Incidence and disease burden of autoimmune inflammatory rheumatic diseases after non-pharmaceutical interventions in the COVID-19 era: A nationwide observational study in Korea.

BACKGROUND: Infections are considered risk factors for autoimmune inflammatory rheumatic diseases (AIRDs), the incidence of which is considered to have been impacted by the COVID-19 pandemic. The impact of non-pharmaceutical interventions (NPIs) on the incidence of AIRDs and their associated health care services and medical expenses in Korea was investigated. METHODS: We included all AIRD cases reported between January 2016 and February 2021 based on the National Health Insurance Service data. We evaluated changes in incidence trends for each AIRD before and after NPI implementation (Feb 2020 to Feb 2021) using segmented regression analysis. Changes in health care utilization and medical costs for each AIRD before and after NPI implementation were also investigated. RESULTS: After NPI implementation, monthly incidence rates declined significantly by 0.205 per 1 000 000 (95% confidence interval [CI], -0.308 to -0.101, p < .001) in patients with systemic lupus erythematosus (SLE). No significant changes in the incidence of all AIRDs other than SLE were observed before and after implementation. Further, annual outpatient department visits per patient were lower during implementation for all diseases, except juvenile idiopathic arthritis (JIA). The prescription days per outpatient visit increased significantly during implementation for all diseases, except JIA and ankylosing spondylitis. During implementation, the total annual medical costs per patient tended to decrease for all diseases, except JIA and mixed connective tissue disease. CONCLUSION: Implementation of NPIs to contain the pandemic led to a reduction in the incidence of SLE and changed patterns of medical care utilization and treatment cost for most AIRDs.

Overlap syndrome of systemic sclerosis with antineutrophil cytoplasmic antibody-associated vasculitis according to 2022 ACR/EULAR criteria.

BACKGROUND/AIMS: This study applied the 2022 American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) criteria for antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) to patients with systemic sclerosis (SSc) and investigated the frequency of overlap syndrome of SSc and AAV (SSc-AAV-OS). METHODS: Among the 232 patients diagnosed with SSc, 105 with signs suggestive of small- or medium-vessel vasculitis, which were defined as the present of interstitial lung disease (ILD), peripheral neuropathy, or suspected renal vasculitis, were included in this study and analyzed. RESULTS: Among the 105 SSc patients, the detection rate of ANCA was 19.0%. When the 2022 ACR/EULAR criteria were applied, the frequency of SSc-AAV-OS was 20.0%, which was much higher than 1.7% reported with previous criteria for AAV. ANCA positivity contributed to the reclassification of SSc-AAV-OS more than ANCA negativity in SSc patients with signs suggestive of small- or medium-vessel vasculitis. CONCLUSION: The frequency of SSc-AAV-OS in SSc patients with signs suggestive of small- or medium-vessel vasculitis at diagnosis was 20.0%. Therefore, we suggest that physicians should perform ANCA tests in SSc patients exhibiting signs suggestive of small- or medium-vessel vasculitis and apply the new criteria for AAV.

Circulating cold-inducible RNA-binding protein levels in microscopic polyangiitis and granulomatosis with polyangiitis : Correlation with disease activity.

OBJECTIVE: This study investigated whether circulating cold-inducible RNA-binding protein (CIRP) could be a biomarker to reflect the current activity, function, and damage status in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). METHODS: This study selected 39 MPA and 26 GPA patients. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-specific indices include the Birmingham Vasculitis Activity Index (BVAS), five-factor score (FFS), the Korean version of the Short-Form 36-Item Health Survey (SF-36) physical component summary (PCS) and mental component summary (MCS), and the vasculitis damage index (VDI). The highest tertile of BVAS was defined as high activity of AAV. RESULTS: The median age of the study subjects was 65.0 years and 53.8% were women. The median BVAS, FFS, SF-36 PCS, MCS, and VDI scores were 12.0, 2.0, 47.5, 50.3, and 3.0, respectively. The median circulating CIRP level was 6.4 ng/mL. Among the four AAV-specific indices, circulating CIRP was significantly correlated with BVAS (r = 0.256). Using the receiver operator characteristic curve, the cut-off of circulating CIRP for high activity of AAV was 6.16 ng/mL. High activity of AAV was identified more frequently in patients with circulating CIRP ≥ 6.16 ng/mL than in those with circulating CIRP < 6.16 ng/mL (48.6% vs. 21.4%). In addition, patients with circulating CIRP ≥ 6.16 ng/mL exhibited a significantly higher risk for high activity of AAV than those with circulating CIRP < 6.16 ng/mL (relative risk 3.474). CONCLUSION: This study suggests the clinical potential of circulating CIRP as a biomarker for reflecting the current BVAS and predicting high activity of AAV in patients with MPA and GPA.

