Infliximab is effective for Takayasu arteritis refractory to glucocorticoid and methotrexate

Effects of resistance exercise on treatment outcome and laboratory parameters of Takayasu arteritis with magnetic resonance imaging diagnosis: A randomized parallel controlled clinical trial

BACKGROUND

Elevated tumor necrosis factor-α (TNF-α) is correlated with refractory Takayasu arteritis (TA), and resistance exercise have been shown to inhibit TNF-α.

HYPOTHESIS

We aimed to explore the effect of resistance exercise in the clinical management of TA.

METHODS

This clinical trial enrolled a total of 342 acute TA patients, who were subsequently randomized to undergo either resistance exercise or relaxation control twice per week for 12 weeks. The disease activity was defined using the primary outcome of Birmingham Vascular Activity Score (BVAS). Secondary outcomes included levels of plasma TNF-α and C-reactive protein (CRP), and the erythrocyte sedimentation rate (ESR).

RESULTS

BVAS scores along with other laboratory parameters obtained from the patients in the resistance exercise group showed a gradual decline throughout the course of the trial. By contrast, outcomes appeared largely unaltered in the relaxation control group patients. Analyses also revealed that plasma TNF-α displayed strong linear correlations with ESR, BVAS scores, and plasma CRP levels.

CONCLUSION

Resistance exercise could substantially improve treatment outcomes as well as laboratory parameters in patients with acute TA, probably through decreasing TNF-α.

Association Between Cerebrovascular Accident and Vasculitis: Myth or Reality?

This article aims to determine an association between vasculitis and cerebrovascular accidents (CVA) and the ideal management plan to decrease the chances of CVA in vasculitis patients. We also attempt to find a preferred treatment regimen that decreases the complications of CVAs in vasculitis patients, thereby resulting in reduced mortality and morbidity. We reviewed both free-access full-text articles and the abstracts of articles behind a paywall. We used the PubMed database and reviewed 89 articles that matched our inclusion and exclusion criteria. In all, 42 out of the 89 articles had the most relevant data for our article. We used the following keywords to search the database: vasculitis, stroke, cerebrovascular accident, ischemic, arteritis, and steroid. We found an association between subtypes of vasculitis, mostly large vessel vasculitis and CVA. We could not identify a specific cutoff value for specific inflammatory markers that can increase the risk of developing CVA. Besides, there are no formal guidelines for the dosage or the route of administration for corticosteroids, which are the cornerstone of treatment for most vasculitis. We found that male giant cell arteritis (GCA) patients have a higher chance of developing CVA than females, Also interestingly, anemia was found to be protective against CVA development in GCA patients. Sometimes, CVA can happen due to the effects of treatments of some types of vasculitis. We recommend establishing further studies about other subtypes of vasculitis and their associations with stroke.

Vasculitis: Decade in Review

BACKGROUND

In the last decade, we have come to better understand and manage the vasculitides. The classification of vasculitides has been revised. Genome- wide association studies and linkage analyses have been undertaken in hope of better understanding the pathogenesis of vasculitides. Comprehensive genetic studies have highlighted new pathways that may guide us in more targeted therapies. Description of the monogenic forms of vasculitis, such as deficiency of adenosine deaminase type 2 (DADA2), Haploinsufficiency of A20 (HA20), have introduced a new perspective to vasculopathies, and introduced alternative treatments for these diseases.

CONCLUSION

In this review, the important discoveries in pathogenesis and consensus treatment recommendations from the past decade will be summarized.

Infliximab biosimilar CT-P13 therapy in patients with Takayasu arteritis with low dose of glucocorticoids: a prospective single-arm study

