Pulmonary involvements of anti-neutrophil cytoplasmic autoantibody-associated renal vasculitis in Japan

Prediction model for respiratory-related mortality in microscopic polyangiitis with interstitial lung disease: multicentre REVEAL cohort study

OBJECTIVE

This study aimed to establish prediction models for respiratory-related mortality in microscopic polyangiitis (MPA) complicated by interstitial lung disease (ILD) using clinical characteristics.

METHODS

We enrolled patients with MPA with ILD between May 2005 and June 2021 in a multicentre cohort of Japanese patients with MPA (REVEAL cohort). We evaluated the demographic, clinical, laboratory, radiological findings, treatments and the presence of honeycombing 1 cm above the diaphragm using chest high-resolution CT (HRCT) on admission. We explored the risk factors predictive of respiratory-related mortality.

RESULTS

Of 115 patients, 26 cases died of respiratory-related diseases during a median follow-up of 3.8 years. Eighteen patients (69%) died due to respiratory infection, three (12%) had diffuse alveolar haemorrhage, and five (19%) had exacerbation of ILD. In univariate analysis, older age, lower percent forced vital capacity (%FVC), lower percent diffusing capacity of carbon monoxide (%DLCO), and the presence of honeycombing in the right lower lobe were identified as risk factors. Additionally, in multivariate analysis adjusted for age and treatment, %FVC, %DLCO and the presence of honeycombing in the right lower lobe were independently associated with respiratory-related mortality. We created prediction models based on the values of %FVC, %DLCO and presence of honeycombing on chest HRCT (termed "MPF model"). The 5-year respiratory-related death-free rate was significantly different between patients with MPA with ILD stratified by the number of risk factors based on the MPF model.

CONCLUSIONS

Our study indicates that the MPF model may help predict respiratory-related death in patients with MPA with ILD.

Development of a novel predictive model for interstitial lung disease in ANCA-associated vasculitis prognostications within the Chinese population

Antineutrophil cytoplasmic antibody vasculitis-associated interstitial lung disease (AAV-ILD) is a potentially life-threatening disease. However, very little research has been done on the condition's mortality risk. Hence, our objective is to find out the factors influencing the prognosis of AAV-ILD and employ these findings to create a nomogram model. Patients with AAV-ILD who received treatment at the First Affiliated Hospital of Zhengzhou University during the period from March 1, 2011, to April 1, 2022 were selected for this research. The development of nomogram entailed a synergistic integration of univariate, Lasso, and multivariate Cox regression analyses. Internal validation ensued through bootstrap techniques involving 1000 re-sampling iterations. Discrimination and calibration were assessed utilizing Harrell's C-index, receiver operating characteristic (ROC) curve, and calibration curve. Model performance was evaluated through integrated discrimination improvement (IDI), net reclassification improvement (NRI), and likelihood ratio test. The net benefit of the model was evaluated using decision curve analysis (DCA). A cohort comprising 192 patients was enrolled for analysis. Throughout observation period, 32.29% of the population died. Key factors such as cardiac involvement, albumin, smoking history, and age displayed substantial prognostic relevance in AAV-ILD. These factors were incorporated to craft a predictive nomogram. Impressively, the model exhibited robust performance, boasting a Harrell's C index of 0.826 and an AUC of 0.940 (95% CI 0.904-0.976). The calibration curves depicted a high degree of harmony between predicted outcomes and actual observations. Significantly enhancing discriminative ability compared to the ILD-GAP model, the nomogram was validated through the IDI, NRI, and likelihood ratio test. DCA underscored the superior predictive value of the predictive model over the ILD-GAP model. The internal validation further affirmed this efficacy, with a mean Harrell's C-index of 0.815 for the predictive model. The nomogram model can be employed to predict the prognosis of patients with AAV-ILD. Moreover, the model performance is satisfactory. In the future, external datasets could be utilized for external validation.

Clinical features and outcomes of small airway disease in ANCA-associated vasculitis

BACKGROUND AND OBJECTIVE

To clarify the prevalence, features and outcomes of small airway disease (SAD) in a Chinese cohort with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) related pulmonary involvement.

METHODS

SAD was recorded when the manifestations of either centrilobular nodules or air trapping were observed according to CT scans, except for infection or other airway-related comorbidities. Baseline and follow-up data were collected retrospectively.

RESULTS

Of the 359 newly diagnosed AAV patients with pulmonary involvement, 92 (25.6%) had SAD, including 79 (85.9%) cases of anti-MPO-ANCA positive, 9 (9.8%) cases of anti-PR3-ANCA positive and 2 (2.2%) cases of double positive. Patients with SAD were more likely to be younger, female, non-smokers, have more ear-nose-throat (ENT) involvement, and have higher baseline Birmingham Vasculitis Activity Score (BVAS) compared to patients without SAD. Several AAV-related SAD patients have improved lung function and CT scans after immunosuppressive therapy. Patients with SAD had a better prognosis compared to those without SAD. When dividing all patients into three groups: isolated SAD (only small airway involvements), SAD with other lower airway involvements, and non-SAD, patients in the SAD with other lower airway involvements group had the highest risk of infection, while patients in the non-SAD group had the worst long-term outcomes. Similar results were observed in anti-MPO-ANCA positive patients when performing subgroup analyses.

CONCLUSION

SAD is a unique manifestation of AAV-related lung involvement and exhibits distinct clinical features. It is vital to focus on SAD because of its association with prognosis and infection in AAV patients, especially in anti-MPO-ANCA positive patients. Moreover, SAD might represent a better response to immunosuppressors.

Outcomes and prognosis of progressive pulmonary fibrosis in patients with antineutrophil cytoplasmic antibody-positive interstitial lung disease

Approximately one-third of fibrosing interstitial lung diseases exhibit progressive pulmonary fibrosis (PPF), a clinicopathological condition distinct yet resembling idiopathic pulmonary fibrosis (IPF). PPF in ANCA-positive ILD (ANCA-ILD) is poorly documented. To clarify incidence, predictors of PPF in ANCA-ILD, and their prognostic impact, 56 patients with ANCA-ILD were followed for ≥ 1 year (April 2004 to April 2021). PPF was defined per ATS/ERS/JRS/ALAT PPF 2022 guideline. We compared PPF and non-PPF in 38 patients with pulmonary function tests and ≥ 1 year follow up. ANCA-ILD (19 male, 19 female; mean age 72 years) comprised 21 patients with microscopic polyangiitis ILD (MPA-ILD) and 17 with ANCA-positive IP without systemic vasculitis (ANCA-IP). PPF occurred in 15/38 (39.5%) overall, and 27% of patients with MPA-ILD and 53% with ANCA-IP. Patient characteristics did not differ between PPF and non-PPF, however, the survival was significantly worse in patients with PPF than those with non-PPF. On multivariate regression analysis, higher age, higher serum SP-D level, and lower baseline %FVC were associated with PPF. In ANCA-ILD, 39.5% of patients demonstrated PPF, which is associated with increased mortality. Predictors of PPF were older age, higher SP-D, and lower baseline %FVC.

