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.

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.

Birmingham vasculitis activity score and the short form 36-item health survey predict current depressive disorders in patients with antineutrophil cytoplasmic antibody-associated vasculitis during the SARS-CoV-2 pandemic

INTRODUCTION

This study compared the frequency and severity of depressive disorders in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV) before and during the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) pandemic using the Korean version of the Center for Epidemiologic Studies Depression Scale-Revised (K-CESD-R) and the Korean version of the Profile of Mood States (K-POMS) depression, and further determined predictors of current depressive disorders in the patients during the pandemic.

METHODS

Of the 61 patients with AAV who participated before the pandemic, 8 patients were transferred to other hospitals, 3 patients died, and 2 patients refused to participate in this study. Finally, 48 patients participated in this study. Depression disorders were defined as K‑CESD-R ≥ 16.

RESULTS

When comparing the patterns of mental health between patients with AAV before and during the pandemic, no change in K‑CESD‑R or K‑POMS subscale scores was observed. Among AAV-related indices, regardless of the pandemic, the short-form 36-item Health Survey (SF-36) mental component score (MCS) and physical component score (PCS) were significantly correlated with K‑CESD‑R and could predict current depressive disorders. When the cut-off of Birmingham vasculitis activity score (BVAS) for depressive disorders was obtained by the receiver operator characteristic curve, it significantly predicted current depressive disorders in patients with AAV during the pandemic, unlike those before the pandemic.

CONCLUSION

We verified that SF-36 MCS and PCS could predict current depressive disorders, regardless of the pandemic, and furthermore, we demonstrated for the first time that BVAS was a predictor of current depressive disorders in patients with AAV during the pandemic unlike those before the pandemic.

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.

Conclusions

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.

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 β 0.241), and sTREM-1 (standardised β 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.

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.

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.

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.

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 (β=0.343 and β=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.

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.

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.

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.

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.

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.

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.

A retrospective analysis of the relationship between anti-cyclic citrullinated peptide antibody and interstitial lung disease in systemic sclerosis

Anti-cyclic citrullinated peptide antibody testing is used to diagnose rheumatoid arthritis and associated with interstitial lung disease in RA. Herein, we investigate the relationship between anti-CCP antibody and ILD in SSc. We performed a retrospective analysis at a tertiary medical center between 2005 and 2019. Patients with SSc, systemic lupus erythematosus, and polymyositis/dermatomyositis (PM/DM) were evaluated for anti-CCP antibody and ILD. Additionally, medical records of SSc patients with ILD were reviewed. SSc patients had the highest anti-CCP antibody positivity rate compared to those with SLE and PM/DM. The incidence of ILD was higher in SSc patients with anti-CCP antibody than in those without. The usual interstitial pneumonia (UIP) incidence was higher in the anti-CCP antibody-positive group than in the anti-CCP antibody-negative group. The DLCO was lower in the anti-CCP antibody-positive group than in the anti-CCP antibody-negative group. On multivariable analysis, factors associated with SSc-ILD were anti-CCP antibody or rheumatoid factor (β coefficient, 2.652 [95% CI 1.472 to 4.776]) and anti-Scl70 antibody (β coefficient, 4.011 [95% CI 2.142 to 7.508]). Anti-CCP antibody may be associated with a higher incidence of ILD in SSc. SSc patients with anti-CCP antibody may have more UIP pattern and lower DLCO.Trial Registration Retrospectively registered.

Clinical impact of antineutrophil cytoplasmic antibody positivity on the occurrence of interstitial lung disease in patients with polymyositis/dermatomyositis

BACKGROUND

This study investigated the clinical impact of antineutrophil cytoplasmic antibody (ANCA) positivity on the occurrence of interstitial lung disease (ILD) in patients with probable and definite polymyositis (PM)/dermatomyositis (DM) who met both the Bohan and Peter and the 2017 European League Against Rheumatism/American College of Rheumatology criteria.

METHODS

The medical records of 75 PM/DM patients were retrospectively reviewed. ANCA and anti-Jo 1 positivity at diagnosis were obtained, and pulmonary function test and chest high-resolution computed tomography results at ILD occurrence were collected. The follow-up duration based on ILD was defined as the period from the time of PM/DM diagnosis to the occurrence of ILD in PM/DM patients with ILD and to the last visit for those without ILD.

RESULTS

The median age was 50.0 years and 21.3% were male. ANCA and anti-Jo 1 were detected in 12 (16.0%) and 26 patients (34.7%), respectively. ILD occurred in 32 patients, 24 of whom had ILD at the time of PM/DM diagnosis. Anti-Jo 1 was detected more often in PM/DM patients without ANCA than those with (39.7% vs. 8.3%). ILD occurred more frequently in PM/DM patients with ANCA than those without ANCA (75.0% vs. 36.5%). However, the occurrence of ILD was not affected by anti-Jo 1 positivity. Furthermore, ANCA-positive PM/DM patients exhibited a significantly lower cumulative ILD-free survival rate than ANCA-negative PM/DM patients (P=0.009).

CONCLUSIONS

ANCA positivity at the time of PM/DM diagnosis might be an important risk factor for ILD in PM/DM patients.

