Biotherapies in Behçet's disease

Behçet's Disease, Pathogenesis, Clinical Features, and Treatment Approaches: A Comprehensive Review

Behçet's disease is a systemic inflammatory disorder of unknown etiology. The disease manifests with diverse clinical symptoms, most commonly recurrent oral and genital ulcers, skin lesions, and uveitis, though it can affect multiple organ systems. Diagnosis is primarily clinical due to the lack of a definitive diagnostic test, and management involves a multidisciplinary approach to control inflammation and manage symptoms. Current treatment strategies involve corticosteroids, immunosuppressive agents, and, increasingly, biological therapies. Behçet's disease exhibits a higher prevalence along the Silk Road, suggesting a role of environmental and genetic factors. Despite significant progress in understanding its clinical characteristics and treatment approaches, gaps remain in our understanding of its pathogenesis. Future research is needed to elucidate the disease's pathophysiology and optimize treatment strategies.

Treatment of non-infectious retinal vasculitis

Retinal vasculitis (RV) refers to an entity in which the retinal vasculature is inflamed, frequently with indications of inflammation elsewhere in the eye. Non-infectious RV can be idiopathic or associated with systemic disease, ocular conditions, and malignancy. It can also be classified based on the vessel affected: artery, vein, or both. Due to the lack of strong evidence-based treatment trials and algorithms for RV, physicians must often rely on their experience, which creates great variability in treating this entity. This article provides an overview of various treatment modalities used in the management of non-infectious RV, with a focus on immunomodulatory therapies. We outline a potential stepwise approach of starting with steroids to control the acute inflammation and subsequently changing to immunomodulatory therapy (IMT) for long-term treatment.

Budd-Chiari syndrome in Behcet's disease: A report of two cases

Budd-Chiari syndrome (BCS) is a rare but severe venous form of Behcet's disease (BD) that is caused by the obstruction of the venous outflow tract that transports blood from hepatic veins into the inferior vena cava. In countries where BD is prevalent, including the Middle East and Far East, BCS awareness is important. In the present study, two cases of BCS are presented in two male Chinese patients with BD. The clinical characteristics, treatment and outcomes were recorded and compared with previous studies, and the features of BD-BCS were summarized. The clinical characteristics of the two patients documented were similar. Each patient presented with insidious onset, abdominal symptoms and recurrent aphthous ulcers. Accurate diagnosis was delayed as other symptoms of BD were overlooked. Each patient responded well to TNF-α inhibitor treatment in combination with cyclophosphamide (CYC). One patient with good compliance was removed from CYC and corticosteroid therapy. Unfortunately, the other patient with poor compliance faced a poor outcome. It was concluded that multiple vessel lesions in ≥2 sites are common in vasculo-BD and that misdiagnosis may occur if other symptoms of BD are not noticed. BD-BCS is associated with a high mortality rate, but appropriate treatment may result in a favorable outcome.

Exploring the role of programmed cell death protein 1 and its ligand 1 in eye diseases

Programmed death receptor-1 (PD-1) and its ligand, PD-L1, as negative co-stimulatory molecules, are indispensable for regulating both physiological and pathological immune responses. The PD-1/PD-L1-mediated signaling pathway has been studied extensively in cancer research and has become a hotspot for biopharmaceuticals and immunotherapy. Furthermore, monoclonal antibodies to PD-1 have just been approved by the US Food and Drug Administration to treat certain types of malignancies. Recent research has unveiled a close association between the PD-1/PD-L1 system and eye diseases. This review describes the expression and physiological functions of PD-1 and its ligand in ocular tissues and summarizes the pathogenic, regulatory, and therapeutic roles of PD-1/PD-L1 system in eye diseases, including uveal melanoma, autoimmune uveitis, autoimmune dry eye, sympathetic ophthalmia, Graves' ophthalmopathy, diabetic retinopathy, herpes simplex keratitis, and trachoma, with the intent of highlighting the potential of PD-1/PD-L1 as novel therapeutic targets or biomarkers for these ocular diseases.