Concordance between practice and published evidence in the management of ANCA-associated vasculitis in Japan: A cross-sectional web-questionnaire survey

OBJECTIVES

We conducted a descriptive study of the physicians' evidence-practice gap for adults covered by the 2017 clinical practice guidelines for the management of antineutrophil cytoplasmic antibody-associated vasculitis in Japan.

METHODS

This web-based survey, conducted between January and February 2021, involved physicians who had treated at least five patients in the preceding year at a regional core hospital. The outcome was the physicians' experience in treating patients with microscopic polyangiitis or granulomatosis with polyangiitis [prevalence with 95% confidence intervals (CIs)], defined as treating at least 60% of their patients with the recommended therapy during the year. A modified Poisson regression analysis was performed to explore the factors associated with concordance.

RESULTS

The 202 participants included 49 pulmonologists, 65 nephrologists, 61 rheumatologists, and other physicians. The concordance was 31.5% (95% CI, 25.1-38.5) of physicians who used cyclophosphamide or rituximab for the induction of remission. Rheumatology showed the highest concordance with published evidence (risk ratio = 2.4; 95% CI, 1.10-5.22, p = .03).

CONCLUSIONS

These results suggest an evidence-practice gap, which varies substantially among subspecialties. Further studies and a new promotional initiative are necessary to close this gap in clinical practice.

Long-term survival, causes of death, and prognostic factors for mortality in patients with microscopic polyangiitis and those with anti-neutrophil cytoplasmic antibody-positive interstitial lung disease: A single-center retrospective study

AIM

To elucidate the clinical features, long-term survival, and prognostic factors for mortality among patients with microscopic polyangiitis (MPA), including those with anti-neutrophil cytoplasmic antibody-positive interstitial lung disease (ILD) (ANCA-ILD), which could be a subset of its variant phenotype.

METHODS

We retrospectively included 76 consecutive patients between 2006 and 2014, diagnosed with MPA according to the European Medicines Agency algorithm using the Chapel Hill Consensus Conference definitions or ANCA-ILD. ILD was classified as usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia pattern using chest computed tomography.

RESULTS

The mean (standard deviation) age of the patients (female, 68%) was 69 (12) years. The median (interquartile range) follow-up period was 68 (33-95) months. Comorbid ILD and glomerulonephritis were observed in 44 (58%) (68% UIP) and 54 (71%) patients, respectively. Comorbid ILD was associated with low survival (P = .0563). There were 17 (39%) and 5 (16%) deaths in the ILD and non-ILD groups, respectively (P = .0404). In the ILD group, 6 and 5 of the deaths were attributed to infection and ILD progression, respectively. In the non-ILD group, 1 and 2 patients expired from subsequently developed ILD and aspiration pneumonia, respectively. Age ≥ 70 years (hazard ratio = 2.78; 95% confidential interval 1.15-6.70) and UIP (3.95; 1.60-9.77) were independent risk factors for mortality.

CONCLUSION

Age ≥ 70 years and ILD with a UIP pattern were associated with high mortality, owing to susceptibility to infection and ILD progression. A more effective and less toxic treatment is required for progressive ILD.

Interstitial lung disease in ANCA-associated vasculitis: associated factors, radiographic features and mortality

OBJECTIVE

To evaluate the prevalence, clinical and radiographic features, and long-term outcomes of interstitial lung disease (ILD) in a United States-based ANCA-associated vasculitis (AAV) cohort.

METHODS

In this retrospective cohort study, we identified cases of ILD within the 2002-2019 Mass General Brigham AAV Cohort, a consecutive inception cohort of PR3- or MPO-ANCA+ AAV patients. ILD diagnosis and classification as fibrotic or non-fibrotic were confirmed by review of available chest imaging by two board-certified radiologists. Cox proportional hazard models, with age as the time scale, were used to estimate the association of AAV-ILD with all-cause mortality.

RESULTS

Of 684 patients in the MGB AAV Cohort, 91 (13%) had ILD which preceded the diagnosis of AAV by a mean of 2.2 years. AAV-ILD patients were older (67 vs 60 years, P < 0.001) than patients without ILD but the distribution of sex and race was similar. AAV-ILD patients were more often MPO-ANCA+ (93% vs 65%, P < 0.001); among MPO-ANCA+ patients (n = 470), 85 (18%) had ILD. The majority of ILD was fibrotic (76%) and UIP was the most common ILD pattern (42%). The baseline forced vital capacity (FVC) % predicted among ILD patients was 81 ± 20%. Fibrotic AAV-ILD was associated with a 58% higher risk of death (aHR 1.58, 95% CI 1.06, 2.37) compared with AAV patients without ILD.

CONCLUSION

ILD is a frequent complication of AAV, especially MPO-ANCA+ AAV, often preceding recognition of AAV. Fibrotic AAV-ILD is associated with a higher risk of death than AAV without ILD.

Anti-Inflammatory and/or Anti-Fibrotic Treatment of MPO-ANCA-Positive Interstitial Lung Disease: A Short Review

The presence of a lung lesion is common in microscopic polyangiitis (MPA), and interstitial lung disease (ILD) can lead to a poor prognosis. Although myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) are often present in patients with MPA, patients with ILD and MPO-ANCA positivity but without other manifestations of systemic vasculitis have also been reported. Therefore, the possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. This problematic matter has influenced the treatment strategy of MPO-ANCA-positive ILD patients without systemic vasculitis. Clinicians should undertake treatment with careful consideration of the four major causes of death in MPO-ANCA-positive ILD: acute exacerbation of ILD, progressive lung fibrosis, infectious comorbidities, and diffuse alveolar hemorrhage. Further, clinicians need to carefully judge whether inflammation or fibrosis is the dominant condition with reference to the patient’s clinical domain and radiopathological lung features. Recently, anti-fibrotic agents such as nintedanib and pirfenidone were shown to be effective in treating various etiologies associated with ILD and have thus led to the widening of treatment options. In this review, the clinical characteristics, radiopathology, prognosis, and therapeutic options in patients with MPO-ANCA-positive ILD are summarized using limited information from previous studies.

Association of M2 macrophages, Th2, and B cells with pathomechanism in microscopic polyangiitis complicated by interstitial lung disease

Objective

To address the pathomechanism of microscopic polyangiitis (MPA) complicated by interstitial lung disease (ILD) using serum biomarker profile and pulmonary histopathology.

Methods

Serum biomarkers from patients with MPA-ILD (n = 32), MPA without ILD (n = 17), and healthy controls (n =10) were examined. Based on the biomarker profiles, principal component analysis (PCA) and cluster analysis were performed to classify patients with MPA-ILD into subgroups. Clinical characteristics and prognosis were assessed for each subgroup. Two lung biopsies were examined following hematoxylineosin staining and immunostaining.

