Comparison of different ANCA detection methods in a predominantly MPO-ANCA-associated vasculitis cohort.

We compared different antineutrophil cytoplasmic antibody (ANCA) detection methods using a predominantly myeloperoxidase (MPO)-ANCA-associated vasculitis cohort. Stored sera from 147 patients with untreated ANCA-associated vasculitis (AAV), including microscopic polyangiitis and granulomatosis with polyangiitis (n = 115 and 32, respectively), and 124 disease controls were tested for P-ANCA and C-ANCA with immunofluorescence (IIF), and for MPO-ANCA and proteinase 3 (PR3)-ANCA with different antigen-specific immunoassays: direct enzyme-linked immunosorbent assay (ELISA), chemiluminescent enzyme immunoassay (CLEIA), third-generation fluorescent enzyme immunoassay (FEIA), and latex turbidimetrical immunoassay (LTIA). In addition, MPO-ANCA and PR3-ANCA titers were calibrated using certified reference materials (CRMs). The sensitivities and specificities for AAV diagnoses were 95% and 94% (IIF), 86% and 98% (ELISA), 93% and 94% (CLEIA), 92% and 96% (FEIA), and 68% and 88% (LTIA). Dual IIF/antigen-specific immunoassay testing reduced diagnostic accuracies from 94% to 93%. The quantitative agreement between ANCA levels measured using CLEIA and FEIA and calibrated using CRMs was not good. In conclusion, this study demonstrated the high performance of antigen-specific immunoassays for AAV diagnosis in a predominantly MPO-ANCA-associated vasculitis cohort and suggested that the benefit of dual IIF/antigen-specific immunoassay testing is limited. Standardizing ANCA measurements using different immunoassays was difficult, even when using CRMs.

Characteristic features of late-onset systemic lupus erythematosus: An observational study of data from the Lupus Registry of Nationwide Institutions.

OBJECTIVE: Late-onset systemic lupus erythematosus (LoSLE) is known to possess characteristics different from those of early-onset SLE (EoSLE), thereby making their diagnosis difficult. This study aimed to assess the characteristic features of LoSLE in Japan, a model country with a super-aged society. METHODS: Data were obtained from the Lupus Registry of Nationwide Institutions, which includes a multicenter cohort of patients with SLE in Japan who satisfied the 1997 American College of Rheumatology revised classification criteria for SLE. Data were compared between patients with LoSLE (≥50 years old at onset) and EoSLE (<50 years old at onset). To identify factors associated with LoSLE, binary logistic regression was used for the multivariate analysis, and missing values were complemented by multiple imputations. We also conducted a sub-analysis for patients diagnosed within 5 years of onset. RESULTS: Out of 929 enrolled patients, 34 were excluded owing to a lack of data regarding onset age. Among the 895 remaining patients, 100 had LoSLE, whereas 795 had EoSLE. The male-to-female ratio was significantly higher in the LoSLE group than in the EoSLE group (0.32 vs 0.11, p < 0.001). With respect to SLEDAI components at onset, patients with LoSLE exhibited a higher frequency of myositis (11.9% vs 3.75%, p = 0.031), lower frequency of skin rash (33.3% vs 67.7%, p < 0.001), and lower frequency of alopecia (7.32% vs 24.7%, p = 0.012). No significant differences in overall disease activity at onset were observed between the two groups. Regarding medical history, immunosuppressants were more commonly used in EoSLE. A multivariate analysis revealed that a higher male proportion and a lower proportion of new rash at onset were independent characteristic features of LoSLE. We also identified late onset as an independent risk factor for a high SDI score at enrollment and replicated the result in a sub-analysis for the population with a shorter time since onset. CONCLUSIONS: We clarified that LoSLE was characterized by a higher male proportion, a lower frequency of skin rash and a tendency to organ damage. Now that the world is faced with aging, our results may be helpful at diagnosis of LoSLE.

Effects of cyclophosphamide administration on ovarian dysfunction in pediatric patients with connective tissue diseases: A systematic scoping review.