Antineutrophil cytoplasmic antibody-associated vasculitis classification by cluster analysis based on clinical phenotypes: a single-center retrospective cohort study.

OBJECTIVE: Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) refers to a group of small vessel inflammatory disorders. Overlapping clinical phenotypes of AAV subgroups continually provoke controversies over their diagnostic and classification criteria. METHODS: Using the agglomerative hierarchical clustering method, we classified 210 Korean patients diagnosed with AAV into mutually exclusive clusters according to Birmingham Vasculitis Activity Score items, ANCA specificity, sex, and age. We analyzed the resulting clusters' outcomes to investigate the clinical significance of the classification. We proposed a distance-based algorithm of patient assignment and explored its clinically relevant modification. RESULTS: In total, 116 patients (55%) had microscopic polyangiitis, 53 (25%) had granulomatosis with polyangiitis, and 42 (20%) had eosinophilic granulomatosis with polyangiitis. Our model grouped the patients into five clusters, namely, "limited proteinase 3 (PR3)-ANCA vasculitis," "generalized PR3-ANCA vasculitis," "ANCA-negative vasculitis," "renal-limited vasculitis," and "myeloperoxidase-ANCA vasculitis." Patients clustered under "generalized PR3-ANCA vasculitis" had a higher relapse rate (hazard ratio [HR] = 2.12, P = 0.067). The incidence of end-stage renal disease was higher in patients belonging to the "renal-limited vasculitis" cluster (HR=1.50, P=0.03), and those in the "ANCA-negative vasculitis" cluster experienced a relatively milder clinical course of AAV (mortality = 0). CONCLUSION: Because the clusters were naturally derived from their distinguished phenotypes and have different clinical courses, our clustering method may be a more clinically relevant classification system for AAV, revealing its phenotypic diversity. We also proposed a simple and intuitive distance-based assignment algorithm, which can be easily modified according to specific clinical needs. Key Points • In this study with a single-center AAV cohort, we showed that AAV can be divided into five distinct subclasses with different disease courses based on the clinical and laboratory features of the patients. • Our study revealed ethnic differences in AAV manifestation and suggests that physicians may need to analyze their own AAV patients to assess the disease status of AAV patients. • We proposed a distance-based cluster membership assignment method that can be clinically modified to fit the specific purpose of grouping patients.

Soluble triggering receptor expressed on myeloid cell-1 reflects the cross-sectional activity of microscopic polyangiitis and granulomatosis with polyangiitis.

Objectives: We investigated whether soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) reflects cross-sectional activity of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). Methods: Forty-seven MPA and 32 GPA patients with well-documented clinical records and stored sera were enrolled. sTREM-1 levels were evaluated using Magnetic Luminex® assay, and disease activity was assessed using Birmingham vasculitis activity score (BVAS). Patients were divided into two groups according to the upper and lower halves of BVAS. Receiver operator characteristic (ROC) curve analysis was used to identify cut-off for determining upper half of BVAS. Linear and binary logistic regression was performed to evaluate the association between sTREM-1 and disease activity and status. Results: The median age of patients was 67.0 years, and 58.2 % were women. The median BVAS and sTREM-1 were 12.0 and 467.1 pg/mL. sTREM-1 was significantly correlated with BVAS along with five-factor score, Short-Form 36-Item Health Surveys, and C-reactive protein. In multivariable linear regression analysis, erythrocyte sedimentation rate (standardised ß 0.241), and sTREM-1 (standardised ß 0.288) were correlated with BVAS. ROC analysis revealed that the cut-off of sTREM-1 for the upper half of BVAS was 474.1 pg/mL. MPA and GPA patients with sTREM-1 ≥474.1 pg/mL exhibited a significantly higher risk for the upper half of BVAS than those without (relative risk 5.932). Multivariable logistic regression analysis demonstrated sTREM-1 ≥474.1 pg/mL (odds ratio 5.662) was associated with the upper half of BVAS. Conclusion: sTREM-1 reflects the activity of MPA and GPA, suggesting its role as a potential biomarker for assessing disease severity.

