Norihiko Ito

Genome-wide association studies identify IL23R - IL12RB2 and IL10 as Behçet's disease susceptibility loci

Behçets disease is a chronic systemic inflammatory disorder characterized by four major manifestations: recurrent ocular symptoms, oral and genital ulcers and skin lesions. We conducted a genome-wide association study in a Japanese cohort including 612 individuals with Behçets disease and 740 unaffected individuals (controls). We identified two suggestive associations on chromosomes 1p31.3 (IL23R-IL12RB2, rs12119179, P = 2.7 × 10−8) and 1q32.1 (IL10, rs1554286, P = 8.0 × 10−8). A meta-analysis of these two loci with results from additional Turkish and Korean cohorts showed genome-wide significant associations (rs1495965 in IL23R-IL12RB2, P = 1.9 × 10−11, odds ratio = 1.35; rs1800871 in IL10, P = 1.0 × 10−14, odds ratio = 1.45).

Effect of intracameral anesthesia on the corneal endothelium

Purpose: To evaluate the effects of intracameral anesthesia on the corneal endothelium. Setting: Department of Ophthalmology, Yokohama City University School of Medicine, Yokohama, Japan. Methods: This study comprised 24 eyes of 12 white rabbits. One eye of 3 rabbits each was injected with preservative‐free lidocaine at concentrations of 0.02, 0.2, or 2% and the fellow eye injected with balanced salt solution (BSS®) as a control. The anesthetic agent was injected into the anterior chamber using a bimanual technique. Immediately after enucleation, the cornea was examined by scanning electron microscopy. Results: Scanning electron microscopy revealed no abnormal findings in the eyes injected with lidocaine 0.02 or 0.2% when compared with eyes in the control group. Scanning electron microscopy of the eyes injected with lidocaine 2% showed irregular hexagonal endothelial cells and a significant loss of microvilli. Conclusion: Intracameral anesthesia with high concentrations of lidocaine risks corneal endothelial damage but at the low concentration usually used in cataract surgery did not appear to have an adverse effect. J Cataract Refract Surg 1998; 24:1377‐1381

Genetic characterization and susceptibility for sarcoidosis in Japanese patients: risk factors of BTNL2 gene polymorphisms and HLA class II alleles.

PURPOSE Sarcoidosis is a heterogeneous and multisystem granulomatous disorder. The etiology still is uncertain, but the disease currently is thought to be triggered by various genetic as well as environmental factors. Recently, an association between sarcoidosis and the butyrophilin-like 2 (BTNL2) gene located in close proximity to the HLA-DRB1 gene was reported. The purpose of our study was to verify the relationship between BTNL2 and HLA risk alleles for the susceptibility to sarcoidosis, and to assess whether the BTNL2 association is independent of the HLA risk alleles. METHODS In our study, 11 single nucleotide polymorphisms (rs28362677, rs2076533, rs2076530, rs2076529, rs2294881, rs3763304, rs2076523, rs28362682, rs3806156, rs9268499, rs3763317), including the functional rs2076530 (G > A) of the BTNL2 gene, and HLA-DRB1 and -DQB1 alleles, were genotyped in 237 Japanese patients diagnosed with sarcoidosis and 287 healthy Japanese control subjects. RESULTS In the patient group, the HLA-DRB1*08:03 (P = 6.15 × 10(-5), odds ratio [OR] = 2.43) and BTNL2 rs2076530_A (P = 6.90 × 10(-6), OR = 1.84) were associated with disease susceptibility. Upon stratification analysis in search for a synergistic effect given the extensive linkage disequilibrium between BTNL2 rs2076530_A and HLA-DRB1*08:03, our results suggested that the risk-bearing allele of these two loci interact negatively. No significant differences were observed in allele frequencies for alleles in patients with ocular and other systemic sarcoidosis. CONCLUSIONS Our studies implicated that the HLA-DRB1 allele is a major contributing genetic factor in the development of sarcoidosis in Japan. However, further studies are needed to verify how HLA or BTNL2 alleles confer the disease phenotype, severity of sarcoidosis.