Serum glycated albumin as a predictive biomarker for renal involvement of antineutrophil cytoplasmic antibody-associated vasculitis in non-diabetic patients

Background

Glycated albumin (GA) is known to reflect the current inflammatory burden in non-diabetes mellitus (DM) patients. In this study, we investigated whether GA at diagnosis could reflect the cross-sectional activity and predict poor outcomes during follow-up in non-DM patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods

The medical records of 118 immunosuppressive drug-naïve AAV patients were retrospectively reviewed, and 76 patients who had both GA and glycated haemoglobin (HbA1c) results but not DM were included in this study. Demographic, clinical, and laboratory data at diagnosis were assessed.

Results

The median age of AAV patients was 61 years, and 31 patients were male. GA was positively correlated with five-factor score (r = 0.282), Birmingham vasculitis activity score (BVAS) assigned to renal manifestation (r = 0.315), and blood urea nitrogen (r = 0.382), whereas negatively correlated with haemoglobin (r = -0.345). AAV patients with end-stage renal disease (ESRD) exhibited significantly higher GA than those without ESRD (15.8% vs. 13.6%). When the cut-off of GA at diagnosis for ESRD was set at GA ≥ 14.25%, AAV patients with GA ≥ 14.25% had a significantly higher risk for ESRD development than those without (relative risk 12.040). In addition, AAV patients with GA ≥ 14.25% exhibited significantly lower cumulative ESRD-free survival rates than those without (P = 0.020).

Conclusion

In conclusion, GA at diagnosis can reflect the cross-sectional BVAS assigned to renal manifestation of AAV and predict ESRD development during follow-up better than HbA1c or GA/HbA1c in AAV patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02913-5.

Modified Body Mass Index at Diagnosis is a Useful Predictor of Mortality in Patients With Antineutrophil Cytoplasmic Antibody-associated Vasculitis

Objective

We investigated whether modified body mass index (mBMI) at diagnosis could predict all-cause mortality during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

Methods

The medical records of 203 AAV patients with BMI ≥18.5 kg/m2 were reviewed. mBMI was calculated using an equation mBMI=BMI (kg/m2)×serum albumin (g/L). All-cause mortality was considered as a poor outcome, and the follow-up duration based on all-cause mortality was defined as the period from AAV diagnosis to death for deceased patients, and the period from AAV diagnosis to the last visit for surviving patients.

Results

The median age was 59.0 years (35.5% were male). The median BMI and mBMI were 22.8 kg/m2 and 813.2 kg · g/m2 · L. Twenty-five patients (12.3%) died. mBMI was well correlated with age, BVAS, FFS, erythrocyte sedimentation rate and C-reactive protein at diagnosis. Deceased patients exhibited significantly lower mBMI at diagnosis compared to surviving patients. AAV patients mBMI ≤570.1 kg · g/m2 · L showed a significantly higher frequency of all-cause mortality (38.5% vs. 8.5%), and furthermore, exhibited a significantly higher risk for all-cause mortality than those with mBMI >570.1 kg · g/m2 · L (RR 6.750). mBMI ≤570.1 kg · g/m2 · L showed a significantly lower cumulative patients' survival rate than those with mBMI >570.1 kg · g/m2 · L. In the multivariable Cox hazards model analysis, either serum albumin or mBMI was significantly associated with all-cause mortality in AAV patients.

Conclusion

In conclusion, mBMI ≤570.1 kg · g/m2 · L at diagnosis may be a useful predictor of all-cause mortality during follow-up additionally to serum albumin in AAV patients.

Fatty Liver Index Independently Predicts All-Cause Mortality in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis but No Substantial Liver Disease

Background

This study investigated whether the fatty liver index (FLI) could predict all-cause mortality and cerebrovascular accident (CVA) during follow-up in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) without substantial liver disease.

Methods

The medical records of 75 AAV patients with AAV were retrospectively reviewed. An equation for the FLI is as follows: FLI = (e0.953×loge(triglycerides)+0.139×BMI+0.718×loge(GGT)+0.053×waistcircumference–15.745)/(1 + e0.953×loge(triglycerides)+0.139×BMI+0.718×loge(GGT)+0.053×waistcircumference–15.745) × 100. The cut-offs of the FLI were obtained using the receiver operator characteristic (ROC) curve analysis.

Results

The mean age at AAV diagnosis was 59.1 years and 42.7% were male. Eight patients (10.7%) died and 8 patients had CVA during follow-up. When the cut-offs of the FLI for all-cause mortality and CVA were set as the FLI ≥ 33.59 and the FLI ≥ 32.31, AAV patients with the FLI over each cut-off exhibited a higher risk for all-cause mortality or CVA than those without (RR 8.633 and 8.129), respectively. In addition, AAV patients with the FLI over each cut-off exhibited a significantly lower cumulative patients’ survival rate or CVA-free survival rate than those without, respectively. In the multivariable Cox analysis, only the FLI ≥ 33.59 at AAV diagnosis was an independent predictor of all-cause mortality during follow-up in AAV patients (HR 10.448).

Conclusion

The FLI at AAV diagnosis can be a potential independent predictor of all-cause mortality and CVA during follow-up in AAV patients. We suggest that physicians measure the FLI at AAV diagnosis and pay more attention to those with a high FLI value for prevention of future mortality and CVA.

