Evaluation of Ministry of Health, Labour and Welfare diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitis compared to ACR/EULAR 2022 classification criteria.

OBJECTIVE: This study aimed to evaluate the Ministry of Health, Labour and Welfare (MHLW) diagnostic criteria for antineutrophil cytoplasmic antibody-associated vasculitis compared to the new American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria. METHODS: Two nationwide cohort studies were used, and participants were categorised as having eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 and MHLW criteria. RESULTS: Of the entire patient population, only 10 (2.1%) were unclassifiable according to the MHLW probable criteria, while a significant number of patients (71.3%) met at least two criteria. The MHLW probable criteria for MPA had some challenges in differentiating between MPA and eosinophilic granulomatosis with polyangiitis, and the same was true for MHLW probable criteria for GPA in differentiating MPA from GPA. Nevertheless, improved classification results were obtained when the MHLW probable criteria were applied in the order of eosinophilic granulomatosis with polyangiitis, MPA, and GPA. CONCLUSIONS: The application of MHLW criteria could categorise a substantial number of patients with antineutrophil cytoplasmic antibody-associated vasculitis into one of the three antineutrophil cytoplasmic antibody-associated vasculitis diseases. The classification was in accordance with the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria when considering the order of application.

Validation of new ACR/EULAR 2022 classification criteria for anti-neutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVE: The objective of this study was to compare the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria with the previous classification algorithm for anti-neutrophil cytoplasmic antibody-associated vasculitis. METHODS: We used data from two nationwide, prospective, inception cohort studies. The enrolled patients were classified as having eosinophilic granulomatosis with polyangiitis (EGPA), granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) according to the new criteria; these criteria were compared with Watts' algorithm. RESULTS: Among 477 patients, 10.7%, 9.9%, and 75.6% were classified as having EGPA, GPA, and MPA, respectively; 6.1% were unclassifiable. Three patients met both the EGPA and MPA criteria, and eight patients met both the GPA and MPA criteria. Of 78 patients with GPA classified using Watts' algorithm, 27 (34.6%) patients were reclassified as having MPA. Ear, nose, and throat involvement was significantly less frequent in patients reclassified as having MPA than in those reclassified as having GPA. Of 73 patients unclassifiable using Watts' algorithm, 62 were reclassified as having MPA. All patients reclassified as having MPA were myeloperoxidase-anti-neutrophil cytoplasmic antibody positive, and 46 had interstitial lung disease. CONCLUSION: Although the American College of Rheumatology/European Alliance of Associations for Rheumatology 2022 criteria cause overlapping multiple criteria fulfilments in some patients, those items contribute to classifying unclassifiable patients using Watts' algorithm into MPA.

Chemoprophylaxis against Pneumocystis jirovecii pneumonia in Japanese patients with ANCA-associated vasculitis: An observational study.

OBJECTIVES: This study investigated the current practice of prophylactic treatment against Pneumocystis jirovecii pneumonia (PCP) and its effectiveness in patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: This study included 319 patients registered from 53 institutions in Japan and newly diagnosed with AAV. During the 2-year observation period, we examined the frequency of usage, effectiveness and safety of prophylactic drugs against PCP. RESULTS: Most patients received prophylactic drugs against PCP with the initiation of immunosuppressive agents, and >50% of them remained on chemoprophylaxis against PCP at 2 years after. The initial daily dose of oral prednisolone and the proportion of cyclophosphamide administration were higher in patients who received chemoprophylaxis against PCP than in those who did not. PCP occurred in nine patients (3%) and resulted in the death of four. The incidence rate of PCP in patients who received chemoprophylaxis was 1.13/100 patient-years (95% confidence interval, 0.38-2.68) and that in those who did not was 2.74 (1.04-6.02). The incidence rate ratio was 0.41 (0.11-1.53). CONCLUSIONS: The markedly low incidence of PCP may be attributed to the continuous chemoprophylaxis against PCP received by >50% of Japanese patients with AAV, although the effectiveness of chemoprophylaxis against PCP was not statistically confirmed.

Exploratory classification of clinical phenotypes in Japanese patients with antineutrophil cytoplasmic antibody-associated vasculitis using cluster analysis.

