Hyperreactivity of neutrophils and abnormal T cell homeostasis: a new insight for pathogenesis of Behçet's disease

The relationship between HLA-B*51 subtypes, clinical manifestations and severity of Behçet's syndrome: a large Italian cohort study

Objectives

Behçet's syndrome (BS) is a chronic multisystemic inflammatory disorder of unclear aetiology. The predominant BS susceptibility locus was identified within HLA-B*51. HLA-B*51 subtypes were previously studied as disease susceptibility markers. Few data are now available about the relationship between B*51 subtypes and clinical phenotype. The aim of this study was to genotype HLA-B*51 subtypes in a series of Italian BS patients and to test the association with clinical manifestations and disease severity (Krause's index).

Methods

HLA-B*51 subtype genotyping for 63 alleles (B*51:01-B*51:63) was performed by PCR after DNA extraction from whole blood of BS patients. The correlation of disease clinical manifestations and severity (Krause's index) with the HLA-B*51 allele and its subtypes was analysed.

Results

We enrolled 241 (140 male and 101 female) BS patients, and HLA-B*51 frequency was 62.7% (151 of 241). One hundred and eight of the HLA-B*51-positive patients carried the B*51:01 subtype (108 of 151, 71.5%), 39 of 151 (25.8%) the B*51:08 subtype, 2 of 151 (1.3%) the B*51:02 subtype, 1 of 151 (0.7%) the B*51:05 subtype, and 1 of 151 (0.7%) the B*51:07 subtype. We found that ocular involvement was statistically associated with HLA-B*51 positivity and with B*51:01 and B*51:08 subtypes (P < 0.05). We also found that disease severity was higher in HLA-B*51-positive patients than in negative patients, but without statistical significance (median Krause's index 5.1 vs 4.1, P > 0.05).

Conclusion

Here, we confirm a high frequency of the HLA-B*51 allele in our group of BS patients. B*51:01 and B*51:08 were found to be the most common subtypes, and an association of both subtypes with ocular involvement was also underlined.

IL-8 Triggers Neutrophil Extracellular Trap Formation Through an Nicotinamide Adenine Dinucleotide Phosphate Oxidase- and Mitogen-Activated Protein Kinase Pathway-Dependent Mechanism in Uveitis

Purpose

To explore the mechanism underlying IL-8-induced neutrophil extracellular trap (NET) formation in patients with ocular-active Behçet's disease (BD) and the effect of inhibiting NET formation on the severity of inflammation in experimental autoimmune uveitis (EAU) mice.

Methods

The serum extracellular DNA and neutrophil elastase (NE) and IL-8 levels in patients with ocular-active BD, the expression of myeloperoxidase, NE, and histone H3Cit in IL-8-induced neutrophils isolated from healthy controls, and the effects of NETs on HMC3 cells were detected. Female C57BL/6J mice were immunized with IRBP651-670 to induce EAU and EAU mice received intravitreal injection of the CXCR2 (IL-8 receptor) antagonist SB225002 or PBS. The serum levels of extracellular DNA, NE, and keratinocyte-derived chemokine (the mouse ortholog of human IL-8) and expression of myeloperoxidase, NE, and histone H3Cit in mouse retinas were detected. Disease severity was evaluated by clinical and histopathological scores.

Results

Serum keratinocyte-derived chemokine expression levels in EAU mice and IL-8 expression levels in patients with ocular-active BD increased. IL-8 notably increased NET formation in a dose-dependent manner through an nicotinamide adenine dinucleotide phosphate oxidase and mitogen-activated protein kinase pathway dependent mechanism. IL-8-induced NET formation damaged HMC3 cells in vitro. Pretreatment with SB225002 notably ameliorated the production of NETs in EAU mice.

Conclusions

Our data confirm that NET formation is induced by IL-8. IL-8-induced NET formation was found to be related to mitogen-activated protein kinase and nicotinamide adenine dinucleotide phosphate pathways. Pretreatment with the CXCR2 antagonist SB225002 alleviated neutrophil infiltration and suppressed NET formation in EAU mice.