To evaluate the efficacy and safety of infliximab biosimilar CT-P13 in patients with active Takayasu arteritis (TAK). In this single-center open-label trial, patients with active TAK received CT-P13 at a starting dose of 5 mg/kg at weeks 0, 2, 6, and then every 8 weeks up to week 46. They were followed up until week 54. From week 14 to week 46, patients with inadequate response received increased dose of CT-P13 by 1.5 mg/kg. Concomitant prednisolone was allowed ≤ 10 mg/day. The primary efficacy end point was the achievement of partial or complete remission at week 30. All patients underwent positron emission tomography–computed tomography (PET–CT) at baseline and week 30. Twelve patients with TAK received CT-P13; one patient with protocol violation was excluded from analysis. Nine (81.8%) patients had taken concomitant prednisolone with median dose of 5.0 mg/day. At week 30, three (27.3%) patients achieved complete remission and six (54.5%) patients achieved partial remission. Statistically significant improvements in modified Indian Takayasu Clinical Activity Score (ITAS2010), ITAS-A, and serum levels of erythrocyte sedimentation rate and C-reactive protein were seen at week 30 from baseline. PET parameters were significantly reduced from baseline to week 30, including maximum standardized uptake value, target-to-vein ratio, target-to-liver ratio, and PET Vascular Activity Score. There were no serious adverse events. Treatment with CT-P13 may lead to improvement in clinical, radiographic, and serological activities with lower glucocorticoid requirement in TAK.

Trial registration number NCT02457585.

Therapeutic advances in the treatment of vasculitis

Considerable therapeutic advances for the treatment of vasculitis of the young have been made in the past 10 years, including the development of outcome measures that facilitate clinical trial design. Notably, these include: a recognition that some patients with Kawasaki Disease require corticosteroids as primary treatment combined with IVIG; implementation of rare disease trial design for polyarteritis nodosa to deliver the first randomised controlled trial for children; first clinical trials involving children for anti-neutrophil cytoplasmic antibody (ANCA) vasculitis; and identification of monogenic forms of vasculitis that provide an understanding of pathogenesis, thus facilitating more targeted treatment. Robust randomised controlled trials for Henoch Schönlein Purpura nephritis and Takayasu arteritis are needed; there is also an over-arching need for trials examining new agents that facilitate corticosteroid sparing, of particular importance in the paediatric population since glucocorticoid toxicity is a major concern.

Vasculitis in children

Primary systemic vasculitides of the young are relatively rare diseases, but are associated with significant morbidity and mortality, particularly if there is diagnostic delay. We provide an overview of paediatric vasculitides with emphasis on key differences in vasculitis presentation and management between children and adults. Significant advances in the field of paediatric vasculitis research include the development of classification criteria and disease outcome tools for paediatric disease; inclusion of paediatric patients in international multicentre randomized controlled trials of therapies in vasculitis; and development of rare disease trial designs for therapeutic trials of paediatric vasculitis. The continuation of unmet needs as well as the exploration of potential therapeutic avenues and considerations in the design of future trials are also discussed.

Recent advances in the medical management of Takayasu arteritis: an update on use of biologic therapies

PURPOSE OF REVIEW

To critically review recent advances in medical management of Takayasu arteritis, with a special focus on the rationale and evidence to support the use of biologic agents in this disease.

RECENT FINDINGS

Multiple case series and observational studies support the use of anti-tumor necrosis factor (TNF) medications, in particular infliximab, in patients who relapse upon tapering steroids and/or adding nonbiologic immunosuppressive agents. However, these medications must be continued to maintain effect, and often patients require increased doses over time. Tocilizumab and rituximab have been shown to lead to improved disease activity in small numbers of Takayasu's patients, including those refractory to anti-TNF treatment.

SUMMARY

Anti-TNF agents are recommended for the treatment of Takayasu's patients who are unable to taper prednisone despite treatment with a nonbiologic immunosuppressive medication. Whether these biologic agents should be considered earlier in the treatment algorithm of these complicated patients remains an area of interest. Tocilizumab and rituximab may also be of benefit in refractory patients. Prospective randomized controlled trials are needed to confirm these findings.

Takayasu's arteritis and its role in causing renal artery stenosis

Takayasu's arteritis is a systemic vasculitis that involves medium- and large-sized arteries. Renal artery involvement is a potential manifestation of TA that occurs in 60% of the patients in India and the Far East. This manifestation can lead to renal failure and/or renovascular hypertension. Renovascular hypertension is generally resistant to medical therapy and often requires additional invasive management strategies, such as angioplasty or surgical bypass. In this review, we present the epidemiology, clinical manifestations, diagnosis and treatment of Takayasu's arteritis with particular emphasis on renal artery stenosis. The aim is to increase the awareness of this condition among clinicians because early diagnosis and the timely introduction of treatment can lead to improved outcomes in this poorly understood clinical enigma.

