Explore the vast range of titles available.

Background: There has been a lack of appropriate classification criteria for vasculitis in children. Objective: To develop a widely accepted general classification for the vasculitides observed in children and specific and realistic classification criteria for common childhood vasculitides (Henoch-Schönlein purpura (HSP), Kawasaki disease (KD), childhood polyarteritis nodosa (PAN), Wegener’s granulomatosis (WG), and Takayasu arteritis (TA)). Methods: The project was divided into two phases: (1) the Delphi technique was used to gather opinions from a wide spectrum of paediatric rheumatologists and nephrologists; (2) a consensus conference using nominal group technique was held. Ten international experts, all paediatricians, met for the consensus conference. Agreement of at least 80% of the participants was defined as consensus. Results: Consensus was reached to base the general working classification for childhood vasculitides on vessel size. The small vessel disease was further subcategorised into “granulomatous” and “non-granulomatous.” Final criteria were developed to classify a child as HSP, KD, childhood PAN, WG, or TA, with changes introduced based on paediatric experience. Mandatory criteria were suggested for all diseases except WG. Conclusions: It is hoped that the suggested criteria will be widely accepted around the world because of the reliable techniques used and the international and multispecialist composition of the expert group involved.

ObjectiveTo examine the performance in adults of the European Alliance of Associations for Rheumatology (EULAR)/Pediatric Rheumatology European Society (PReS)-endorsed Ankara 2008 classification criteria for IgA vasculitis (IgAV).MethodsThe EULAR/PReS/Ankara 2008 classification criteria for IgAV were applied to patients enrolled in an international observational cohort which included patients with IgAV and comparators with other forms of small-vessel and medium-vessel vasculitis. After the initial assessment of the performance of the criteria, possible revisions to increase the performance were tested. The revised criteria were then assessed in an independent validation cohort within a multicentre Turkish vasculitis registry.ResultsThe dataset consisted of 178 IgAV cases and 1705 comparators. The Ankara 2008 criteria require skin involvement plus one of the following four criteria: abdominal pain, a biopsy showing IgA deposition, arthritis or arthralgia, or renal involvement (any haematuria and/or proteinuria). The specificity of the criteria improved when a positive test for anti-neutrophil cytoplasmic autoantibody or blood cryoglobulins was considered an exclusion criterion. The revised criteria had a sensitivity of 76.4% (95% CI 69.8% to 82.2%) and a specificity of 94.5% (95.0% CI 93.4% to 95.1%). In the validation set, the sensitivity and specificity of the revised criteria were 97.8% (95% CI 94.0% to 99.0%) and 85.0% (95.0% CI 78.0% to 90.0%), respectively.ConclusionThe revised EULAR/PReS-endorsed Ankara 2008 IgAV classification criteria perform well in adults with IgAV and are appropriate for use in clinical research.