OBJECTIVE: This systematic scoping review assess the effect of cyclophosphamide (CY) administration during childhood on ovarian function in patients with juvenile-onset connective tissue diseases. METHODS: A MEDLINE database search was conducted using terms related to CY, juvenile-onset connective tissue diseases, and ovarian function. Studies were included if they met specific criteria. RESULTS: The search, conducted on 28 November 2023, yielded 3328 references. After a two-stage screening process, six observational studies on systemic lupus erythematosus patients were included. All studies had a high risk of confounding bias, as none adjusted for confounding variables. Two studies assessing clinical ovarian dysfunction found no clear difference between CY and non-CY groups. However, statistical differences were observed in hormonal profiles. Decreased ovarian reserve was more frequent in CY-exposed patients. Two studies showed significantly higher follicle-stimulating hormone (FSH) levels in the CY group, while one showed a trend towards higher FSH levels without statistical significance. CONCLUSION: This review suggested that CY use in childhood may not conclusively have clinically significant effects on ovarian function. Further investigation needed on CY's effect on hormonal levels, fertility, and pregnancy outcomes.

Effect of Shared Decision-Making on Trust in Physicians in the Management of Systemic Lupus Erythematosus: The Trust Measurement for Physicians and Patients With Systemic Lupus Erythematosus Prospective Cohort Study.

OBJECTIVE: Few studies have explored whether the involvement of patients in shared decision-making (SDM) is beneficial to the management of systemic lupus erythematosus (SLE). Therefore, this study investigated the relationship between patient participation in SDM and their trust in physicians using data from the Trust Measurement in Physicians and Patients With SLE (TRUMP2-SLE) study. METHODS: Data regarding the nine-item Japanese version of the Shared Decision-Making Questionnaire (SDM-Q-9) scores, Trust in Physician Scale (TIPS) scores, and Abbreviated Wake Forest Physician Trust Scale (A-WFPTS) scores for interpersonal trust in a physician and trust in the medical profession were collected from patients with SLE who visited the outpatient clinics of five facilities in Japan through a self-administered questionnaire. The relationships among these scores were analyzed by general linear models with cluster-robust variance. RESULTS: This study included 433 patients with SLE. The median baseline TIPS and A-WFPTS (attending physician version) scores were 82 (73-93) and 80 (70-95), respectively. A higher baseline SDM-Q-9 score was correlated with an increase in the TIPS score at one year (coefficient per 10-point [pt] increase, 0.94 pts, 95% confidence interval [CI] 0.16-1.72). A higher baseline SDM-Q-9 score was correlated with a higher A-WFPTS score for interpersonal trust (coefficient per 10-pt increase, 2.20 pts, 95% CI 1.44-2.96). The baseline SDM-Q-9 score was also correlated with an increase in the general physician version of the A-WFPTS score at one year (coefficient per 10-pt increase, 1.29 pts, 95% CI 0.41-2.18). CONCLUSION: Engagement of patients with SLE in SDM elevates their trust in the attending physicians and health care providers, potentially enhancing doctor-patient relationships and overall health care trust.

Predictive validity of Lupus Patient-Reported Outcome for damage accrual in patients with systemic lupus erythematosus: the LUNA Registry.

OBJECTIVES: The predictive validity of disease-specific quality of life (QOL) remains unknown in patients with systemic lupus erythematosus (SLE), although disease-specific measures are equally or more responsive to changes than generic QOL. We aimed to examine the predictive validity of the Lupus patient-reported outcome (PRO) for damage accrual. METHODS: Patients with SLE and ≥2 measurements over time were included in Japanese nationwide multicentre registry (LUNA). The Lupus PRO questionnaire contains both health-related (HR) and non-HR-QOL measures. Damage accrual was evaluated using the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI). We examined the association between the Lupus-PRO score at baseline and longitudinal SDI scores using mixed-effects models adjusted for prognostic factors. RESULTS: Among 1295 patients, those with higher HR-QOL of Lupus PRO at baseline demonstrated a significantly lower increase in SDI (-0.005/year, 95% confidence interval [CI]: -0.007 to - 0.004, p < 0.001). According to the categorisation of HR-QOL based on tertile, a similar dose-dependent effect of HR-QOL on longitudinal SDI was identified (second vs first tertile category: -0.101/year, 95% CI: -0.172 to - 0.030; third tertile category: -0.211/year, 95% CI: -0.281 to - 0.142). Non-HR-QOL was not significantly associated with the SDI scores. Among the HR-QOL domains, cognition, procreation, and physical health were significantly associated with the total SDI scores over time. HR-QOL was associated with corticosteroid-dependent and -independent SDI scores. CONCLUSION: A higher HR-QOL of Lupus PRO was associated with a lower increase in SDI scores. Our findings imply the importance of disease-specific HR-QOL measurements in assessing prognosis.