The proportion of C1q-high and ISG15-high monocytes in the skin of patients with Behçet disease

Behçet disease (BD) is a chronic systemic vasculitis that is clinically characterized by recurrent oral ulcers, genital ulcers, uveitis, and skin lesions. Here, we conducted bulk RNA-seq of skin samples from 4 BD patients and 4 normal controls (NCs). A total of 260 differentially expressed genes (DEGs), including 99 upregulated and 161 downregulated genes, were detected in the skin lesions of BD patients compared to NCs. These DEGs were mainly enriched in the following biological processes: the activation and migration of immune cells, the release of proinflammatory factors, and the IFN-γ signaling pathway. The top upregulated DEGs were CXCL10, CXCL9, FCGR3A, GBP5, GBP4, LILRB2, ADIPOQ, PLIN1, SLC43A2, and MYO1G. Using the deconvolution method CIBERSORT, we analyzed the immune cells subtypes in the skin of BD by integrating the single cell RNA-seq data from PBMC (GSE198616) and bulk RNA-seq data of skin. There was a higher proportion of C1q+ and ISG15 + monocyte subtypes in skin of BD. IHC staining of CD14 and CD16 showed that the monocyte number increased in the skin of BD. IF staining confirmed there was a higher proportion of the C1Q + Mono and ISG15 + Mono subsets in the skin of BD patients. Moreover, we analyzed the average expression level of the top upregulated genes in immune cell types found in PBMC from BD patients and NCs. Almost all the top upregulated genes expressed in monocytes. CXCL10 was specifically expressed in ISG15 + monocyte, and GBP5, GBP4 and IFI44L were expressed more strongly in ISG15 + monocytes. LILRB2 was expressed more strongly in CD16⁺ monocytes and C1Q + monocytes. In conclusion, our study identified that the IFN-γ pathway was activated in skin of BD and the proportion of C1q+ and ISG15 + monocyte subtype increased in the skin of BD.

The pro-inflammatory effect of triglyceride on human CD4+ T cells and experimental autoimmune uveitis

Aberrant lipid metabolism plays a role in inflammation and progression of autoimmune diseases but the definite mechanism remains unclear. In this study we investigate lipidomic profiles in Behçet's disease (BD) and the role of triglyceride (TAG) in the pathogenesis of autoimmune uveitis. Lipidomics revealed a distinct lipid metabolite profile including increased TAG metabolites in plasma of active BD patients. TAG could stimulate the proliferation, IL-17 and IFN-γ expression by CD4⁺ T cells and Th1, Th17 cell differentiation in vitro, but did not influence neutrophils. A922500 inhibited the TAG generation, ameliorated the EAU severity, decreased Th17 frequency and IL-17 expression by CD4⁺ T cells in vivo. The proteomocis analysis showed an up-regulation of apoptosis-related protein, Pik3r2, in CD4⁺ T cells from A922500-treated mice. In conclusion, TAG can stimulate human CD4⁺ T cells and the inhibition of its generation could significantly ameliorate EAU activity in association with down-regulated Th17 cell response.

Novel Insights Into Gene Signatures and Their Correlation With Immune Infiltration of Peripheral Blood Mononuclear Cells in Behcet's Disease

Background

Behcet’s disease (BD) is a chronic inflammatory disease that involves systemic vasculitis and mainly manifests as oral and genital ulcers, uveitis, and skin damage as the first clinical symptoms, leading to gastrointestinal, aortic, or even neural deterioration. There is an urgent need for effective gene signatures for BD’s early diagnosis and elucidation of its underlying etiology.

Methods

We identified 82 differentially expressed genes (DEGs) in BD cases compared with healthy controls (HC) after combining two Gene Expression Omnibus datasets. We performed pathway analyses on these DEGs and constructed a gene co-expression network and its correlation with clinical traits. Hub genes were identified using a protein–protein interaction network. We manually selected CCL4 as a central hub gene, and gene-set enrichment and immune cell subset analyses were applied on patients in high- and low-CCL4 expression groups. Meanwhile, we validated the diagnostic value of hub genes in differentiating BD patients from HC in peripheral blood mononuclear cells using real-time PCR.

Results

Twelve hub genes were identified, and we validated the upregulation of CCL4 and the downregulation of NPY2R mRNA expression. Higher expression of CCL4 was accompanied by larger fractions of CD8 + T cells, natural killer cells, M1 macrophages, and activated mast cells. Receiver operator characteristic curves showed good discrimination between cases and controls based on the expression of these genes.

Conclusion

CCL4 and NPY2R could be diagnostic biomarkers for BD that reveal inflammatory status and predict vascular involvement in BD, respectively.

