Daiju Iwata

Ocular features of behçet's disease : An international collaborative study

Objective: To investigate the clinical features of ocular lesions in Behçet’s disease in different countries. Methods: A descriptive questionnaire survey was performed. Results: 25 eye centres in 14 countries returned questionnaires on prevalent cases in 2006. Clinical data were analysed on 1,465 patients with ocular lesions. Recurrent oral aphthous ulcers were reported in 94.5%, skin lesions in 69.5% and genital ulcers in 61.4%. Most of the patients had bilateral and recurrent intraocular inflammation. Poor visual acuity was seen in 18.9% in women, but 24.8% in men (p<0.01). Panuveitis was seen more in men than in women (p<0.01). 23% of the patients had visual acuity equal to or worse than 20/200 at the final visit. The patients with poor vision were more frequently in India, Iran and Japan than in other countries (p<0.01). Conclusions: We report the largest contemporary international case series of patients with ocular involvement in Behçet’s disease. Panuveitis was significantly more frequent in men than women, and men tended to have a worse visual prognosis. There were some differences in the clinical pattern of Behçet’s disease in different countries. Despite modern treatment, the disease still carries a poor visual prognosis with one-quarter of the patients blind.

Effect of high fat diet on NKT cell function and NKT cell-mediated regulation of Th1 responses.

Diet is one of the important factors that modulate immune responses. In the present study, we have examined the capacity of dietary lipids to modify immune responses in mice and we have investigated the contribution of glycolipid‐reactive natural killer T (NKT) cells in this process. Mice fed, high fat diet (HFD; 21.2% fat, 0.20% cholesterol) for 3 weeks, as compared with mice fed standard fat diet (SFD; 4.3% fat, 0.03% cholesterol), showed significantly reduced interferon‐γ production in sera at 6 or 12 h after intraperitoneal injection of an NKT cell ligand, α‐galactosylceramide. In contrast, production of interleukin‐13 was significantly higher at 2 and 6 h in HFD fed mice compared with mice on SFD. No difference was detected in the serum interleukin‐4 levels between these two groups of animals. The proportion of NKT cells in spleen and liver was reduced in mice fed HFD compared with those on SFD. In addition, activation of NKT cells assessed by up‐regulation of CD69 was suppressed specifically in liver from mice fed HFD. Recall responses of conventional T cells and delayed‐type hypersensitivity (Th1 type) against ovalbumin were significantly suppressed in mice fed HFD in comparison with those fed SFD. This suppression was not observed in CD1d−/− mice, suggesting that NKT cells in mice fed HFD played a role in suppressing Th1 responses. Taken together, our findings suggest a critical link between NKT cells, dietary lipid and adaptive immune responses.

Choroidal thickening prior to anterior recurrence in patients with Vogt–Koyanagi–Harada disease

Aim To assess choroidal thickness changes associated with anterior segment recurrences in patients with Vogt–Koyanagi–Harada (VKH) disease using enhanced depth imaging optical coherence tomography (EDI-OCT). Methods EDI-OCT images were obtained periodically from 11 patients with VKH disease (22 eyes) who were followed-up due to anterior segment recurrences. Subfoveal choroidal thickness (SCT) values at the following stages were evaluated: (1) during the remission phase, (2) 1 month before detecting the anterior recurrence, (3) during the anterior recurrence and (4) after systemic prednisolone (PSL) treatment leading to remission. In comparison with SCT values in remission as baseline, the changing ratios of SCT were statistically analysed at subsequent three stages. Results The average of the SCT changing ratios compared with the remission phase significantly increased to 1.45±0.11 during anterior segment recurrences (p=0.00044) lacking any funduscopic signs of posterior involvement. Interestingly, the average SCT ratio 1 month before detecting the recurrence had already increased to 1.30±0.08 (p=0.002). After the PSL treatment, the ratio of SCT recovered to 0.95±0.03, which was equivalent to the remission level. However, in patients with their remission SCT values less than 240 µm, the SCT ratio did not increase significantly at any time points evaluated. Conclusions The choroid in eyes with VKH disease thickened in association with the anterior segment recurrence, and this thickening was observed prior to the recurrence. EDI-OCT may be useful for detecting latent choroidal inflammation in VKH disease, whereas it may not for patients with the relatively thin choroid. Trial registration number The trial registration number of the internal review board of Hokkaido University Hospital is 014-0384.