OBJECTIVE To test the usefulness of the Chapel Hill nomenclature, supplemented with surrogate parameters, as diagnostic criteria for primary vasculitides. METHODS To prospectively evaluate vasculitis patients according to a standardised clinical and para-clinical programme. In accordance with the Chapel Hill publication surrogate parameters were used: proteinuria, haematuria and red blood cell casts (glomerulonephritis), angiographic or ultrasonic demonstration of aneurysms or stenoses (arteritis), radiological lung infiltrates or cavitations of more than one month's duration (granuloma in the lungs), bloody nasal discharge or crusts, chronic sinusitis, otitis and/or mastoiditis, bone and/or cartilage destruction, and acute hearing loss (granuloma in upper airways). RESULTS The following entities were diagnosed: giant cell arteritis (n=14), Takayasu arteritis (n=1), polyarteritis nodosa (n=2), Wegener's granulomatosis (n=27), Churg-Strauss syndrome (n=2), microscopic polyangiitis (n=12), Henoch-Schönlein purpura (n=2), cutaneous leucocytoclastic angiitis (n=37), and secondary vasculitis (n=21). Giant cell arteritis and cutaneous leucocytoclastic angiitis were in all cases diagnosed by biopsy. Using the Chapel Hill nomenclature supplemented with surrogate parameters, only 8 of 27 patients were diagnosed with Wegener's granulomatosis, and 3 of 12 cases with microscopic polyangiitis. The number of patients in the remaining diagnostic entities were considered to few to evaluate. CONCLUSIONS The Chapel Hill nomenclature, supplemented with surrogate parameters, failed to act as diagnostic criteria in Wegener's granulomatosis and microscopic polyangiitis. The following diagnostic criteria are proposed for Wegener's granulomatosis: (1) Biopsy or surrogate parameter for granulomatous inflammation in the respiratory system and (2) Biopsy verified necrotising vasculitis in small to medium sized vessels or biopsy/surrogate parameter for glomerulonephritis or positive PR3-ANCA test and (3) Lack of eosinophilia in blood and biopsy samples. The following diagnostic criteria are proposed for microscopic polyangiitis: (1) Biopsy verified necrotising vasculitis in small vessels and/or glomerulonephritis with few or no immune deposits and (2) Involvement of more than one organ system as indicated by biopsy verified vasculitis in small to medium sized vessels or surrogate parameter for glomerulonephritis and (3) Lack of biopsy and surrogate parameter for granulomatous inflammation in the respiratory system. Using these criteria all Wegener's patients and 9 of 12 patients with microscopic polyangiitis could be diagnosed.

Key Points Anti-neutrophil cytoplasmic antibodies (ANCAs) specific for leukocyte proteinase 3 and myeloperoxidase — PR3-ANCAs and MPO-ANCAs, respectively — define distinct conditions among patients with ANCA-associated vasculitides (AAV) Classification of patients with small-vessel vasculitis based on ANCA specificity is feasible and could provide timely and clinically relevant diagnostic information more readily than clinical syndromes based on current classification systems Patients with PR3-AAV and MPO-AAV do not share the same genetic background and have only some pathophysiologic mechanisms in common ANCA specificity predicts response to induction therapies: rituximab is more effective than cyclophosphamide in patients with PR3-AAV (by contrast, both treatments are similarly effective in patients with MPO-AAV) ANCA specificity predicts differences in long-term prognosis: patients with PR3-ANCAs are at higher risk of relapse than patients with MPO-ANCAs Future studies should evaluate whether the duration of immunosuppressive maintenance therapy should be different for patients with PR3-AAV versus those with MPO-AAV after remission induction The type of anti-neutrophil cytoplasmic antibody (ANCA) seems to be a major determinant of clinical presentation in ANCA-associated vasculitides (AAV). The authors of this Review argue that ANCA specificity for PR3 or MPO provides clinically useful information and should be used in the classification of AAV. The anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) are a heterogeneous group of rare syndromes characterized by necrotizing inflammation of small and medium-sized blood vessels and the presence of ANCAs. Several clinicopathological classification systems exist that aim to define homogeneous groups among patients with AAV, the main syndromes being microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA) and eosinophilic GPA (EGPA). Two main types of ANCA can be detected in patients with AAV. These ANCAs are defined according to their autoantigen target, namely leukocyte proteinase 3 (PR3) and myeloperoxidase (MPO). Patients with GPA are predominantly PR3-ANCA-positive, whereas those with MPA are predominantly MPO-ANCA-positive, although ANCA specificity overlaps only partially with these clinical syndromes. Accumulating evidence suggests that ANCA specificity could be better than clinical diagnosis for defining homogeneous groups of patients, as PR3-ANCA and MPO-ANCA are associated with different genetic backgrounds and epidemiology. ANCA specificity affects the phenotype of clinical disease, as well as the patient's initial response to remission-inducing therapy, relapse risk and long-term prognosis. Thus, the classification of AAV by ANCA specificity rather than by clinical diagnosis could convey clinically useful information at the time of diagnosis.