Changes in the Gut Microbiome Contribute to the Development of Behcet's Disease via Adjuvant Effects

Behcet’s disease (BD) is associated with considerable gut microbiome changes. However, it still remains unknown how the composition of the gut microbiome exactly affects the development of this disease. In this study, transplantation of stool samples from patients with active ocular BD to mice via oral gavage was performed. This resulted in decreases of three short chain fatty acids (SCFAs) including butyric acid, propionic acid and valeric acid in the feces of the BD-recipient group. Intestinal barrier integrity of mice receiving BD feces was damaged as shown by a decreased expression of tight junction proteins and was associated with the release of Lipopolysaccharides (LPS) in the circulation. The mice also showed a higher frequency of splenic neutrophils as well as an enrichment of genes associated with innate immune responses in the neutrophils and CD4 + T cells as identified by single cell RNA sequencing. Analysis of neutrophils and T cells functions in these mice showed an enhanced mesenteric lymph node and splenic Th1 and Th17 cell differentiation in association with activation of neutrophils. Transplantation of BD feces to mice and subsequent induction of experimental uveitis (EAU) or encephalomyelitis (EAE) led to an exacerbation of disease in both models, suggesting a microbial adjuvant effect. These findings suggest that the gut microbiome may regulate an autoimmune response via adjuvant effects including increased gut permeability and enhancement of innate immunity.

Assessment of Cytokine Release against Oral Mucosal Cell Line Culture (TR146) Stimulated by Neutrophil Elastase Associated with Behcet's Disease

Aim

Cytokines and chemokines may be involved in the onset of oral ulcer in Behcet's disease. The aim of our study is to assess the cytotoxic effects of proinflammatory cytokines and chemokines on reconstructed oral mucosal cell line (TR146) when treated with different concentrations of neutrophil elastase (NE).

Objective

For this purpose, a culture of the oral mucosal model (OMM) prepared from a cell line derived from an oral squamous cell carcinoma of buccal mucosa (TR146) is treated with different concentrations of neutrophil elastase. The cultures were incubated for 4- and 24-hour intervals and designed as follows: culture + artificial saliva served as the negative control; culture + 0.01% SLS (sodium lauryl sulphate) served as the positive control; and culture + NE (10, 50, 100, and 200 nM) served as the treated group.

Materials and Methods

We used sandwich ELISA technique to isolate IL-1β (interleukin 1β), IL-8, and TNF-α (tumor necrosis factor).

Results

We found no significant level of IL-8 and TNF-α when treated with different concentrations of neutrophil elastase after 4- and 24-hour incubation. The IL-1β level was slightly higher when treated with 100 and 200 nM NE after 24 hours of incubation although a significantly high level was observed at 100 nM NE after 4 hours of incubation. Hence, we found an increase in the level of IL-1β when stimulating the reconstructed oral mucosal model (OMM) with different concentrations of NE. This is a preliminary in vitro study; however, further research is required to evaluate the cytotoxic effects of cytokines and chemokines released when treated with NE. Moreover, high concentrations of NE are recommended to stimulate the release of cytokines and chemokines against the OMM.

Behçet's Disease and Etanercept: Eighty Weeks of Experience

Behçet's disease (BD) is a chronic, relapsing inflammatory disease that involves multiple organs. Besides standard therapy, some patients with severe, non-responding disease experienced therapeutic blockage of the activity of TNF with encouraging results. We report the case of a patient affected with BD refractory to Ciclosporin, azathioprine and corticosteroid therapy with orogenital ulcerations, optic nerve ischemia, arthritis and erythema nodosum. The patient was treated with etanercept, a TNF-α blocker, 25 mg twice a week. From the second administration of etanercept, the patient showed an improvement in oral and genital ulcers, of erythema nodosum, and in visual acuity. ESR and CRP also showed a dramatic reduction returning to normal, and after eight weeks immunosuppressive therapy could be discontinued because of complete remission of oral-genital ulcers and of erythema nodosum. From week 24 to the last control carried out at week 80, the patient showed clinical and laboratory disease remission. Etanercept long-term therapy was demonstrated to be safe and effective in our patient with refractory BD, and allowed to spare steroids and other immunosuppressive drugs, thus preventing the related side-effects.

Behçet’s disease and cardiovascular involvement

Behcet’s disease (BD) is a multisystem disease of unknown etiology characterized by chronic relapsing orogenital ulcers, uveitis and systemic involvement including articular, gastrointestinal, cardiopulmonary, neurological and vascular pathology. The incidence and nature of cardiac involvement are not clearly elucidated. Cardiovascular manifestations have been reported in 7-46% of patients and mortality occurs in up to 20% of those patients with marked vascular involvement. Sporadic cases of endocarditis, myocarditis, pericarditis, acute myocardial infarction, aortic aneurysm, ventricular thrombosis, congestive cardiomyopathy and valvular dysfunction have been reported. This review discusses the general aspects of the pathogenic mechanisms and clinical features cardiovascular involvement in BD, and provides the data of cardiovascular involvement in a cohort of Italian BD patients.

Ocular Behçet disease: current therapeutic approaches

PURPOSE OF REVIEW

To alert physician to timely recognition and current treatment of recurrent hypopyon iridocyclitis or panuveitis in ocular Behçet disease (OBD).