Headache in systemic lupus erythematosus: The LUNA registry cross-sectional study.

OBJECTIVES: This study investigated the clinically relevant factors for headaches in patients with systemic lupus erythematosus (SLE) using a registry from a Japanese multicenter cohort. METHODS: This cross-sectional study analysed the clinical information of patients with SLE who experienced headache episodes using the Migraine Disability Assessment (MIDAS) questionnaire. Significant findings in the comparisons between patients with headache (HA patients) and those without headache (non-HA patients) and in the comparisons depending on the grades of headache-induced disability in daily life based on the MIDAS scores were evaluated. Multivariate logistic regression analyses were performed to identify the relevant factors for headache. RESULTS: We analyzed 369 patients (median age, 45 years; female, 90.8%), including 113 HA patients who were significantly younger than non-HA patients (p < .005). HA patients had significantly higher frequencies of photosensitivity, rashes, and mucosal ulcers than non-HA patients (p < .05). Age and photosensitivity were significantly associated with headache (odds ratio (OR) 0.93, 95% confidence interval (CI) 0.95-0.99; OR 2.11, 95% CI 1.29-3.49, respectively). In the HA patients, hypocomplementemia was significantly associated with a disability of more than mild grade (OR 2.89, 95% CI 1.14-7.74), while rash was significantly observed in those presenting with moderate and severe disability. CONCLUSION: This study suggests that photosensitivity is a relevant manifestation of headache in patients with SLE. Persistent hypocomplementemia can contribute to headache-induced disability in daily life, whereas a rash may be a dominant manifestation in patients presenting with moderate/severe headache-induced disability.

Evaluating the safety profile of calcineurin inhibitors: cancer risk in patients with systemic lupus erythematosus from the LUNA registry-a historical cohort study.

BACKGROUND: Previous studies have shown conflicting evidence regarding the incidence of cancer in patients with systemic lupus erythematosus (SLE) compared with that in healthy individuals. Calcineurin inhibitors (CNIs) such as cyclosporine and tacrolimus have been widely used to treat SLE; however, their effects on cancer risk remain unclear. We aimed to investigate the incidence of cancer in patients with SLE and determine the potential association between CNI use and cancer risk. METHODS: The standardized incidence ratio (SIR) of cancer among patients with lupus in the Lupus Registry of Nationwide Institutions (LUNA) was calculated based on the age-standardized incidence rate of cancer reported by Japan's Ministry of Health, Labour and Welfare. We also examined the association between CNI exposure and cancer risk, while considering potential confounding factors. The analysis accounted for confounding variables such as age, sex, smoking history, maximum glucocorticoid dose, treatment history with cyclophosphamide, ongoing hydroxychloroquine, Systemic Lupus International Collaboration Clinics/American College of Rheumatology Damage Index (SDI) value (excluding cancer occurrence), comorbidity of diabetes mellitus, and smoking history. RESULTS: The study included 704 patients with SLE (625 females; 88.8%) with a median age of 44 years [interquartile range (IQR) = 34-55] years. The median past maximum glucocorticoid dose was 40 mg/day [IQR = 30-60 mg/day], and the SDI at registration was 1 [IQR = 0-2]. Among the patients, 246 (35.1%) had smoking histories, and 38 (5.4%) experienced cancer complications. Gynecological malignancies accounted for 63.2% of all cancers. The SIR of cancer in the LUNA cohort was 1.08 (95% confidence interval [CI] = 0.74-1.43). No statistically significant risks of cancer were found in relation to CNI treatment history; the odds ratio using multiple logistic regression was 1.12 (95% CI = 0.42-3.00), the risk ratio using standardization was 1.18 (95% CI = 0.47-2.16), and the risk ratio using inverse probability weighting was 1.8 (95% CI = 0.41-4.66). CONCLUSIONS: The incidence of cancer in patients with SLE in the LUNA cohort did not significantly differ from that in the general population. These findings suggest that CNI treatment in this cohort did not pose a risk factor for cancer development.

