IgA Vasculitis in Adults: a Rare yet Challenging Disease.

PURPOSE OF REVIEW: IgA vasculitis (IgAV) is a rare and poorly understood systemic vasculitis in adults. Its diagnosis and treatment remain a challenge. Herein, we review the clinical manifestations, diagnosis, management, and prognosis of IgAV in adults. RECENT FINDINGS: The clinical course of IgAV in adults appears to be different from pediatric IgAV, especially due to its higher risk of evolving into end-stage renal disease. Rising awareness and interest in adult-onset IgA vasculitis has resulted in recent increasing number of publications on different treatment experiences. However, there is still controversy over the role of glucocorticoid (GC) and different immunosuppressive therapies such as cyclophosphamide, rituximab, and mychophenolate mofetil for more severe IgAV. Data regarding potential benefits of targeting the mucosal immune system, toll-like receptors, complements, and tyrosine kinase inhibitors in the treatment of IgA nephropathy are emerging. High quality evidence or guidelines in the treatment of severe IgAV are lacking and there is still a great need for controlled trials.

NK cell killer Ig-like receptor repertoire acquisition and maturation are strongly modulated by HLA class I molecules.

The interaction between clonally distributed inhibitory receptors and their activating counterparts on NK cells and HLA class I molecules defines NK cell functions, but the role of HLA class I ligands in the acquisition of their receptors during NK development is still unclear. Although some studies demonstrated that HLA-C affects the expression of killer Ig-like receptors (KIR), other studies showed that NK cells acquire their KIR repertoire in a stochastic manner. Only when infected with human CMV is an expansion of self-specific KIR(+) NKG2C(+) NK cells detected. To gain more insight into this question, we compared the coexpression of different KIR molecules, NKG2A, CD8, and CD57, on NK cells in healthy donors and seven patients with deficient HLA class I expression due to mutations in one of the TAP genes. Our results show a correlation between the presence/absence of HLA class I molecules and the coexpression of their receptors. In an HLA class I low-expression context, an increase in KIR molecules' coexpression is detected on the NKG2A(+) CD8(+) subset. In functional assays, hyporesponsiveness was observed for TAP-deficient NK cells derived from four patients. In contrast, NK cells from patient five were functional, whereas CD107a(+) and IFN-γ(+) CD56(dim) NK cells presented a different pattern of HLA class I receptors compared with healthy donors. Taken together, our results provide strong evidence for the role of HLA class I molecules in NK cell maturation and KIR repertoire acquisition.

Thrombosis in vasculitis.

PURPOSE OF REVIEW: To review the association of thrombosis and vasculitis and discuss some of the proposed causal mechanisms. RECENT FINDINGS: It is becoming increasingly evident that various systemic inflammatory diseases such as vasculitis are associated with an increased risk of both venous and arterial thrombosis. Increasing evidence supports the use of immunosuppression in the management of venous thrombosis in Behçet's disease. An increased incidence of thromboembolic disease in antineutrophil cytoplasmic antibody-associated vasculitis has been recognized, especially during periods of active disease. In addition, a higher risk of ischemic heart disease in these patients has also been observed. As in giant cell arteritis, recent evidence supports the role of aspirin in the prevention of ischemic events in Takayasu's disease. SUMMARY: Thromboembolic disease is an important complication of several forms of systemic vasculitis, and it may result in significant morbidity and mortality. Many questions such as the role for screening of asymptomatic patients, prevention of thrombosis, and duration of anticoagulation in patients with vasculitis remain unanswered. Future studies exploring the mechanisms of thrombosis and its link to inflammation may provide insights in predicting patients at a higher risk for thrombosis and improve outcomes.

Churg-Strauss syndrome and persistent heart failure: active disease or damage?