RECENT FINDINGS

Interferon-α, rituximab, intravitreal triamcinolone, and biological response modifiers by tumor necrosis factor inhibitors such as infliximab and adalimumab are being used increasingly for the treatment of severe sight-threatening ocular inflammation including retinal vasculitis and cystoid macular edema (CME).

SUMMARY

Biological agents offer tremendous potential in the treatment of OBD. Given that OBD predominantly afflicts the younger adults in their most productive years, dermatologist, rheumatologist, internist, or general practitioners supervising patients with oculo-articulo-oromucocutaneous syndromes should be aware of systemic Behçet disease. Early recognition of ocular involvement is important and such patients should strongly be instructed to visit immediately an ophthalmologist, as uveitis management differs from extraocular involvements with high ocular morbidity from sight-threatening complications due to relapsing inflammatory attacks in the posterior segment of the eye. A single infliximab infusion should be considered for the control of acute panuveitis, whereas repeated long-term infliximab infusions were proved to be more effective in reducing the number of episodes in refractory uveoretinitis with faster regression and complete remission of CME.

Serum galectin-3 levels in patients with Behçet's disease: association with disease activity over a long-term follow-up

BACKGROUND

There is a need for a laboratory marker that correlates with the clinical activity of Behçet's disease (BD).

OBJECTIVE

We aimed to investigate whether serum galectin-3 (Gal-3) levels were affected during the course of the disease with regard to disease activity.

METHODS

A total of 131 subjects were involved in the study as follows: Group 1: BD active (n = 39); Group 2: BD inactive (n = 31); Group 3: Disease controls with leucocytoclastic vasculitis confirmed with a skin biopsy (n = 22); and Group 4: Healthy control subjects (n = 39). The BD patients were followed regularly and samples were taken in their active and inactive periods of the disease over a 2-year period.

RESULTS

Serum Gal-3 levels were significantly higher in active BD patients (mean 2.38) than inactive BD patients (mean 0.63; P < 0.0001) and the healthy control subjects (mean 0.75; P < 0.0001). There was no significant difference between the leucocytoclastic vasculitis and active BD patients (P = 0.093). Serum Gal-3 levels were positively correlated with clinical activity scores of active BD patients (r = 0.66, P < 0.0001). In addition, the Gal-3 levels were significantly higher in the active disease period when compared with the inactive period during the follow-up. There were no significant differences between the two inactive periods of the disease among the same patients. Further analyses revealed that patients with vascular involvement had significantly higher Gal-3 levels than the other active BD patients (mean 7.57; P = 0.007).

LIMITATIONS

The limitation of the study is the small number of patients with vascular involvement in the active BD patient group.

CONCLUSION

Gal-3 levels are correlated with the activity of Behçet's disease especially with the vascular involvement.

Genetic susceptibility to Behcet's disease: role of genes belonging to the MHC region

OBJECTIVE

To review the progress in the field of MHC-related genetic susceptibility to Behçet's disease (BD).

METHOD

Systematic review of the English literature between 1 January 1980 and 31 January 2010 using Medline. Case-control, population-based, observational cohort studies investigating the association between BD and HLA-B*51 subtypes, classical and non-classical HLA alleles and other HLA-related genes were selected. The geographical distribution of BD and these susceptibility genes was also taken into consideration. Case and familial case reports were excluded except for case series with more than two patients.

RESULTS

Ninety articles plus 17 obtained from other sources were included in the systematic review. We have found high evidence that a core component of genetic susceptibility to BD is within the MHC region being primarily related to an HLA-B*51 subtype: HLA-B*5101/B*510101. Moreover, HLA-A*26, HLA-B*15, HLA-B*5701 and TNF-α -1031C were independently associated with BD. Data suggest that other HLA (HLA-C, HLA-DR) and HLA-related [MHC Class I chain-related gene A (MIC-A), TNF-α] genes may play a role in BD co-susceptibility or pathogenesis. Finally, the distinctive geographical distribution of BD suggested an evolutionary selection of HLA-B*51 subtypes as the major susceptibility factors for BD.

CONCLUSION

Further studies must be addressed to clarify the functional relevance of the different genes found to be associated with disease susceptibility and the potential interactions between genes located within and outside the MHC region.

Vitamin levels in Behçet's disease

OBJECTIVE

To determine the role of oxidative stress and the antioxidant defense mechanism in the etiopathogenesis of active and inactive Behçets disease. In line with this objective, the present study aimed to examine the levels of nitric oxide (NO) and malondialdehyde (MDA), which are the end products of oxidant stress, and vitamins, which are non-enzymatic antioxidants, for the diagnosis and particularly the follow-up of Behçet's disease.