Novel strategy for the treatment of refractory vasculitis syndrome

The recent development of biologic therapies capable of selectively targeting components of the immune system has revolutionized the treatment of inflammatory arthritides. The increase in the use of biologic agents coupled with expansion in the knowledge of the pathogenesis of vascular inflammation has led to their application in the treatment of primary systemic vasculitis. Biological therapies appear to have a place in the therapeutic strategy for ANCA-associated systemic vasculitides, at least for patients whose disease is refractory to conventional therapy. The use of biologics as targeted therapies has also, in reverse, improved our understanding of the pathophysiology of vascular inflammation. However, the precise indications for TNF-alpha inhibitors or anti-CD20 monoclonal antibodies have not yet been defined. These biologics must be prescribed extremely cautiously and only in trial settings, especially in view of the adverse effects. (*English Translation of J Jpn Coll Angiol, 2009, 49: 75-79).

Renovascular hypertension--is it fibromuscular dysplasia or Takayasu arteritis

Renovascular hypertension (RVH) can be caused by many different diseases, with the most common being fibromuscular dysplasia (FMD) and Takayasu arteritis (TA). A strikingly different diagnostic pattern is seen in children with RVH from different parts of the world. In Europe and North America, these children are mainly diagnosed as having FMD while in Asia and South Africa they will most often get a diagnosis of TA. When comparing the clinical diagnosis for FMD and TA, it becomes obvious that there is a great deal of overlap between the definitions of these two conditions. Different ways to come to the most accurate diagnosis using imaging of the blood vessel wall and positron emission tomography (PET) will be discussed. How an accurate diagnosis should influence the treatment of the children with these conditions will also be addressed.

Takayasu arteritis developing during treatment of ulcerative colitis with infliximab

A 22-year-old female with ulcerative colitis that was successfully treated with infliximab (IFX), and remained stable following tapered discontinuation of prednisolone, developed anterior neck pain and elevation of C-reactive protein following her fourth administration of IFX. She was diagnosed with Takayasu arteritis (TA) based on neck ultrasound and computed tomography angiography. This is the first report describing the development of TA during treatment of UC with IFX.

Anti TNF-α in refractory Takayasu's arteritis: cases series and review of the literature

Takayasu arteritis (TA) is a rare large vessels vasculitis. Conventional therapy consists of glucocorticoids which may be associated with other immunosuppressive drugs. However, some patients fail to achieve remission with conventional treatment. The use of anti-tumor necrosis factor-α (TNF-α) in patients with difficult to treat TA could be useful. We report here the main characteristics, treatment and outcome of 84 patients (5 personal cases and 79 patients from the literature) with refractory Takayasu arteritis treated with anti TNF-α. The mean age was 28.5years [median 26.0years, range 7-61years], with 74/83 (89%) of female. All patients, except one, were inadequately controlled with other immunosuppressive regimens before anti TNF-α therapy. First line of anti-TNF-α included infliximab (IFX) in 81% (68/84) and etanercept (ETA) in 19% (16/84). Most patients received IFX at 5mg/kg associated to methotrexate or azathioprine. Thirty one out of 84 (37%) patients achieved a complete remission, and 45 (53.5%) were partial responders. There were 8 (9.5%) non responders at all. Twenty seven out of 84 (32%) patients needed to increase the dose of anti TNF-α because of uncontrolled disease and 15 (18%) needed to change of anti TNF-α. Glucocorticoids have been tapered in 41/79 (52%) [from 20mg (13.1-60) to 2.5mg (0-10) daily, at baseline and after anti-TNF, respectively, p<0.0001] and discontinued in 31/77 (40%). After a median follow-up of 10months [range 3-82], 17 (20%) side effects were recorded leading to discontinuation of anti TNF-α in 8 cases. They included mainly infections, and hypersensitivity reactions. In conclusion, anti-TNF-α are an efficient therapy in refractory TA patients although side effects are observed in 20% of cases. Further studies are warranted to assess the long term efficacy and safety of anti-TNF in TA and to better define if they should be prescribed earlier in the course of TA.

[Biologic therapies in the systemic vasculitides]

Several biological therapies have been evaluated in systemic vasculitis. Anti TNF-α agents may have a role in the treatment of Takayasu's arteritis and probably in giant cell arteritis. In Kawasaki's disease, infliximab is an option in subjects with intravenous immunoglobulin-resistant disease. Anti TNF-α cannot be recommended to treat ANCA-associated vasculitis. Anti-T lymphocyte globulin and alemtuzumab could have a role in the treatment of ANCA associated vasculitis, although current information about these two biological treatments comes from conventional resistant treatment cases, so the high incidence of complications and relapses observed with these treatment may be intrinsic to the severity of the disease and not related to the biological agents.