The nomenclature and classification of vasculitis has been difficult and controversial for many decades. This is problematic both for research on vasculitis as well as clinical care of patients with vasculitis. The first (1994) International Chapel Hill Consensus Conference on the Nomenclature of Systemic Vasculitides (CHCC) proposed names and definitions for the most common forms of vasculitis. Since then, there have been substantial advances in our understanding of vasculitis and changes in medical terminology. In addition, CHCC 1994 did not propose a nomenclature for some relatively common forms of vasculitis, such as vasculitis secondary to other diseases. To address these issues, a second International Chapel Hill Consensus Conference was held in 2012. The goals were to change names and definitions as appropriate, and add important categories of vasculitis not included in CHCC 1994. This overview summarizes the 2012 CHCC and points out the changes compared to the 1994 CHCC. Notable changes include the introduction of new terms such as granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis and immunoglobulin A vasculitis and the inclusion of categories for variable vessel vasculitis and secondary forms of vasculitis.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disorder which affects small- and, to a lesser degree, medium-sized vessels. ANCA-associated vasculitis encompasses three disease phenotypes: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). This classification is largely based on clinical presentations and has several limitations. Recent research provided evidence that genetic background, risk of relapse, prognosis, and co-morbidities are more closely related to the ANCA serotype, proteinase 3 (PR3)-ANCA and myeloperoxidase (MPO)-ANCA, compared to the disease phenotypes GPA or MPA. This finding has been extended to the investigation of biomarkers predicting disease activity, which again more closely relate to the ANCA serotype. Discoveries related to the immunopathogenesis translated into clinical practice as targeted therapies are on the rise. This review will summarize the current understanding of the immunopathogenesis of ANCA-associated vasculitis and the interplay between ANCA serotype and proposed disease biomarkers and illustrate how the extending knowledge of the immunopathogenesis will likely translate into development of a personalized medicine approach in the management of ANCA-associated vasculitis.

Objectives To validate the previously proposed classification criteria for Henoch–Schönlein purpura (HSP), childhood polyarteritis nodosa (c-PAN), c-Wegener granulomatosis (c-WG) and c-Takayasu arteritis (c-TA). Methods Step 1: retrospective/prospective web-data collection for children with HSP, c-PAN, c-WG and c-TA with age at diagnosis ≤18 years. Step 2: blinded classification by consensus panel of a representative sample of 280 cases. Step 3: statistical (sensitivity, specificity, area under the curve and κ-agreement) and nominal group technique consensus evaluations. Results 827 patients with HSP, 150 with c-PAN, 60 with c-WG, 87 with c-TA and 52 with c-other were compared with each other. A patient was classified as HSP in the presence of purpura or petechiae (mandatory) with lower limb predominance plus one of four criteria: (1) abdominal pain; (2) histopathology (IgA); (3) arthritis or arthralgia; (4) renal involvement. Classification of c-PAN required a systemic inflammatory disease with evidence of necrotising vasculitis OR angiographic abnormalities of medium-/small-sized arteries (mandatory criterion) plus one of five criteria: (1) skin involvement; (2) myalgia/muscle tenderness; (3) hypertension; (4) peripheral neuropathy; (5) renal involvement. Classification of c-WG required three of six criteria: (1) histopathological evidence of granulomatous inflammation; (2) upper airway involvement; (3) laryngo-tracheo-bronchial involvement; (4) pulmonary involvement (x-ray/CT); (5) antineutrophilic cytoplasmic antibody positivity; (6) renal involvement. Classification of c-TA required typical angiographic abnormalities of the aorta or its main branches and pulmonary arteries (mandatory criterion) plus one of five criteria: (1) pulse deficit or claudication; (2) blood pressure discrepancy in any limb; (3) bruits; (4) hypertension; (5) elevated acute phase reactant. Conclusion European League Against Rheumatism/Paediatric Rheumatology International Trials Organisation/Paediatric Rheumatology European Society propose validated classification criteria for HSP, c-PAN, c-WG and c-TA with high sensitivity/specificity.