Behçet's disease: New insights into pathophysiology, clinical features and treatment options

Behçet's disease (BD) is a rare systemic vasculitis characterized by oral aphthous ulcers, genital ulcers, ocular lesions and other systemic manifestations. BD occurs most frequently in Eurasian populations along the ancient trading route known as the "Silk Road" which extends from eastern Asia to the Mediterranean basin. The causes of BD are unknown: it is believed to be due to an autoimmune process triggered by an infectious or environmental agent in genetically predisposed individuals. HLA-B51 allele located in the MHC locus, on chromosome 6p, has been the most strongly associated risk factor for BD in areas along the Old Silk Route. Herpes simplex virus-1 and Streptococcus have been postulated as possible environmental triggers of BD. T cell homeostasis perturbation, especially Th1 and Th17 expansion and decreased regulation by Tregs are now supposed to be the cornerstone of BD pathogenesis. The histology shows vasculitis that involves both arteries and veins, and vessels of any size. BD is a systemic vasculitis with significant neutrophil infiltration, endothelial cell swelling, and fibrinoid necrosis. The diagnosis of BD is only supported by clinical criteria and requires the exclusion of other diagnoses based on clinical presentation. There are no pathognomonic laboratorial findings of BD. This rare disease often leads to blindness and fatal systemic involvement. Main causes of death include major vessel disease and central nervous system involvement. Corticosteroids are commonly used to treat clinical manifestations of BD in combination with immunosuppressant drugs. Tumor necrosis factor (TNF)-blocking agents such as Infliximab, Etanercept, and Adalimumab have been reported to have success in patients with BD.

Antagonist Anti-CD28 Therapeutics for the Treatment of Autoimmune Disorders

The effector functions of T lymphocytes are responsible for most autoimmune disorders and act by directly damaging tissues or by indirectly promoting inflammation and antibody responses. Co-stimulatory and co-inhibitory T cell receptor molecules are the primary pharmacological targets that enable interference with immune-mediated diseases. Among these, selective CD28 antagonists have drawn special interest, since they tip the co-stimulation/co-inhibition balance towards efficiently inhibiting effector T cells while promoting suppression by pre-existing regulatory T-cells. After having demonstrated outstanding therapeutic efficacy in multiple models of autoimmunity, inflammation and transplantation, and safety in phase-I studies in humans, selective CD28 antagonists are currently in early clinical development for the treatment of systemic lupus erythematous and rheumatoid arthritis. Here, we review the available proof of concept studies for CD28 antagonists in autoimmunity, with a special focus on the mechanisms of action.

Breaking the Magic: Mouth and Genital Ulcers with Inflamed Cartilage Syndrome

Mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome refers to a condition in which features of Behcet’s disease (BD) and relapsing polychondritis (RP) occur in the same individual. The existence of MAGIC syndrome suggests a potential common etiology for BD and RP. However, connecting these two diseases and referring to this condition as MAGIC syndrome might have been premature, as there is currently insufficient knowledge on BD and RP. In this critical review, we argue that these two clinical entities could possibly be unique disease processes rather than two ends of the same disease spectrum. Distinguishing the clinical difference between BD and RP is critical for the management of patients diagnosed with MAGIC syndrome, as biological therapeutic approaches for BD and RP differ. Also, inaccurate perception regarding the relationship of these two diseases could mislead researchers in their endeavors to unravel the pathophysiological mechanisms behind these two diseases.

Novel CD28 antagonist mPEG PV1-Fab' mitigates experimental autoimmune uveitis by suppressing CD4+ T lymphocyte activation and IFN-γ production

Autoimmune Uveitis is an important chronic inflammatory disease and a leading cause of impaired vision and blindness. This ocular autoimmune disorder is mainly mediated by T CD4⁺ lymphocytes poising a T_H1 phenotype. Costimulatory molecules are known to play an important role on T cell activation and therefore represent interesting therapeutical targets for autoimmune disorders. CD28 is the prototypical costimulatory molecule for T lymphocytes, and plays a crucial role in the initiation, and maintenance of immune responses. However, previous attempts to use this molecule in clinical practice achieved no success. Thus, we evaluated the efficacy of mPEG PV1-Fab’ (PV1), a novel selective CD28 antagonist monovalent Fab fragment in the treatment of Experimental Autoimmune Uveitis (EAU). Here, we showed that PV1 treatment decreases both average disease score and incidence of EAU. A decrease in the activation profile of both T CD4⁺ and T CD8⁺ eye-infiltrating lymphocytes was evidenced. In the periphery, T CD4⁺ cells from PV1-treated mice also showed a decrease in their activation status, with reduced expression of CD69, CD25, and PD-1 molecules. This suppression was not dependent on Treg cells, as both their frequency and absolute number were lower in PV1-treated mice. In addition, frequency of CD4⁺IFN-γ⁺ T cells was significantly lower in PV1-treated group, but not of IL-17-producing T cells. Moreover, after specific restimulation, PV1 blockade selectively blocked IFN-γ production by CD4⁺ lymphocytes Taken together, our data suggest that mPEG PV1-Fab’ acts mainly on IFN-γ-producing CD4⁺ T cells and emphasize that this specific CD28 blockade strategy is a potential specific and alternative tool for the treatment of autoimmune disorders in the eye.