Immunological Aspects of Systemic Vasculitis

Primary vasculitis are commonly multifactorial disorders involving environmental, genetic and immunological factors. Several immune-based effector mechanisms are implicated in the vascular wall damage. These effector mechanisms commonly imply auto-antibodies or immune complexes - mediated cytotoxicity but the contribution of a T-cell mediated immune response has also been described, particularly in large vascular vasculitis. Despite advances in understanding the pathophysiological mechanisms of vasculitis, the triggering events initiating the disease remain largely undefined in most cases. This review highlights the recent advances in the etiopathogenesis of primary vasculitis. A better understanding of the immunological aspects of these disorders may provide insight into the development of novel therapeutical strategies.

Biologic agents in systemic vasculitis

The treatment of systemic necrotizing vasculitis has made great strides in both efficacy and outcomes. Standard therapies, however, are associated with numerous side effects, and not all patients will respond to conventional immunosuppression. These realities have prompted the search for safer and more efficacious treatments, most notably among biologic agents. For example, the role of TNF-α in the pathophysiology of several vasculitides has led to the investigation of targeted inhibitors of this cytokine, albeit with mixed results. There have been some disappointing results in the area of giant cell arteritis and Wegener's granulomatosis (granulomatosis with polygiitis), but anti-TNF therapy has shown promise in the treatment of Takayasu's arteritis, although additional trials to demonstrate its efficacy are required. Anti-B-cell therapy seems to be the most promising advance in the management of these diseases. Complete and partial responses have been seen in both primary and secondary mixed cryoglobulinemic vasculitis. Recent trials have demonstrated that rituximab is effective for the treatment of Wegener's granulomatosis and microscopic polyangiitis. These trials have, however, raised concerns regarding the long-term safety of these agents. The future holds promise for additional targeted therapies with improved patient response and fewer side effects.

Takayasu's arteritis with associated aortic insufficiency and coronary ostial obliteration

PURPOSE

To describe the presentation, assessment, and management of Takayasu's arteritis (TA), a rare vascular condition exhibited predominantly in females in their second and third decades of life.

DATA SOURCES

Thorough review of current scientific literature was obtained from electronic databases and medical journals (CINAHL and PubMed). A case study is presented to illustrate TA, which was reviewed and approved by the Human Subjects Committee for the release of protected health information.

CONCLUSIONS

Clinical presentation of TA varies depending on the location of vessel involvement. Diagnosis is challenging because of the complex pathogenesis of TA. The chronic nature of TA requires ongoing evaluation and adjustment of medication regimens. The patient's quality of life is improved with maintenance of TA in a quiescent state.

IMPLICATIONS FOR PRACTICE

Presentation of a young woman with symptoms suggestive of vascular inflammatory changes should prompt consideration of TA within the differential diagnosis.

Large vessel vasculitis

Takayasu arteritis is a chronic granulomatous disease of the aorta and its major branches that usually affects women during the second and third decades of life, but it has been reported in young children. This review details the clinical, pathological and radiological features, differential diagnoses and management of the condition, focusing chiefly on the disease in children. The recent definition of Takayasu arteritis is discussed. The condition should be considered in patients with unexplained arterial hypertension or unexplained inflammatory syndromes without signs of localization. Since the disease may be life-threatening and progressive, early recognition is necessary to initiate appropriate therapy. Patients with persistent ischaemic symptoms including hypertension might benefit from revascularization procedures.

[Systematic review on the use of adalimumab in autoinmune. Efficacy and safety in 54 patients]

OBJECTIVE

To analyze published evidence about adalimumab use in autoimmune diseases.

METHODS

Systematic review of MEDLINE database of citations included from January 1990 to December 2008 employing the terms "adalimumab" and the different systemic autoimmune diseases.