Infliximab Monotherapy Versus Infliximab and Colchicine Combination Therapy in Patients with Behçet’s Disease

Purpose: To compare infliximab monotherapy with infliximab and colchicine combination therapy in Behçet’s disease. Methods: Clinical records of 14 Behçet’s disease patients who were administered infliximab with or without colchicine were retrospectively reviewed. Patients who were given other immunosuppresants after initiation of infliximab therapy were excluded. The frequency of ocular attacks and best-corrected visual acuity were investigated. Results: Seven patients received monotherapy and 7 received combination therapy. The mean frequency of ocular attacks significantly decreased from 2.14 to 0.22 per 6 months in monotherapy group and from 2.57 to 0.18 per 6 months in combination therapy group. No significant difference was observed between both groups in the frequency of ocular attacks and in changes in best-corrected visual acuity during 0 to 24 months. Conclusions: Infliximab is as efficacious as infliximab and colchicines together in Behçet’s disease treatment. This study suggests that colchicine administration is not necessary in Behçet’s disease patients receiving infliximab.

Bilateral herpes simplex keratitis in a patient with chronic graft-versus-host disease

Purpose To describe a case of bilateral herpes simplex keratitis accompanying chronic graft-versus-host disease (GVHD). Design Observational case report. Case report An 11-year-old boy with myelocytic leukemia underwent allogeneic bone marrow transplantation. He developed symptoms of the skin, eyes, and mouth, and lip biopsy indicated chronic GVHD. Persistent keratitis with corneal filaments and neovascularization was noted in both eyes. Sodium hyaluronate, autoserum, and 0.1% fluorometholone eyedrops were instilled for approximately 2 years to treat this keratitis, and there were no other ocular changes. Bilateral herpes simplex keratitis developed with geographic ulcers after topical betamethasone therapy, but responded to acyclovir ointment. Conclusions Herpes keratitis should be considered in the differential diagnosis of bilateral keratitis in patients with reduced immunocompetence. During the course of chronic GVHD, corneal herpes may occur, so ocular treatment with topical corticosteroids should be managed by an ophthalmologist to monitor sight-threatening conditions such as corneal herpes.

Semaphorin 3A controls allergic and inflammatory responses in experimental allergic conjunctivitis

AIM To assess the efficacy of topical Semaphorin-3A (SEMA3A) in the treatment of allergic conjunctivitis. METHODS Experimental allergic conjunctivitis (EAC) mice model induced by short ragweed pollen (SRW) in 4-week-old of BALB/c mice, mice were evaluated using haematoxylin and eosin (H&E) staining, immunofluorescence and light microscope photographs. Early phase took the samples in 24h after instillation and late phase took the samples between 4 to 14d after the start of treatment. The study use of topical SEMA3A (10 U, 100 U, 1000 U) eye drops and subconjunctival injection of SEMA3A with same concentration. For comparison, five types of allergy eyedrops were quantified using clinical characteristics. RESULTS Clinical score of composite ocular symptoms of the mice treated with SEMA3A were significantly decreased both in the immediate phase and the late phase compared to those treated with commercial ophthalmic formulations and non-treatment mice. SEMA3A treatment attenuates infiltration of eosinophils entering into conjunctiva in EAC mice. The score of eosinophil infiltration in the conjunctiva of SEMA3A 1000 U-treated group were significantly lower than low-concentration of SEMA3A treated groups and non-treated group. SEMA3A treatment also suppressed T-cell proliferation in vitro and decreased serum total IgE levels in EAC mice. Moreover, Treatment of SEMA3A suppressed Th2-related cytokines (IL-5, IL-13 and IL-4) and pro-inflammatory cytokines (IFN-γ, IL-17 and TNF-α) release, but increased regulatory cytokine IL-10 concentration in the conjunctiva of EAC mice. CONCLUSIONS SEMA3A as a biological agent, showed the beneficial activity in ocular allergic processes with the less damage to the intraocular tissue. It is expected that SEMA3A may be contributed in patients with a more severe spectrum of refractory ocular allergic diseases including allergic conjunctivitis in the near future.