A novel patient cluster in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) may be identified in Japan. We performed multiple correspondence and cluster analysis regarding 427 clinically diagnosed AAV patients excluding eosinophilic granulomatosis with polyangiitis. Model 1 included the ANCA phenotype, items of the Birmingham Vasculitis Activity Score, and interstitial lung disease; model 2 included serum creatinine (s-Cr) and C-reactive protein (CRP) levels with model 1 components. In seven clusters determined in model 1, the ANCA-negative (n = 8) and proteinase 3-ANCA-positive (n = 41) groups emerged as two distinct clusters. The other five myeloperoxidase-ANCA-positive clusters were characterized by ear, nose, and throat (ENT) (n = 47); cutaneous (n = 36); renal (n = 256), non-renal (n = 33); and both ENT and cutaneous symptoms (n = 6). Four clusters in model 2 were characterized by myeloperoxidase-ANCA negativity (n = 42), without s-Cr elevation (< 1.3 mg/dL) (n = 157), s-Cr elevation (≥ 1.3 mg/dL) with high CRP (> 10 mg/dL) (n = 71), or s-Cr elevation (≥ 1.3 mg/dL) without high CRP (≤ 10 mg/dL) (n = 157). Overall, renal, and relapse-free survival rates were significantly different across the four clusters in model 2. ENT, cutaneous, and renal symptoms may be useful in characterization of Japanese AAV patients with myeloperoxidase-ANCA. The combination of s-Cr and CRP levels may be predictive of prognosis.

Usefulness of tissue inhibitor of metalloproteinase 1 as a predictor of sustained remission in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: We previously identified tissue inhibitor of metalloproteinase 1 (TIMP-1) as a biomarker of disease activity that distinguished mildly or highly active antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) from remission 6 months after the initiation of remission-induction therapy. In the present study, we investigated whether TIMP-1 is clinically useful as a predictor of relapse and sustained remission in AAV patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) during maintenance therapy. METHODS: The relationship between serum TIMP-1 levels and clinical outcomes in AAV patients receiving maintenance therapy was assessed using the follow-up data of a Japanese large-cohort study (the RemIT-JAV-RPGN study) and data collected from AAV patients on maintenance therapy in our hospital (the MAAV-EU study). RESULTS: In the RemIT-JAV RPGN study, serum levels of TIMP-1 were significantly higher in mildly active AAV patients with MPA and GPA 6 months after the initiation of remission-induction therapy than in patients in remission. Regarding maintenance therapy, elevated levels of TIMP-1 in patients in remission were associated with relapse and/or difficulty reducing the glucocorticoid dosage after 6 to 12 months. In the MAAV-EU study, serum levels of TIMP-1 were elevated in relapsed patients 6 months before relapse, earlier than the increase in serum levels of CRP. Analyses of both studies revealed that approximately 30% of patients in remission with a serum TIMP-1 level ≥ 150 ng/mL relapsed after 6 to 12 months, while the majority of patients with a TIMP-1 level < 150 ng/mL sustained remission for at least 12 months. CONCLUSION: We herein demonstrated that TIMP-1 is more useful as a predictive biomarker of sustained remission than as a predictor of relapse in maintenance therapy for AAV. TIMP-1 levels < 150 ng/mL are important for the long-term maintenance of remission and may be an indicator for the tapering or cessation of treatment.

Rationale of concomitant cyclophosphamide for remission-induction in patients with antineutrophil cytoplasmic antibody-associated vasculitis: A propensity score-matched analysis of two nationwide prospective cohort studies.

OBJECTIVES: We evaluated the effectiveness of cyclophosphamide for patients with microscopic polyangiitis and granulomatosis with polyangiitis. METHODS: Patients treated with cyclophosphamide and glucocorticoid (cyclophosphamide group) or glucocorticoid alone (non-cyclophosphamide group) for remission-induction were enrolled from two Japanese nationwide prospective inception cohort studies. The effectiveness and safety outcomes were compared before and after propensity score (PS)- matching. RESULTS: Proportion of patients achieving Birmingham Vasculitis Activity Score (BVAS)-remission and BVAS-remission plus a daily prednisolone dosage of ≤10 mg (GC-remission) by Month 6 were not significantly different between cyclophosphamide and non-cyclophosphamide groups before (n = 144 and 155) and after (n = 94 for each group) PS-matching. In myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA)-positive PS-matched patients, GC-remission by Month 6 was superior in CYC group (n = 82) than in non-CYC group (n = 91) (49 vs. 31%, p = .020). Overall, end-stage renal disease-free and relapse-free survival rates, Vasculitis Damage Index score, and proportions of serious infection were comparable between the two groups both in the unmatched and PS-matched patients. Prednisolone doses at any point after treatment initiation in the PS-matched patients were lower in the cyclophosphamide group than in a non-cyclophosphamide group. CONCLUSIONS: Concomitant cyclophosphamide use may improve GC-remission by Month 6 in MPO-ANCA-positive patients and could exert glucocorticoid sparing effect.