Predicting the depressive status using empirical dietary inflammatory index in patients with antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

This study investigated whether the empirical dietary inflammatory index (eDII) score is associated with the inflammatory burden as well as the depressive status in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

Eighty-four patients with AAV participated in this study. Birmingham vasculitis activity score (BVAS) and short-form 36-item Health Survey mental component summary (SF-36 MCS) were considered as indices assessing the inflammatory burden and depressive status, respectively. The eDII includes 16 food components and consists of three groups: -9 to -2, the low eDII group; -1 to +1, the moderate eDII group; and +2 to +10, the high eDII group. Furthermore, the lower eDII group includes both the low and moderate eDII groups.

RESULTS

The median age was 64.5 years (36 men). The eDII scores inversely correlated with SF-36 MCS (r = -0.298, p = 0.006) but not with BVAS. SF-36 MCS significantly differ between the lower and higher eDII groups (69.7 vs. 56.7, p = 0.016), but not among the low, moderate and high eDII groups. Additionally, when patients with AAV were divided into two groups according to the upper limit of the lowest tertile of SF-36 MCS of 55.31, patients in the higher eDII group exhibited a significantly higher risk for the lowest tertile of SF-36 MCS than those in the lower eDII group (RR 3.000).

CONCLUSION

We demonstrated for the first time that the eDII could predict the depressive status by estimating SF-36 MCS without utilising K-CESD-R ≥ 16 in patients with AAV.

Incidence and Patterns of Interstitial Lung Disease and Their Clinical Impact on Mortality in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: Korean Single-Centre Observational Study

Objectives

This study investigated the frequency and patterns of interstitial lung disease (ILD) and their clinical effect on all-cause mortality during the follow-up period in patients with antineutrophil cytoplasmic antibody- (ANCA-) associated vasculitis (AAV) in Korea.

Methods

The medical records of 255 AAV patients with ILD were retrospectively reviewed. ILD and its patterns, the usual interstitial pneumonia (UIP) and non-UIP patterns, were confirmed using high-resolution computed tomography both at AAV diagnosis and during follow-up. Forced vital capacity (FVC) and diffusing capacity of the lung for carbon monoxide (DLCO) were also obtained.

Results

The median age was 65.0 years, and 34.9% were male. ILD occurred in 53 patients, among whom 49.1% developed ILD after AAV diagnosis. Among AAV subtypes, the frequencies of ILD were significantly higher in both patients with microscopic polyangiitis (MPA) and those with AAV having myeloperoxidase (MPO)-ANCA (or P-ANCA) compared to other subtypes. However, there was no statistical significance in AAV subtypes or FVC/DLCO ratio between patients with the UIP and non-UIP patterns. In particular, the cumulative patients' survival rate was lower in patients with AAV and ILD than in those without ILD.

Conclusions

ILD occurred in one-fifth of Korean patients with AAV in this study and was associated with MPA and MPO-ANCA (or P-ANCA). In addition, ILD significantly increased the rate of all-cause mortality in these patients with AAV. Therefore, we suggest the need for more attention and more frequent regular visit for patients with AAV and ILD regardless of the time of ILD occurrence.

Anti-Citrullinated Peptide Antibody Expression and Its Association with Clinical Features and Outcomes in Patients with Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

Background and objectives: Anti-citrullinated peptide antibody (ACPA), a characteristic antibody detected in rheumatoid arthritis, could be linked to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) via the formation of neutrophil extracellular traps. We investigated the rate of ACPA positivity in patients with AAV and evaluated the association of ACPAs with their clinical features and outcomes. Materials and Methods: A total of 168 AAV patients with both ACPA and ANCA results at diagnosis were identified. Clinical and laboratory variables, including the disease-specific indices of Birmingham Vasculitis Activity Score (BVAS) and Five-Factor Score (FFS), were investigated. All-cause mortality, relapse, and end-stage renal disease, as well as interstitial lung disease (ILD) were evaluated as outcomes of the patients, and the Kaplan–Meier survival analysis was used to compare the event-free survival rates of the groups. Results: Fifteen (8.9%) and 135 (80.4%) patients were positive for ACPA and ANCA, respectively. There were no significant differences in the baseline variables of ACPA-negative and ACPA-positive patients. The absolute titre of ACPAs also did not significantly correlate with BVAS, FFS, erythrocyte sedimentation rate, or C-reactive protein. In addition, there was no difference noted regarding overall, relapse-free, and ESRD-free survival rates between ACPA-negative and ACPA-positive AAV patients. However, when the patients were divided into four groups according to ACPA and ANCA status, differences were present in the outcomes, and the ACPA-positive ANCA-positive group exhibited the lowest cumulative relapse-free survival rate, while no significant difference was present in the relapse between the ANCA-positive ANCA-positive, ACPA-positive ANCA-negative, and ACPA-negative ANCA-positive groups. Finally, the cumulative ILD-free survival rates were comparable between ACPA-positive and ACPA-negative AAV patients. Conclusions: The detection of ACPA expression is not uncommon in AAV. However, the presence of ACPA did not influence patients’ basal characteristics and outcomes, suggesting that further exploration of the role of this antibody is needed in patients with AAV.

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.

Association Between Idiopathic Cutaneous Leukocytoclastic Angiitis and ANCA-negative Microscopic Polyangiitis

Objective

This study retrospectively reviewed the process of classifying antineutrophil cytoplasmic antibody (ANCA)-negative granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) in a cohort of patients with ANCA-associated vasculitis (AAV), and investigated the association between recurrent idiopathic cutaneous leukocytoclastic angiitis and ANCA-negative MPA.