Investigation of β-D-Glucan Values in the Vitreous

PURPOSE beta-D-glucan values in the vitreous were investigated in order to evaluate their usefulness for the diagnosis of fungal endophthalmitis. METHODS The vitreous or vitreous perfusate were collected from twenty-six patients who underwent vitreous surgery at the Department of Ophthalmology, Yokohama City University, School of Medicine and beta-D-glucan values in these samples were examined. RESULTS Two samples with fungal endophthalmitis showed remarkably high concentration beta-D-glucan values. The other samples, except one, without fungal endophthalmitis showed significantly low beta-D-glucan values of less than 10.0 pg/ml. CONCLUSION It is expected that beta-D-glucan values in the vitreous may be more sensitive than culture methods, and may be useful for the diagnosis of fungal endophthalmitis.

Common variants in the COL4A4 gene confer susceptibility to lattice degeneration of the retina.

Lattice degeneration of the retina is a vitreoretinal disorder characterized by a visible fundus lesion predisposing the patient to retinal tears and detachment. The etiology of this degeneration is still uncertain, but it is likely that both genetic and environmental factors play important roles in its development. To identify genetic susceptibility regions for lattice degeneration of the retina, we performed a genome-wide association study (GWAS) using a dense panel of 23,465 microsatellite markers covering the entire human genome. This GWAS in a Japanese cohort (294 patients with lattice degeneration and 294 controls) led to the identification of one microsatellite locus, D2S0276i, in the collagen type IV alpha 4 (COL4A4) gene on chromosome 2q36.3. To validate the significance of this observation, we evaluated the D2S0276i region in the GWAS cohort and in an independent Japanese cohort (280 patients and 314 controls) using D2S0276i and 47 single nucleotide polymorphisms covering the region. The strong associations were observed in D2S0276i and rs7558081 in the COL4A4 gene (Pc = 5.8×10−6, OR = 0.63 and Pc = 1.0×10−5, OR = 0.69 in a total of 574 patients and 608 controls, respectively). Our findings suggest that variants in the COL4A4 gene may contribute to the development of lattice degeneration of the retina.

Staining internal limiting membrane with a mixture of BBG and sodium hyaluronate

Aims To evaluate the intraoperative applicability and safety of a mixture of brilliant blue G and sodium hyaluronate (visco-BBG) for staining the inner limiting membrane (ILM). Methods A retrospective consecutive case series. Seventy-four eyes that had undergone ILM peeling were studied. During vitrectomy, ILM peeling with visco-BBG (visco-BBG group) was performed on 40 eyes; 12 with a macular hole (MH), 26 with an epimacular membrane (ERM) and 2 with a retinal detachment due to a MH (MHRD). ILM peeling with BBG dissolved in balanced salt solution (BSS-BBG group) was performed on 34 eyes; 9 with a MH, 23 with an ERM and 2 with a MHRD. The main outcome measures were the distribution of the dye within the vitreous cavity and the retinal sensitivity in the MH patients of the two groups by microperimetry. Results The visco-BBG was injected over the retina where the ILM was intended to be peeled, and it stained the ILM in all cases. It did not disperse throughout the vitreous cavity or into the subretinal space. The BSS-BBG dispersed throughout the vitreous cavity, and its distribution was difficult to control. The two solutions did not stain the epiretinal membranes or any residual posterior hyaloid membrane. The difference in the retinal sensitivity between the two patients with MH of two groups was not significant. No complications were found in the visco-BBG group, although an accidental retinal perforation was found in one eye of the BSS-BBG group. Transmission electron microscopy confirmed that the membrane peeled was the ILM. Conclusions Visco-BBG can be a useful method to assist macular surgery and can overcome some of the disadvantages of conventional BBG solutions dissolved in BSS.