The epidemiology of antineutrophil cytoplasmic antibody-associated vasculitis in northwestern Turkey

Aging in Granulomatosis with Polyangiitis and Microscopic Polyangiitis: From Pathophysiology to Clinical Management

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) predominantly affect individuals aged 55-75 years, with granulomatosis with polyangiitis (GPA) being diagnosed most often between 55 and 65 years and microscopic polyangiitis (MPA) between 65 and 75 years. Owing to the general increase in life expectancy, the average age at diagnosis increases, encompassing also those over 75 years old. Unfortunately, the exclusion of these older patients from many clinical trials has limited our understanding of the progression of these diseases in older subjects. The role of immunosenescence and aging in AAV pathogenesis and progression is underexplored, despite potential implications in the understanding of the disease, and potentially for disease management. Although AAV manifestations are largely consistent across age groups, certain features, such as renal involvement and the association with interstitial lung disease, may be more prevalent in older patients. Frailty must be a key consideration in therapeutic decision-making, especially when balancing the efficacy of immunosuppressants with potential side effects. Recent evidence supports the use of rituximab in addition to low-dose glucocorticoids for remission induction in life- or organ-threatening AAV, including in older populations. Furthermore, preliminary evidence supports that avacopan might be as efficient as glucocorticoids in these patients. The immunosuppressive treatment of AAV reduces the immune response to environmental pathogens, with rituximab worsening age-related hypogammaglobulinemia. Thus, prophylactic measures, including vaccination and Pneumocystis pneumonia prevention, as well as strategies to mitigate glucocorticoid side effects, should be implemented in AAV management.

Epidemiology of ANCA vasculitis in northern Spain

OBJECTIVES

The incidence of anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) shows disparate results due to variable classification criteria and heterogeneous population series. We aimed to estimate the incidence of AAV in a well-defined population with standardized classification criteria.

METHODS

This was a population-based study of AAV patients diagnosed from January 2000 to December 2023 in Cantabria, northern Spain. Patients were classified according to ACR/EULAR 2022 into granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), or unclassified vasculitis if the criteria were not met. Eosinophilic granulomatosis with polyangiitis patients were not included. The annual incidence rates were estimated by cases over 1 000 000 (106) (95% CI) including overall AVV, type of AAV, sex and year of diagnosis. A literature review was also performed.

RESULTS

We included 152 patients [80M/72F; mean age 70.6 (13.18) years]. They were classified as MPA (67; 44%), GPA (64; 42.2%), and unclassified vasculitis (21; 13.8%). Annual incidence was 13.4 (95% CI: 10, 16.8)/106 [male 14.5 (95% CI: 10.5, 18.5); female 12.1 (95% CI: 8.7, 15.6)]. The Annual incidence of MPA was 5.9 (95% CI: 4, 7.8)/106 and GPA 5.6 (95% CI: 3.9, 7.3)/106. The mean annual incidence increased from 6.1 (95% CI: 4.5, 7.7)/106 to 16.5 (595% CI: .6, 27.4)/106 in the last 3 years, particularly in GPA from 2.3 (95% CI: 0.3, 4.9)/106 to 8.2 (95% CI: 2, 14.5)/106. The prevalence of AAV was 184.7 (95% CI: 181, 188)/106.

CONCLUSION

During a 20-year period we found that the incidence of AAV (GPA and MPA) in northern Spain was higher than in southern Spain, but lower than northern European countries. An increase in the incidence was observed in the last years.

New Insights into Pathogenesis and Treatment of ANCA-Associated Vasculitis: Autoantibodies and Beyond

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of rare systemic diseases affecting small-caliber vessels. The damage caused by AAV mainly involves the lung and kidneys. AAV includes three different types: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Although the different phenotypic forms of AAV share common features, recent studies have shown that there are significant differences in terms of pathogenetic mechanisms involving both the adaptive and innate immune systems. Advances in our understanding of pathogenesis have enabled the development of immuno-targeted therapies. This review illustrates the characteristics of the various forms of AAV and the new therapies available for this disease that can have lethal consequences if left untreated.

Development and internal validation of a model to predict long-term survival of ANCA associated vasculitis

Objectives

Risk stratification and prognosis prediction are critical for appropriate management of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV). Herein, we aim to develop and internally validate a prediction model specifically for long-term survival of patients with AAV.

Methods

We thoroughly reviewed the medical charts of patients with AAV admitted to Peking Union Medical College Hospital from January 1999 to July 2019. The Least Absolute Shrinkage and Selection Operator method and the COX proportional hazard regression was used to develop the prediction model. The Harrell's concordance index (C-index), calibration curves and Brier scores were calculated to evaluate the model performance. The model was internally validated by bootstrap resampling methods.