Results

T-cell and macrophage polarization was skewed toward the T helper (Th) 2 cells and M2 macrophages in MPA-ILD group relative to that in MPA without ILD group. The PCA allowed classification of the 19 biomarker profiles into three groups: (1) B cell- and neutrophil-related cytokines, vascular angiogenesis-related factors, extracellular matrix-producing factors, (2) Th1-driven cytokines, M1 macrophagedriven cytokines and Th2-driven cytokines, and (3) M2 macrophage -induced and - driven cytokines. The cluster analysis stratified the patients with MPA-ILD into clinically fibrotic dominant (CFD) and clinically inflammatory dominant (CID) groups. Notably, severe infections were significantly higher in the CFD group than in the CID group. Immunohistochemical staining demonstrated intense CXCL13 staining in B cells and Th2 cells in the interstitium of MPA-ILD lungs.

Conclusion

Activation of M2 macrophages, Th2 cells, and B cells plays a key role in the pathomechanism of MPA-ILD. Classification of MPA-ILD based on serum biomarker profile would be useful in predicting the disease activity and the complication of severe infection in MPA-ILD.

Beyond Systemic Lupus Erythematosus and Anti-Phospholipid Syndrome: The Relevance of Complement From Pathogenesis to Pregnancy Outcome in Other Systemic Rheumatologic Diseases

Evidence about the relevance of the complement system, a highly conserved constituent of the innate immunity response that orchestrates the elimination of pathogens and the inflammatory processes, has been recently accumulated in many different rheumatologic conditions. In rheumatoid arthritis, complement, mainly the classical pathway, contributes to tissue damage especially in seropositive subjects, with complement activation occurring in the joint. Data about complement pathways in psoriatic arthritis are dated and poorly consistent; among patients with Sjögren syndrome, hypocomplementemia exerts a prognostic role, identifying patients at risk of extra-glandular manifestations. Hints about complement involvement in systemic sclerosis have been recently raised, following the evidence of complement deposition in affected skin and in renal samples from patients with scleroderma renal crisis. In vasculitides, complement plays a dual role: on one hand, stimulation of neutrophils with anti-neutrophil cytoplasmic antibodies (ANCA) results in the activation of the alternative pathway, on the other, C5a induces translocation of ANCA antigens, favouring the detrimental role of antibodies. Complement deposition in the kidneys identifies patients with more aggressive renal disease; patients with active disease display low serum levels of C3 and C4. Even though in dermatomyositis sC5b-9 deposits are invariably present in affected muscles, data on C3 and C4 fluctuation during disease course are scarce. C3 and C1q serum levels have been explored as potential markers of disease activity in Takayasu arteritis, whereas data in Behçet disease are limited to in vitro observations. Pregnancies in women with rheumatologic conditions are still burdened by a higher rate of pregnancy complications, thus the early identification of women at risk would be invaluable. A fine-tuning of complement activation is required from a physiological progression of pregnancy, from pre-implantation stages, through placentation to labour. Complement deregulation has been implicated in several pregnancy complications, such as recurrent abortion, eclampsia and premature birth; low complement levels have been shown to reliably identify women at risk of complications. Given its physiologic role in orchestrating pregnancy progression and its involvement as pathogenic effector in several rheumatologic conditions, complement system is an attractive candidate biomarker to stratify the obstetric risk among women with rheumatologic conditions.

Pulmonary involvement of ANCA-associated vasculitis in adult Chinese patients

Objective

The aim of this study was to clarify the clinical characteristics and long-term outcomes of ANCA-associated vasculitis (AAV) patients with pulmonary involvement from a single Chinese cohort.

Methods

Newly diagnosed AAV patients with pulmonary involvement, as defined by CT, were recruited from January 2010 to June 2020. Clinical data and CT images were collected retrospectively. Baseline CTs were evaluated and re-classified into four categories: interstitial lung disease (ILD), airway involvement (AI), alveolar hemorrhage (AH), and pulmonary granuloma (PG).

Results

A total of 719 patients were newly diagnosed with AAV, 366 (50.9%) of whom combined with pulmonary involvement at baseline. Among the AAV cases with pulmonary involvement, 55.7% (204/366) had ILD, 16.7% (61/366) had AI alone, 14.8% (54/366) had PG, and 12.8% (47/366) had AH alone. During follow-up of a median duration of 42.0 months, 66/366 (18.0%) patients died, mainly died from infections. Survival, relapse, and infection were all significantly different based on the radiological features. Specifically, the ILD group tends to have a poor long-term prognosis, the PG group is prone to relapse, and the AI group is apt to infection. The AH group has a high risk of both early infection and relapse, thus a poor short-term prognosis.

Conclusion

AAV patients with diverse radiological features have different clinical characteristics and outcomes. Therefore, the intensity of immunosuppressive therapy must be carefully valued by considering the baseline CT findings among AAV patients with pulmonary involvement.

Myeloperoxidase and associated lung disease: Review of the latest developments

Myeloperoxidase (MPO) anti-neutrophil cytoplasmic antibodies (ANCA) are often detected in association with a variety of lung pathologies, the most common being interstitial lung disease (ILD). A growing cohort of patients are being diagnosed with MPO-ANCA in the context of ILD without ANCA-associated vasculitis. Clinically and radiologically, there is little to differentiate this cohort from MPO-ANCA-negative ILD patients; however, the pathophysiology is likely different and different treatments are likely required. We present here a brief summary of the proposed pathophysiology of MPO-ANCA-positive ILD, and a more detailed review of the latest evidence on management, including monitoring for development of ANCA-associated vasculitis, immunosuppression, anti-fibrotics, and novel agents that have yet to be trialled in human experiments.

Natural history and screening of interstitial lung disease in systemic autoimmune rheumatic disorders

Interstitial lung disease (ILD) is a relatively frequent manifestation of systemic autoimmune rheumatic disorders (SARDs), including systemic sclerosis (SSc), rheumatoid arthritis (RA), idiopathic inflammatory myopathies (IIM), systemic lupus erythematosus (SLE), primary Sjögren's syndrome (pSS), and anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis. Interstitial pneumonia with autoimmune features (IPAF) has been proposed to describe patients with ILD who have clinical or serological findings compatible with SARDs but they are not sufficient for a definite diagnosis. ILD may present with different patterns among patients with SARDs, but most commonly as nonspecific interstitial pneumonia (NSIP), with the exception of RA and ANCA vasculitis that more often present with usual interstitial pneumonia (UIP). The natural history of ILD is quite variable, even among patients with the same SARD. It may present with subclinical features following a slow progressively course or with acute manifestations and clinically significant rapid progression leading to severe deterioration of pulmonary function and respiratory failure. The radiographic pattern of ILD, the extent of the disease, the baseline pulmonary function, the pulmonary function deterioration rate over time and clinical variables related to the primary SARD, such as age, sex and the clinical phenotype, are considered prognostic factors for SARDs-ILD associated with adverse outcomes and increased mortality. Different modalities can be employed for ILD detection including clinical evaluation, pulmonary function tests, high resolution computed tomography and novel techniques such as lung ultrasound and serum biomarkers. ILD may determine the clinical outcome of SARDs, since it is associated with significant morbidity and mortality and therefore screening of patients with SARDs for ILD is of great clinical importance.