2020 international consensus on ANCA testing beyond systemic vasculitis.

This document follows up on a 2017 revised international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in granulomatosis with polyangiitis and microscopic polyangiitis and focuses on the clinical and diagnostic value of ANCA detection in patients with connective tissue diseases, idiopathic interstitial pneumonia, autoimmune liver diseases, inflammatory bowel diseases, anti-glomerular basement membrane (GBM) disease, infections, malignancy, and during drug treatment. Current evidence suggests that in certain settings beyond systemic vasculitis, ANCA may have clinical, pathogenic and/or diagnostic relevance. Antigen-specific ANCA targeting proteinase-3 and myeloperoxidase should be tested by solid phase immunoassays in any patient with clinical features suggesting ANCA-associated vasculitis and in all patients with anti-GBM disease, idiopathic interstitial pneumonia, and infective endocarditis associated with nephritis, whereas in patients with other aforementioned disorders routine ANCA testing is not recommended. Among patients with autoimmune liver diseases or inflammatory bowel diseases, ANCA testing may be justified in patients with suspected autoimmune hepatitis type 1 who do not have conventional autoantibodies or in case of diagnostic uncertainty to discriminate ulcerative colitis from Crohn's disease. In these cases, ANCA should be tested by indirect immunofluorescence as the target antigens are not yet well characterized. Many questions concerning the optimal use of ANCA testing in patients without ANCA-associated vasculitis remain to be answered.

International Consensus on ANCA Testing in Eosinophilic Granulomatosis with Polyangiitis.

An international consensus on anti-neutrophil cytoplasm antibodies (ANCA) testing in eosinophilic granulomatosis with polyangiitis (EGPA) is presented. ANCA, specific for myeloperoxidase (MPO), can be detected in 30-35% of EGPA patients. MPO-ANCA should be tested with antigen-specific immunoassays in any patient with eosinophilic asthma and clinical features suggesting EGPA, including constitutional symptoms, purpura, polyneuropathy, unexplained heart, gastrointestinal or kidney disease, and/or pulmonary infiltrates or hemorrhage. A positive MPO-ANCA result contributes to the diagnostic work­up for EGPA. Patients with MPO-ANCA associated EGPA have more frequently vasculitis features, such as glomerulonephritis, neuropathy, and skin manifestations than patients with ANCA negative EGPA. However, the presence of MPO-ANCA is neither sensitive nor specific enough to identify whether a patient should be subclassified as having "vasculitic" or "eosinophilic" EGPA. At present, ANCA status cannot guide treatment decisions, that is, whether cyclophosphamide, rituximab or mepolizumab should be added to conventional glucocorticoid treatment. In EGPA, monitoring of ANCA is only useful when MPO-ANCA was tested positive at disease onset.

Associated factors of poor treatment outcomes in patients with giant cell arteritis: clinical implication of large vessel lesions.