Results

A total of 653 patients were included in the study, including 303 patients with microscopic polyangiitis, 245 patients with granulomatosis with polyangiitis and 105 patients with eosinophilic granulomatosis with polyangiitis, respectively. During a median follow-up of 33 months (interquartile range 15-60 months), 120 deaths occurred. Age at admission, chest and cardiovascular involvement, serum creatinine grade, hemoglobin levels at baseline and AAV sub-types were selected as predictive parameters in the final model. The optimism-corrected C-index and integrated Brier score of our prediction model were 0.728 and 0.109. The calibration plots showed fine agreement between observed and predicted probability of all-cause death. The decision curve analysis (DCA) showed that in a wide range of threshold probabilities, our prediction model had higher net benefits compared with the revised five factor score (rFFSand) and the birmingham vasculitis activity score (BVAS) system.

Conclusion

Our model performs well in predicting outcomes of AAV patients. Patients with moderate-to-high probability of death should be followed closely and personalized monitoring plan should be scheduled.

Environmental factors influencing the risk of ANCA-associated vasculitis

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of diseases characterized by inflammation and destruction of small and medium-sized blood vessels. Clinical disease phenotypes include microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The incidence of AAV has been on the rise in recent years with advances in ANCA testing. The etiology and pathogenesis of AAV are multifactorial and influenced by both genetic and environmental factors, as well as innate and adaptive immune system responses. Multiple case reports have shown that sustained exposure to silica in an occupational environment resulted in a significantly increased risk of ANCA positivity. A meta-analysis involving six case-control studies showed that silica exposure was positively associated with AAV incidence. Additionally, exposure to air pollutants, such as carbon monoxide (CO), is a risk factor for AAV. AAV has seasonal trends. Studies have shown that various environmental factors stimulate the body to activate neutrophils and expose their own antigens, resulting in the release of proteases and neutrophil extracellular traps, which damage vascular endothelial cells. Additionally, the activation of complement replacement pathways may exacerbate vascular inflammation. However, the role of environmental factors in the etiology of AAV remains unclear and has received little attention. In this review, we summarized the recent literature on the study of environmental factors, such as seasons, air pollution, latitude, silica, and microbial infection, in AAV with the aim of exploring the relationship between environmental factors and AAV and possible mechanisms of action to provide a scientific basis for the prevention and treatment of AAV.

Systematic Review and Metaanalysis of Worldwide Incidence and Prevalence of Antineutrophil Cytoplasmic Antibody (ANCA) Associated Vasculitis

Objective: In this study, we aimed to evaluate the worldwide incidence and prevalence of ANCA-associated vasculitis (AAV). Methods: A systematic search of Medline and Embase was conducted until June 2020 for studies that analyzed the incidence and prevalence of patients aged >16 years diagnosed with AAV in different geographical areas. A meta-analysis was undertaken to estimate the pooled incidence per million person-years and prevalence per million persons in AAV overall and for each subtype of AAV: granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). The 95% confidence interval (CI) and I2 for heterogeneity were calculated. Results: The meta-analysis included 25 studies that met the inclusion criteria and covered a total of 4547 patients with AAV. Frequency increased over time. The global pooled incidence (95% CI) was 17.2 per million person-years (13.3−21.6) and the global pooled prevalence (95% CI) was 198.0 per million persons (187.0−210.0). The pooled incidence per million person-years for each AAV subtype varied from highest to lowest, as follows: GPA, 9.0; MPA, 5.9; and EGPA, 1.7. The individual pooled prevalence per million persons was, as follows: GPA, 96.8; MPA, 39.2; and EGPA, 15.6. AAV was more predominant in the northern hemisphere. By continent, a higher incidence in America and pooled prevalence of AAV was observed in America and Europe. Conclusion: The pooled incidence and prevalence of AAV seem to be increasing over time and are higher in the case of GPA. AAV was generally more frequent (incidence and prevalence) in the northern hemisphere.