Interstitial lung disease with myeloperoxidase-antineutrophil cytoplasmic antibody-associated vasculitis in elderly patients

Anti-neutrophil cytoplasmic antibodies-associated vasculitis (AAV) occurs in elderly people, and patients with anti-myeloperoxidase autoantibodies (MPO-ANCA)-positive AAV are often complicated with interstitial lung disease (ILD). This study aimed to evaluate the age-related clinical features of elderly patients with MPO-ANCA-positive AAV-ILD. This study retrospectively investigated 63 patients with MPO-ANCA-positive AAV-ILD, all of whom were 65 years or older at diagnosis. Clinical characteristics, causes of death and survival rates among three groups stratified by age (65-74 years, n = 29; 75-79 years, n = 18; over 80 years, n = 16) were compared. This study also examined the association with severe infections in these patients. Among the three age groups, there were significant differences in sex (P = 0.032), serum Krebs von den Lungen-6 (P < 0.01), and total ground-glass opacity score (P = 0.011). The causes of death were mainly severe infections and complications of ILD. Kaplan-Meier curve analysis showed a significantly lower 5-year survival rate in the oldest group (P < 0.01). Regarding severe infections in these patients, the 5-year cumulative incidence of severe infections was higher in the patients receiving steroid pulse therapy (P = 0.034). The clinical characteristics of MPO-ANCA-positive AAV-ILD differ with age in elderly patients, with age being an important poor prognostic factor in these patients. The administration of steroid pulse therapy is a significant risk factor of severe infection in MPO-ANCA-positive elderly patients with AAV-ILD.

Risikostratifizierung bei ANCA-assoziierten Vaskulitiden

ANCA-assoziierte Vaskulitiden (AAV) sind nekrotisierende Vaskulitiden der kleinen bis mittelgroßen Gefäße, welche die Granulomatose mit Polyangiitis (GPA), die mikroskopische Polyangiitis (MPA) und die Eosinophile Granulomatose mit Polyangiitis (EGPA) umfassen. AAV gehen häufig mit Organfunktion-bedrohenden Manifestationen und einer entsprechend erhöhten Mortalität einher. Für die Planung von Diagnostik, Therapie und Langzeitbetreuung ist daher eine Risikostratifizierung im Hinblick auf Mortalität, Entwicklung schwerer Organinsuffizienzen, insbesondere einer terminalen Niereninsuffizienz, mögliche Therapieresistenz, Rezidive, Infektionen und Malignome erforderlich. Wichtige Risikofaktoren für erhöhte Mortalität und/oder terminale Niereninsuffizienz sind neben der renalen Beteiligung per se eine bereits zum Zeitpunkt der Diagnose deutlich eingeschränkte renale Funktion einschliesslich initialer Dialysepflichtigkeit, eine hohe initiale Aktivität der AAV gemessen am Birmingham Vaskulitis Activity Score, aber auch kardiale und gastrointestinale Manifestationen, Infektionen, Anämie sowie ein Alter von>65 Jahren. Histologisch ist der Nachweis chronischer irreversibler glomerulärer und tubulärer Läsionen in der Nierenbiopsie mit einer schlechten Prognose im Hinblick auf die Nierenfunktion assoziiert. Basierend auf der histopathologischen Klassifikation der ANCA-assoziierten Glomerulonephritis (GN) ist der Befund einer sklerosierenden GN mit einer besonders ungünstigen Prognose assoziiert, während die fokale GN sehr selten zur terminalen Niereninsuffizienz führt. MPO-ANCA zeigen eine Assoziation mit chronischen Läsionen in der Nierenbiopsie sowie erhöhter Mortalität und erhöhtem Risiko für terminale Niereninsuffizienz. Im Hinblick auf die pulmonale Beteiligung sind alveoläre Hämorrhagie und interstitielle Lungenerkrankung mit einer erhöhten Mortalität assoziiert. Bei EGPA wird die Prognose entscheidend durch die Kardiomyopathie bestimmt. Risikofaktoren für Rezidive weichen erheblich von denen für Mortalität und terminale Niereninsuffizienz ab. Ein erhöhtes Rezidivrisiko besteht bei Nachweis von PR3-ANCA, GPA und pulmonaler Beteiligung. Auch bei granulomatösen Läsionen, Beteiligung des oberen Respirationstraktes und kardiovaskulären Manifestationen wird ein erhöhtes Rezidivrisiko beschrieben. Im Gegensatz zur Assoziation einer initial schlechten Nierenfunktion mit Mortalität und terminaler Niereninsuffizienz, wurde für Patienten mit initial guter Nierenfunktion ein erhöhtes Rezidivrisiko gezeigt. Weitere Risikofaktoren für Rezidive sind Staphylokokken-Besiedelung der Nase, frühere Rezidive und ANCA-Positivität nach Remissionsinduktion. Titeranstieg oder Wiederauftreten von ANCA zeigen nur eine moderate Beziehung zum Rezidivrisiko. Der prädiktive Wert für Rezidive ist offenbar bei bestimmten Subgruppen, wie bei Patienten mit renaler Beteiligung und pulmonaler Hämorrhagie sowie bei mit Rituximab-behandelten Patienten besser als bei Patienten mit granulomatösen Manifestationen. Daher ist eine Therapieentscheidung allein auf Basis der Entwicklung der ANCA-Titer nicht möglich. Risikofaktoren für schwere Infektionen sind höher dosierte und prolongierte Glukokortikoidtherapie, Leuko- und Lymphopenie, höheres Lebenalter, Niereninsuffizienz und pulmonale Beteiligung. Die Malignomrate insbesondere für Nicht-Melanom-Hauttumoren, Harnblasenkarzinome und Leukämie ist bei AAV erhöht und zeigt eine Assoziation mit hohen kumulativen Cyclophosphamiddosen. Da insbesondere frühzeitige irreversible Organschäden die Prognose bestimmen und Rezidive die Entwicklung irreversibler Schäden treiben, sind frühestmögliche Diagnose und Therapie sowie rasches Erkennen und Vermeiden von Rezidiven essentiell für die Risikominimierung.

Incidence and clinical predictors of infections in patients treated with severe systemic ANCA-associated vasculitis

BACKGROUND

Immunosuppressive therapy has improved the outcome of ANCA-associated vasculitis (AAV), but infectious morbidity and mortality remained high. Recognizing its risk factors seems crucial for prevention, aiming to increase survival of these patients.

