surface epithelium serves a critical function as the defensive front line of the innate immune system. While the detection of microbes is arguably its most important task, an exaggerated host defense reaction to endogenous bacterial flora may initiate and perpetuate inflammatory mucosal responses. The ability of cells to recognize pathogen-associated molecular patterns (PAMPs) mainly depends on the expression of a family of Toll-like receptors (TLRs). A healthy ocular surface is not inflammatory, even though ocular surface epithelium is in constant contact with bacteria and bacterial products. In this study, we show that human ocular surface epithelial cells, both corneal and conjuctival epithelial cells, respond to viral double-stranded RNA mimic polyI:C to produce pro-inflammatory cytokines through TLR3, while they fail to respond functionally to lipopolysaccharide, a TLR4 ligand. Moreover, human ocular surface epithelium responds to flagellins from ocular pathogenic, but not ocular non-pathogenic bacteria, to produce pro-inflammatory cytokines through TLR5. Thus, ocular surface epithelial cells selectively respond to microbial components and induce limited inflammation; immune-competent cells can recognize microbial components through TLRs and induce the inflammation. The unique innate immune response of the ocular surface epithelium may contribute to its coexistence with commensal bacteria. Inflammatory bowel disease is thought to result from an abnormal response to the gut microbiota. Thus, we also considered the possibility of an association between ocular surface inflammation and a disordered innate immune response. IkappaBzeta is important for TLR signaling, in mice, its knock-out produced severe, spontaneous ocular surface inflammation, the eventual loss of goblet cells, and spontaneous perioral inflammation, suggesting that dysfunction/abnormality of innate immunity can lead to ocular surface inflammation.

Prostaglandin E2–EP3 signaling suppresses skin inflammation in murine contact hypersensitivity

BACKGROUND Prostaglandin (PG) E(2) exerts a variety of actions through 4 G protein-coupled receptors designated as EP(1), EP(2), EP(3), and EP(4). We have reported that PGE(2) acts on EP(3) in airway epithelial cells and exerts anti-inflammatory actions in ovalbumin-induced murine allergic asthma. Although EP(3) is also expressed in skin and PGE(2) is produced abundantly during skin allergic inflammation, the role of PGE(2)-EP(3) signaling in skin allergic inflammation remains unknown. OBJECTIVE We sought to investigate whether PGE(2)-EP(3) signaling exerts anti-inflammatory actions in skin allergic inflammation. METHODS We used a murine contact hypersensitivity (CHS) model and examined the role of EP(3) by using an EP(3)-selective agonist, ONO-AE-248 (AE248), and EP(3)-deficient mice. The inflammation was evaluated by the thickness and histology of the hapten-challenged ear. Inflammation-associated changes in gene expression and effects of AE248 were examined by means of microarray analysis of the skin. Localization of EP(3) was examined by staining for beta-galactosidase knocked in at the EP(3) locus in EP(3)-deficient mice. EP(3) action was also examined in cultured keratinocytes. RESULTS Administration of AE248 during the elicitation phase significantly suppressed CHS compared with that seen in vehicle-treated mice. Microarray analysis revealed that administration of AE248 inhibited the gene expression of neutrophil-recruiting chemokines, including CXCL1, at the elicitation site. X-gal staining in EP(3)-deficient mice revealed EP(3) expression in keratinocytes, which was further confirmed by anti-EP(3) antibody in wild-type mice. In cultured keratinocytes AE248 suppressed CXCL1 production induced by TNF-alpha. CONCLUSION PGE(2)-EP(3) signaling inhibits keratinocytes activation and exerts anti-inflammatory actions in murine CHS.