MATERIALS AND METHODS

The study group consisted of a total of 60 individuals: 40 of whom were Behçet's disease patients and 20 were healthy individuals. Of the 40 Behçet's patients, 29 had the active and 11 had the inactive (stable) form of the disease.

RESULTS

Although plasma MDA and NO (its stable form nitrite) levels in the total patient group were statistically significantly higher than those in the control group (p<0.06), there was no statistically significant difference as such between inactive Behçet's patients and the control group (p>0.05). Vitamin E, C, B1, B2 and flavin mononucleotide (FMN) values were significantly lower in the patient group in comparison with the control group (p<0.05). There was no statistically significant difference in other vitamin values.

DISCUSSION

It is contemplated that measurement of such oxidative stress factors as MDA and NO and an accompanying evaluation of the antioxidant defense system can be significant in the diagnosis and treatment follow-up of Behçet's disease.

Antitumor necrosis factor-alpha therapy for early postoperative recurrence of gastrointestinal Behçet's disease: report of a case

Behçet's disease is a chronic, relapsing, systemic inflammatory disease characterized by recurrent oral and genital ulcers, skin lesions, and ocular lesions. Gastrointestinal tract is occasionally involved in Behçet's disease, and the typical gastrointestinal lesions are punched-out, discrete mucosal ulcerations. Corticosteroids, 5-aminosalicylic acid derivatives, thalidomide, and immunomodulators have been used to treat Behçet's disease. Some patients with gastrointestinal Behçet's disease undergo surgical management because of the refractoriness to these medical measures or complications, such as perforation and bleeding. Even after successful surgery, postoperative complications, such as poor healing of the anastomosis site and postoperative ulcer recurrence, are so common that repeated operations are frequently required. However, there have been few reports addressing the most effective way to reduce and treat postoperative complications and recurrences. We describe a patient with Behçet's disease involving the distal ileum, who was treated with infliximab as rescue therapy of an unhealed anastomosis site and early recurrent ulcers after a distal ileocecectomy because of persistent bleeding. Abdominal pain from recurrent ulcers improved by the fifth day after the infliximab infusion and almost disappeared by the second week. An ileocolonoscopy performed 15 days after the infliximab infusion showed near complete healing of the recurrent ulcers. This report suggests that infliximab may be an effective novel therapy for the management of early postoperative complications and recurrences in gastrointestinal Behçet's disease.

Myocardial Functional and Textural Findings of the Right and Left Ventricles and Their Association with Cellular Adhesion Molecules in Behçet's Disease

AIM

This study was designed to assess whether ultrasonic reflectivity, evaluated by integrated backscatter analysis was associated with the severity of inflammation and diastolic dysfunction of the left (LV) and right ventricles (RV) in Behçet's disease (BD).

METHODS

The study consisted of 20 patients with BD and 18 healthy controls. The expression of CD11b and CD63 on the surface of granulocytes and monocytes were measured by flow cytometry. RV and LV diastolic functions were assessed by tricuspid and mitral annular tissue Doppler recordings, respectively. Backscatter cyclic variation (CV) and maximal intensity (IB) were measured in RV lateral wall, interventricular septum, and posterior LV wall from parasternal long-axis view, apex from apical four-chamber view, anterior, inferior, and lateral LV walls from parasternal short axis view.

RESULTS

The mean fluorescence intensity (MFI) of CD11b on granulocytes and CD63 on monocytes in BD patients was higher than those of controls. Patients with BD had smaller mitral and tricuspid annular early diastolic wave velocities and early/late diastolic wave velocity ratios (E/A) than controls. MFI of CD11b and CD63 was inversely correlated with tricuspid and mitral annular E/A in BD patients. CV of RV and global CV of LV were found to be diminished in BD patients than controls. CV of RV and global CV of LV showed a direct correlation with tricuspid and mitral annular E/A ratio, respectively.

CONCLUSION

There is an association between the levels of cellular adhesion molecules, deterioration of diastolic function, and altered myocardial ultrasonic reflectivity in BD.

The role of chemokines and their receptors in uveitis

T-cell-dependent immunological events are increasingly being regarded as extremely important in the pathogenesis of uveitis. Several studies have also shown that macrophages are major effectors of tissue damage in uveitis. Neutrophils are also thought to play a central role in the pathogenesis of Behçet's disease. Chemokines are a superfamily of 8 to 10-kDa secreted proteins that direct the recruitment of leukocytes to sites of inflammation. The specific biological effects of chemokines are mediated by a family of seven transmembrane-spanning G-protein-coupled receptors. Recent studies of animals and humans suggest that chemokines and their receptors play a key role in leukocyte recruitment into the eye in uveitis. A strategy for blocking chemokines or chemokine receptors could be a new approach for treatment of uveitis.