METHODS

We investigated the incidence and types of infections and assessed predictive factors in 132 patients with severe systemic AAV.

RESULTS

Patients with lower than median incidence of total infections/patient-year during induction had lower baseline serum creatinine, dialysis requirement and Charlson comorbidity index (CCI), compared to those with higher than median incidence (P = 0.037; P = 0.024; P = 0.001; respectively). In subgroups with below and above than median number of severe infections/patient-year during induction, differences were found in baseline creatinine (P = 0.002) and dialysis requirement (P = 0.001); comparing the same cohorts during maintenance immunosuppression, baseline dialysis requirement, diabetes, CCI, and dose of cyclophosphamide (CYC) administered as induction therapy differed significantly (P = 0.019; P = 0.015; P = 0.001; P = 0.015, respectively). Severe infections were predicted by baseline serum creatinine (OR 1.002 [CI 1.001-1.003]) and pulmonary manifestation (OR 2.153 [CI 1.017-4.560]) during induction immunosuppression. In multivariable Cox regression model all-cause mortality was independently predicted by severe infection (HR 1.998 [CI 1.214-3.287]). Among the 168 positive cultures Gram-negative bacteria were responsible for blood stream infections in 33%, and respiratory tract infections in 72%.

CONCLUSIONS

Advanced renal failure, pulmonary involvement and high degree of comorbidities increase the risk of infection in AAV. Those who suffer infection during induction immunosuppression have worse long-term survival. Our findings indicate the need for high vigilance for infections and close follow-up of comorbidities when treating AAV.

Clinical features and long-term outcomes of interstitial lung disease with anti-neutrophil cytoplasmic antibody

Background

Patients with interstitial lung disease (ILD) are occasionally positive for anti-neutrophil cytoplasmic antibodies (ANCAs). Differences between ILDs secondary to microscopic polyangiitis (MPA) and isolated ANCA-positive idiopathic interstitial pneumonia (IIP) remain unclear. The aim of this study was to explore the differences in clinical features and outcomes between MPA-associated ILDs and isolated ANCA-positive IIPs.

Methods

We reviewed 1338 ILDs patients with available ANCA results and retrospectively analysed 80 patients who were ANCA-positive. MPA-associated ILDs (MPA-ILDs group) and isolated ANCA-positive IIPs (ANCA-IIPs group) were compared.

Results

Among 80 patients with ANCA-positive ILDs, 31 (38.75%) had MPA-ILDs, and 49 (61.25%) had isolated ANCA-positive IIPs. Compared with ANCA-IIPs group, patients in MPA-ILDs group had a higher proportion of fever (p = 0.006) and higher neutrophil count (p = 0.011), erythrocyte sedimentation rate (ESR) (p < 0.001) and C-reactive protein (CRP) (p = 0.005). Multivariable analysis showed that ESR level was an independent risk factor for mortality in all 80 ANCA-positive ILDs patients (HR 1.028, p = 0.001). Survival in MPA-ILDs group was lower than that in ANCA-IIPs group, and further stratified analysis revealed that ANCA-IIPs patients with elevated ESR or CRP had a worse prognosis than those with normal inflammation markers, with 5-year cumulative survival rates of 60.00%, 86.90% and 100.00% in MPA-ILDs and ANCA-IIPs with and without elevated inflammation markers, respectively.

Conclusions

Among patients with ANCA-positive ILDs, the prognoses of ANCA-IIPs with normal inflammation markers, ANCA-IIPs with elevated inflammation markers and MPA-ILDs were sequentially poorer. Therefore, stratified treatment should be considered in the management of ILDs patients positive for ANCAs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-021-01451-4.

Impact of interstitial lung disease on mortality in ANCA-associated vasculitis: A systematic literature review and meta-analysis

Several retrospectivee described the association of interstitial lung disease (ILD) and ANCA-associated vasculitis (AAV). However, the relationship between the ILD and mortality in AAV patients have not been established so far. This study aims to estimate the relevance of AAV-associated-ILD (AAV-ILD) and mortality risk by conducting a systematic review and meta-analysis.A comprehensive systematic review was conducted in accordance with the guidelines of PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses). PubMed, Embase.com and the Cochrane Library (Wiley) were searched for original observational studies. Summary estimates were derived with a random-effects model and reported as risk ratio (RR), tested for publication bias and heterogeneity. Ten retrospective cohort studies were included, comprising 526 AAV-ILD patients enrolled from 1974 to 2018. Meta-analysis yielded a pooled RR of 2.90 (95% confidence interval 1.77–4.74) for death among those with AAV-ILD compared to control group. UIP pattern was associated with an even poorer prognosis in comparison to non-UIP pattern (RR 4.36, 95% confidence interval 1.14–16.78). Sensitivity analysis suggested that the meta-RR result was not skewed by a single dominant study. ILD might be associated with a higher mortality risk in AAV patients.

CCL2 Produced by CD68+/CD163+ Macrophages as a Promising Clinical Biomarker of Microscopic Polyanigiitis-Interstitial Lung Disease

OBJECTIVES

Microscopic polyangiitis (MPA) is often complicated by interstitial lung disease (ILD); however, biomarkers that can be used to diagnose and predict the progression of MPA-ILD have not been identified. In this study we evaluated various serum biomarkers in MPA-ILD to assess their diagnostic and predictive performance.

METHODS

We enrolled 49 patients with anti-neutrophil cytoplasmic antibody (ANCA)+ MPA and 10 healthy controls, with 32 of the MPA patients also presented ILD. The presence of ILD was assessed by high-resolution computed tomography and evaluated by ground-glass opacity and fibrosis score. We compared 16 biomarker profiles among MPA-ILD patients, those without ILD, and healthy controls and extracted biomarkers with higher levels in MPA-ILD groups to determine correlations with disease activity and other biomarkers. Three lung biopsies were examined by hematoxylin-eosin staining and immunostaining.

RESULTS

Initial serum C-C motif chemokine ligand 2 (CCL2) levels were significantly higher in the MPA-ILD group than those of the MPA group, and were significantly higher in MPA-ILD patients 1 year after immunosuppressive therapy than those before treatment. Initial serum CCL2 levels positively correlated with an increased fibrosis score during the year after treatment and with initial serum platelet-derived growth factor levels. Immunohistochemical staining showed intense CCL2 signals in CD68+/CD163+ macrophages and metaplastic epithelial cells in MPA-ILD lungs.

CONCLUSION

CCL2 is associated with MPA-ILD pathogenesis and suggested its potential efficacy as a useful marker for diagnosing and predicting MPA-ILD progression. Therefore, targeting CCL2 in alveolar CD68+/CD163+ macrophages might represent a therapeutic intervention in ANCA+ MPA-ILD.