Renal histopathological predictors of end-stage kidney disease in ANCA-associated vasculitis with glomerulonephritis: a single-centre study in Korea.

This study investigated whether histopathological classification and histologic lesion scores could significantly and independently predict the progression to end-stage kidney disease (ESKD) in Korean patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis-glomerulonephritis (AAV-GN). This study included 113 patients with AAV-GN confirmed by kidney biopsy. The glomerular, tubulointerstitial, and vascular lesions were systematically assessed using a scoring system. The scoring system was adopted from the Banff scoring system but also the Oxford study and the revision of the ISN/RPS. For comparison, the scores were classified into two groups; the low, and the high, and the difference was investigated between ESKD and non-ESKD groups using Cox proportional analysis. At diagnosis, the median age was 59.0 years and 33.6% were males. Of 113 patients, 44.2% had ESKD progression during follow-up. There were significant differences in several kidney-, inflammation-, and AAV-pathogenesis-related variables between AAV-GN patients with ESKD and those without. The sclerotic class exhibited the worst renal prognosis among the four histopathological classes. Among histopathological features, high interstitial fibrosis, tubular atrophy and global glomerulitis scores were significantly associated with ESKD progression. Whereas multivariable Cox analysis revealed only a high global glomerulitis score which means global endocapillary hypercellularity in a larger number of glomeruli is an independent predictor of ESKD progression. Moreover, among clinical and histopathological features, a high global glomerulitis score could also predict ESKD progression in addition to serum blood urea nitrogen and creatinine. This study demonstrated the worst renal prognosis for the sclerotic class and first discovered that a high global glomerulitis score was an independent predictor of ESKD in patients with AAV-GN.

A prognostic immune nutritional index can predict all-cause mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

Background: Studies have proposed that nutritional and immune-related markers are relevant with patient outcomes of various medical conditions and could be a useful indicator of patient prognostication. Objectives: This study investigated whether a prognostic immune nutritional index (PINI) at diagnosis could predict adverse clinical outcomes in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Design: A retrospective, single-centre observational cohort analysis of patients with AAV. Methods: All-cause mortality and end-stage renal disease (ESRD) were investigated outcomes during the observation period. PINI was calculated by serum albumin (g/mL) × 0.9 - monocyte count (/mm3) × 0.0007, and the optimal cut-off of PINI was obtained using a Youden index-based bootstrapping method. Cox hazard analyses were performed to identify independent predictors of patient outcomes. Results: Of the 250 eligible patients, the median age of patients was 60.0 years, and 34.0% were men. During the disease course, 33 (13.2%) died and 42 (16.8%) developed ESRD, respectively. The ideal PINI cut-offs for all-cause mortality and ESRD were set as ⩽2.47 and ⩽3.12 (sensitivity and specificity of 75.1% and 60.6% for mortality and 46.2% and 78.6% for ESRD). AAV patients with PINI ⩽2.47 and those with PINI ⩽3.12 exhibited significantly higher rates for all-cause mortality and ESRD compared to those with PINI >2.47 and >3.12. In the multivariable Cox analysis, PINI ⩽2.47 (hazard ratio [HR]: 3.173, 95% confidence interval [CI]: 1.129, 8.916, p = 0.029) was independently associated with all-cause patient mortality; however, PINI ⩽3.12 was not independently associated with ESRD (HR: 1.097, 95% CI: 0.419, 2.870, p = 0.850). Conclusion: Findings from this study demonstrated PINI could predict all-cause patient mortality in AAV, and a higher clinical attention is warranted in those with PINI ⩽2.47 at initial diagnosis.