ANCA-Associated Vasculitis in Latin America: A Systematic Literature Review: About Their Epidemiology and Their Clinical Features

ABSTRACT

Most of the existing literature, including epidemiological studies and clinical trials, on antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) include North American (mainly United States and Canada), European, and Asian populations. Few studies have focused on multiethnic populations such as the one from Latin America. Racial and ethnic differences in the incidence of AAV could partially explain the comparatively low number of AAV studies originating in Latin America. However, given the racial/ethnic diversity as well as socioeconomic differences existing in this region, better reporting of AAV presentations and outcomes in Latin America could highlight valuable gaps on the understanding and treatment of these patients. Recently, larger case series and studies have provided better clinical information regarding AAV patients in Latin American countries; however, further information is needed to address gaps such as risk factors, genetic profiles, clinical features, and predictors of clinical outcomes. For these reasons, we have performed a systematic literature review to enhance our understanding of AAV patients in Latin America. We have included 11 articles focused on the epidemiological and clinical features of AAV in Latin America; some similarities and differences with AAV in other regions are shown in these articles. We have identified differences in their prevalence across Latin American countries, which may reflect reporting bias or true ethnic differences among the countries. Our findings should encourage further investigation into AAV in Latin America; such studies will hopefully lead to the optimal management of these patients.

Global epidemiology of vasculitis

The many forms of vasculitis are characterized by inflammation of blood vessels, leading to potentially long-term sequelae including vision loss, aneurysm formation and kidney failure. Accurate estimation of the incidence and prevalence has been hampered by the absence of reliable diagnostic criteria and the rarity of these conditions; however, much progress has been made over the past two decades, although data are still lacking from many parts of the world including the Indian subcontinent, China, Africa and South America. Giant cell arteritis occurs in those aged 50 years and over and seems to mainly affect persons of northern European ancestry, whereas Takayasu arteritis occurs mainly in those aged under 40 years. By contrast, Kawasaki disease mainly occurs in children aged under 5 years and is most common in children of Asian ancestry, and IgA vasculitis occurs in children and adolescents. Although much less common than giant cell arteritis, the different forms of antineutrophil cytoplasmic antibody-associated vasculitis are being increasingly recognized in most populations and occur more frequently with increasing age. Behçet syndrome occurs most commonly along the ancient silk road between Europe and China. Much work needs to be done to better understand the influence of ethnicity, geographical location, environment and social factors on the development of vasculitis.

Predictors of renal and patient outcomes in anti-neutrophil cytoplasmic antibody-associated vasculitis: Our single-center, tertiary care experience

Objectives

This study aims to assess the different predictors of renal and patient prognosis in anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) patients with and without renal involvement.

Patients and methods

A total of 79 patients (51 males, 28 females; mean age: 57.3±14.2 years; range, 18 to 71 years) with AAV between January 2006 and November 2019 were retrospectively analyzed. Demographic and laboratory data including the complement 3 (C3) serum levels and renal biopsy findings were extracted from the electronic and printed medical records of the hospital registry. Survival, renal survival, remission, and relapse outcomes were analyzed.

Results

A total of 35% of the patients with renal involvement progressed to end-stage renal disease (ESRD). The dialysis requirement at the time of admission (hazard ratio [HR]: 21.95 [2.93-164.22]; p=0.003), estimated glomerular filtration rate (eGFR) (HR: 0.97 [0.94-0.99]; p=0.024) and Five-Factor Score (FFS) ≥2 at the time of diagnosis (HR: 3.59 [1.08-11.94]; p=0.037) were the predictors of ESRD. The five-year patient survival rate was 87.1%. The only predictor of mortality was age (HR: 1.07 [1.01-1.14]; p=0.024). The patients with hypocomplementemia (22%) had a lower remission rate (p=0.049), FFS ≥2 at the time of diagnosis (p=0.026), and higher levels of hematuria (p=0.004) and proteinuria (p=0.037). The FFS ≥2 at the time of diagnosis was an independent predictor of relapse (HR: 8.9 [1.02-77.36]; p=0.047).

Conclusion

Our study suggests that the baseline renal function and FFS ≥2 at the time of diagnosis are the major prognostic factors for progression to ESRD in AAV patients. In addition, AAV patients with hypocomplementemia may have a lower remission rate.

An update on the epidemiology of ANCA-associated vasculitis

ANCA-associated vasculitis (AAV) includes granulomatosis with polyangiitis, microscopic polyangiitis and eosinophilic granulomatosis with polyangiitis. Epidemiological studies in AAV are important in understanding possible aetiologic mechanisms and facilitating healthcare planning. However, epidemiological studies present a number of challenges including clear definition of cases differentiated from other clinical disorders, and identification of cases due to the rarity of AAV. The aim of this review is to summarize different aspects on the epidemiology of ANCA-associated vasculitis from different geographical areas throughout the world. During the past three decades, development of classification criteria worldwide, including the ACR classification of 1990, the Chapel Hill consensus definitions updated in 2012 and the EMA algorithm has facilitated epidemiology studies in AAV. The available epidemiological studies reported in AAV suggest that incidence and prevalence may have increased over the past 30 years. Possible explanations for this increase may be a genuine increase in incidence, the evolution of classification criteria and the definition, and availability and wider use of ANCA serology to aid diagnosis, and greater physician awareness through education. The age-specific incidence for the whole group of AAV showed a clear increase with age. However, there has been a clear shift in the peak age at onset towards a higher age during the last 20-30 years. In addition, variation in incidence of AAV between men and women has been clearly evident in a number of epidemiological studies.