Evaluation of poor prognostic factors of respiratory related death in microscopic polyangiitis complicated by interstitial lung disease

The prognosis of microscopic polyangiitis (MPA) with interstitial lung disease (ILD) is significantly worse than that of MPA without ILD. However, the clinical characteristics in MPA-ILD, especially poor prognostic factors, are not elucidated. We evaluated demographic, clinical, laboratory, and radiological findings, treatments, and outcomes of 80 patients with MPA, and investigated prognostic factors of respiratory-related death in patients with myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) positive MPA-ILD. Ground-glass opacity and fibrosis were evaluated as scores on high-resolution computed tomography (HRCT). The presence of ILD was consistent with a high risk of respiratory-related death (hazard ratio, 4.8; P = 0.04). Multivariable logistic regression analyses using propensity scoring showed right or left lower lobe fibrosis score to be significantly associated with respiratory-related death (P = 0.0005 and 0.0045, respectively). A right or left lower lobe fibrosis score ≥ 2, indicating the presence of honeycombing at 1 cm above the diaphragm, was determined to be the best cut-off value indicating a poor prognosis. The 5-year survival rate was significantly lower in patients with right or left lower lobe fibrosis score ≥ 2 (survival rates: 37% and 19%, respectively) than those with a score < 2 (71% and 68%, respectively) (P = 0.002 and 0.0007, respectively). These findings suggest that the presence of honeycomb lesions in bilateral lower lobes on chest HRCT was associated with respiratory-related death in patients with MPO-ANCA positive MPA-ILD.

Prognosis of pulmonary fibrosis presenting with a usual interstitial pneumonia pattern on computed tomography in patients with myeloperoxidase anti-neutrophil cytoplasmic antibody-related nephritis: a retrospective single-center study

Background

Myeloperoxidase anti-neutrophil cytoplasmic antibody-related nephritis (MPO-ANCA nephritis) is occasionally accompanied by lung abnormalities such as pulmonary fibrosis. However, the clinical features of pulmonary fibrosis in patients with MPO-ANCA nephritis have not been well documented. This study was performed to compare the prognosis of a usual interstitial pneumonia (UIP) pattern of lung fibrosis in patients with MPO-ANCA nephritis with the prognosis of idiopathic pulmonary fibrosis (IPF).

Methods

We retrospectively reviewed the medical records of 126 patients with MPO-ANCA nephritis and identified 31 with a UIP pattern of lung fibrosis on high-resolution or thin-slice computed tomography (CT). We compared the characteristics and prognosis of these patients with those of 32 patients with IPF. In 18 patients from both groups, we assessed and compared the decline in lung volume over time using three-dimensional (3D) CT images reconstructed from thin-section CT data.

Results

The numbers of male and female patients were nearly equal among patients with MPO-ANCA nephritis exhibiting a UIP pattern; in contrast, significant male dominancy was observed among patients with IPF (p = 0.0021). Significantly fewer smokers were present among the patients with MPO-ANCA nephritis with a UIP pattern than among those with IPF (p = 0.0062). There was no significant difference in the median survival time between patients with MPO-ANCA nephritis with a UIP pattern (50.8 months) and IPF (55.8 months; p = 0.65). All patients with IPF in this cohort received antifibrotic therapy (pirfenidone or nintedanib). Almost half of the deaths that occurred in patients with MPO-ANCA nephritis with a UIP pattern were caused by non-respiratory-related events, whereas most deaths in patients with IPF were caused by respiratory failure such as acute exacerbation. In the 3D CT lung volume analyses, the rate of decline in lung volume was equivalent in both groups.

Conclusions

MPO-ANCA nephritis with a UIP pattern on CT may have an unfavorable prognosis equivalent to that of IPF with a UIP pattern treated with antifibrotic agents.

Clinical characteristics and outcomes in microscopic polyangiitis patients with renal involvement: a study of 124 Chinese patients

BACKGROUND

Microscopic polyangiitis (MPA) is a systemic autoimmune disease, and renal involvement is frequently present in MPA. MPA patients with renal involvement may have a worse prognosis. In this study, we aimed to evaluate the prognostic factors associated with all-cause death and renal survival in MPA patients with renal involvement.

METHODS

A retrospective observational cohort study was performed. One hundred twenty-four patients newly diagnosed with MPA with renal involvement excluding end-stage renal disease (ESRD) who were hospitalized at the First Affiliated Hospital of Chongqing Medical University from January 2012 to July 2017 were included. All the survivors were followed up with until July 2018. The clinical and laboratory data at the time of the initial MPA diagnosis were collected, and the predictive values of the variables for mortality and renal outcome were analysed.

RESULTS

Among the 124 patients, 52 were men (41.9%) and 72 were women (58.1%), and the age range was from 25 to 85 years (63.9±10.6 years). Seventy-six patients (61.3%) had pulmonary involvement. Multivariate Cox analysis revealed that age≥65 years (HR: 2.437; P=0.021), serum creatinine≥500 μmol/L (HR=2.207; P=0.009) and interstitial lung disease (ILD) (HR=2.366; P=0.013) were associated with mortality. Cox multivariate analysis identified that serum creatinine≥500 μmol/L (HR=8.236; P<0.001) and ILD (HR=2.649; P=0.001) were independent detrimental factors for renal survival, and immunosuppressive treatment was a protective factor for renal survival (HR=0.349; P=0.001). The area under the ROC curve (AUC) of the serum creatinine level at diagnosis was 0.705 for mortality and 0.870 for progression to ESRD or the doubling of serum creatinine.

CONCLUSIONS

Age, serum creatinine level at diagnosis and ILD were independent predictors of mortality in MPA patients with renal involvement. Serum creatinine level at diagnosis, ILD and immunosuppressive treatment were independently related to renal survival.

Plasma Exchange Therapy to Reduce Mortality in Japanese Patients With Diffuse Alveolar Hemorrhage and Microscopic Polyangiitis

Diffuse alveolar hemorrhage (DAH) is well known as a serious complication of microscopic polyangiitis (MPA). We examined the effectiveness of plasma exchange (PLEX) therapy to reduce mortality in Japanese DAH patients with MPA. This retrospective, double-center, observational cohort study included 20 DAH patients with MPA who were admitted to Juntendo University Hospital or Juntendo Koto Geriatric Medical Center between April 1998 and March 2018. The primary outcome was non-disease-specific mortality. The 1-year survival rate of patients with PLEX therapy (N = 4) was higher than that of patients with conventional therapy (N = 16, 75% and 13%, respectively, P = 0.037). Higher values of the 1996 Five-Factor Score (FFS) and 2009 FFS were associated with increased mortality, with hazard ratios of 2.29 (P = 0.040) and 2.41 (P = 0.043), respectively, by Cox univariate analysis. We investigated PLEX therapy for reducing mortality in DAH patients with MPA, and the 1996 FFS and 2009 FFS were both independent prognostic factors.