Methods

The medical records of 242 patients with AAV were retrospectively reviewed Of 49 patients with ANCA-negative AAV, 24 patients with ANCA-negative eosinophilic GPA (EGPA) were excluded, because ANCA positivity or negativity is not critical in classifying EGPA Ultimately, 25 patients with ANCA-negative GPA and MPA were analysed in this study The classification of GPA and MPA were based on the 2007 European Medicines Agency algorithm for AAV.

Results

The median age of patients with ANCA-negative GPA and MPA was 540 years and 24% were male Of the 25 patients without ANCA, 8 patients were classified as GPA and 17 as MPA Eight patients with ANCA-negative GPA were easily confirmed as definitive GPA Fourteen of the 17 patients ANCA-negative MPA were classified as MPA based on histological features suggestive of AAV without granuloma formation and the absence of surrogate markers for GPA Meanwhile, three of the patients that were ANCA-negative exhibited only recurrent idiopathic cutaneous leukocytoclastic angiitis without other major organs affected and thus were classified as possible MPA Within one year, they were classified as definitive MPA based on ANCA positivity and/or renal histology.

Conclusion

Recurrent idiopathic cutaneous leukocytoclastic angiitis may be associated with ANCA-negative MPA in patients who exhibit cutaneous necrotising vasculitis.

A retrospective analysis of antineutrophil cytoplasmic antibody-associated vasculitis aiming for an equation prediction end-stage renal disease

We provided a predictable method that measures the risk of progression to end-stage renal disease (ESRD) in patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) by using a few routine serum markers of kidney functions at diagnosis. In a retrospective cohort study, the medical records of 254 AAV patients were reviewed. We derived a novel equation for the prediction of the progression to ESRD using variables with a P-value < 0.1 in the multivariable Cox hazard model analysis. We assigned a weight to each variable according to the slopes like a coefficient of a linear equation. The median age of the AAV patients was 59 years and 42 AAV patients progressed to ESRD. In the multivariable Cox analysis using variables with significance in the univariable analysis, MPO-ANCA (or P-ANCA) positivity, blood urea nitrogen, serum creatinine, and serum albumin tended to be associated with the progression to ESRD (P-value < 0.1). We develop an Equation for predicting ESRD in AAV (EPEA) using those variables with the slope of each one. When the cut-off of EPEA was set as -0.094, AAV patients with EPEA ≥ -0.094 had a significantly higher risk of progression to ESRD than those with EPEA < -0.094 (RR, 39.622). AAV patients with EPEA ≥ -0.094 exhibited a significantly lower ESRD-free survival rate than those with EPEA < -0.094. We provided a method to obtain EPEA and demonstrated its predictive potential for ESRD in immunosuppressive drug-naïve AAV patients. Key points • A novel equation for the prediction of the progression to ESRD was developed using variables with a P-value < 0.1 in the multivariable Cox hazard model analysis. A weight was assigned to each variable according to the slopes like a coefficient of a linear equation. • An optimal cut-off of EPEA for progression to ESRD was obtained using the receiver operator characteristic (ROC) curve analysis. • AAV patients with EPEA more than the cut-off had a significantly higher risk of progression to ESRD than those without (RR, 39.622). • AAV patients with EPEA more than the cut-off exhibited a significantly lower ESRD-free survival rate than those without.

Serum Clusterin Level Could Reflect the Current Activity of Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

PURPOSE

We investigated whether serum clusterin levels could reflect the current antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV)-specific indices.

MATERIALS AND METHODS

Fifty-seven patients with AAV and 40 healthy controls were included in this study. AAV-specific indices included the Short-Form 36-Item Health Survey Physical and Mental Component Summaries (SF-36 PCS and MCS) scores, Birmingham vasculitis activity score (BVAS), five-factor score (FFS), and vasculitis damage index. Clinical and laboratory data and AAV-specific indices were obtained at blood collection. The highest tertile of BVAS (≥16) was defined as high activity of AAV.

RESULTS

The median age of AAV patients was 64.0 years and 19 patients were male. SF-36 PCS score (r=0.328), SF-36 MCS score (r=0.289), BVAS (r=-0.404), erythrocyte sedimentation rate (r=-0.336), and C-reactive protein levels (r=-0.421) were significantly correlated with serum clusterin levels. In the multivariable linear regression analysis using AAV-specific indices and serum clusterin levels, both FFS (β=0.412) and serum clusterin levels (β=-0.250) were significantly associated with BVAS. When the optimal serum clusterin cut-off level for high activity of AAV was identified as 130.45 µg/mL, patients with serum clusterin level ≤130.45 µg/mL had a significantly higher risk for high activity of AAV than did those without (relative risk 7.194). Patients with AAV exhibited significantly lower serum clusterin levels than did healthy controls (168.2 µg/mL vs. 230.5 µg/mL).

CONCLUSION

Serum clusterin levels could reflect the current disease activity in patients with AAV.

Serum progranulin as a predictive marker for high activity of antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

This study investigated whether serum progranulin could act as a predictive marker for high disease activity of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV).

METHODS

Fifty-eight AAV patients were included in this study. Clinical and laboratory data were obtained at blood collection. The Short-Form 36-Item Health Survey Physical and Mental Component Summaries (SF-36 PCS and SF-36 MCS), Birmingham Vasculitis activity score (BVAS), Five-Factor Score (FFS), and Vasculitis Damage Index (VDI) were assessed as AAV-specific indices. Whole blood was collected and serum samples were isolated and stored at -80°C. Serum progranulin concentration was quantified by ELISA kits.