Churg-Strauss syndrome (CSS) is a rare small-vessel vasculitis typically associated with adult-onset asthma, peripheral and tissue hypereosinophilia, migratory pulmonary infiltrates, upper respiratory tract symptoms, and clinical evidence of systemic vasculitis. Cardiac involvement is a well-recognized complication with an estimated prevalence of 60%. Heart disease is associated with poor prognosis, accounting for almost 50% mortality in CSS. We present a case of a 48-year-old woman with CSS complicated by congestive heart failure with left ventricular ejection fraction of 25%, who was initially treated with long course of high-dose steroids without any clinical or echocardiographic improvement. She was referred to our hospital 1 year later and was initiated with cyclophosphamide 2 mg/kg per day and prednisone 60 mg/d followed by slow taper. Subsequently, the patient had remarkable improvement. Patient was then transitioned to azathioprine for 1.5 years with sustained disease remission. It may be difficult to determine myocardial disease activity status versus tissue damage in CSS with prolonged duration of heart failure symptoms. This is the first case report demonstrating that CSS cardiac disease may remain active despite 1 year of corticosteroid therapy, and significant improvement or remission can still be achieved by administering more aggressive cytotoxic immunosuppressive therapy.

Eosinophilic granulomatosis with polyangiitis.

This review aims to describe the epidemiology, pathogenesis, clinical manifestations, diagnosis, treatment, and prognosis of eosinophilic granulomatosis with polyangiitis (EGPA). Eosinophilic granulomatosis with polyangiitis is a small to medium vessel necrotizing vasculitis, typically classified with granulomatosis with polyangiitis (GPA) and microscopic polyangitis (MPA) as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). However, less than 50% of patients with EGPA have a positive ANCA test. Among all the vasculitides, asthma and eosinophilia are unique features of EGPA. Eosinophilic granulomatosis with polyangiitis is very rare and the diagnosis may be missed as the disease evolves over time. Polyneuropathies are common and may be severe, requiring aggressive immunosuppressive therapy. Heart involvement is the most common cause of death in EGPA. Biopsy of involved tissue supports a clinically suspected diagnosis but is not always feasible. Treatment of EGPA is primarily dictated by the severity of disease and prognostic factors. More severe disease frequently requires the use of aggressive therapy such as cyclophosphamide. Once treatment is initiated, patients can achieve good control of symptoms; unfortunately, disease relapses are common and prolonged treatment with corticosteroids is often necessary for asthma management. A better understanding of the disease heterogeneity is needed for the development of better therapies.

Vasculitis Mimics and Other Related Conditions.

The approach to diagnosis of primary systemic vasculitis can be challenging, often requiring consideration of important secondary causes of vasculitis and non-inflammatory mimics. An atypical pattern of vascular involvement and/or atypical features of primary vasculitis (eg, cytopenia, lymphadenopathy) should prompt a more thorough investigation into other diseases. Herein, we review selected mimics organized by the size of blood vessels typically affected.

Recurrence rate of venous thromboembolic events in granulomatosis with polyangiitis.