A retrospective study on the epidemiology of ANCA-associated vasculitis in two Australian health districts

BACKGROUND

ANCA-associated vasculitis (AAV) is more prevalent in rural Australia compared to metropolitan areas suggesting a role of environment in disease pathogenesis. However, the prevalence of environmental risk factors in Australian AAV patients has not been described.

AIMS

To compare the incidence of AAV between two health districts (Illawarra Shoalhaven local health district (ISLHD), a mixed rural/metropolitan region, and South Eastern Sydney local health district (SESLHD), a metropolitan region) in Australia and its relationship to environmental exposures.

METHODS

Cases of AAV from 2002 to 2017 were retrospectively identified from ISLHD and SESLHD using electronic medical records. Eligible participants were invited to complete a standardised questionnaire examining their exposure to silica, solvents, metal, dust, farming, gardening, and sunlight.

RESULTS

156 cases of AAV were identified from 2002 to 2017. A higher cumulative incidence of AAV was observed in the ISLHD (184.2 [95% confidence interval (CI) 143.6-232.7] per million) compared to SESLHD (102.6 [95% CI 82.1-126.8] per million). Over 50% of the cohort had high levels of silica and solvents exposure, based on self-reported questionnaires. There was no significant relationship between region and exposure to silica (p=0.96), solvents (p=0.44), metal (p=0.33), dust (p=0.25), farming (p=0.90), gardening (p=0.93), or sunlight (p=0.55).

CONCLUSIONS

We found a higher incidence of AAV in ISLHD compared to SESLHD with high levels of exposure to silica and solvents in both regions based on self-reported questionnaires. Prospective systematic collection of data, such as a registry of AAV, is warranted to further explore the relationship between environmental exposures and AAV. This article is protected by copyright. All rights reserved.

Epidemiology of Granulomatosis with Polyangiitis in Poland, 2011-2015

Granulomatosis with polyangiitis (GPA) is a form of vasculitis that affects small- and medium-sized vessels in many organs. The aim of the study was to describe the epidemiology of GPA in Poland in 2011-2015, including the incidence and prevalence rates. The authors conducted a retrospective, population-based study, using hospital discharge records with GPA diagnosis. GPA incidence was estimated on the basis of the data from the Polish hospital morbidity study carried out by the National Institute of Public Health. The final study group consisted of 1491 patients (749 females, 742 males) who were first time hospitalized with the diagnosis of GPA. The average annual incidence of GPA in Poland was 7.7/1,000,000 (95% CI, 4.1-11.4), and the point prevalence at the end of 2015 was 36/1,000,000. A statistically significant decrease in the GPA incidence was noticed in this study. A 1-year survival rate for GPA was 94%. In conclusion, the incidence and prevalence rates of GPA in Poland are similar to that reported in other European countries. The study provides recent epidemiological data on GPA in Poland, which may be useful for comparisons with other geographical regions.

ANCA associated vasculitis in patients from Saudi Arabia

Objective:

To explore clinical and laboratory features, therapy and outcome of antineutrophil cytoplasmic antibodies (ANCA) associated vasculitis (AAV) patients from our tertiary care center.

Methods:

This study of AAV patients seen in Rheumatology clinics at King Khalid University hospital (KKUH), King Saud University, Riyadh during the period 1990-2014 was carried out retrospectively. Demographic, clinical, haematological and immunological parameters along with therapy, complications and outcome were retrieved from patients' medical charts. Different characteristics were compared between the three groups of AAV; GPA (Granulomatosis with polyangiitis), MPA (Microscopic polyangiitis) and EGPA (Eosinophilic granulomatosis with polyangiitis).