Increased renal damage in hypocomplementemic patients with ANCA-associated vasculitis: retrospective cohort study

INTRODUCTION

The complement system has an important role in the pathogenesis of vasculitis associated with antineutrophilic cytoplasmic antibody (AAV) mainly at the level of the kidneys because patients with complement deposits on the glomerular basal membrane present more aggressive disease compared with those with pauci-immune vasculitis.

AIM

To analyze the association of hypocomplementemia with the clinical manifestations, laboratory data, renal histology, progress to renal insufficiency, and mortality of patients with AAV.

METHODS

Retrospective cohort study (2000-2007) included 93 patients with AAV. Hypocomplementemia is defined as having C3 values lower than 80 mg/dL or C4 values below 15 mg/dL. Demographic, statistical, clinical, hematological, serological, and histopathological characteristics of all the patients with and without diagnosis of hypocomplementemia were compared. In order to evaluate variable independence, a logistic regression analysis was used.

RESULTS

Ninety-three patients were studied of whom 63 (67.7%) had complement dosage at the moment of AAV diagnosis. Seven patients (11.1%) presented hypocomplementemia and a greater kidney involvement compared with normocomplementemic patients. Thirty renal biopsies were analyzed and 4 (13.3%) showed immunocomplex (IC) or complement deposits by an immunofluorescence test (IFT). Patients with "non-pauci-immune" AAV also presented terminal chronic renal disease (TCRD).

CONCLUSION

There is an association between low complement and the degree of renal damage in patients with AAV. Patients with renal biopsies confirming IC and/or complement deposits showed more aggressive renal disease. Key Points • The complement system has an important role in the pathogenesis of vasculitis associated to antineutrophilic cytoplasmic antibody. • The studies in murine models confirming the complement activation by alternative pathway and particularly the receptor C5a (C5aR) is necessary for the development of glomerulonefritis. • Complement deposit observed in the renal biopsies of patients diagnosed with AAV was correlated to greater kidney damage, greater proteinuria and major disease activity compared to patients diagnosed with typical pauci-immune vasculitis. • The presence of hypocomplementemia at the onset of the disease was also associated with a greater organ involvement, poor prognosis and greater mortality.

Improvement of Alveolar Hemorrhaging in an Elderly and Renally Impaired Patient with Relapsing Anti-neutrophil Cytoplasmic Autoantibody-associated Vasculitis by Single Infusion of Rituximab

Rituximab (RTX) has become a therapeutic option for inducing remission of anti-neutrophil cytoplasmic autoantibody-associated vasculitis (AAV). However, the optimum dosage of RTX to induce remission of AAV and reduce adverse events, such as infection, remains unclear. We herein report an elderly and renally impaired patient with alveolar hemorrhaging due to refractory AAV who was successfully treated with single infusion of RTX. Single infusion of RTX may be a therapeutic option in refractory AAV patients who are vulnerable to infections.

Pulmonary vasculitis

Systemic vasculitides frequently affect the pulmonary vasculature. As the signs and symptoms of pulmonary vasculitis are variable and nonspecific, diagnosis and treatment represent a real challenge. Vasculitides should be given consideration, as these diseases present severe manifestations of rapidly progressing pulmonary disease. Examining other organs usually affected by vasculitides (e.g., the skin and kidneys) and determining autoantibody levels are essential to a better management of the disease. A radiological study would also contribute to establishing a diagnosis. The lungs are commonly involved in small-vessel vasculitis, anti-glomerular basement membrane disease, and vasculitides associated with antineutrophil cytoplasmic antibodies. Associated life-threatening diffuse alveolar haemorrhages and irreversible damage to other organs-usually the kidneys-are severe complications that require early diagnosis. Vasculitides are rare diseases that affect multiple organs. An increasing number of treatments-including biological agent-based therapies-requiring cooperation between specialists and centers have become available in the recent years. In the same way, clinicians should be familiar with the complications associated with immunosuppressive therapies.

Hémorragies intra-alvéolaires

L’hémorragie intra-alvéolaire (HIA), maladie rare, est une urgence thérapeutique, car elle peut conduire rapidement vers une insuffisance respiratoire aiguë asphyxiante avec décès. La triade, hémoptysie–anémie–infiltrat radiologique, suggère le diagnostic d’HIA, mais elle peut manquer dans deux tiers des cas, y compris chez des patients en détresse respiratoire. La tomodensitométrie thoracique peut aider dans les formes atypiques. Le diagnostic d’HIA repose sur la réalisation d’un lavage bronchoalvéolaire. Les étiologies en sont très nombreuses. Il importera de séparer, en urgence, les HIA d’origine non immune, avec un dépistage de celles d’origine septique qui doivent bénéficier d’une enquête microbiologique ciblée et cardiovasculaire avec la réalisation d’une échographie cardiaque, des HIA immunes (les vascularites liées aux anticorps anticytoplasme des polynucléaires neutrophiles, les connectivites et le syndrome de Goodpasture), avec la recherche d’autoanticorps et la réalisation de biopsies au niveau des organes facilement accessibles. La biopsie pulmonaire doit rester exceptionnelle. En cas d’HIA immune inaugurale, un traitement par stéroïdes et cyclophosphamide peut être débuté. Les indications du rituximab commencent à être mieux établies. Le bénéfice des échanges plasmatiques est débattu. En cas de réapparition d’infiltrats pulmonaires, chez un patient suivi pour une HIA immune, on s’efforcera d’écarter une infection dans un premier temps.

Pulmonary Involvement in Systemic Vasculitis

PURPOSE OF REVIEW

The purpose of this study is to describe the most relevant advances concerning lung involvement in the ANCA-associated vasculitides (excluding eosinophilic granulomatosis with polyangiitis which may have different disease mechanisms). Focus is on pathophysiology, recent important imagenological procedures, treatment, and outcome.

RECENT FINDINGS

Emerging information exists on potential newly investigated diagnostic procedures (v.g. transbronchial cryobiopsies), detailed tomographic abnormalities, the potential favorable role of rituximab and the still uncertain one of plasma exchange in the treatment, and the increasing description of interstitial lung disease. Survival is reduced in case of both, diffuse alveolar hemorrhage and diffuse parenchymal disease. There is the need to expand the knowledge concerning better long-term treatment options with specific regimes, and to incorporate other measures regarding integral treatment in patients afflicted with lung involvement these maladies, as the outcome seems adverse in this scenario.