Objective: The incidence of first-time venous thromboembolic events (VTEs) is high in granulomatosis with polyangiitis (GPA). The incidence of recurrent VTEs is unknown. We aimed to describe the recurrence rate of second VTEs in patients with GPA. Methods: Retrospective chart review was performed in patients with GPA and at least one VTE at a single centre from 2002 to 2016. Inclusion criteria were 1990 ACR criteria or 2012 Revised International Chapel Hill nomenclature for GPA, at least two follow-up visits, at least one VTE during the study period, and VTE occurrence after or within 3 months before GPA diagnosis. Second VTE event-free survival rates were estimated. Results: Out of 147 patients initially screened for GPA and with at least one VTE, 84 met inclusion criteria. Median age at first VTE was 57 years. Incidence rate for second VTE was 8.4 events per 100 patient-years (95% CI: 5.7, 12.3). Eighty-three point three per cent of first VTEs and 57.7% of second VTEs occurred when disease was active (P < 0.001). Renal involvement and constitutional symptoms at the time of first VTE were associated with VTE recurrence. Conclusion: GPA has a high rate of VTE recurrence compared with the reported data in the general population with unprovoked VTE. Our results suggest that VTE in GPA is a recurrent co-morbidity, not always during active vasculitis, and more so in those with renal involvement and constitutional symptoms at the time of first VTE.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Kawasaki Disease.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of Kawasaki disease (KD), focusing on clinical scenarios more commonly addressed by rheumatologists. METHODS: Sixteen clinical questions regarding diagnostic testing, treatment, and management of KD were developed in the Patient/Population, Intervention, Comparison, and Outcomes (PICO) question format. Systematic literature reviews were conducted for each PICO question. We used the Grading of Recommendations, Assessment, Development and Evaluation method to assess the quality of evidence and formulate recommendations. Each recommendation required consensus from at least 70% of the Voting Panel. RESULTS: We present 1 good practice statement, 11 recommendations, and 1 ungraded position statement to guide the management of KD and clinical scenarios of suspected KD. These recommendations for KD are focused on situations in which input from rheumatologists may be requested by other managing specialists, such as in cases of treatment-refractory, severe, or complicated KD. The good practice statement affirms that all patients with KD should receive initial treatment with intravenous immunoglobulin (IVIG). In addition, we developed 7 strong and 4 conditional recommendations for the management of KD or suspected KD. Strong recommendations include prompt treatment of incomplete KD, treatment with aspirin, and obtaining an echocardiogram in the setting of unexplained macrophage activation syndrome or shock. Conditional recommendations include use of IVIG with other adjuvant agents for patients with KD and high-risk features of IVIG resistance and/or coronary artery aneurysms. These recommendations endorse minimizing risk to the patient by using established therapy promptly at disease onset and identifying situations in which adjunctive therapy may be warranted. CONCLUSION: These recommendations provide guidance regarding diagnostic strategies, use of pharmacologic agents, and use of echocardiography in patients with suspected or confirmed KD.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Kawasaki Disease.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of Kawasaki disease (KD), focusing on clinical scenarios more commonly addressed by rheumatologists. METHODS: Sixteen clinical questions regarding diagnostic testing, treatment, and management of KD were developed in the Patient/Population, Intervention, Comparison, and Outcomes (PICO) question format. Systematic literature reviews were conducted for each PICO question. We used the Grading of Recommendations, Assessment, Development and Evaluation method to assess the quality of evidence and formulate recommendations. Each recommendation required consensus from at least 70% of the Voting Panel. RESULTS: We present 1 good practice statement, 11 recommendations, and 1 ungraded position statement to guide the management of KD and clinical scenarios of suspected KD. These recommendations for KD are focused on situations in which input from rheumatologists may be requested by other managing specialists, such as in cases of treatment-refractory, severe, or complicated KD. The good practice statement affirms that all patients with KD should receive initial treatment with intravenous immunoglobulin (IVIG). In addition, we developed 7 strong and 4 conditional recommendations for the management of KD or suspected KD. Strong recommendations include prompt treatment of incomplete KD, treatment with aspirin, and obtaining an echocardiogram in the setting of unexplained macrophage activation syndrome or shock. Conditional recommendations include use of IVIG with other adjuvant agents for patients with KD and high-risk features of IVIG resistance and/or coronary artery aneurysms. These recommendations endorse minimizing risk to the patient by using established therapy promptly at disease onset and identifying situations in which adjunctive therapy may be warranted. CONCLUSION: These recommendations provide guidance regarding diagnostic strategies, use of pharmacologic agents, and use of echocardiography in patients with suspected or confirmed KD.

Role of non-invasive multimodality imaging in autoimmune pericarditis.

Systemic autoimmune diseases are an important cause of pericardial involvement and contribute to up to ∼22% cases of pericarditis with a known aetiology. The underlying mechanism for pericardial involvement varies with each systemic disease and leads to a poor understanding of its management. Multimodality imaging establishes the diagnosis and determines the type and extent of pericardial involvement. In this review, we elaborate upon various pericardial syndromes associated with different systemic autoimmune and autoinflammatory diseases and the multitude of imaging modalities that can be used to further characterize autoimmune pericardial involvement. Lastly, these forms of pericarditis have a greater likelihood of recurrence, and clinicians need to understand their unique treatment approaches to improve patient outcomes.

Kawasaki Disease: A Systematic Review and Meta-Analysis of Benefits and Harms of Common Treatments.

