Interstitial pneumonia associated with MPO-ANCA: Clinicopathological features of nine patients

Clinical significance of microscopic polyangiitis with interstitial lung disease and bronchiectasis: probability of preexisting comorbidities

BACKGROUND

The association between pulmonary involvement and microscopic polyangiitis (MPA) has been increasingly recognized in recent years. Whether interstitial lung disease (ILD) and bronchiectasis (BE) are disease manifestations of MPA, preexisting comorbidities or important complications remains unclear. The purpose of this study was to determine the clinical characteristics and prognosis of MPA with pulmonary involvement to further guide clinical management.

METHODS

The data for 97 patients with a definitive diagnosis of MPA were retrospectively reviewed. The MPA diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria. The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Forty-seven out of the 97 (48.5%) patients who were diagnosed with MPA presented with pulmonary involvement, including 37 patients with ILD, 12 patients with BE and two patients with diffuse alveolar haemorrhage (DAH). ILD and BE antedated MPA in 56.76% and 75.00% of the patients, respectively. Compared with that in the MPA-BE group, the serum LDH level (222.86 ± 68.19 vs. 171.58 ± 31.43, p = .016) in the MPA-ILD group was significantly higher. In the multivariate Cox analysis, elevated serum creatinine (HR 4.08, confidence interval (CI) 1.38-12.05, p = .011) was an independent risk factor for shorter survival in MPA patients with pulmonary involvement, and treatment with glucocorticoid pulse cyclophosphamide therapy (HR 0.095, 95% CI 0.019-0.47, p = .004) was independently associated with prolonged survival. Among the patients in the MPA-ILD group, acute exacerbations of ILD (HR 4.55 CI 1.16-17.86, p = .029) and elevated serum creatinine (HR 4.95, CI 1.39-17.54, p = .014) were independently associated with a poor prognosis, and treatment with glucocorticoids (HR 0.057, 95% CI 0.012-0.28, p < .001) was independently associated with significant prolongation of survival.

CONCLUSIONS

Patients with MPA have a high prevalence of pulmonary involvement, and ILD is the most common subtype of MPA. ILD and BE can be considered preexisting comorbidities of MPA. Elevated serum creatinine was associated with shorter survival. However, remission induction regimens with glucocorticoids and/or immunosuppressants may improve this outcome.

Immune-mediated lung diseases: A narrative review

The role of immunity in the pathogenesis of various pulmonary diseases, particularly interstitial lung diseases (ILDs), is being increasingly appreciated as mechanistic discoveries advance our knowledge in the field. Immune-mediated lung diseases demonstrate clinical and immunological heterogeneity and can be etiologically categorized into connective tissue disease (CTD)-associated, exposure-related, idiopathic, and other miscellaneous lung diseases including sarcoidosis, and post-lung transplant ILD. The immunopathogenesis of many of these diseases remains poorly defined and possibly involves either immune dysregulation, abnormal healing, chronic inflammation, or a combination of these, often in a background of genetic susceptibility. The heterogeneity and complex immunopathogenesis of ILDs complicate management, and thus a collaborative treatment team should work toward an individualized approach to address the unique needs of each patient. Current management of immune-mediated lung diseases is challenging; the choice of therapy is etiology-driven and includes corticosteroids, immunomodulatory drugs such as methotrexate, cyclophosphamide and mycophenolate mofetil, rituximab, or other measures such as discontinuation or avoidance of the inciting agent in exposure-related ILDs. Antifibrotic therapy is approved for some of the ILDs (e.g., idiopathic pulmonary fibrosis) and is being investigated for many others and has shown promising preliminary results. A dire need for advances in the management of immune-mediated lung disease persists in the absence of standardized management guidelines.

Clinical significance of acute exacerbation in interstitial lung disease with antineutrophil cytoplasmic antibody: an indicator of poor prognosis

BACKGROUND

The association between interstitial lung disease (ILD) and antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has been increasingly recognized in recent years. The clinical features and prognostic differences between AAV-associated ILD and isolated ANCA-positive idiopathic interstitial pneumonias (IIPs) remain unclear. The purpose of this study was to determine the clinical significance and prognosis of ANCA-positive ILD to further guide clinical management.

METHODS

This study retrospectively reviewed the data of 379 ILD patients with available ANCA results and ultimately analysed 49 ANCA-positive patients. AAV diagnosis was based on the 2012 revised Chapel Hill Consensus Conference (CHCC) criteria, and 33 of 49 patients were diagnosed with microscopic polyangiitis (MPA). The baseline clinical information and laboratory parameters were collected and analysed at each patient's initial diagnosis.