Implication of Serious Infections in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis for the First Cycle of Rituximab: A Pilot Study in a Single Korean Center.

Objective: This study investigated the clinical implications of serious infections in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) who received the first cycle of rituximab (RTX) during the first 6 months of follow-up. Methods: The medical records of 36 AAV patients treated with RTX were reviewed. A weekly dose of 375 mg/m2 RTX was administered for 4 weeks to all patients along with glucocorticoids. Serious infections were defined as those requiring hospitalization. All-cause mortality during the first 6 months of follow-up was counted. The follow-up duration was defined as the period from the first RTX infusion to 6 months after the first RTX infusion. Results: The median age was 60.5 years, and 16 patients were male. Seven of 36 patients (19.4%) died and three AAV patients had five cases of serious infection such as enterocolitis, pulmonary aspergillosis, atypical pneumonia, cytomegalovirus pneumonia, and cellulitis. AAV patients with serious infections during the first 6 months of follow-up exhibited a significantly lower cumulative survival rate than those without serious infections (p<0.001). However, we found no independent predictor of serious infections using the Cox hazard model analysis. Conclusion: Serious infection is an important predictor of all-cause mortality in Korean patients with AAV who received their first cycle of RTX but there were no significant variables to predict the occurrence of serious infections at the first RTX. Thus, in cases refractory to other induction therapies, RTX should be strongly considered, despite an increase in mortality rate.

New index using triglyceride glucose-body mass index for predicting mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

Background: This study aimed to investigate whether triglyceride glucose-body mass index (TyG-BMI) and a new index using TyG-BMI (NITGB) could predict all-cause mortality in non-obese patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Methods: The medical records of 78 non-obese AAV patients (BMI < 23.0 kg/m2 for Asians) were retrospectively reviewed. TyG-BMI was calculated by the equation: Ln (triglyceride × fasting glucose/2) × BMI. To develop NITGB, we assigned a weight of a number close to an 0.1 decimal integer to each variable according to the slopes for independent variables with P-value < 0.1 in the multivariable Cox analysis. Results: The median age was 54.3 years and five patients died. When non-obese AAV patients were divided into two groups based on TyG-BMI ≥ 187.74, those with TyG-BMI ≥ 187.74 exhibited a significantly higher risk for all-cause mortality than those without (RR 9.450). Since age (HR 1.324), Birmingham vasculitis activity score (BVAS; HR 1.212), and TyG-BMI ≥ 187.74 (HR 12.168) were independently associated with all-cause mortality, NITGB was developed as follows: age + 0.2 × BVAS + 2.5 × TyG-BMI ≥ 187.74. When non-obese AAV patients were divided into two groups based on NITGB ≥ 27.36, those with NITGB ≥ 27.36 showed a significantly higher risk for all-cause mortality than those without (RR 284.000). Both non-obese AAV patients with TyG-BMI ≥ 187.74 and those with NITGB ≥ 27.36 exhibited significantly higher cumulative rates of all-cause mortality than those without. Conclusion: NITGB along with TyG-BMI could predict all-cause mortality in non-obese AAV patients.

Acute Brain Infarction in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Korean Single-Center Study.

OBJECTIVES: This study investigated the clinical and radiological features of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with acute brain infarction, using a cohort of Korean patients with AAV. METHODS: This study included 263 patients with AAV. Acute brain infarction was defined as infarction that occurred within 7 days or less. The brain territories affected by acute brain infarction were investigated. Active AAV was arbitrarily defined as the highest tertile of Birmingham Vasculitis Activity Score (BVAS). RESULTS: The median age at diagnosis was 59.0 years, and 35.4% were male. Fourteen cases of acute brain infarction occurred in 12 patients (4.6%), which was calculated as 1332.2 per 100,000 patient-years and 10 times higher than the incidence rate in the Korean general population. Patients with AAV with acute brain infarction exhibited significantly older age, increased BVAS at diagnosis, and a more frequent history of prior brain infarction compared with those without. The brain territories affected in AAV patients were middle cerebral artery (50.0%), multiple territories (35.7%), and posterior cerebral artery (14.3%). Lacunar infarction and microhemorrhage were observed in 42.9% and 71.4% of cases, respectively. Prior brain infarction and BVAS at diagnosis were independently associated with acute brain infarction (hazard ratios, 7.037 and 1.089). Patients with AAV with prior brain infarction or BVAS for active AAV exhibited significantly lower cumulative acute brain infarction-free survival rates than those without. CONCLUSION: Acute brain infarction was observed in 4.6% of AAV patients, and both prior brain infarction and BVAS at diagnosis were independently associated with acute brain infarction.