The first presentation of a case of nail-patella syndrome newly diagnosed at the onset of rheumatoid arthritis: a case report.

BACKGROUND: Nail-patella syndrome (NPS) is a rare autosomal dominant disorder that is characterized by dysplasia of the nails, hypoplasia and/or dislocation of the patella and the presence of iliac horns. Using the CARE guidelines, we present the first reported case of NPS that was newly diagnosed at the onset of rheumatoid arthritis (RA). CASE PRESENTATION: A 74-year-old man was admitted to our hospital due to an 8-month history of arthralgia in bilateral wrists, elbows and fingers. He had a past history of glaucoma and left patella dislocation that had been operatively recentered at the age of 15 years. Laboratory data showed elevated levels of serum C-reactive protein and rheumatoid factor and an elevated titer of anti-SS-A antibodies, while estimated glomerular filtration rate (eGFR), titers of other antibodies and the results of a urinary test were normal. An X-ray showed deformity of bilateral radial heads and the right elbow, and magnetic resonance imaging (MRI) of his hands showed synovitis and erosion in the multiple swollen joints of the wrists and fingers. In addition to these typical features of RA, he had bilateral thumb nail dysplasia with mild hypoplasia of bilateral patellae and iliac horns as shown by the X-ray. He was diagnosed as having autosomal dominant disorder NPS co-existing with RA and he was treated with methotrexate in combination with an oral Janus kinase (JAK) inhibitor, leading to induction of remission. CONCLUSIONS: We have presented a rare case of NPS that was newly diagnosed at the onset of RA. Clinical and radiographic findings of NPS are highlighted in this case report for diagnosing NPS on the basis of typical manifestations.

Immunosuppressive Treatment for an anti-U1 Ribonucleoprotein Antibody-positive Patient with Pulmonary Arterial Hypertension.

A 34-year-old woman with pulmonary arterial hypertension (PAH) was admitted to the hospital. She had been diagnosed with PAH three years earlier and treated with triple vasodilator therapy. She was positive for anti-U1 ribonucleoprotein antibodies but did not show any other symptoms associated with autoimmune diseases. Corticosteroid and cyclophosphamide therapy was administered, suspecting the involvement of immunological pathophysiology. After 3 weeks, the mean pulmonary artery pressure decreased from 50 to 38 mmHg without any change in the vasodilators. Immunosuppressive therapy was effective in this patient with PAH with an anti-U1 ribonucleoprotein-antibody-positive response and might be an option for patients with these specific features.

Predictors of damage accrual in patients with antineutrophil cytoplasmic antibody-associated vasculitis: A nationwide prospective study.

OBJECTIVES: This study elucidated the prognosis and risk factors associated with damage accrual during long-term remission maintenance therapy for patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV). METHODS: We obtained data from 120 patients registered in a nationwide prospective cohort study on remission induction therapy in Japanese patients with AAV and rapidly progressive glomerulonephritis (RemIT-JAV-RPGN), who achieved remission at 24 months after treatment initiation and were followed up for additional 24 months. The primary outcome was the vasculitis damage index (VDI) score at Month 48, and the secondary outcome included risk factors associated with increased total VDI at Month 48. RESULTS: The understudied patients comprised 52 men and 68 women aged 68 ± 13 years. Between Months 25 and 48, the patients' survival rate was 95% (114/120). End-stage renal disease developed in seven patients by Month 48, and 64 cases had increased VDI. The multivariable analysis results revealed that oral prednisolone (PSL) doses at Month 24 were associated with damage accrual between Months 24 and 48. CONCLUSIONS: VDI accrual was observed in more than half of patients with AAV during maintenance therapy, and increased VDI scores were associated with oral PSL doses 24 months after initiating remission induction therapy in Japan.