RESULTS

The median age of patients was 63.0 years (19 men). The median BVAS was 11.0, and the median serum progranulin level was 49.0 ng/ml. Serum progranulin was significantly correlated with BVAS, FFS, erythrocyte sedimentation rate, C-reactive protein level, SF-36 PCS, haemoglobin, and serum albumin. Severe AAV was arbitrarily defined as the highest tertile of BVAS (BVAS ≥16). When the cut-offs of serum progranulin were set as 55.16 ng/ml and 43.01 ng/ml for severe AAV, AAV patients with serum progranulin ≥55.16 and 43.01 ng/ml had significantly higher risks of severe AAV than those without (relative risk (RR) 4.167 and 4.524, respectively).

CONCLUSIONS

Progranulin might play an anti-inflammatory role in AAV pathogenesis and serum progranulin could be used as a predictive marker for high activity of AAV.

Clinical significance of large unstained cell count in estimating the current activity of antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

We investigated whether large unstained cell (LUC) count could estimate the current high activity according to Birmingham vasculitis activity score (BVAS) in patients with antineutrophil cytoplasmic antibody (ANCA) positive ANCA-associated vasculitis (AAV).

METHODS

We retrospectively reviewed the medical records of 176 immunosuppressive drug-naïve patients with ANCA positive AAV. Clinical and laboratory data at diagnosis, including LUC count, were collected. High BVAS was defined as the highest tertile of BVAS (BVAS ≥ 15) in this study.

RESULTS

The median age was 61.0 years, and 64.8% were female. The median LUC count was 60.0 mm³ , and LUC was detected in 106 patients. LUC count was significantly correlated with BVAS, age, white blood cell count, haemoglobin, platelet count, serum albumin, erythrocyte sedimentation rate and C-reactive protein. Overall, the median BVAS in AAV patients with LUC positivity was significantly higher than that in those without (14.0 vs 10.0). When the cut-off of LUC count for the current high BVAS was set as BVAS ≥ 15 mm³ , AAV patients with LUC count ≥ 15 mm³ had a significantly higher risk for the current high BVAS than those with LUC count < 15 mm³ (relative risk 2.596). However, in the multivariable linear and logistic regression analyses, LUC did not seem to estimate the current BVAS independently among clinical and laboratory variables.

CONCLUSION

LUC count was significantly correlated with the current BVAS and LUC count ≥ 15 mm³ could estimate the current high BVAS in patients with ANCA positive AAV.

Efficacy of tacrolimus as maintenance therapy after cyclophosphamide for treating antineutrophil cytoplasmic antibody-associated vasculitis

Azathioprine (AZA), methotrexate, or rituximab is used for the maintenance therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Although the efficacy of tacrolimus (TAC) in various autoimmune diseases has been demonstrated, there have been few reports on the efficacy of TAC in AAV. We investigated the efficacy of TAC as maintenance therapy for AAV and compared its efficacy with that of AZA.We retrospectively analyzed the medical records of 81 patients with AAV who received cyclophosphamide as induction therapy and AZA or TAC as maintenance therapy. All-cause death, relapse, and progression to end-stage renal disease (ESRD) were analyzed.Among 81 patients with AAV, 69 patients received AZA alone, 6 patients received TAC alone, and 6 patients received TAC after AZA for maintenance therapy. Overall, 11 patients (13.6%) died, 30 patients (37.0%) experienced relapse, and 16 patients (19.8%) progressed to ESRD during a median of 33.8 months. No significant differences were observed in cumulative patients', relapse-free, and ESRD-free survival rates between patients administered AZA alone and TAC alone. There were no significant differences in the cumulative patients' and relapse-free survival rate between patients who received AZA alone and TAC after AZA. However, the cumulative ESRD-free survival rate was lower in patients who received TAC after AZA than in those who received AZA alone (P = .027).Patients who received TAC as maintenance therapy showed a higher incidence of ESRD than those who received AZA; however, this might be attributed to the lack of efficacy of AZA rather than the low ESRD prevention effect of TAC.

Nutrition Risk Index Score at Diagnosis Can Effectively Predict Poor Prognosis in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVES

This study investigated whether the nutritional risk index (NRI) score at diagnosis might be useful for anticipating poor prognosis, in particular, all-cause mortality and end-stage renal disease (ESRD) in patients with antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

The medical records of 242 immunosuppressive drug-naïve patients with AAV were retrospectively reviewed. Data at diagnosis and poor prognosis and medications during follow-up were assessed. The NRI score was calculated by 1.519 × serum albumin (g/L) + 41.7 × present (kg)/ideal body weight (kg).

RESULTS

The median age at diagnosis of patients with AAV (131 microscopic polyangiitis, 62 granulomatosis with polyangiitis, and 49 eosinophilic granulomatosis with polyangiitis) was 60 years (85 male). During follow-up, twenty-nine patients (12.0%) died after a period of 35.9 months, and 42 patients (17.4%) had ESRD for a period of 30.0 months. Using the receiver operator characteristic curve, the cutoffs of the NRI scores for all-cause mortality and ESRD were calculated as NRI ≤ 101.95 (sensitivity, 46.5%; specificity, 89.7%) and NRI ≤ 99.85 (sensitivity, 57.0%; specificity, 83.3%). In the multivariable Cox hazard model analyses, age (hazard ratio [HR], 1.035), five-factor score (HR, 1.623), and the NRI score ≤ 101.95 (HR, 4.262) were independent predictors of all-cause mortality, whereas, five-factor score (HR, 1.516), hypertension (HR, 1.906), and the NRI score ≤ 99.85 (HR, 3.623) were independent predictors of ESRD occurrence during follow-up in patients with AAV.