Soluble Tyro-3 and Axl may reflect the current activity and renal involvement in patients with microscopic polyangiitis and granulomatosis with polyangiitis.

OBJECTIVES: This study investigated whether soluble Tyro-3 (sTyro-3), sAxl, and sMer could reflect the current activity in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA). METHODS: This study retrospectively reviewed the medical records of 76 patients with MPA and GPA, and measure the serum concentrations of sTyro-3, sAxl, and sMer using the stored serum at AAV diagnosis. Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-specific indices included Birmingham vasculitis activity index (BVAS), five-factor score, the short-form 36-item health survey, and vasculitis damage index. High AAV activity was defined as the highest tertile of BVAS. RESULTS: The median age of the 47 MPA and 29 GPA patients was 66.0 years and 43.4% were men. The serum concentrations of sTyro-3 and sAxl were significantly correlated with BVAS and the total score of renal manifestation. The serum concentrations of sTyro-3 and sAxl were independently correlated with BVAS (ß=0.343 and ß=0.310, respectively). In addition, the serum concentrations of sTyro-3 and sAxl were independently associated with the renal involvement of MPA and GPA (OR 1.003 and OR 1.055, respectively). CONCLUSIONS: This study demonstrated the potential of the serum concentrations of sTyro-3 and sAxl to reflect the current activity and renal involvement in patients with MPA and GPA.

Predictive potential of albumin-alkaline phosphatase ratio for cerebrovascular accident in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

BACKGROUND: This study investigated the predictive potential of the albumin-to-alkaline phosphatase ratio (AAPR) for cerebrovascular accident (CVA) occurrence in patients with antineutrophil cytoplasmic antibody-associated vasculitis. METHODS: This study included 239 AAV patients and reviewed their medical records retrospectively. AAPR was calculated using the following formula: AAPR = serum albumin (g/dL)/serum alkaline phosphatase (IU/L). CVA was defined only as cerebral infarction after AAV diagnosis in this study. In patients with CVA and those without CVA, the follow-up duration based on CVA was defined as the period from AAV diagnosis to CVA occurrence and to the last visit day, respectively. RESULTS: The median age of 239 AAV patients (130 microscopic polyangiitis, 64 granulomatosis with polyangiitis, and 45 eosinophilic granulomatosis with polyangiitis) was 59.0 years and 32.6% were men. The median serum albumin and alkaline phosphatase levels, and AAPR were 3.7 g/dL, 70.5 IU/L and 0.051, respectively. Nineteen patients had CVA during the median follow-up duration of 34.8 months. Using the receiver operator characteristic curve analysis, the optimal cut-off of AAPR for CVA occurrence was obtained as ≤ 0.035. AAV patients with AAPR ≤ 0.035 showed a significantly higher risk of CVA occurrence after AAV diagnosis than those with AAPR >0.035 (relative risk 5.000, p < 0.001). In the multivariable Cox analysis, only AAPR ≤ 0.035 was independently associated with CVA occurrence among AAV patients (hazard ratio 3.195, 95% confidence interval 1.014, 10.062). CONCLUSION: This study demonstrated the predictive potential of AAPR calculated at AAV diagnosis for CVA occurrence after AAV diagnosis among AAV patients.

Serum soluble interleukin-7 receptor alpha levels are negatively correlated with the simultaneous activity of antineutrophil cytoplasmic antibody-associated vasculitis.