Amelioration of Experimental Autoimmune Uveoretinitis with Nuclear Factor-κB Inhibitor Dehydroxy Methyl Epoxyquinomicin in Mice

Purpose. Experimental autoimmune uveoretinitis (EAU), a Th1/Th17 cell-mediated autoimmune disease induced in mice, serves as a model of human endogenous uveitis. In this model, proinflammatory cytokines and various stimuli activate the transcriptional factor, nuclear factor-kappaB (NF-kappaB), in the retina. The therapeutic effect of the NF-kappaB inhibitor, dehydroxy methyl epoxyquinomicin (DHMEQ), was examined on EAU. Methods. EAU was induced in B10.BR mice by K2 peptide immunization. DHMEQ (40 mg/kg/d) was administered daily by intraperitoneal injection. Clinical severity and histopathologic severity were assessed. Translocation of NF-kappaB p65 into the nucleus in EAU retina was assessed. T cells were collected from draining lymph nodes of the K2-immunized mice to examine antigen (Ag)-specific T-cell active responses and cytokine production in vitro. Results. Disease onset was significantly delayed in DHMEQ-treated mice (15.6 days) compared with untreated mice (12.6 days; P < 0.01). Histologic severity was significantly milder in DHMEQ-treated mice (score, 1.13) than in controls (score, 2.33; P < 0.05). DHMEQ suppressed the Ag-specific T-cell active responses and downregulated the productions of Th-1 type cytokines in vitro in a dose-dependent manner. Alternation was not observed in Th-2 type cytokines. Pretreatment of primed T cells or Ag-presenting cells with DHMEQ reduced T-cell activation and Th1/Th17 cytokine production. DHMEQ treatment suppressed the translocation of the NF-kappaB p65 subunit into the nuclei. Conclusions. Systemic administration of DHMEQ suppressed NF-kappaB translocation in the retina, which might have reduced the inflammation of ocular tissues. DHMEQ-mediated regulation of NF-kappaB p65 could be a therapeutic target for the control of endogenous ocular inflammatory diseases.

Low prevalence of juvenile-onset Behcet's disease with uveitis in East/South Asian people.

Aim: There is little information on the demographic and clinical characteristics of Behçet’s disease in children in different parts of the world. We sought to provide this information through a questionnaire survey of specialist eye centres. Methods: Descriptive questionnaires were collected from 25 eye centres in 14 countries. The questionnaire surveyed details of juvenile-onset Behçet’s disease with uveitis. Ethnic groups, clinical features, treatments and prognosis of paediatric-age Behçet’s disease were examined on a worldwide scale. Results: The clinical data of 135 juvenile-onset and 1227 adult-onset patients with uveitis were collected. The average age of disease diagnosis in the children was 11.7 years old. Of the ethnic groups identified 54% were from Middle East, 43% from Europe, but only 2% from East/South Asian countries. By contrast, 19.2% of adult patients were from East or South Asia. The frequency of genital ulcers in juvenile patients was 38.7%, which was significantly lower than in adult cases (53.5%; p<0.01). Conclusions: Behçet’s disease with uveitis was less common in children than in adults in East/South Asia. Although the clinical features of the systemic disease were similar in children and adults, there was a lower frequency of genital ulceration in children.

Prevention of experimental autoimmune uveoretinitis by blockade of osteopontin with small interfering RNA.

Osteopontin (OPN) is elevated during the progression of experimental autoimmune uveoretinitis (EAU) in C57BL/6 (B6) mice. Furthermore, EAU symptoms are ameliorated in OPN knockout mice or in B6 mice treated with anti-OPN antibody (M5). Recently, OPN has been shown to promote the Th1 response not only in the extracellular space as a secretory protein but also in cytosol as a signaling component. Thus, we attempted to reduce OPN in both compartments by using a small interfering RNA (siRNA) targeting the OPN coding sequence (OPN-siRNA). EAU was induced in B6 mice by immunization with human interphotoreceptor retinoid-binding protein (hIRBP) peptide sequence 1-20. The OPN- or control-siRNA was administered with hydrodynamic methods 24 h before and simultaneously with immunization (prevention regimen). When plasma OPN levels were quantified following siRNA administration with the prevention regimen, the level in the OPN-siRNA-treated group was significantly lower than that in the control-siRNA-treated group. Accordingly, the clinical and histopathological scores of EAU were significantly reduced in B6 mice when siRNA caused OPN blockade. Furthermore, TNF-alpha, IFN-gamma, IL-2, GM-CSF and IL-17 levels in the culture supernatants were markedly suppressed in the OPN-siRNA-treated group, whereas the proliferative responses of T lymphocytes from regional lymph nodes against immunogenic peptides was not significantly reduced. On the other hand, the protection was not significant if the mice received the OPN-siRNA treatment on day 7 and day 8 after immunization when the clinical symptoms appeared overt (reversal regimen). Our results suggest that OPN blockade with OPN-siRNA can be an alternative choice for the usage of anti-OPN antibody and controlling uveoretinitis in the preventive regimen.