Background: The classification of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN) for epidemiology studies is confusing. The existing schemes such as American College of Rheumatology (ACR) criteria, Chapel Hill Consensus Conference (CHCC) definitions and Lanham criteria produce overlapping and conflicting classifications, making it difficult to compare incidence figures. Aim: To develop a consensus method of using these criteria and definitions for epidemiological studies to permit comparison without confounding by classification. Methods: A stepwise algorithm was developed by consensus between a group of doctors interested in the epidemiology of vasculitis. The aim was to categorise patients with Wegener’s granulomatosis, microscopic polyangiitis (MPA), Churg–Strauss syndrome (CSS) and PAN into single clinically relevant categories. The ACR and Lanham criteria for CSS, and ACR criteria for Wegener’s granulomatosis were applied first, as these were considered to be the most specific. Surrogate markers for Wegener’s granulomatosis were included to distinguish Wegener’s granulomatosis from MPA. MPA was classified using the CHCC definition and surrogate markers for renal vasculitis. Finally, PAN was classified using the CHCC definition. The algorithm was validated by application to 20 cases from each centre and 99 from a single centre, followed by a paper case exercise. Results: A four-step algorithm was devised. It successfully categorises patients into a single classification. There was good correlation between observers in the paper case exercise (91.5%; unweighted κ = 0.886). Conclusion: The algorithm achieves its aim of reliably classifying patients into a single category. The use of the algorithm in epidemiology studies should permit comparison between geographical areas.

Objective This study aimed to evaluate the utility of ANCA specificity as a primary criterion for classifying AAV subtypes to simplify the diagnostic process without compromising accuracy. Methods A retrospective cohort study was conducted involving 310 patients diagnosed with AAV between January 2015 and December 2023 across three tertiary care centers affiliated with Peking University. Patients were reclassified using three methods: the European Medicines Agency (EMA) algorithm, the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) criteria, and ANCA specificity-based classification. Concordance between classification systems was assessed using Cohen’s kappa coefficients. Results ANCA specificity-based classification demonstrated substantial to almost perfect agreement with the 2022 ACR/EULAR criteria for MPA/MPO-AAV (kappa = 0.806) and GPA/PR3-AAV (kappa = 0.663). Many patients initially classified as GPA under the EMA algorithm were reclassified as MPA when using ANCA specificity. EGPA classification remained consistent across all methods (kappa = 0.725 between EMA and ACR/EULAR), suggesting that ANCA specificity is less critical for EGPA. The use of ANCA specificity simplified the classification process, aligning closely with the underlying pathophysiology of AAV subtypes. Conclusion ANCA specificity serves as a valuable adjunct in the classification of AAV, particularly for distinguishing between MPA and GPA. Utilizing ANCA serotypes can simplify the diagnostic process, potentially facilitating earlier diagnosis and targeted treatment. For EGPA, traditional classification criteria remain effective. Incorporating ANCA specificity into clinical practice may enhance diagnostic accuracy and improve patient outcomes in AAV management. Key Points • ANCA-based classification aligns strongly with the 2022 ACR/EULAR criteria for MPA and GPA, providing a simplified diagnostic approach. • Adopting this approach can streamline the classification process, reduce invasive procedures, and enable earlier diagnosis while maintaining high concordance with established systems.

The 2003 International Society of Nephrology/Renal Pathology Society (ISN/RPS) pathological classification system of lupus nephritis specified the importance of vascular damage and indicated this should be included in the diagnostic summary. Few pathological studies of lupus nephritis, however, focus on the patterns of renal vascular involvement. Here we assessed renal vascular lesions in lupus nephritis based on the 2003 ISN/RPS classification system and evaluated their association with clinical and pathological data in a large cohort from a single center in China. Among 341 patients with lupus nephritis, 279 were diagnosed with single or multiple renal vascular lesions that included 253 with vascular immune complex deposits, 82 with atherosclerosis, 60 with thrombotic microangiopathy, 13 with noninflammatory necrotizing vasculopathy, and 2 with true renal vasculitis. Patients with thrombotic microangiopathy had the poorest renal outcome. In multivariate Cox hazard analysis after inclusion of renal vascular lesions, the new chronicity index score became a significantly better independent risk factor for renal outcome (hazard ratio 2.32). Thus, renal vascular lesions are common in lupus nephritis and closely correlate with clinical disease activity and renal outcome. Inclusion of a detailed description of renal vascular lesions in the ISN/RPS classification of lupus nephritis may strengthen its predictive value for renal outcome.