OBJECTIVES: This study investigated whether serum soluble interleukin-7 receptor alpha (sIL-7Rα) levels could reflect the simultaneous activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). METHODS: Sixty patients with AAV were included in this study. AAV-related variables and clinical and laboratory data were collected at the two-time points (at early high and late low BVAS) for each patient along with blood sampling. Serum sIL-7Rα levels and the populations of CD3+CD4+ and CD3+CD8+ T cells expressing membranous IL-7Rα (mIL-7Rα) were compared between patients at different time points and between patients and healthy controls. RESULTS: Serum sIL-7Rα levels were significantly lower in AAV patients at early high BVAS than in those at late low BVAS, and the direction of change in serum sIL-7Rα levels increased as BVAS decreased. Serum sIL-7Rα levels were inversely correlated with BVAS, erythrocyte sedimentation rate and C-reactive protein levels. In addition, serum sIL-7Rα levels in AAV patients at early high BVAS exhibited significantly lower levels than those in healthy controls. Particularly, AAV patients at early high BVAS showed significantly increased populations of CD3+ T cells and CD3+CD8+ T cells expressing mIL-7Rα compared to those at late low BVAS. CONCLUSIONS: This study demonstrated that not only serum sIL-7Rα levels but also the populations of CD3+ and CD3+CD8+ T cells expressing m IL-7Rα were negatively correlated with simultaneous BVAS in patients with AAV. Therefore, we suggest that serum sIL-7Rα levels can be an additional and useful biomarker for assessing the simultaneous activity of AAV.

Lung function trajectory of rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVES: To explore the course of lung function and RA disease activity and predictive factors for deteriorating lung function in patients with RA-interstitial lung disease (ILD). METHODS: The Korean Rheumatoid Arthritis-Interstitial Lung Disease cohort is a multicentre, prospective observational cohort. Patients with RA-ILD were enrolled and followed up annually for 3 years for RA disease activity and ILD status assessment. Group-based modelling was used to cluster a similar predicted percentage of forced vital capacity (FVC%) patterns into trajectories. RESULTS: This study included 140 patients who underwent at least two pulmonary function tests. Four distinctive trajectories for predicted FVC% were 'improving' [n = 11 (7.9%)], 'stable' [n = 68 (38.4%)], 'slowly declining' [n = 54 (48.6%)] and 'rapidly declining' [n = 7 (5.0%)]. Most (77.7%) patients maintained or improved to low RA disease activity. The lung function trajectory was not comparable to the RA disease activity trajectory. Age ≥70 years [relative risk (RR) 10.8 (95% CI 1.30, 89.71)] and early RA diagnosed within the preceding 2 years [RR 10.1 (95% CI 1.22, 84.2)] were associated with increased risk for rapidly declining predicted FVC%. The risk for deterioration or mortality increased in patients with a simultaneous diagnosis of RA and ILD within 24 weeks [RR 9.18 (95% CI 2.05, 41.0)] and the extent of lung involvement [RR 3.28 (95% CI 1.12, 9.60)]. CONCLUSION: Most patients with RA-ILD experienced stable or slowly declining lung function. In 5% of patients, predicted FVC% deteriorated rapidly, especially in older adults with early RA. The lung function trajectory was not comparable to the RA disease activity trajectory.

Comparison of the 2022 ACR/EULAR Classification Criteria for Antineutrophil Cytoplasmic Antibody-Associated Vasculitis with Previous Criteria.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) comprises group of small vessel vasculitides, including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). In 2022, the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) jointly proposed new classification criteria for AAV (the 2022 ACR/EULAR criteria). In this review, we briefly summarize the 2022 ACR/EULAR criteria for GPA, MPA, and EGPA, and introduce our clinical experience with applying them to patients who were previously diagnosed with AAV based on three criteria: firstly, the classification criteria for GPA and EGPA proposed by the ACR in 1990; secondly, the algorithm for the classification of AAV and polyarteritis nodosa proposed by the European Medicines Agency algorithm in 2007 (the 2007 EMA algorithm); and thirdly, the revised International Chapel Hill Consensus Conference nomenclature of vasculitides in 2012 (the 2012 CHCC definitions). We found that concordance rate was highest in patients with MPA (96.6%), followed by those with EGPA (86.3%) and GPA (73.8%). In addition, compared to previous criteria, we noted several issues of the undervalued or overvalued items in the 2022 ACR/EULAR criteria for classifying AAV and provided several suggestions. To increase the diagnostic accuracy and reduce the discordance rate among the new and previous criteria for AAV, we suggest that the previous criteria should be considered together with the 2022 ACR/EULAR criteria when applying the classification criteria for AAV to patients suspected of AAV.