RESULTS

Our search identified 241 potentially relevant citations. 154 were retrieved for detailed evaluation. Finally, 18 were selected as relevant, including 54 patients. The reported diseases were as follow: Behçet disease in 16 patients, idiopathic uveitis in 13, sarcoidosis in 5, uveitis associated with rheumatologic diseases in 5 (psoriasis in 2, ankylosing spondylitis in 1, juvenile idiopathic arthritis in 1, Crohn disease in 1), Vogt-Koyanagi-Harada disease in 4, Birdshot uveitis in 4, vasculitis in 3 (1 temporal arteritis, 1 Takayasu's disease, 1 skin vasculitis associated with rheumatoid arthritis), adult onset Still disease in 2, relapsing polychondritis in 1 and systemic sclerosis in 1. The clinical spectrum included uveitis (39 cases), skin and/or mucosae (9), vasculitis (3), arthritis (6), lung (3). These patients were refractory to standard therapy, including corticosteroids (42 cases, 78%), immunosuppressants (42, 78%) and biologics (29, 54%). Fifty (93%) patients responded to adalimumab. The clinical response was similar in those patients who had been treated with other biologic and in those who had not received biologic therapy before adalimumab. The patients were followed for 11.9 months. Twelve (22%) patients relapsed. Five (9%) patients suffer some side effect (3 local skin reaction, 1 angioedema, 1 lung fibrosis). One patient (2%) died due to progression of her disease.

CONCLUSIONS

Available data about the use of adalimumab in autoinmune diseases come from case reports and uncontrolled studies, that include patients with severe disease and refractory to standard therapy. In this setting, it seems to be an effective and safe treatment option, especially in patients with uveitis and Behçet's disease. This initial data must be confirmed by controlled assays before extending adalimumab use.

[Vasculitis and hereditary small vessel diseases]

In younger patients with stroke, cerebral vasculitis and hereditary small vessel diseases should be considered as important differential diagnoses. Since the clinical course of cerebral vasculitis is highly variable, diagnostic workup, which includes laboratory tests, CSF analysis, cranial magnetic resonance imaging and biopsy, is often challenging. Therapy should be initiated on an interdisciplinary basis and includes immunosuppressive induction and maintenance regimes. Hereditary small vessel diseases, e.g. CADASIL or Fabry's disease, can mimic clinical features of cerebral vasculitis. Their diagnosis which is based on family history, typical clinical features and genetic analysis often has implications for treatment and genetic counselling.

[Anti-TNFalpha therapy in systemic autoimmune and/or inflammatory diseases]

TNFalpha plays a crucial role in the physiopathology of a large number of auto-immune and/or inflammatory systemic diseases. In addition to authorized indications including rheumatoid arthritis, ankylosing spondylitis, Crohn disease, ulcerative colitis, psoriatic arthritis and plaque psoriasis, TNFalpha blockers have been tested in a wide range of auto-immune and/or inflammatory diseases. TNFalpha blockers might be an option in refractory ANCA-associated vasculitis, sarcoïdosis, adult onset Still disease, Behçet disease, AA amyloïdosis and TRAPS. However, pertaining to the limited number of prospective randomized trails available, the small number of patients included and the poor methodology, it is difficult to define their place in the therapeutic strategy in these conditions. The therapeutic effect of TNFalpha blockers is often suspensive and disease flares are frequently observed during sustained treatment, as in the case of Behçet's disease. Published data do not support the use of TNFalpha blockers in connective tissue diseases.

Takayasu disease on the centenary of its discovery

Takayasu disease was first reported in 1908 by Mikito Takayasu as "a case of peculiar changes in the central retinal vessels." Because in these patients the pulse of the radial artery is impalpable, investigations focusing on the ischemic symptoms of the upper body were conducted. In 1948, Shimizu and Sano named this pathological condition "pulseless disease." Since then, the lesions of Takayasu disease have been detected not only in the aortic arch and its main branches but also in various vessels, including the abdominal aorta and renal arteries. The ocular symptoms of Takayasu disease are considered to be due to ischemia in the retina and choroid. The typical wreath-like arteriovenous anastomosis around the disc reported by Takayasu is observed at a relatively late stage of the disease. The characteristic fundus findings of Takayasu disease include tortuosity and dilatation of the central retinal artery and vein, retinal arteriovenous anastomosis, prominent retinal vasculature, microaneurysms in the capillaries, occlusion of retinal arterioles, soft exudate, choked disc, and optic atrophy. Fluorescein angiography reveals retinal microaneurysms, sludging, slower blood flow, dilatation of retinal vessels, leakage of fluorescence dye due to increased vascular permeability, and arteriovenous anastomosis. Arteriovenous anastomosis initially appears in the periphery at the early stage, and in the arteriovenous crossing at the advanced stage. Systemic administration of corticosteroids is required to prevent vascular stenosis during the early stages of Takayasu disease. Reconstruction of the carotid artery may improve subjective symptoms and fundus findings.