CONCLUSIONS

The NRI score at diagnosis may be a useful index to anticipate all-cause mortality and ESRD occurrence during follow-up in patients with AAV.

The Efficacy of Mycophenolate Mofetil in Remission Maintenance Therapy for Microscopic Polyangiitis and Granulomatosis with Polyangiitis

PURPOSE

The present study compared the efficacy of mycophenolate mofetil (MMF) with that of azathioprine (AZA) in Korean patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA).

MATERIALS AND METHODS

The medical records of 69 patients with MPA and GPA who received cyclophosphamide and subsequently received AZA or MMF for remission maintenance therapy were reviewed. All-cause mortality, relapse, end-stage renal disease (ESRD), cerebrovascular accident, and cardiovascular disease were evaluated as poor outcomes. Having a lower Birmingham Vasculitis Activity Score (BVAS) was defined as the lowest tertile of BVAS (BVAS ≤11 in this study).

RESULTS

In comparative analysis of the occurrence of poor outcomes among patients taking AZA only, MMF only, and MMF after AZA, patients taking MMF only exhibited a significantly lower cumulative ESRD-free survival rate than patients taking AZA only (p=0.028). In terms of ESRD occurrence between the groups based on BVAS at diagnosis, among patients with MPA and GPA with higher BVAS at diagnosis, patients taking MMF only exhibited a significantly lower cumulative ESRD-free survival rate than those taking AZA only (p=0.047). Among patients with MPA and GPA with the lowest tertile of BVAS at diagnosis, cumulative ESRD-free survival rates did not differ.

CONCLUSION

With regard to ESRD occurrence, the efficacy of MMF in remission maintenance therapy was less effective than AZA in patients with MPA and GPA. However, among patients with lower BVAS, there was no difference in the occurrence of poor outcomes between patients taking MMF and those taking AZA.

Male Sex Is a Significant Predictor of All-cause Mortality in Patients with Antineutrophil Cytoplasmic Antibody-associated Vasculitis

BACKGROUND

We investigated and compared the initial clinical features at diagnosis and the poor outcomes during follow-up in Korean patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) based on sex.

METHODS

The medical records of 223 immunosuppressive drug-naïve patients with AAV were reviewed. Age, body mass index (BMI), smoking history, AAV subtypes, ANCA positivity, clinical manifestations, Birmingham vasculitis activity score (BVAS), five-factor score (FFS), erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) at diagnosis were collected. All-cause mortality, end-stage renal disease (ESRD), cerebrovascular accident (CVA) and cardiovascular disease (CVD) were assessed as the poor outcomes of AAV during follow-up.

RESULTS

The median age was 59.0 years and 74 of 223 AAV patients (33.2%) were men. Among variables at diagnosis, male patients exhibited higher BMI than female. However, there were no differences in other demographic data, AAV subtypes, ANCA positivity, BVAS, FFS, ESR and CRP between the two groups. Male patients received cyclophosphamide more frequently, but there were no significant differences in the frequencies of the poor outcomes of AAV between the two groups. Male patients exhibited a significantly lower cumulative patients' survival rate than female patients during the follow-up period based on all-cause mortality (P = 0.037). In the multivariable analysis, both male sex (hazard ratio [HR], 2.378) and FFS (HR, 1.693) at diagnosis were significantly and independently associated with all-cause mortality during follow-up.

CONCLUSION

Male sex is a significant and independent predictor of all-cause mortality in AAV patients.

Association between follistatin-related protein 1 and the functional status of patients with anti-neutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND

Follistatin-like 1 (FSTL1) plays both pro-inflammatory and anti-inflammatory roles in the inflammatory processes. We investigated whether serum FSTL1 could predict the current anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV)-specific indices.

METHODS

We randomly selected 74 patients with AAV from a prospective and observational cohort of Korean patients with AAV. Clinical and laboratory data and AAV-specific indices were recorded. FSTL1 concentration was determined using the stored sera. The lowest tertile of the short-form 36-item health survey (SF-36) was defined as the current low SF-36. The cutoffs of serum FSTL1 for the current low SF-36 physical component summary (PCS) and SF-36 mental component summary (MCS) were extrapolated by the receiver operator characteristic curve.

RESULTS

The median age was 62.5 years (55.4% were women). Serum FSTL1 was significantly correlated with SF-36 PCS (r =  - 0.374), SF-36 MCS (r = -0.377), and C-reactive protein (CRP) (r = 0.307), but not with Birmingham vasculitis activity score (BVAS). In the multivariable linear regression analyses, BVAS, CRP, and serum FSTL1 were independently associated with the current SF-36 PCS (β = -0.255, β = -0.430, and β = -0.266, respectively) and the current SF-36 MCS (β = -0.234, β =-0.229, and β = -0.296, respectively). Patients with serum FSTL1 ≥779.8 pg/mL and those with serum FSTL1 ≥841.6 pg/mL exhibited a significantly higher risk of having the current low SF-36 PCS and SF-36 MCS than those without (relative risk 7.583 and 6.200, respectively).