Clinical practice guidelines of the Japan Research Committee of the Ministry of Health, Labour, and Welfare for Intractable Vasculitis for the management of microscopic polyangiitis and granulomatosis with polyangiitis: The 2023 update - secondary publication.

OBJECTIVE: To revise the 2017 clinical practice guidelines (CPG) for the management of microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) to reflect advancements in the field. METHODS: Similar to the 2017 CPG, the Grading of Recommendations, Assessment, Development, and Evaluation system was adopted for this revision. The intended users of this CPG include patients diagnosed with MPA or GPA in Japan and their families and healthcare professionals, including specialists and non-specialists. Based on a scoping review, four clinical questions (CQs) of the 2017 guidelines were modified, and six new CQs were added. RESULTS: We suggest a combination of glucocorticoid and cyclophosphamide or rituximab for remission induction therapy. In cases where cyclophosphamide or rituximab is used, we suggest the use of avacopan over high-dose glucocorticoid. Furthermore, we suggest against the use of plasma exchange in addition to the standard treatment in severe cases of MPA/GPA. Finally, we suggest the use of glucocorticoid and rituximab over glucocorticoid and azathioprine for remission maintenance therapy. CONCLUSIONS: The recommendations have been updated based on patient preference, certainty of evidence, benefit and risk balance, and cost.

Effect of Attending Rheumatologists' Big 5 Personality Traits on Patient Trust in Patients With Systemic Lupus Erythematosus: The TRUMP2-SLE Project.

OBJECTIVE: Differences in communication styles based on physicians' personality traits have been identified, particularly in primary care, and these physician-related factors can be important in building patient-physician trust. This study examined the effects of rheumatologists' personality traits on patients' trust in their attending rheumatologists. METHODS: This cross-sectional study included adult Japanese patients with systemic lupus erythematosus (SLE) at 5 academic medical centers between June 2020 and August 2021. The exposures were the Big 5 personality traits (ie, extraversion, agreeableness, openness, conscientiousness, and emotional stability) of attending rheumatologists using the Japanese version of the 10-Item Personality Inventory scale (1-7 points each). The outcome was the patients' trust in their attending rheumatologist using the Japanese version of the 5-item Wake Forest Physician Trust Scale (0-100 points). A general linear model was fitted. RESULTS: The study included 505 patients with a mean age of 46.8 years; 88.1% were women. Forty-three attending rheumatologists (mean age: 39.6 years; 23.3% female) were identified. After multivariable adjustment, higher extraversion and agreeableness were associated with higher trust (per 1-point increase, 3.76 points [95% CI 1.07-6.45] and 4.49 points [95% CI 1.74-7.24], respectively), and higher conscientiousness was associated with lower trust (per 1-point increase, -2.17 points [95% CI -3.31 to -1.03]). CONCLUSION: Whereas higher extraversion and agreeableness of attending rheumatologists led to higher patient trust in their rheumatologist, overly high conscientiousness may lead to lower trust resulting from the physicians' demand of responsibility and adherence to instructions from patients with SLE.

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.

Survey of Japanese nephrologists' use of clinical practice guidelines for rapidly progressive glomerulonephritis.

BACKGROUND: The guidelines in Japan for the treatment of rapidly progressive glomerulonephritis (RPGN) have been revised; the latest update was released in 2020. We investigated the actual usage of the new guidelines in Japan. METHODS: We distributed a survey electronically to board-certified nephrologists throughout Japan from December 15, 2021 to January 31, 2022. The survey focused on anti-neutrophil cytoplasmic antibody (ANCA)-associated RPGN and anti-glomerular basement membrane (GBM)-antibody RPGN, plus the treatment strategies and infection-prevention measures used. RESULTS: The survey was completed by 155 certified nephrologists from medical facilities across Japan. Their responses regarding treatment procedures revealed that ANCA-associated RPGN was treated with immunosuppressants and/or biologics by 58.1% of the survey respondents, and with plasma exchange (PE) in combination with corticosteroids by 21.3%. Regarding anti-GBM-antibody RPGN, 78.1% of the respondents used corticosteroids in combination with PE (63.2%), cyclophosphamide (CY) (23.9%), or rituximab (RTX) (8.4%), suggesting a discrepancy between clinical practice and the actual use of the guidelines. Trimethoprim-sulfamethoxazole was prescribed as prophylaxis by 94.8% of the respondents, reflecting the widespread recognition of the need to prevent infectious disease in patients with RPGN. CONCLUSIONS: The survey responses revealed how Japan's new RPGN guidelines are used in actual clinical practice. Our findings will contribute to the guidelines' dissemination and implementation.