Advances in the use of biologic agents for the treatment of systemic vasculitis

PURPOSE OF REVIEW

Due to the well known toxicities of cyclophosphamide, substantial interest exists in finding other therapies to treat primary systemic vasculitis. Biologic agents have been proposed as an alternative to cyclophosphamide for these disorders because of their recent success in treating other rheumatic diseases. This article reviews the current state-of-the-art therapy with regards to the use of biologic agents as treatments for systemic vasculitis.

RECENT FINDINGS

The greatest amount of experience with these agents for the treatment of systemic vasculitis is with antitumor necrosis factor agents, pooled intravenous immunoglobulin, and anti-B-cell therapies such as rituximab. Intravenous immunoglobulin is already a standard therapy for Kawasaki's disease, but should also be considered for the treatment of vasculitis associated with antineutrophil cytoplasmic antibodies when standard therapies are either ineffective or contraindicated. Early experience with tumor necrosis factor inhibitors indicates that they may be effective for the treatment of Takayasu's arteritis, but their role in the treatment of other forms of vasculitis remains controversial. Early experience with rituximab for the treatment of several forms of vasculitis has been quite promising, but must be confirmed by ongoing randomized clinical trials.

SUMMARY

Biologic agents represent the next evolution in treatment for the primary systemic vasculitides. Greater understanding of these diseases has allowed us to move further away from nonspecific, highly toxic therapies toward a more directed approach. As our experience with these agents increases, they will likely form the keystone of treatment in the near future.

Drug insight: anti-tumor necrosis factor therapies for the vasculitic diseases

The introduction of targeted biologic agents directed against tumor necrosis factor (TNF) has represented a novel and exciting avenue for investigation into therapies for the vasculitic diseases. In vasculitic diseases that are associated with granuloma formation, anti-TNF agents are a particularly attractive approach to treatment in that their mechanism of action targets immunologic pathways that are thought to have a role in disease pathogenesis. To date, a number of important trials have investigated the use of anti-TNF agents in patients with a vasculitic disease: most notably, Wegener's granulomatosis, giant-cell arteritis, Takayasu's arteritis, and Behçet's disease. Randomized, placebo-controlled trials of anti-TNF therapies for vasculitic diseases have advanced our knowledge not only in terms of their clinical results but also by demonstrating that networks of researchers can conduct multicenter trials in these uncommon diseases. Experience with the use of anti-TNF agents in patients with Wegener's granulomatosis or giant-cell arteritis has emphasized the crucial role of randomized trials in determining whether a treatment is effective, even in the face of promising preliminary data. Caution is necessary in clinical practice until such data become available.

Giant cell and Takayasu arteritis

PURPOSE OF REVIEW

Giant cell arteritis and Takayasu arteritis are well known large vessel vasculitides with an unknown etiology. As they have similar clinical features, this short article reviews recent advances in clinical and pathophysiological findings, focusing in particular on papers published in the past year.

RECENT FINDINGS

Delayed gadolinium-enhanced magnetic resonance imaging showed delayed hyperenhancement in the aortic wall in Takayasu arteritis. This technique may be useful in monitoring disease activity or inflammation in the arterial wall and can be used for small vessels such as temporal arteries in giant cell arteritis with high-resolution imaging. Evidence is accumulating that antitumor necrosis factor-alpha monoclonal antibody therapy can be useful for patients refractory to corticosteroid and/or immunosuppressant treatment. Functional promoter polymorphisms of genes encoding inducible nitric oxide synthase and I-kappaB-like protein were suggested to be associated with susceptibility to giant cell arteritis and Takayasu arteritis, respectively.

SUMMARY

Advances in imaging technique will make it possible to evaluate inflammatory activity of the vascular lesions and provide a useful guide for treatment of giant cell arteritis and Takayasu arteritis. Further understanding of the pathophysiological mechanism may contribute to the development of new medicine targeting critical factors in the pathogenesis, such as antitumor necrosis factor-alpha agents.