BACKGROUND: Relapses frequently occur in giant cell arteritis (GCA), and long-term glucocorticoid therapy is required. The identification of associated factors with poor treatment outcomes is important to decide the treatment algorithm of GCA. METHODS: We enrolled 139 newly diagnosed GCA patients treated with glucocorticoids between 2007 and 2014 in a retrospective, multi-center registry. Patients were diagnosed with temporal artery biopsy, 1990 American College of Rheumatology classification criteria, or large vessel lesions (LVLs) detected by imaging based on the modified classification criteria. Poor treatment outcomes (non-achievement of clinical remission by week 24 or relapse during 52 weeks) were evaluated. Clinical remission was defined as the absence of clinical signs and symptoms in cranial and large vessel areas, polymyalgia rheumatica (PMR), and elevation of C-reactive protein (CRP) levels. A patient was determined to have a relapse if he/she had either one of the signs and symptoms that newly appeared or worsened after achieving clinical remission. Re-elevation of CRP without clinical manifestations was considered as a relapse if other causes such as infection were excluded and the treatment was intensified. Associated factors with poor treatment outcomes were analyzed by using the Cox proportional hazard model. RESULTS: Cranial lesions, PMR, and LVLs were detected in 77.7%, 41.7%, and 52.5% of the enrolled patients, respectively. Treatment outcomes were evaluated in 119 newly diagnosed patients who were observed for 24 weeks or longer. The mean initial dose of prednisolone was 0.76 mg/kg/day, and 29.4% received any concomitant immunosuppressive drugs at baseline. Overall, 41 (34.5%) of the 119 patients had poor treatment outcomes; 13 did not achieve clinical remission by week 24, and 28 had a relapse after achieving clinical remission. Cumulative rates of the events of poor treatment outcomes in patients with and without LVLs were 47.5% and 17.7%, respectively. A multivariable model showed the presence of LVLs at baseline was significantly associated with poor treatment outcomes (adjusted hazard ratio [HR] 3.54, 95% CI 1.52-8.24, p = 0.003). Cranial lesions and PMR did not increase the risk of poor treatment outcomes. CONCLUSION: The initial treatment intensity in the treatment algorithm of GCA could be determined based upon the presence or absence of LVLs detected by imaging at baseline.

Adult-onset Still's disease-like manifestation accompanied by the cancer recurrence after long-term resting state.

A 72-year-old woman presented 9 months ago with skin rash on her bilateral forearms, which was followed by intermittent high fever, and stiffness and swelling of her bilateral fingers. She was diagnosed with seronegative rheumatoid arthritis (RA). She had a past history of breast cancer and had undergone breast preservation surgery 13 years previously. During admission in our hospital, she developed high fever and leukocytosis with a relapsing skin rash, sore throat, polyarthralgia and increased levels of serum ALT/AST and ferritin, all of which fulfilled Yamaguchi's criteria for adult-onset Still's disease (AOSD). While we tried to exclude other diseases that may show AOSD-like manifestations, pancytopenia rapidly developed and bone marrow biopsy strongly suggested the diagnosis of macrophage activating syndrome (MAS). Accordingly, steroid pulse therapy was begun, followed by oral glucocorticoid therapy. Thereafter, all of her symptoms improved, but systemic rash, inflammatory signs and pancytopenia gradually progressed. The results of bone marrow pathology, which returned 2 weeks after the beginning of treatment, revealed hemophagocytosis with CK7-positive/CK20-negative atypical cells that suggested recurrence of breast cancer in the bone marrow, thus all of her AOSD-like symptoms were considered to be paraneoplastic manifestations of late-onset metastatic breast cancer. She was treated successfully with chemotherapy. When we see the patients showing AOSD-like symptoms with a history of malignancy, we should consider the possibility of paraneoplastic syndrome due to cancer recurrence.

Histopathological classification of anti-neutrophil cytoplasmic antibody-associated glomerulonephritis in a nationwide Japanese prospective 2-year follow-up cohort study.

BACKGROUND: The prognostic value of the EUVAS-proposed histopathological classification of anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis has been evaluated throughout the world. Here, we performed a Japanese nationwide biopsy survey to assess the association between this histopathological classification and renal prognosis after 2-year follow-up in ANCA-associated glomerulonephritis. METHODS: We collected 67 renal biopsy materials of the 321 entries in the RemIT-JAV-RPGN cohort study, and assessed their histologies. Based on the EUVAS-proposed histopathological classification and some histological parameters, we statistically evaluated renal survival and the comparison of renal function for 2 years. RESULTS: Based on the histopathological classification, the largest number of biopsy samples belonged to the Focal class, followed by the Mixed, Crescentic, and Sclerotic classes (n = 30, 19, 10, 8, respectively). Although the number of events might be too low (four patients with renal death) to make this conclusion, the Focal and Mixed classes had higher renal-survival rates compared to the others in the renal-survival curve. Comparing renal function among all classes, the estimated glomerular filtration rate (eGFR) throughout 2-year follow-up period was significantly higher in the Focal class compared to the other 3 classes. The eGFR-values in the Crescentic, Mixed, and Sclerotic classes increased with time. Based on both combined results, the Focal class could be the best prognosis. CONCLUSION: This histopathological classification was valuable for both the stratification of renal function and the estimation of partial renal survival during 2-year follow-up in ANCA-associated glomerulonephritis.