CONCLUSION

Serum FSTL1 could predict the current functional status in AAV patients.

Efficacy of the fibrosis index for predicting end-stage renal disease in patients with antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

Kidney involvement is a major manifestation of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and may progress to end-stage renal disease (ESRD), requiring renal replacement therapy. Unfortunately, there is no reliable kidney-specific index for predicting the progression of renal disease to ESRD. The fibrosis index (FI) reflects the degree of fibrosis in chronic liver disease. This study aimed to investigate whether the FI at the time of diagnosis could predict the development of ESRD in AAV patients.

METHODS

We retrospectively reviewed the medical records of 211 immunosuppressive drug-naïve AAV patients and extrapolated the cut-off FI value for predicting the development of ESRD using receiver operating characteristic curves. The associations between the FI and clinical outcomes, including mortality, relapse, and ESRD development, were determined.

RESULTS

Overall, 39 (18.5%) patients developed ESRD owing to the progression of AAV-associated renal disease. The median FI was higher in AAV patients with ESRD than in those without (1.61 vs 1.04; P = .001). The FI cut-off was 1.72. The incidence of ESRD was higher in patients with FI ≥ 1.72 at the time of diagnosis than in those with an FI < 1.72 at the time of diagnosis (relative risk: 4.655; 95% confidence interval: 2.242-9.662; P < .001). Kaplan-Meier survival analysis revealed that patients with an FI ≥ 1.72 at the time of diagnosis exhibited significantly lower ESRD-free survival rates than those with an FI < 1.72 at the time of diagnosis (P < .001).

CONCLUSION

FI ≥ 1.72 at the time of diagnosis may be an independent predictive marker for ESRD in AAV patients.

Total Haemolytic Complement Activity at Diagnosis as an Indicator of the Baseline Activity of Antineutrophil Cytoplasmic Antibody-associated Vasculitis

Objective

The total haemolytic complement activity (CH50) assay evaluates the functioning of the complement system Accumulating evidence indicates that the activation of the complement system plays a critical role in the pathogenesis of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) Therefore, this study aimed to investigate whether CH50 levels at diagnosis could reflect the baseline activity of AAV.

Methods

This retrospective study included 101 immunosuppressive drug-naïve patients with AAV At diagnosis, all patients underwent clinical assessments for disease activity, including measurement of the Birmingham Vasculitis Activity Score (BVAS) and Five Factor Score (FFS), and laboratory evaluations, such as tests for CH50, C3, and C4 levels The association between CH50 levels and disease activity was determined.

Results

The median BVAS and FFS at diagnosis were 120 and 10, respectively, whereas the median CH50 level was 604 U/mL There was a negative correlation between the CH50 level and BVAS (r=-0241; p=0015) A CH50 cut-off value of 621 U/mL was used to classify the patients into two groups: patients with CH50 levels <621 U/mL (low-CH50 group) and those with CH50 levels ≥621 U/mL (high-CH50 group) The low-CH50 group had a higher proportion of patients with high disease activity, based on the BVAS, than the high-CH50 group (525% vs 238%, p=0004) Additionally, the low-CH50 group exhibited a lower relapse-free survival rate than the high-CH50 group; however, this difference was not statistically significant (p=0082).

Conclusion

Low CH50 levels at diagnosis may reflect high baseline activity of AAV.

Correlation between serum cysteine-rich protein 61 and disease activity of antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVES

Cysteine-rich protein 61 (CYR61) stimulates protein kinase B (Akt)-mediated nuclear factor-kappa B (NF-κB) signalling leading to an increase in pro-inflammatory cytokines, which play important roles in the pathogenesis of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). Hence, we investigated whether serum CYR61 was correlated with disease activity of AAV in a single-centre prospective cohort.

METHODS

Seventy-two patients with AAV were randomly selected and included. Serum CYR61, interleukin (IL)-6 and IL-8 levels were quantified with the patients' stored sera, and clinical and laboratory data at the time of blood sampling were collected. Spearman's correlation and linear regression analysis was conducted to analyse the correlation between continuous variables. The optimal cut-off of serum CYR61 for predicting high disease activity was identified using the receiver operator characteristic curve. Birmingham vasculitis activity score (BVAS) was used as a measure to assess disease activity, and high disease activity was defined as BVAS ≥ 12.

RESULTS

Serum CYR61 significantly correlated with BVAS (r = 0.249), erythrocyte sedimentation rate (r = 0.283), C-reactive protein (r = 0.298) and serum IL-6 (r = 0.319). However, a linear association was not found between CYR61 and BVAS (β = 0.102, P = 0.304). The relative risk (RR) for high disease activity in AAV patients with serum CYR61 ≥ 236.2 pg/mL was higher than those with serum CYR61 < 236.2 pg/mL (RR 3.316, P = 0.018).

CONCLUSION

Even though serum CYR61 was not directly proportional to the increase of BVAS, it could be predictive of high disease activity in AAV. Key Points • Serum CYR61 was significantly correlated with BVAS along with ESR, CRP and serum IL-6. • The cut-off of serum CYR61 for high disease activity of AAV was obtained as 236.2 pg/mL. • AAV patients with serum CYR61 ≥ 236.2 pg/mL had increased risk of having higher disease activity than those with serum CYR61 < 236.2 pg/mL (RR 3.316, P = 0.018).