OBJECTIVE: Kawasaki disease (KD) is a self-limited vasculitis affecting medium-sized vessels with a predilection for the coronary arteries. Although treatment reduces the likelihood of developing of coronary artery aneurysms, 5% of patients still develop aneurysms despite treatment, making KD the leading cause of acquired heart disease in children in the United States. Consequently, there is a great deal of interest in optimizing treatment regimens, particularly for higher-risk patients, to decrease morbidity. The aim of this systematic review is to support the development of the American College of Rheumatology/Vasculitis Foundation for the diagnosis and management of KD, focusing on the more complex scenarios in which rheumatologists may become involved, such as high-risk and refractory disease. METHODS: Eighty-nine articles were considered for full review in this systematic literature review to address 16 Population, Intervention, Comparison, and Outcome questions related to KD. Data were abstracted in hierarchical fashion. Randomized control trials (RCTs) were considered first; if none were identified or if they contained insufficient information, comparative observational studies were then viewed, followed by single-arm observational studies/single arms from comparative studies. Only observational studies with more than 10 subjects with vasculitis were included. RESULTS: Eight RCTs and 28 observational studies that addressed the questions were identified. Two questions were addressed by RCTs, seven questions had at least some comparative observational studies, three questions were only addressed by single-arm data, and four questions had no relevant studies. CONCLUSION: This systematic review evaluates the benefits and harms of treatments for KD beyond first-line therapy.

Giant Cell Arteritis: A Systematic Review and Meta-Analysis of Test Accuracy and Benefits and Harms of Common Treatments.

This systematic review compares treatment options for patients with giant cell arteritis (GCA) and evaluates the test accuracy of studies used in diagnosing and monitoring GCA. These studies were used to inform evidence-based recommendations for the American College of Rheumatology (ACR)/Vasculitis Foundation (VF) vasculitis management guidelines. A systematic review and search of articles in English in Ovid Medline, PubMed, Embase, and the Cochrane Library was conducted. Articles were screened for suitability, and studies presenting the highest level of evidence were given preference. Three hundred ninety-nine full-text articles addressing GCA questions were reviewed to inform 27 Population, Intervention, Comparison, and Outcome questions. No benefit was found with intravenous glucocorticoids (GCs) compared with high-dose oral GCs in patients with cranial ischemic symptoms (27.4% vs 12.3%; odds ratio [OR] 2.39 [95% confidence interval (CI) 0.75-7.62], [very low certainty of evidence]). Weekly tocilizumab with a 26-week GC taper was superior to a 52-week GC taper in patients achieving remission (risk ratio 4.00 [95% CI 1.97-8.12], [low certainty of evidence]). Non-GC immunosuppressive therapies with GCs compared with GCs alone showed no statistically significant in relapse at 1 year (OR 0.87 [95% CI 0.73-1.04], [moderate certainty of evidence]) or serious adverse events (OR 0.81 [95% CI 0.54-1.20]; [moderate certainty of evidence]). Temporal artery biopsy has a sensitivity of 61% (95% CI 38%-79%) and a specificity of 98% (95% CI 95%-99%) in patients with a clinical diagnosis of suspected GCA. This comprehensive systematic review synthesizes and evaluates the benefits and harms of different treatment options and the accuracy of commonly used tests for the diagnosis and monitoring of GCA.

Polyarteritis Nodosa: A Systematic Review of Test Accuracy and Benefits and Harms of Common Treatments.

OBJECTIVE: The object of this study was to analyze the benefits and harms of different treatment options and to analyze test accuracy used in the evaluation of patients with primary systemic polyarteritis nodosa (PAN). METHODS: A systematic search of published English-language literature was performed in Ovid Medline, PubMed, Embase, and the Cochrane Library from the inception of each database through August 2019. Articles were screened for suitability in addressing patient, intervention, comparison, and outcome questions, with studies presenting the highest level of evidence given preference. RESULTS: Of 137 articles selected for data abstraction, we analyzed 21 observational studies and seven randomized controlled trials (RCTs). The results showed indirect evidence that a deep skin biopsy provides good diagnostic accuracy. A combined nerve and muscle biopsy should be obtained for patients with PAN with peripheral neuropathy. Cyclophosphamide with high-dose glucocorticoids (GCs) is effective as an induction treatment for newly diagnosed active and severe PAN. GC monotherapy is adequate in the majority of patients with nonsevere PAN, although it has a high relapse rate with GC taper. There was insufficient data in determining the optimal duration of non-GC and GC maintenance therapy. Tumor necrosis factor inhibitors are effective treatment for patients with deficiency of adenosine deaminase 2 (DADA2) with stroke and vasculitis manifestations. CONCLUSION: This comprehensive systematic review synthesizes and evaluates the harms and benefits of different treatment options and the accuracy of commonly used tests for the diagnosis of systemic PAN. Data for diagnosis and management of PAN and DADA2 are mostly limited to observational studies. More high-quality RCTs are needed.