Systematic review and meta-analysis for 2017 clinical practice guidelines of the Japan research committee of the ministry of health, labour, and welfare for intractable vasculitis for the management of ANCA-associated vasculitis.

OBJECTIVES: To provide evidence for the revision of clinical practice guideline (CPG) for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) by the Japan Research Committee for Intractable Vasculitis. METHODS: PubMed, CENTRAL, and the Japan Medical Abstracts Society were searched for articles published between January 1994 and January 2015 to conduct systematic review (SR), and the quality of evidence was assessed with GRADE approach. RESULTS: Nine randomized controlled trials (RCTs) and two non-RCTs were adopted for remission induction therapy, three RCTs and two non-RCTs for plasma exchange, and five RCTs and one non-RCT for remission maintenance therapy. A significant difference was found in efficacy and safety for the following comparisons. In the non-RCT adopted for remission induction therapy, glucocorticoid (GC) + cyclophosphamide (CY) was significantly superior to GC monotherapy regarding remission. GC + intravenous CY for remission induction therapy was superior to GC + oral CY regarding death at one year, serious adverse events, and serious infection. Concomitant use of plasma exchange for remission induction therapy of AAV with severe renal dysfunction reduced risk of end-stage renal disease versus non-users at month 3. CONCLUSION: This SR provided necessary evidence for developing CPG for the management of ANCA-associated vasculitis.

Tenosynovitis with Rice Body Formation Due to Mycobacterium Intracellulare Infection After Initiation of Infliximab Therapy.

BACKGROUND Rheumatoid arthritis tenosynovitis is difficult to discriminate from non-tuberculous tenosynovitis on the basis of radiological and pathological findings. CASE REPORT A 74-year-old woman with a 4-year history of rheumatoid arthritis was referred to our hospital to undergo treatment for uncontrollable tenderness and swelling in her right third metacarpophalangeal joint, right wrist, and left knee joint. In the previous year, she underwent surgery at a local hospital for the swelling in her right metacarpophalangeal joint, the information of which was not known precisely, but the swelling subsided in due course after an operation. We treated the patient with infliximab (monthly intravenous infusions of 150 mg), but 2 months later, she complained of exacerbation of the swelling in her right third metacarpophalangeal joint and right wrist, and fluid discharge that contained Mycobacterium intracellulare. After synovectomy and aggressive debridement in the palmar side of the right wrist, she was diagnosed as having granulomatous tenosynovitis caused by the M. intracellulare infection and abundant rice body formation in the right carpal tunnel area. We considered the rice bodies inside and outside the bursa, along with a history of tenosynovitis exacerbation after initiation of infliximab therapy (tumor necrosis factor alpha inhibitor [TNFi]), to be related to the M. intracellular infection. CONCLUSIONS Tenosynovitis caused by atypical mycobacteria is uncommon and usually affects the hand or wrist. Therefore, for early diagnosis, mycobacterial infection should be considered in cases of indolent chronic granulomatous tenosynovitis, especially in RA cases that recur after TNFi therapy is started.

Association Between Reappearance of Myeloperoxidase-Antineutrophil Cytoplasmic Antibody and Relapse in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Subgroup Analysis of Nationwide Prospective Cohort Studies.

OBJECTIVE: To evaluate clinical links between levels of myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and relapse in patients with ANCA-associated vasculitis (AAV) using a data set from 2 nationwide prospective cohort studies. METHODS: From the cohort studies, MPO-ANCA-positive patients who achieved remission during the 6 months after remission induction therapy were enrolled. We measured MPO-ANCA levels at months 0, 3, 6, 12, 18, 24, and at the time of relapse. The primary outcome measure was relapse. A nested case-control analysis and multivariable analysis were performed to investigate the relationship between ANCA reappearance and relapse. RESULTS: Of 271 patients, 183 were classified as having microscopic polyangiitis, 34 as having granulomatosis with polyangiitis, 15 as having eosinophilic granulomatosis with polyangiitis, and 39 were unclassifiable. The median age was 73 years, and 165 (61%) were female. In 195 patients (72%), MPO-ANCA levels decreased to normal levels within 6 months after commencement of treatment, and MPO-ANCA reappeared in 73 of 181 patients (40%) with complete follow-up data. Reappearance of MPO-ANCA was more frequent in patients with relapse than in 75 age- and sex-matched control patients without relapse (odds ratio 26.2 [95% confidence interval 8.2-101], P < 0.0001) after adjustment for confounding factors. CONCLUSION: Reappearance of MPO-ANCA could be a clinically useful biomarker for predicting relapse in patients with MPO-ANCA-positive AAV in remission. This suggests that routine MPO-ANCA monitoring should be implemented in this patient population.