Methotrexate, leflunomide and tacrolimus use and the progression of rheumatoid arthritis-associated interstitial lung disease.

OBJECTIVE: To examine the association between MTX, LEF and tacrolimus use and the progression of RA-associated interstitial lung disease (ILD). METHODS: The Korean RA-ILD cohort prospectively enrolled patients with RA-associated ILD at multiple centres from 2015 to 2018 and followed up with them for 3 years. ILD progression was defined by any of the followings: a decrease of ≥10% in forced vital capacity, a decrease of ≥15% in the diffusing capacity of the lung for carbon monoxide, or death from respiratory failure. RESULTS: Of 143 patients, 64 patients experienced ILD progression during a median follow-up period of 33 months. The use of MTX [adjusted hazard ratio (aHR), 1.06; 95% CI, 0.59, 1.89], LEF (aHR, 1.75; 95% CI, 0.88, 3.46) and tacrolimus (aHR, 0.94; 95% CI, 0.52, 1.72) did not increase the risk of ILD progression. However, the association between LEF use and the risk of ILD progression was significant in subgroups with poor lung function (aHR, 8.42; 95% CI, 2.61, 27.15). Older age, male sex, a shorter RA duration, higher RA disease activity and extensive disease at baseline were independently associated with ILD progression. CONCLUSION: None of the three treatments increased the risk of RA-associated ILD progression, except for LEF, which increased the risk of ILD progression in patients with severe ILD. The appropriate use of conventional synthetic disease-modifying antirheumatic drugs considering RA disease activity and ILD severity would be important for the management of RA-associated ILD.

Reclassification of previously diagnosed GPA patients using the 2022 ACR/EULAR classification criteria.

OBJECTIVES: This study applied the 2022 criteria for granulomatosis with polyangiitis (GPA) proposed by the ACR and EULAR (the 2022 ACR/EULAR criteria) to Korean patients with previously diagnosed GPA to investigate the number of patients who could be reclassified as having GPA. METHODS: Sixty-five patients with GPA, who met the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides and the 2007 European Medicines Agency algorithm for GPA, were included in this study. They were reclassified based on the 2022 ACR/EULAR criteria. RESULTS: Of the 65 patients, 48 patients (73.8%) were reclassified as having GPA. A patient could not be reclassified as having GPA if the patient did not have a total score of 5 despite granulomas on biopsy or clear GPA surrogate markers. Among the 17 patients unclassified as having GPA, 16 patients were reclassified as having MPA and one as having unclassifiable vasculitis, and furthermore, 94.1% of them harboured MPO-ANCA (or perinuclear (P)-ANCA). CONCLUSION: The concordance rate between the 2022 ACR/EULAR criteria for GPA and the previous criteria in patients with previously diagnosed GPA was 73.8%. Although the 2022 ACR/EULAR criteria are the product of the most advanced methodologic process, it should be noted that there were some consequences of distorting the CHCC definition, and further discussion is required, especially with respect to the weightage of the items.

Application of the 2022 ACR/EULAR criteria for microscopic polyangiitis to patients with previously diagnosed microscopic polyangiitis.