Takayasu Arteritis: a Systematic Review and Meta-Analysis of Test Accuracy and Benefits and Harms of Common Treatments.

OBJECTIVE: Takayasu's arteritis (TAK) is a granulomatous large-vessel vasculitis primarily affecting the aorta and its proximal branches. TAK can be a difficult disease to diagnose and manage given the rarity of the disease as well as current limitations in biomarkers, imperfect imaging modalities, and few randomized controlled trials. METHODS: In developing the American College of Rheumatology/Vasculitis Foundation guideline for the management of TAK, we performed an extensive systematic literature review to guide our recommendations. We included RCTs first. When RCTs were not available, we included observational studies that reported on patient-important outcomes for the intervention and comparison. When studies with comparative data were not available, we included case series that present patient-important outcomes for either the intervention or the comparison. RESULTS: Three hundred forty-seven articles were included for full review to answer 27 population, intervention, comparison, and outcome questions related to TAK. Ten studies were evaluated that addressed the use of glucocorticoids (GCs), non-GC nonbiologic therapies, as well as biologics in treating TAK. A total of 33 studies, including 8 comparative studies, were included to determine the test accuracy of commonly available diagnostic tests for TAK. CONCLUSION: This comprehensive systematic review synthesizes and evaluates the benefits and harms of different treatment options and the accuracy of commonly used tests for the management of TAK.

Eosinophilic Granulomatosis with Polyangiitis: A Systematic Review and Meta-Analysis of Test Accuracy and Benefits and Harms of Common Treatments.

OBJECTIVE: Eosinophilic granulomatosis with polyangiitis (EGPA) is part of a group of vasculitides commonly referred to as antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), in addition to granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and renal-limited vasculitis. Patients with EGPA characteristically have asthma and marked peripheral eosinophilia with only approximately 30% to 35% of patients being myeloperoxidase (MPO)-ANCA positive, distinguishing it from other forms of AAV (1,2). The aim of this systematic review is to support the development of the American College of Rheumatology/Vasculitis Foundation guideline for the management of EGPA. METHODS: A systematic review was conducted of the literature for seven forms of primary systemic vasculitis (GPA, MPA, EGPA, polyarteritis nodosa, Kawasaki disease, giant cell arteritis, and Takayasu arteritis). The search was done for articles in English using Ovid Medline, PubMed, Embase, and the Cochrane Library. Articles were screened for suitability in addressing population/patients, intervention, comparator, and outcomes (PICO) questions, with studies presenting the highest level of evidence given preference. Two independent reviewers conducted a title/abstract screen and full-text review for each eligible study. RESULTS: The initial search, conducted in August 2019, included 13 800 articles, of which 2596 full-text articles were reviewed. There were 190 articles (addressing 34 PICO questions) reporting on the diagnosis and management of EGPA. CONCLUSION: This comprehensive systematic review synthesizes and evaluates the accuracy of commonly used tests for EGPA as well as benefits and toxicities of different treatment options.

Granulomatosis With Polyangiitis and Microscopic Polyangiitis: A Systematic Review and Meta-Analysis of Benefits and Harms of Common Treatments.