Risk Factors for Relapse of Antineutrophil Cytoplasmic Antibody-associated Vasculitis in Japan: A Nationwide, Prospective Cohort Study.

OBJECTIVE: The aim was to elucidate the prognosis and risk factors associated with relapse during longterm remission maintenance therapy for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: Patients with newly diagnosed AAV (n = 156) were registered in the Remission Induction Therapy in Japanese patients with ANCA-associated Vasculitides (RemIT-JAV) study, and among them, 83 patients who achieved remission were enrolled and followed up for 24 additional months in our nationwide, prospective cohort study (Co-RemIT-JAV; registration number UMIN 000006373). Patterns of maintenance therapy, effectiveness, and safety were evaluated from months 25 to 48 after the RemIT-JAV. The primary outcome measure was the rate of relapse. Secondary outcome measures included overall and renal survival, risk factors associated with relapse, and incidence rates of serious infections. RESULTS: The patients comprised 35 men and 48 women aged 65.3 ± 12.6 years. Between months 25 and 48, the survival rate was 95% (79/83). Causes of death included 1 thyroid cancer, 1 infection, and 2 unknown reasons. Four patients had developed endstage renal disease (ESRD) by Month 24; 1 developed ESRD beyond Month 25. The relapse rate was 24% (20/83) from months 25 to 48. Multivariable analysis revealed that oral prednisolone ≤ 2.5 mg/day at Month 24 was a significant risk factor for relapse between months 25 and 48 (HR = 3.1, 95% CI 1.1-8.5). CONCLUSION: One-quarter of patients with AAV relapsed during maintenance therapy, and relapse was associated with the dose of oral prednisolone 24 months after the initiation of remission induction therapy in Japan.

Association of ETS1 polymorphism with granulomatosis with polyangiitis and proteinase 3-anti-neutrophil cytoplasmic antibody positive vasculitis in a Japanese population.

ETS proto-oncogene 1, transcription factor (ETS1) is involved in various immune responses. Genome-wide association studies on systemic lupus erythematosus in Chinese populations identified the association of ETS1 polymorphism in 3' untranslated region, rs1128334A, which was associated with lower ETS1 expression. In view of substantial sharing of susceptibility genes across multiple autoimmune diseases, we examined whether ETS1 is associated with a rare autoimmune rheumatic disease, anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Association of rs1128334 was tested in 466 Japanese patients with AAV and 1099 healthy controls by logistic regression analysis under the additive model. AAV patients were classified into 285 microscopic polyangiitis (MPA), 92 granulomatosis with polyangiitis (GPA), 56 eosinophilic GPA, and 33 unclassifiable AAV, according to the European Medicines Agency (EMEA) algorithm. Among the patients, 376 were positive for MPO-ANCA and 62 for PR3-ANCA. When the patients were classified according to the EMEA classification, rs1128334A allele was significantly increased in GPA (P = 0.0060, P c = 0.030, odds ratio (OR), 1.54; 95% confidence interval (CI), 1.13-2.10). With respect to the ANCA specificity, significant association was observed in PR3-ANCA positive AAV (P = 0.0042, P c = 0.021, OR, 1.72; 95% CI, 1.19-2.49). In conclusion, ETS1 polymorphism was suggested to be associated with GPA and PR3-ANCA positive AAV in a Japanese population.