Possibility of inducing anterior chamber-associated immune deviation by TGF-β2 treatment of monocytes isolated from Behcet's patients

Murine macrophages treated with TGF-beta2 are capable of inducing anterior chamber-associated immune deviation (ACAID), and these macrophages are characterized by impaired IL-12 production and CD40 expression, consequently failing to promote Th1 cell differentiation. In this study, we investigated whether human monocytes can also acquire the specific functions by TGF-beta2 treatment, even when the monocytes are isolated from patients with Behcet's disease (BD). Adherent monocytes isolated from peripheral blood mononuclear cells (PBMC) of 16 BD patients and 16 healthy controls, were cultured overnight with or without 5 ng/ml of TGF-beta2. Then, TGF-beta2-treated or untreated adherent cells were co-cultured with allogeneic CD4(+) T cells obtained from healthy subjects. TGF-beta2 treatment inhibited the abilities of adherent monocytes obtained from BD patients to stimulate the proliferation and IFN-gamma production of allogeneic CD4(+) T cells. The reduced IFN-gamma production was also confirmed by IFN-gamma mRNA expression in the co-cultured T cells. IL-12 production and CD40 molecule expression by adherent monocytes obtained from BD patients were strikingly reduced by TGF-beta2 treatment. These results suggest a possibility that adherent monocytes isolated from BD patients may acquire a property to induce ACAID by treatment with TGF-beta2.

Chemokines and gelatinases in the aqueous humor of patients with active uveitis

PURPOSE

To investigate the involvement of the chemokines CXCL10/IP-10, CXCL11/I-TAC, CXCL8/1L-8, CXCL6/GCP-2, CCL3/MIP-1alpha, and CCL18/PARC, and gelatinases A and B in uveitis.

DESIGN

Prospective, experimental, case-control study.

METHODS

Aqueous humor samples from 30 patients with active uveitis, and 14 control patients and paired serum samples were assayed for chemokines with specific enzyme-linked immunosorbent assays (ELISAs) and for gelatinase levels by quantitative zymography.

RESULTS

In control AH, none of the chemokines was detected. Gelatinase A was detected in all samples, and gelatinase B was detected in only one sample. In patients with uveitis, IP-10 was detected in all AH samples, whereas I-TAC, IL-8, GCP-2, MIP-1alpha, and PARC were detected in three, 16, six, two, and 12 samples, respectively. IP-10 levels were significantly higher in AH samples than those of serum (P =.006). Gelatinase A was detected in 29 AH samples and gelatinase B was detected in 26 samples. Gelatinase A levels were significantly higher in AH samples from patients than those of controls (P <.0001). In 11 AH samples, gelatinase B was detected in complex with lipocalin (NGAL). Disease activity correlated significantly with the levels of IP-10 (r =.627; P <.0001), gelatinase A (r =.508; P =.002), gelatinase B (r =.685; P <.0001), and NGAL-gelatinase B complex (r =.595; P <.0001).

CONCLUSIONS

These data suggest a pathogenic role of the T lymphocyte chemoattractant IP-10 and gelatinases in the recruitment and activity of T cells into the eye in patients with uveitis and in the pathogenesis of uveitis.

Immunopathology of the noninfectious posterior and intermediate uveitides

The posterior and intermediate uveitides share an underlying immune etiology; however, they can be clinically and immunopathologically distinguished. Although the initiating stimuli for posterior and intermediate uveities are not known, it is believed that an exogenous agent (such as a bacterium or a virus) or an endogenous molecule may induce disease. In either case, T-helper lymphocytes in conjunction with human leukocyte antigens are likely to be involved. This review examines the epidemiology, histology, immunopathology, and theories of pathogenesis of several posterior and intermediate uveitides, including sympathetic ophthalmia, Vogt-Koyanagi-Harada syndrome, Behçet's disease, sarcoidosis, intermediate uveitis, white dot syndromes, and birdshot retinochoroidopathy.

Potential new therapeutic options in Behçet's syndrome

Behçet's syndrome is a multisystem disorder that causes orogenital ulceration, skin lesions and intraocular inflammation with uveitis and retinal vasculitis. A proportion of affected individuals also develop vascular and central nervous system manifestations, with significant morbidity and mortality. Although the aetiopathogenesis of Behçet's syndrome is poorly understood, the condition is considered to be driven, at least in part, by autoimmune mechanisms. Conventional therapy relies on available anti-inflammatory and immunomodulatory agents, and, in view of the paucity of controlled clinical trials, it is to a large extent empirical. Oral ulcers can often be treated by topical application of corticosteroids. In addition to corticosteroids, agents used to treat ocular inflammation and significant systemic manifestations include colchicine, thalidomide, azathioprine, mycophenolate mofetil, cyclosporin, tacrolimus, cyclophosphamide and chlorambucil. The response to these agents is variable and there is a distinct need for more effective rational treatment. Over the last decade, a number of open studies have produced promising results using recombinant interferon-alpha preparations. Evaluating, in a methodical manner, the other new biological agents that are becoming available for the treatment of inflammatory diseases offers great promise, not only for effective management but also for providing insights into aetiopathogenesis.