OBJECTIVE: The aim of this systemic review is to compare different treatments for patients with granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) to inform evidence-based recommendations for the American College of Rheumatology (ACR)/Vasculitis Foundation (VF) Vasculitis Management Guidelines. METHODS: A systemic review was conducted by searching articles in English using OVID Medline, PubMed, Embase, and the Cochrane Library. Articles were screened for suitability in addressing PICO questions, with studies presenting the highest level of evidence given preference. RESULTS: A total of 729 full-text articles addressing GPA and MPA PICO questions were reviewed. For remission induction, rituximab was shown to be noninferior to cyclophosphamide (CYC) (odds ratio [OR]: 1.55, moderate certainty of evidence). The addition of plasma exchange to induction therapy in severe disease did not improve the composite end point of death or end stage renal disease (hazard ratio [HR]: 0.86 [95% confidence interval CI: 0.65, 1.13], moderate certainty of evidence). In nonsevere disease, methotrexate was noninferior to CYC for induction of remission (remission at 6 months of 90% vs. 94%). For maintenance of remission, methotrexate and azathioprine showed no difference in the risk of relapse over a mean follow-up of 29 months (HR: 0.92, [95% CI: 0.52, 1.65]low certainty of evidence). As maintenance therapy, rituximab was superior to a tapering azathioprine strategy in major relapse-free survival at 28 months (HR: 6.61, [95% CI: 1.56, 27.96], moderate certainty of evidence). In two randomized trials, longer-term azathioprine maintenance therapy (>24 months) is associated with fewer relapses without an increase in adverse events. CONCLUSION: This comprehensive systematic review synthesizes and evaluates the benefits and toxicities of different treatment options for GPA and MPA.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis. METHODS: Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel. RESULTS: We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions. CONCLUSION: These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of antineutrophil cytoplasmic antibody-associated vasculitis (AAV), including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). METHODS: Clinical questions regarding the treatment and management of AAV were developed in the population, intervention, comparator, and outcome (PICO) format (47 for GPA/MPA, 34 for EGPA). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the quality of evidence and formulate recommendations. Each recommendation required ≥70% consensus among the Voting Panel. RESULTS: We present 26 recommendations and 5 ungraded position statements for GPA/MPA, and 15 recommendations and 5 ungraded position statements for EGPA. This guideline provides recommendations for remission induction and maintenance therapy as well as adjunctive treatment strategies in GPA, MPA, and EGPA. These recommendations include the use of rituximab for remission induction and maintenance in severe GPA and MPA and the use of mepolizumab in nonsevere EGPA. All recommendations are conditional due in part to the lack of multiple randomized controlled trials and/or low-quality evidence supporting the recommendations. CONCLUSION: This guideline presents the first recommendations endorsed by the American College of Rheumatology and the Vasculitis Foundation for the management of AAV and provides guidance to health care professionals on how to treat these diseases.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Polyarteritis Nodosa.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of systemic polyarteritis nodosa (PAN). METHODS: Twenty-one clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for systemic, non-hepatitis B-related PAN. Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to assess the quality of evidence and formulate recommendations. Each recommendation required ≥70% consensus among the Voting Panel. RESULTS: We present 16 recommendations and 1 ungraded position statement for PAN. Most recommendations were graded as conditional due to the paucity of evidence. These recommendations support early treatment of severe PAN with cyclophosphamide and glucocorticoids, limiting toxicity through minimizing long-term exposure to both treatments, and the use of imaging and tissue biopsy for disease diagnosis. These recommendations endorse minimizing risk to the patient by using established therapy at disease onset and identify new areas where adjunctive therapy may be warranted. CONCLUSION: These recommendations provide guidance regarding diagnostic strategies, use of pharmacologic agents, and imaging for patients with PAN.

2021 American College of Rheumatology/Vasculitis Foundation Guideline for the Management of Giant Cell Arteritis and Takayasu Arteritis.

OBJECTIVE: To provide evidence-based recommendations and expert guidance for the management of giant cell arteritis (GCA) and Takayasu arteritis (TAK) as exemplars of large vessel vasculitis. METHODS: Clinical questions regarding diagnostic testing, treatment, and management were developed in the population, intervention, comparator, and outcome (PICO) format for GCA and TAK (27 for GCA, 27 for TAK). Systematic literature reviews were conducted for each PICO question. The Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of the evidence. Recommendations were developed by the Voting Panel, comprising adult and pediatric rheumatologists and patients. Each recommendation required ≥70% consensus among the Voting Panel. RESULTS: We present 22 recommendations and 2 ungraded position statements for GCA, and 20 recommendations and 1 ungraded position statement for TAK. These recommendations and statements address clinical questions relating to the use of diagnostic testing, including imaging, treatments, and surgical interventions in GCA and TAK. Recommendations for GCA include support for the use of glucocorticoid-sparing immunosuppressive agents and the use of imaging to identify large vessel involvement. Recommendations for TAK include the use of nonglucocorticoid immunosuppressive agents with glucocorticoids as initial therapy. There were only 2 strong recommendations; the remaining recommendations were conditional due to the low quality of evidence available for most PICO questions. CONCLUSION: These recommendations provide guidance regarding the evaluation and management of patients with GCA and TAK, including diagnostic strategies, use of pharmacologic agents, and surgical interventions.