Impact of treatment of hyperkalaemia on quality of life: design of a prospective observational cohort study of long-term management of hyperkalaemia in patients with chronic kidney disease or chronic heart failure in Japan.

INTRODUCTION: Hyperkalaemia (HK) is a frequent complication in patients with chronic kidney disease (CKD) and/or chronic heart failure (CHF). HK must be managed, both to protect patients from its direct clinical adverse outcomes and to enable treatment with disease-modifying therapies including renin-angiotensin-aldosterone system inhibitors. However, the experiences of patients undergoing treatment of HK are not clearly understood. Optimising treatment decisions and improving long-term patient management requires a better understanding of patients' quality of life (QOL). Thus, the aims of this research are: (1) to describe treatment patterns and the impact of treatment on a patient's QOL, (2) to study the relationships between treatment patterns and the impact of treatment on a patient's QOL and (3) to study the relationships between the control of serum potassium (S-K) and the impact of treatment on a patient's QOL, in patients with HK. METHODS AND ANALYSIS: This is a prospective cohort study with 6 months of follow-up in 30-40 outpatient nephrology and cardiology clinics in Japan. The participants will be 350 patients with CKD or CHF who received their first potassium binders (PB) prescription to treat HK within the previous 6 months. Medical records will be used to obtain information on S-K, on treatment of HK with PBs and with diet, and on the patients' characteristics. To assess the impact of treatment on a patient's QOL, questionnaires will be used to obtain generic health-related QOL, CKD-specific and CHF-specific QOL, and PB-specific QOL. Multivariable regression models will be used to quantify how treatment patterns and S-K control are related to the impact of treatment on a patient's QOL. ETHICS AND DISSEMINATION: Institutional review boards at all participating facilities review the study protocol. Patient consent will be obtained. The results will be published in international journals. TRIAL REGISTRATION NUMBER: NCT05297409.

Trends in prevalence, treatment use, and disease burden in patients with eosinophilic granulomatosis with polyangiitis in Japan: real-world database analysis.

OBJECTIVES: Report the prevalence of eosinophilic granulomatosis with polyangiitis (EGPA) and describe oral corticosteroid (OCS) use and disease burden before and after mepolizumab approval in 2018 for EGPA in Japan. METHODS: Two retrospective studies (GSK IDs: 218083; 218084) used two databases: 1) the JMDC insurer database (Japanese health insurer claims) was used to report annual EGPA prevalence and OCS use in mepolizumab-treated patients; 2) Medical Data Vision database was used to report annual treatment use, OCS dose, relapses, and healthcare resource utilization (HCRU) in patients with EGPA. RESULTS: EGPA prevalence (95% confidence interval) increased from 4.2 (0.1, 23.4) in 2005 to 58.6 (53.2, 64.5) per 1,000,000 in 2020. Median OCS dose (mg/day) decreased from a range of 4.8-7.7 during 2010-2017 to 4.5-4.8 during 2018-2020 (lowest dose in 2020). The proportion of patients with prednisolone-equivalent daily OCS dose >10 mg decreased from 2017 (11.9%) to 2020 (10.3%), while the median dose halved. The proportion of patients with EGPA relapses (64.3% to 41.6%) and hospitalisation (27.8% to 23.6%) decreased from 2010 to 2020. CONCLUSIONS: EGPA prevalence increased between 2005 and 2020. With the introduction of mepolizumab for EGPA in 2018, real-world OCS use, relapses and HCRU decreased.