Results:

We identified 34 AAV patients (21 males: 13 females; 31 Saudis: 3 non-Saudis) comprising of 23 GPA, 2 MPA and 9 EGPA cases. The mean age of onset was 42.1±17.6 years (range 11-75) and mean duration of disease was 8.7± 5.1 years (range 1-20). The most frequently affected system was pulmonary in all AAV (73.5%), GPA (65.2%) and EGPA (100%) while it was renal in MPA (100%) patients. Ophthalmological and upper airways involvement was higher in GPA. Neurological involvement was higher in EGPA (p<0.05). ANCA were detected in 79.4% of AAV patients, of them c-ANCA were 77.8% and p-ANCA 22.2%. ANCA was positive in 91.3% GPA, 100% MPA and 44.4% EGPA patients. In GPA c-ANCA were detected in 80.9% and p-ANCA in 17.4%, in MPA, c-ANCA were detected in 50% and p-ANCA in 50%, in EGPA, c-ANCA were observed in 75% and p-ANCA in 25%. GPA patients had PR3 specificity in 93.3%, and MPO in 6.7%, PR3 was present in all MPA patients (100%), while EGPA patients had MPO (100%). Therapy administered were corticosteroids (100%), intravenous cyclophosphamide (58.8%), azathioprine (50%) and rituximab (11.8%). Infections were noted in 29.4%.

Conclusions:

The 10-year survival in our AAV patients was 95%. ANCA pattern was similar to Caucasian AAV patients and different from Japanese and Chinese AAV patients.

The Epidemiology of Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis in Olmsted County, Minnesota: A Twenty-Year US Population-Based Study

OBJECTIVE

To estimate the annual incidence, prevalence, and mortality of antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) and its subsets, granulomatosis with polyangiitis (Wegener's) (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (Churg-Strauss) (EGPA), in a US-based adult population.

METHODS

All medical records of patients with a diagnosis of, or suspicion of having, AAV in Olmsted County, Minnesota from January 1, 1996 to December 31, 2015 were reviewed. AAV incidence rates were age- and sex-adjusted to the 2010 US white population. Age- and sex-adjusted prevalence of AAV was calculated on January 1, 2015. Survival rates observed in the study cohort were compared with expected rates in the Minnesota population.

RESULTS

Of the 58 incident cases of AAV in Olmsted County during the study period, 23 (40%) were cases of GPA, 28 (48%) were cases of MPA, and 7 (12%) were cases of EGPA. Overall, 28 (48%) of the patients with AAV were women and 57 (98%) were white. The mean ± SD age at diagnosis was 61.1 ± 16.5 years. Thirty-four patients (61%) had myeloperoxidase (MPO)-ANCAs, and 17 (30%) were positive for proteinase 3 (PR3)-ANCAs; 5 (9%) were ANCA-negative. The annual incidence of AAV was 3.3 per 100,000 population (95% confidence interval [95% CI] 2.4-4.1). The incidence rates of GPA, MPA, and EGPA were 1.3 (95% CI 0.8-1.8), 1.6 (95% CI 1.0-2.2), and 0.4 (95% CI 0.1-0.6), respectively. The overall prevalence of AAV was 42.1 per 100,000 (95% CI 29.6-54.6). The mortality rate among AAV patients overall, and among patients with EGPA, those with MPA, and those with MPO-ANCAs, was increased in comparison to the Minnesota general population (each P < 0.05), whereas mortality rates among patients with GPA, those with PR3-ANCAs, and ANCA-negative patients did not differ from that in the general population.

CONCLUSION

The annual incidence of AAV in Olmsted County, Minnesota over the 20 years of the study was 3.3 per 100,000, with a prevalence of 42.1 per 100,000, which is substantially higher than the rates reported in other areas worldwide. The incidence of GPA was similar to that of MPA. Patients with MPA and those with EGPA, but not patients with GPA, experienced higher rates of mortality than that in the Minnesota general population. MPO-ANCAs were a marker of poor survival in this population of patients with AAV.

Hospital Morbidity Database for Epidemiological Studies on Churg-Strauss Syndrome

Churg-Strauss syndrome or more accurately eosinophilic granulomatosis with polyangiitis (EGPA) is a small-vessel necrotizing vasculitis with a characteristic late-onset allergic rhinitis and asthma. The use of hospital morbidity database is an important element of the epidemiological analysis of this rare disease. The present study was undertaken to assess the incidence of EGPA and factors related to its epidemiology in Poland; the first analysis of the kind in Poland, enabling a comparison in the European context. This is a retrospective, population-based study using hospital discharge records with EGPA diagnosis, collected for a National Institute of Public Health survey covering the period from 2008 to 2013. The group consisted of 344 patients (206 females and 138 males) with the first-time hospitalization for EGPA. The major findings are that the annual incidence of EGPA in Poland was 1.5 per million (95% confidence intervals: 1.2-1.8), with the point prevalence of 8.8 per million at the end of 2013. A greater incidence of EGPA was observed in the regions with urban predominance. We conclude that discharge records may be a useful element of epidemiological studies on EGPA.