Circulating LL37 targets plasma extracellular vesicles to immune cells and intensifies Behçet's disease severity

Behçet's disease (BD) activity is characterised by sustained, over-exuberant immune activation, yet the underlying mechanisms leading to active BD state are poorly defined. Herein, we show that the human cathelicidin derived antimicrobial peptide LL37 associates with and directs plasma extracellular vesicles (EV) to immune cells, thereby leading to enhanced immune activation aggravating BD pathology. Notably, disease activity was correlated with elevated levels of circulating LL37 and EV plasma concentration. Stimulation of healthy PBMC with active BD patient EVs induced heightened IL1β, IFNα, IL6 and IP10 secretion compared to healthy and inactive BD EVs. Remarkably, when mixed with LL37, healthy plasma-EVs triggered a robust immune activation replicating the pathology inducing properties of BD EVs. The findings of this study could be of clinical interest in the management of BD, implicating LL37/EV association as one of the major contributors of BD pathogenesis. Abbreviations: BD: Behçet's disease; EV: extracellular vesicle; BB: binding buffer; AnV: annexin V; autologEV: autologous extracellular vesicles; alloEV: allogeneic extracellular vesicles.

Autoimmunity in 2014

Our PubMed search for peer-reviewed articles published in the 2014 solar year retrieved a significantly higher number of hits compared to 2013 with a net 28 % increase. Importantly, full articles related to autoimmunity constitute approximately 5 % of immunology articles. We confirm that our understanding of autoimmunity is becoming a translational paradigm with pathogenetic elements rapidly followed by new treatment options. Furthermore, numerous clinical and pathogenetic elements and features are shared among autoimmune diseases, and this is well illustrated in the recent literature. More specifically, the past year witnessed critical revisions of our understanding and management of antiphospholipid syndrome with new exciting data on the pathogenicity of the serum anti-beta2 glycoprotein autoantibody, a better understanding of the current and new treatments for rheumatoid arthritis, and new position papers on important clinical questions such as vaccinations in patients with autoimmune disease, comorbidities, or new classification criteria. Furthermore, data confirming the important connections between innate immunity and autoimmunity via toll-like receptors or the critical role of T regulatory cells in tolerance breakdown and autoimmunity perpetuation were also reported. Lastly, genetic and epigenetic data were provided to confirm that the mosaic of autoimmunity warrants a susceptible individual background which may be geographically determined and contribute to the geoepidemiology of diseases. The 2014 literature in the autoimmunity world should be cumulatively regarded as part of an annus mirabilis in which, on a different level, the 2014 Annual Meeting of the American College of Rheumatology in Boston was attended by over 16,000 participants with over selected 3000 abstracts.

Behçet's disease physiopathology: a contemporary review

Behçet’s disease, also known as the Silk Road Disease, is a rare systemic vasculitis disorder of unknown etiology. Recurrent attacks of acute inflammation characterize Behçet’s disease. Frequent oral aphthous ulcers, genital ulcers, skin lesions and ocular lesions are the most common manifestations. Inflammation is typically self-limiting in time and relapsing episodes of clinical manifestations represent a hallmark of Behçet’s disease. Other less frequent yet severe manifestations that have a major prognostic impact involve the eyes, the central nervous system, the main large vessels and the gastrointestinal tract. Behçet’s disease has a heterogeneous onset and is associated with significant morbidity and premature mortality. This study presents a current immunological review of the disease and provides a synopsis of clinical aspects and treatment options.

Pulmonary artery aneurysms in Behçet's disease treated with anti-TNFα: A case series and review of the literature

Behçet's disease (BD) is a systemic inflammatory disorder of unknown aetiology. Pulmonary haemorrhage from ruptured pulmonary artery aneurysms (PAA) in this condition carries a high mortality but treatment has largely been empiric with use of glucocorticoids and cyclophosphamide. Tumour necrosis factor α (TNF-α) was recently recognised as a mediator in the pathogenesis of BD inflammatory lesions. TNFα inhibitors have been shown in various case reports/series to have beneficial effects in uveoretinitis, entero-Behçet's, neuro-Behçet's and BD arthritis. We describe the efficacy and tolerability of infliximab in 2 patients with Behçet's disease complicated by pulmonary vasculitis admitted to our unit during the years 2004-2015, and discuss the previously published data in this area.

Association of Disease Activity with Serum and Tear IL-2 Levels in Behçet Disease

PURPOSE

To investigate the association of Behçet disease activity with serum and tear interleukin-2 levels.

METHODS

The study was designed as a prospective case control study. The study population consisted of 45 patients with Behçet disease and 24 age and sex-matched healthy participants. Behçet disease patients were classified as active (24 patients) or inactive (21 patients) according to disease activity. Serum and tear interleukin-2 levels were determined using the enzyme-linked immunosorbent assay method.