Fibrinogen to albumin ratio reflects the activity of antineutrophil cytoplasmic antibody-associated vasculitis

Background

We investigated whether fibrinogen to albumin ratio (FAR) at diagnosis could reflect the cross‐sectional activity and predict poor outcomes in patients with antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV).

Methods

This cross‐sectional study included 54 immunosuppressant drug‐naïve patients with AAV who had the results of plasma fibrinogen and serum albumin at diagnosis. Clinical and laboratory data at diagnosis were collected, and all‐cause mortality, cerebrovascular accident, cardiovascular disease, end‐stage renal disease occurrences were assessed as poor outcomes. FAR was calculated by the following equation: FAR = plasma fibrinogen (g/dl)/serum albumin (g/dl).

Results

The median age was 65.5 years, and 59.3% of patients were men (33 MPA, 13 GPA and 8 EGPA). FAR was significantly correlated with Birmingham vasculitis activity score (BVAS; r = 0.271), erythrocyte sedimentation rate (ESR; r = 0.668) and C‐reactive protein (CRP; r = 0.638). High BVAS was defined as BVAS ≥16, and the cut‐off of FAR at diagnosis was set as 0.118. AAV patients with FAR at diagnosis ≥0.118 had a significantly higher risk for the cross‐sectional high BVAS than those without (RR 3.361). In the univariable linear regression analysis, CRP (β = 0.383) and FAR (β = 0.297) were significantly correlated with BVAS at diagnosis. However, in the multivariable analysis, none of them was correlated with the cross‐sectional BVAS. FAR at diagnosis could not predict poor outcomes during follow‐up in AAV patients.

Conclusions

Fibrinogen to albumin ratio at diagnosis could reflect the cross‐sectional BVAS but could not predict poor outcomes in patients with AAV.

The novel fibrosis index at diagnosis may predict all-cause mortality in patients with antineutrophil cytoplasmic antibody-associated vasculitis without substantial liver diseases

OBJECTIVES

Antineutrophil cyto plasmic antibody-associated vasculitis (AAV) is a fatal disease. Currently, predictors of mortality due to AAV are based on the distribution of organ involvement. The novel fibrosis index (NFI) is an index composed of laboratory results that reflect the degree of liver fibrosis. This study aimed to evaluate whether NFI can predict poor outcomes in patients with AAV without substantial liver disease.

METHODS

A total of 210 patients with immunosuppressive drug-naïve AAV were retrospectively reviewed. NFI was calculated as follows: NFI=(serum bilirubin × (alkaline phosphatase)2)/(platelet count×(serum albumin)2). NFI cut-off was set at 1.24 (the highest quartile). Poor outcomes were defined as all-cause mortality, relapse, and end-stage renal disease (ESRD).

RESULTS

During the median 34.5 months of follow-up, 21 patients (10%) died, 72 patients (34.3%) relapsed, and 38 patients (18.1%) had ESRD due to AAV progression. The median calculated NFI was 0.61, and it was higher in AAV patients with all-cause mortality than in those without mortality, but the difference was not statistically significant (1.26 vs. 0.59). AAV patients with NFI at diagnosis ≥1.24 exhibited a significantly lower cumulative patient survival rate than those with NFI at diagnosis <1.24 (p=0.002). Multivariate Cox hazard model analysis showed that NFI at diagnosis ≥1.24 was an independent predictor of all-cause mortality in AAV (hazard ratios [HR] 2.850, 95% confidence interval [CI] 1.026, 7.910).

CONCLUSIONS

NFI ≥1.24, which may be an independent predictive marker for all-cause mortality in AAV patients without substantial liver disease.

Serum vitamin D level correlates with disease activity and health-related quality of life in antineutrophil cytoplasmic antibody-associated vasculitis

BACKGROUND AND OBJECTIVE

The association between vitamin D levels and disease activity has been established in patients with several autoimmune rheumatic diseases. We aimed to examine the association between vitamin D and disease activity of antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

Fifty-four AAV patients and 50 age- and sex-matched healthy controls without vitamin D supplements were included. Clinical and laboratory data were evaluated during the assessment of vitamin D levels. Two different forms of vitamin D in the sera-25(OH)D, which is the sum of 25(OH)D2 and 25(OH)D3, and 25(OH)D3, which only includes 25(OH)D in its D3 form-were measured, and the relationship between vitamin D and the obtained data was assessed. Variations in vitamin D levels relative to the season were also evaluated.

RESULTS

Patients with AAV demonstrated considerably lower 25(OH)D serum levels than healthy controls (16.0 vs. 20.4 ng/mL, p = 0.016), and the proportion of individuals with vitamin D deficiency was higher in patients with AAV than in healthy controls (68.5% vs. 48.0%, p = 0.035). Both serum 25(OH)D and 25(OH)D3 were positively associated with the 36-item Short-form Health Survey (SF-36) physical component summary and SF-36 mental component summary (MCS) scores. A negative correlation was observed between 25(OH)D and 25(OH)D3 serum levels and Birmingham vasculitis activity score (BVAS), C‑reactive protein (CRP), and white blood cell count. Linear regression analysis indicated haemoglobin and 25(OH)D levels to be independently associated with BVAS and CRP and 25(OH)D levels with SF-36 MCS score. No seasonal variations were observed in vitamin D levels.

CONCLUSION

The results from this study suggest that vitamin D levels could provide clinically useful information in AAV.