HLA-B51 Carriers are Susceptible to Ocular Symptoms of Behçet Disease and the Association between the Two Becomes Stronger towards the East along the Silk Road: A Literature Survey

ABSTRACT Purpose: Behçet disease (BD) is predominantly found between East Asia and the Mediterranean basin along the historic Silk Road. HLA-B51 is known to be strongly associated with BD. We investigated the association between HLA-B51 and the ocular manifestations of BD among various ethnic groups. Methods: A literature survey was conducted, and 18 articles written in English were reviewed. Results: A strong correlation was found between HLA-B51 and ocular lesions in the entire cohort discussed in the reviewed articles (OR = 1.76, p = 0.000057). HLA-B51 was shown to have a strong association with ocular manifestations of BD patients in East-Eurasian (OR = 2.40, p = 0.0030) and Middle-Eurasian (OR = 1.87, p = 0.0045), but not in West-Eurasian (OR = 1.28, p = 0.35) areas. This correlation seemed to become stronger towards the east. Conclusions: A meta-analysis showed that the correlation became stronger towards the east along the Silk Road. The study results may facilitate understanding of the etiology and characteristics of BD.

Choroidal circulation impairment during the anterior recurrence of Vogt-Koyanagi-Harada disease confirmed with indocyanine green angiography and laser speckle flowgraphy.

To assess choroidal inflammation‐related circulatory changes associated with the anterior recurrence of Vogt–Koyanagi–Harada (VKH) disease, using indocyanine green angiography (ICGA) and laser speckle flowgraphy (LSFG).

Amelioration of experimental autoimmune uveoretinitis by inhibition of glyceraldehyde‐derived advanced glycation end‐product formation

AGEs are permanently modified macromolecule derivatives that form through nonenzymatic glycation of amino groups of proteins. Glycer‐AGEs are highly toxic and play an important role in the pathogenesis of chronic inflammatory diseases. However, the contribution of glycer‐AGEs to the pathogenesis of uveitis is unclear. In this study, we measured serum levels of glycer‐AGEs in 100 patients with endogenous uveitis (22 with HLA‐B27‐associated uveitis, 20 with VKH disease, 14 with Behçets disease, and 44 with sarcoidosis) and 33 healthy volunteers. We then examined the effect of the AGE inhibitor in a mouse model of human endogenous uveitis (EAU) by continuous oral administration of pyridoxamine at 200 or 400 mg/kg/day. Regardless of the etiology, serum glycer‐AGE levels were significantly higher in patients with uveitis than in healthy subjects. Treatment with 400 mg/kg pyridoxamine significantly reduced the clinical and histological severity of EAU and was accompanied by a significant decrease in serum and retinal glycer‐AGE levels and suppression of translocation of NF‐κB p65 into the nucleus of retinal cells. Serum glycer‐AGE levels may therefore serve as a biomarker of human uveitis, as well as systemic inflammation, and may contribute to the progression of uveitis, including diabetic iritis, via the activation of NF‐κB.

Experimental autoimmune uveitis and other animal models of uveitis: An update

Over the past several decades, animal models of autoimmune uveitis directed at eye-specific antigens (Ags) have been developed. These have allowed researchers to understand the basic mechanisms that lead to these diseases and also recently helped the researchers in translational research for therapeutic interventions. Experimental autoimmune uveitis (EAU) is an animal disease model of human endogenous uveitis and can be induced in susceptible animals by immunization with retinal Ags. Ever since the first description of EAU in mice in 1988, several animal models of uveitis has been described by researchers. Disease-specific model for cytomegalovirus retinitis and tubercular uveitis has evolved our understanding of these complex entities. Endotoxin induced uveitis is another useful model for anterior uveitis, which is not an autoimmune process and is triggered by injection of bacterial endotoxin (lipopolysaccharides) resulting in a rapid short lasting uveitis. The current article will give an insight into the various EAU animal models and their current implications in translational research. The article will also highlight the different grading systems for EAU in the animal model.