RESULTS

The mean serum and tear interleukin-2 levels of the active disease, inactive disease, and control groups were 17.04 ± 5.02 and 32.61 ± 16.53 pg/mL; 15.20 ± 4.68 and 29.61 ± 8.30 pg/mL; and 14.22 ± 4.18 and 28.89 ± 8.73 pg/mL, respectively. There was no statistically significant difference between the groups with respect to all measured data.

CONCLUSIONS

There was no significant difference in serum or tear IL-2 levels between Behçet patients and controls; there was no association of disease activity with serum and tear IL-2 levels.

Autoimmunity and autoinflammation as the yin and yang of idiopathic recurrent acute pericarditis

Autoimmunity and autoinflammation are generally considered as mutually exclusive mechanisms of diseases but may concur to specific syndromes. Idiopathic recurrent acute pericarditis (IRAP) is defined as the recurrence of pericardial symptoms at any point following the prior cessation of acute pericarditis, and the latency is generally 6 weeks. Manifestations of pericarditis such as pericardial friction rub, electrocardiographic changes, and pericardial effusion are less frequent in the subsequent episodes compared to the index attack, and in some cases the only clinical sign is represented by a suggestive chest pain. Several autoimmune diseases may manifest with pericarditis which is often related to viral infections, while postviral pericarditis may in turn display a nonspecific autoimmune background. Similarly, autoinflammatory syndromes such as familial Mediterranean fever and tumor necrosis factor receptor-associated periodic syndrome are characterized by self-limiting pericardial symptoms. Corticosteroids are generally effective, thus supporting the autoimmune nature of IRAP, but dramatic results are obtained with interleukin-1 blocking agents in corticosteroid-dependent cases, pointing to a pathogenic role for the inflammasome. Based on these observations, we submit that IRAP represents a paradigmatic example of the putative coexistence of autoimmunity and autoinflammation: the main aim of this review is to critically discuss the hypothesis as well as the current understanding of this enigmatic clinical condition.

Effectiveness and tuberculosis-related safety profile of interleukin-1 blocking agents in the management of Behçet's disease

Behçet's disease (BD) is a multi-systemic disorder of unknown etiology characterized by relapsing oral-genital ulcers, uveitis, and involvement of the articular, gastrointestinal, neurologic, and vascular systems. Although the primum movens of this condition remains unknown, a tangled plot combining autoimmune and autoinflammatory pathways has been hypothesized to explain its start and recurrence. In-depth analysis of BD pathogenetic mechanisms, involving dysfunction of multiple proinflammatory molecules, has opened new modalities of treatment: different agents targeting interleukin-1 have been studied in recent years to manage the most difficult and multi-resistant cases of BD. Growing experience with anakinra, canakinumab and gevokizumab is discussed in this review, highlighting the relative efficacy of each drug upon the protean BD clinical manifestations. Safety and tolerability of interleukin-1 antagonists in different doses have been confirmed by numerous observational studies on both large and small cohorts of patients with BD. In particular, the potential for Mycobacterium tuberculosis reactivation and tuberculosis development appears to be significantly lower with interleukin-1 blockers compared to tumor necrosis factor-α inhibitors, thus increasing the beneficial profile of this approach.

Immunotherapeutic strategies in autoimmune uveitis

Autoimmune uveitis is an organ-specific disorder characterized by irreversible lesions to the eye that predominantly affect people in their most productive years and is among the leading causes of visual deficit and blindness. Currently available therapies are effective in the treatment of a wide spectrum of uveitis, but are often associated with severe side effects. Here, we review ongoing research with promising immunomodulatory therapeutic strategies, describing their specific features, interactions and the responses triggered by the targeted immune molecules that aim to minimize clinical complications and the likelihood of disease relapse. We first review the main features of the disease, diagnostic tools, and traditional forms of therapy, as well as the animal models predominantly used to understand the pathogenesis and test the novel intervention approaches aiming to control the acute immune and inflammatory responses and to dampen chronic responses. Both exploratory research and clinical trials have targeted either the blockade of effector pathways or of their companion co-stimulatory molecules. Examples of targets are T cell receptors (CD3), their co-stimulatory receptors (CD28, CTLA-4) and corresponding ligands (B7-1 and B7-2, also known as CD80 and CD86), and cytokines like IL-2 and their receptors. Here, we summarize the available evidence on effectiveness of these treatments in human and experimental uveitis and highlight a novel CD28 antagonist monovalent Fab′ antibody, FR104, which has shown preclinical efficacy suppressing effector T cells while enhancing regulatory T cell function and immune tolerance in a humanized graft-versus-host disease (GVHD) mice model and is currently being tested in a mouse autoimmune uveitis model with encouraging results.