Possible physiological roles of proteolytic products of actin in neutrophils of patients with Behçet's disease

A truncated actin with an N-terminus of Met-44 is known to be selectively increased in neutrophils of patients with Behçet's disease and to be generated proteolytically by PMN-elastase (Yamashita S. et al., Biol. Pharm. Bull., 23, 519-522 (2000); Biol. Pharm. Bull., 24, 119-122 (2001)). In this study, the functions of the N-terminal peptide consisting of Asp-2 to Val-43 of beta-actin (42-merP) and the truncated actin with an N-terminus of Met-44 were examined. We first confirmed that the 42-merP existed in the patient plasma. The motility of human peripheral blood neutrophils and neutrophilic granulocytes differentiated from HL-60 cells was suppressed by the 42-merP. Furthermore, when neutrophil-like cells from HL-60 cells were preincubated with 10 nm 42-merP, migration of the cells induced by chemotactic factors such as fMLP and IL-8 was suppressed. The release of PMN-elastase, which is a neutrophil granular enzyme that is responsible for the production of the 42-merP and truncated actin, was suppressed by pretreating the neutrophils with 42-merP before fMLP-stimulation. The truncated actin was unable to polymerize in 0.1 M KCl, suggesting that the increase of truncated actin damages the reconstitution capacity of actin in neutrophils of the patients. These results suggest that the increase of 42-merP and truncated actin in patients with Behçet's disease changes functions of neutrophils

The evaluation of lipid peroxidation and adenosine deaminase activity in patients with Behçet's disease

OBJECTIVE

Despite unknown etiology, immunologic alterations and neutrophil hyperfunctions may be involved in the etiopathogenesis of Behçet's Disease (BD). The purpose of the study was to investigate whether adenosine deaminase (ADA) activity, accepted as a nonspecific marker of T lymphocyte activation, may have a potential role in BD, and also may be related to the production of reactive oxygen species (ROS) by neutrophils.

DESIGN AND METHODS

ADA activities and malondialdehyde (MDA; endproduct of lipid peroxidation induced by ROS) levels in both plasma and erythrocytes were spectrophotometrically measured in 25 patients with BD and also in 25 healthy controls.

RESULTS

ADA activity was found to be higher in plasma, but lower in erythrocytes; plasma and erythrocyte MDA levels were higher in BD patients than those of controls. In addition, plasma ADA activity was positively related to MDA levels in both plasma (p < 0.05) and erythrocytes (p < 0.01). There was also positive correlation between MDA levels (p < 0.05), but negative correlations between ADA activities (p < 0.01) and also between ADA and MDA values in erythrocytes (p < 0.01) of BD patients.

CONCLUSION

These findings may provide some evidence for a potential role of T lymphocyte activation in BD as reflected by increased plasma ADA activity, and for the presence of possible interrelationship between activated T cells and neutrophil hyperfunctions, such as ROS generation, as reflected by increased MDA levels.

Characterization of a protease responsible for truncated actin increase in neutrophils of patients with Behçet's disease

As described previously (Yamashita S. et al., Biol. Pharm. Bull., 23, 519-522 (2000)), high levels of a truncated actin with an N-terminus of Met-44 were detected in neutrophils of patients with Behcet's disease. Since the increase of the truncated actin in neutrophils of patients may be important for understanding the pathology of Behçet's disease, the mechanism of the truncated actin formation was studied. First, to investigate the presence of a specific protease, which cleaves the actin at the site between Val-43 and Met-44, a peptide with a partial amino acid sequence of actin from the N-terminal Pro-38 to Asp-51 was synthesized as the protease substrate. The synthesized peptide was digested with cytosolic fractions of neutrophils from patients and healthy volunteers, and digestion products were analyzed by C18-reverse phase HPLC. The chromatograms of these samples showed that an endoprotease, which cleaved the peptide at a specific site, was present in cytosolic fractions of neutrophils from patients with Behçet's disease. Then, the effects of various kinds of protease inhibitors on the digestion of the peptide were investigated in order to identify the responsible endoprotease. The digestion of the peptide was suppressed by 4-(2-aminoethyl) benzenesulfonylfluoride (AEBSF, a serine protease inhibitor) and N-methoxysuccinyl-Ala-Ala-Pro-Val chloromethylketone (CMK, a polymorphonuclear (PMN)-elastase inhibitor) in the presence of EDTA. Furthermore, PMN-elastase was found to cleave the substrate peptide and actin at the site between Val-43 and Met-44. These results lead to the conclusion that the PMN-elastase is responsible for cleavage of actin at the N-terminal site between Val-43 and Met-44 in neutrophils from patients with Behçet's disease.