Targeted proteomics reveals promising biomarkers of disease activity and organ involvement in antineutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: Targeted proteomics, which involves quantitative analysis of targeted proteins using selected reaction monitoring (SRM) mass spectrometry, has emerged as a new methodology for discovery of clinical biomarkers. In this study, we used targeted serum proteomics to identify circulating biomarkers for prediction of disease activity and organ involvement in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: A large-scale SRM assay targeting 135 biomarker candidates was established using a triple-quadrupole mass spectrometer coupled with nanoflow liquid chromatography. Target proteins in serum samples from patients in the active and remission (6 months after treatment) stages were quantified using the established assays. Identified marker candidates were further validated by enzyme-linked immunosorbent assay using serum samples (n = 169) collected in a large-cohort Japanese study (the RemIT-JAV-RPGN study). RESULTS: Our proteomic analysis identified the following proteins as biomarkers for discriminating patients with highly active AAV from those in remission or healthy control subjects: tenascin C (TNC), C-reactive protein (CRP), tissue inhibitor of metalloproteinase 1 (TIMP1), leucine-rich alpha-2-glycoprotein 1, S100A8/A9, CD93, matrix metalloproteinase 9, and transketolase (TKT). Of these, TIMP1 was the best-performing marker of disease activity, allowing distinction between mildly active AAV and remission. Moreover, in contrast to CRP, serum levels of TIMP1 in patients with active AAV were significantly higher than those in patients with infectious diseases. The serum levels of TKT and CD93 were higher in patients with renal involvement than in those without, and they predicted kidney outcome. The level of circulating TNC was elevated significantly in patients with lung infiltration. AAV severity was associated with markers reflecting organ involvement (TKT, CD93, and TNC) rather than inflammation. The eight markers and myeloperoxidase (MPO)-ANCA were clustered into three groups: MPO-ANCA, renal involvement (TKT and CD93), and inflammation (the other six markers). CONCLUSIONS: We have identified promising biomarkers of disease activity, disease severity, and organ involvement in AAV with a targeted proteomics approach using serum samples obtained from a large-cohort Japanese study. Especially, our analysis demonstrated the effectiveness of TIMP1 as a marker of AAV activity. In addition, we identified TKT and CD93 as novel markers for evaluation of renal involvement and kidney outcome in AAV.

Position paper: Revised 2017 international consensus on testing of ANCAs in granulomatosis with polyangiitis and microscopic polyangiitis.

Anti-neutrophil cytoplasmic antibodies (ANCAs) are valuable laboratory markers used for the diagnosis of well-defined types of small-vessel vasculitis, including granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA). According to the 1999 international consensus on ANCA testing, indirect immunofluorescence (IIF) should be used to screen for ANCAs, and samples containing ANCAs should then be tested by immunoassays for proteinase 3 (PR3)-ANCAs and myeloperoxidase (MPO)-ANCAs. The distinction between PR3-ANCAs and MPO-ANCAs has important clinical and pathogenic implications. As dependable immunoassays for PR3-ANCAs and MPO-ANCAs have become broadly available, there is increasing international agreement that high-quality immunoassays are the preferred screening method for the diagnosis of ANCA-associated vasculitis. The present Consensus Statement proposes that high-quality immunoassays can be used as the primary screening method for patients suspected of having the ANCA-associated vaculitides GPA and MPA without the categorical need for IIF, and presents and discusses evidence to support this recommendation.

Comparison of the Phenotype and Outcome of Granulomatosis with Polyangiitis Between UK and Japanese Cohorts.

OBJECTIVE: There are differences in the frequencies of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis subgroups between different geographic regions, and we have reported differences in the phenotype of microscopic polyangiitis between Europe and Japan. In this retrospective observational study, we compared phenotypes and outcomes of granulomatosis with polyangiitis (GPA) between the United Kingdom and Japan. METHODS: We identified 128 UK and 82 Japanese patients with GPA diagnosed between 2000 and 2012. We evaluated baseline characteristics including ANCA status and organ involvement, treatment, patient and renal survival, and time to first relapse. RESULTS: Median age at onset was higher in Japan than in the UK (62.2 yrs vs 57.5 yrs, p < 0.01). The proportion of patients with proteinase 3 (PR3)-ANCA was lower in Japan than in the UK (61.0% vs 85.2%, p < 0.01), while the proportion of myeloperoxidase-ANCA was higher in Japan than the UK (34.1% vs 8.6%, p < 0.01). Serum creatinine at diagnosis was lower in Japan than the UK (68.1 µmol/l vs 101.0 µmol/l, p < 0.01). Respiratory involvement was more frequent in Japan than the UK (69.5% vs 40.6%, p < 0.01). In both countries, most patients received both glucocorticoids and cyclophosphamide. At 60 months the cumulative survival rates were 87.6% and 94.3% in Japan and the UK, respectively (p = 0.03). At 60 months the cumulative relapse rates were 37.1% and 68.1% in Japan and the UK, respectively (p < 0.01). CONCLUSION: Japanese patients with GPA were older at disease onset, with less PR3-ANCA positivity, milder renal dysfunction, and more frequent respiratory involvement than UK patients. The relapse-free survival rate was higher in Japan than the United Kingdom.