OBJECTIVES: This study applied the 2022 American College of Rheumatology/European Alliance of Associations for Rheumatology (the 2022 ACR/EULAR) criteria for microscopic polyangiitis (MPA) to patients with previously diagnosed MPA as per the 2007 European Medicines Agency algorithm (the 2007 EMA algorithm) and the 2012 revised International Chapel Hill Consensus Conference nomenclature of vasculitides (the 2012 CHCC definitions) The concordance rate between the new and old criteria was investigated. METHODS: This study included 117 patients with MPA, and the new criteria were applied to these patients. MPA could be classified when the total score is ≥5. RESULTS: The median age was 64.0 years. The concordance rate between the new and old criteria reached 96.6%. Four patients with previously diagnosed MPA were unclassified. Of these, three patients without myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) (or perinuclear [P]-ANCA) were not reclassified as having MPA according to the new criteria, despite histopathological findings that were suggestive of MPA based on both the 2007 EMA algorithm and the 2012 CHCC definitions. Conversely, three of four patients with both MPO-ANCA (or P-ANCA) and proteinase 3 (PR3)- ANCA (or cytoplasmic [C]-ANCA) were reclassified as having both MPA and granulomatosis with polyangiitis (GPA) simultaneously according to the 2022 ACR/EULAR criteria for MPA and GPA. CONCLUSIONS: In the new criteria, excessively high score was assigned to MPO-ANCA (or P-ANCA) and MPA-specific histopathological findings were not considered. Hence, the 2007 EMA algorithm and the 2012 CHCC definitions can be applied as additional criteria to complex cases.

Cancer-associated vasculitides: a single-centre case series.

OBJECTIVES: This study investigated the frequency of cancer-associated vasculitis, the types of associated cancers and vasculitides, and the temporal relationship in Korean patients who were diagnosed with both cancers and vasculitides. METHODS: This study performed a digital search of the clinical data repository using selected diagnostic terms of vasculitides among patients diagnosed with cancers from May 2001 to May 2021. The time gap between the time of diagnosis of 'cancers' and that of 'vasculitides' was limited to 3 years. The types of cancers and vasculitides were reviewed. RESULTS: The mean age of 73 patients with both cancers and vasculitides with a time gap of fewer than 3 years was 53.0 years and 42.5% were men. Of the 215,897 patients with cancers, 73 patients were also diagnosed with vasculitides (0.034%). The most common type of cancer was thyroid cancer (28.8%), followed by lymphoma (13.7%), whereas the most frequent type of vasculitis associated with cancer was Behcet disease (52.1%), followed by granulomatosis with polyangiitis (12.3%). The median time gap between cancer and vasculitis was - 17.0 days. Among vasculitides, Behcet disease was closely associated with various cancers compared to other types. Twenty-one patients exhibited both cancers and vasculitides between 0 and 90 days after the diagnosis of the corresponding cancer. CONCLUSION: The frequency of cancer-associated vasculitis was 0.034% in Korean patients. The types of cancers and vasculitides in cancer-associated vasculitis and the distributions of sex and age may be dependent on ethnic and geographic differences. Key Points • The frequency of cancer-associated vasculitis was 0.034% in Korean patients. • The most common cancer and vasculitis in cancer-associated vasculitis were thyroid cancer and Behcet disease. • The types of cancers and vasculitides in cancer-associated vasculitis seemed to be dependent on ethnic and geographic differences.

Soluble immune checkpoint molecules in patients with antineutrophil cytoplasmic antibody-associated vasculitis.

Immune checkpoint molecules balance immune effector responses with regulatory reactions. We speculated that soluble immune checkpoint molecules are involved in dysregulation of the immune response and autoimmunity. We evaluated the association between soluble immune checkpoint molecules and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). A total of 56 patients with AAV from a prospective observational cohort and 40 healthy controls (HCs) were analyzed. Soluble PD-1, PD-L1, PD-L2, CTLA-4, CD28, CD80, CD86, ICOS, TIM-3, BTLA, CD40, LAG-3, TLR-2, and CD27 were measured in stored sera using the Milliplex MAP assay. Paired analyses were performed before and after the treatment. AAV-specific indices, including Birmingham vasculitis activity score, five factor score , vasculitis damage index, and blood samples, were collected. Patients with AAV had higher levels of sPD-L1, sCD28, sCD80, sCD86, sICOS, sTIM-3, sLAG-3, sTLR-2, and sCD27 and lower level of sCTLA-4 than HCs (p < 0.05). Patients with AAV had higher serum sCD28, sCD80, sTIM-3, and sCD27 levels than HCs at baseline and decreased after treatment. Furthermore, the serum levels of sCD28 and sTIM-3 were significantly correlated with disease activity. This study demonstrated altered concentrations of serum soluble immune checkpoint molecules in patients with AAV. In particular, sCD28 and sTIM-3 may act as surrogate markers of AAV disease activity.