Novel approaches to Behçet's disease

Behçet's disease is a systemic inflammatory disorder. The patients have repeated exacerbations and remissions of the symptoms. This disease may produce a wide variety of symptoms. In mild cases, mucocutaneous lesions are only the symptoms during the whole clinical course, whereas ocular lesions, which occur in about 70% of the patients, can cause blindness. Involvement of the gastrointestinal tract, CNS and large vessels is less frequent, but sometimes life-threatening. Colchicine, NSAIDs, corticosteroids and immunosuppressants are employed for the treatment of Behçet's disease with therapies tailored to individual patients depending on clinical manifestations. Cyclosporin A is the most effective drug for ocular lesions at the present, but its neurotoxicity, which occurs in 20-30% of patients receiving cyclosporin A, restricts usage of the agent. Many patients are still suffering from a severe form of uveitis and serious neurological symptoms, which are resistant to any conventional therapies. New drugs have been investigated for Behçet's disease. IFN-alpha therapy has shown significant efficacy for common symptoms including ocular lesions without any serious adverse effects. Thalidomide and its analogues also appear to be applicable to this disease. Monoclonal antibody to TNF-alpha is now in clinical trials. These novel therapeutic approaches may provide much needed treatment options for patients with Behçet's disease.

Intracardiac thrombus in Behçet's disease: a systematic review

BACKGROUND

Intracardiac thrombus formation is a rare but serious complication of Behçet's disease. We aimed to review the clinical and pathologic correlates of cardiac thrombus formation in the context of Behçet's disease.

METHODS AND RESULTS

A comprehensive search of the medical literature was conducted using MEDLINE including bibliographies of all selected articles. Although the disease has a unique geographic distribution, being most common in the population of the ancient Silk Route, cases complicated by intracardiac thrombus have mostly originated from the Mediterranean basin and the Middle East. Young men appear to be most at risk, with the right heart the most frequent site of involvement. The first symptoms and signs of the disease frequently precede systemic organ manifestations. In those cases in which intracardiac thrombus occurs, it is apparent in more than half of cases on first recognition of the disease.

CONCLUSION

A diagnosis of Behçet's disease should be considered if a patient presents with a mass in the right-sided cardiac chambers, even in the absence of the characteristic clinical features of the condition. This is particularly applicable if the patient is a young man from the Mediterranean basin or the Middle East.

Interferon alfa-2b, colchicine, and benzathine penicillin versus colchicine and benzathine penicillin in Behçet's disease: a randomised trial

BACKGROUND

Sight-threatening eye involvement is a serious complication of Behçet's disease. Extraocular complications such as arthritis, vascular occlusive disorders, mucocutaneous lesions, and central-nervous-system disease may lead to morbidity and even death. We designed a prospective study in newly diagnosed patients without previous eye disease to assess whether prevention of eye involvement and extraocular manifestations, and preservation of visual acuity are possible with combination treatments with and without interferon alfa-2b.

METHODS

Patients were randomly assigned 3 million units interferon alfa-2b subcutaneously every other day for the first 6 months plus 1.5 mg colchicine orally daily and 1.2 million units benzathine penicillin intramuscularly every 3 weeks (n=67), or colchicine and benzathine penicillin alone (n=68). The primary endpoint was visual-acuity loss. Analysis was by intention to treat.

FINDINGS

Significantly fewer patients who were treated with interferon had eye involvement than did patients who did not receive interferon (eight vs 27, relative risk 0.21 [95% CI 0.09-0.50], p<0.001). Ocular attack rate was 0.2 (SD 0.62) per year with interferon therapy and 1.02 (1.13) without interferon therapy (p=0.0001). Visual-acuity loss was significantly lower among patients treated with interferon than in those without interferon (two vs 13, relative risk 0.13 [95% CI 0.03-0.60], p=0.003). Arthritis episodes, vascular events, and mucocutaneous lesions were also less frequent in patients treated with interferon than in those not receiving interferon. No serious side-effects were reported.

INTERPRETATION

Therapy with interferon alfa-2b, colchicine, and benzathine penicillin seems to be an effective regimen in Behçet's disease for the prevention of recurrent eye attacks and extraocular complications, and for the protection of vision.