Diffuse Alveolar Hemorrhage Developing Immediately after Immunosuppressive Treatments in a Patient with Granulomatosis with Polyangiitis Who Had Pulmonary Nodules

A 65-year-old man was diagnosed with granulomatosis with polyangiitis (GPA) based on the detection of high myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), vasculitis and granulomas in a lung biopsy specimen and crescentic glomerulonephritis in a kidney biopsy specimen. Soon after the initiation of intravenous methylprednisolone pulse therapy (mPSL pulse) and intravenous cyclophosphamide pulse therapy (IVCY), the patient experienced cough and hemoptysis. Based on emerging anemia and bilateral diffuse lung consolidation on computed tomography, we judged that diffuse alveolar hemorrhage (DAH) was complicated by GPA. The patient's DAH improved following additional mPSL pulse and IVCY. Physicians should be aware of the possible occurrence of DAH, even when a patient's symptoms improve after mPSL pulse and IVCY.

Anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus

Background

The clinical significance of anti-neutrophil cytoplasmic antibodies in patients with new-onset systemic lupus erythematosus, especially in systemic disease accompanied by interstitial lung disease remains to be elucidated.

Objectives

This study was designed to investigate the role of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients.

Methods

A hundred and seven patients with new-onset SLE were enrolled. Presence of anti-neutrophil cytoplasmic antibodies in the sera was assessed by indirect immunofluorescence as well as enzyme linked immunosorbent assay against proteinase-3 and myeloperoxidase. Clinical features and laboratory parameters of patients were also recorded. All patients were subjected to chest X-ray, chest high-resolution computed tomography and pulmonary function test.

Results

Forty-five systemic lupus erythematosus patients (45/107, 42%) were seropositive for anti-neutrophil cytoplasmic antibodies. Compared with anti-neutrophil cytoplasmic antibodies-negative patients, the anti-neutrophil cytoplasmic antibodies-positive patients had significantly higher incidence of renal involvement, anemia, and Raynaud's phenomenon as well as decreased serum level of complement 3/complement 4 and elevated erythrocyte sedimentation rate. In addition, there was a positive correlation between serum anti-neutrophil cytoplasmic antibodies level and disease activity of systemic lupus erythematosus. Furthermore, prevalence of interstitial lung disease in the anti-neutrophil cytoplasmic antibodies -positive patients (25/45, 55.6%) was obviously higher than that in the anti-neutrophil cytoplasmic antibodies-negative patients (15/62, 24.2%).

Study limitations

The sample size was limited and the criteria for screening new-onset systemic lupus erythematosus patients might produce bias.

Conclusions

The level of anti-neutrophil cytoplasmic antibodies in new-onset systemic lupus erythematosus patients correlates positively with the disease activity and the prevalence of interstitial lung disease.

Interstital lung disease in ANCA vasculitis

Anti-neutrophil cytoplasmic antibodies (ANCA) vasculitides are immune-mediated disorders that primarily affect small blood vessels of the airway and kidneys. Lung involvement, one of the hallmarks of microscopic polyangiitis and granulomatosis with polyangiitis, is associated with increased mortality and morbidity. In recent years, several retrospective series and case reports have described the association of interstitial lung disease (ILD) and ANCA vasculitis, particularly those positive for ANCA specific for myeloperoxidase. In the majority of these patients pulmonary fibrosis occurs concurrently or predates the diagnosis of ANCA vasculitis. More importantly, these studies have shown that ILD has an adverse impact on the long-term prognosis of ANCA vasculitis. This review focuses on the main clinical and radiologic features of pulmonary fibrosis associated with anti-neutrophil cytoplasmic antibodies. Major histopathology features, prognosis and therapeutic options are summarized.

Antineutrophilic cytoplasmic antibody-associated vasculitis with hypocomplementemia has a higher incidence of serious organ damage and a poor prognosis

A relationship between antineutrophilic cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and complement has been shown, and complement has an important role in the pathogenesis of AAV. The clinical characteristics of AAV with hypocomplementemia still remain unclear.We conducted an observational study of 81 patients with AAV (median onset age 71 years; 58% female). Using medical records, we analyzed the patients' baseline variables, laboratory data, clinical symptoms, and therapeutic outcomes after treatments including episodes of relapses, initiation of dialysis, and death. We defined hypocomplementemia as the state in which at least one of the following was lower than the lower limit of the normal range: complement 3 (C3), complement 4 (C4), and total complement activity (CH50).Sixteen patients (20%) had hypocomplementemia at their diagnosis of AAV. Compared to the AAV patients without hypocomplementemia (n = 65), those with hypocomplementemia had significantly higher rates of the occurrence of skin lesions (8 [50%] vs. 8 [12%], P = 0.002), diffuse alveolar hemorrhage (DAH) (6 [38%] vs. 5 [8%], P = 0.006), and thrombotic microangiopathy (TMA) (3 [19%] vs. 0 [0%], P = 0.007). The AAV patients with hypocomplementemia had significantly lower platelet levels (16.5 × 10 vs. 24.9 × 10 cells/μL, P = 0.023) compared to those without hypocomplementemia. More positive immune complex deposits in renal biopsy specimens were seen in the AAV patients with hypocomplementemia than in those without hypocomplementemia (4 [80%] vs. 2 [18%], P = 0.036). Assessed by a log-rank test, hypocomplementemia at disease onset was significantly associated with death (P = 0.033).Hypocomplementemia in AAV at the disease onset was a risk factor for the serious organ damage, and a life prognostic factor. It is thus very important to pay attention to the levels of complement at the diagnosis of AAV.

Interstitial Lung Disease with ANCA-associated Vasculitis

The association between interstitial lung disease (ILD) and anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), particularly microscopic polyangiitis (MPA), has been described in a number of case reports and case series reports in the last 2 decades. In addition, patients with pulmonary fibrosis and ANCA positivity but without other manifestations of systemic vasculitis have also been reported. Pulmonary fibrosis was clinically manifested at the time of diagnosis in the majority of AAV patients that developed this condition. Moreover, ANCA-positive conversion occurs in patients initially diagnosed with idiopathic pulmonary fibrosis, and as a result, other manifestations of systemic vasculitis develop in some of these patients. There is significant predominance of myeloperoxidase (MPO)-ANCA and MPA in patients with AAV and ILD. Radiological and pathological findings generally demonstrate usual interstitial pneumonia (pattern) in the lungs of these patients. In most studies, AAV patients with ILD have a worse prognosis than those without it.

Diffuse alveolar hemorrhage emerging one week after starting high-dose corticosteroid therapy for granulomatosis with polyangiitis (GPA) with systemic lupus erythematosus (SLE)

A 69-year-old man was diagnosed with granulomatosis with polyangiitis (GPA) based on the presence of skin granuloma, refractory otitis media, renal insufficiency and myeloperoxidase-antineutrophil cytoplasmic antibody positivity and slight lung opacity. He was treated with high-dose corticosteroid therapy. Despite the initial improvement of his renal function and a decrease in his C-reactive protein level, he suffered from an alveolar hemorrhage one week after the start of corticosteroid therapy. An anti-dsDNA antibody test was positive and the patient had hypocomplementemia. Elements of both GPA and systemic lupus erythematosus were thought to have affected his clinical course.