RESULTS

Among 49 ANCA-positive ILD patients, the high-resolution computed tomography (HRCT) pattern was mainly usual interstitial pneumonia (UIP) (59.18%), followed by nonspecific interstitial pneumonia (NSIP) (26.53%). The C-reactive protein (CRP) level (43.89± 40.61 versus 18.74± 20.05, p = 0.028) and erythrocyte sedimentation rate (ESR) (71.97± 42.73 versus 40.69± 28.46, p = 0.011) were significantly higher in the MPA-ILD group than in the ANCA-IIP group. Haemoglobin (113.09 ± 24.47 versus 132.19± 13.34, p = 0.006) and albumin (32.95± 5.84 versus 36.52± 3.94, p = 0.032) levels were significantly lower. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients [hazard ratio (HR) 3.38, 95% confidence interval (CI) 1.32-8.67, p = 0.040]. In the multivariable Cox analysis, a diagnosis of MPA (HR 3.91, 95% CI 1.07-14.08, p = 0.038) and acute exacerbation (AE) of ILD (HR 9.43, 95% CI 2.89-30.30, p < 0.001) were significantly independently associated with shorter survival in ANCA-positive ILD patients, and the NSIP pattern (HR 0.07, 95% CI 0.01-0.41, p = 0.003) was independently associated with prolonged survival.

CONCLUSION

ANCA-ILD patients mostly have myeloperoxidase (MPO)-ANCA positivity and an MPA diagnosis. Survival was shorter among MPA-ILD patients than among ANCA-IIP patients. Respiratory failure and AE were associated with poorer prognosis. Early antifibrotic treatment may be a reasonable treatment option in fibrotic ILD patients with ANCA positivity.

Interstitial Lung Disease in ANCA-Associated Vasculitis: Pathogenic Considerations and Impact for Patients' Outcomes

PURPOSE OF REVIEW

This review provides an update on recent advances in the diagnosis, pathogenesis, clinical presentation, histopathological findings, and treatment approaches for antineutrophil cytoplasmic antibody (ANCA) vasculitis-associated interstitial lung disease (AAV-ILD) with a focus on literature published in the last 3 years.

RECENT FINDINGS

Although there is no validated definition of AAV-ILD, which contributes to some of the heterogeneity seen in study results, there has been an increasing number of publications in recent years on this topic. Most patients with AAV-ILD have MPO-ANCA vasculitis, and this association appears to reduce their 5-year-survival to 60-66% (Sun et al. BMC Pulm Med 21(1), 2021, Maillet et al. J Autoimmun 106, 2020). Median age of diagnosis ranges from mid-60 s to mid-70 s (Ando et al. Respir Med 107(4), 2013), Kagiyama et al. BMJ Open Respir Res 2(1):1-9, 2015, Hozumi et al. Lung 194(2):235-42, 2016, Liu et al. Chest 156(4):715-23, 2019, Maillet et al. J Autoimmun 106, 2020, Wurmann et al. Sarcoidosis Vasc Diffuse Lung Dis 37(1):37-42, 2020, Watanabe et al. BMC Pulm Med 19(1), 2019). Computed tomography (CT) chest imaging for patients with AAV-ILD often shows a usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia (NSIP) pattern (12-58% and 13-61%, respectively) (Sun et al. BMC Pulm Med 21(1), 2021, Maillet et al. J Autoimmun 106, 2020, Wurmann et al. Sarcoidosis Vasc Diffuse Lung Dis 37(1):37-42, 2020, Watanabe et al. BMC Pulm Med 19(1), 2019, Baqir at al. Sarcoidosis Vasc Diffuse Lung Dis Off J WASOG 36(3):195-201, 2019). Additionally, lung biopsies typically do not demonstrate active inflammation, or capillaritis, questioning whether these patients should be treated with either immunotherapy or anti-fibrotic therapy, or both (Hozumi et al. Lung 194(2):235-42, 2016, Liu et al. Chest 156(4):715-23, 2019, Kitching at al. Nat Rev Dis Prim 6(1):71, 2020, Tanaka et al. Respir Med 106(12):1765-70, 2012). Besides immunosuppressive treatments, recent advances in anti-fibrotic therapy may offer patients with progressive AAV-ILD an alternative and/or more effective and individualized treatment option.

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.

Antineutrophil cytoplasmic antibody-associated interstitial lung disease: a review

Over the past three decades, an increasing number of publications have reported the association between interstitial lung disease (ILD) and anti-neutrophil cytoplasmic antibody (ANCA) or ANCA-associated vasculitis (AAV). With this increased awareness, we have reviewed the literature to date and provide an update in this narrative review. The vast majority of cases of ILD have been shown to be in the setting of positive anti-myeloperoxidase antibody and can be present in up to 45% of patients of microscopic polyangiitis, though cases of ILD associated with proteinase 3 ANCA have rarely been reported. Pulmonary fibrosis and ANCA positivity can occur with or without systemic involvement. The pathogenetic mechanisms establishing the relationship between ANCA and the development of pulmonary fibrosis remain unclear. Histologic and radiographic features of ANCA-ILD most commonly reveal usual interstitial pneumonia or non-specific interstitial pneumonia patterns, though other atypical features such as bronchiolitis have been described. ILD in the setting of AAV has been associated with worse outcomes, and thus early identification and treatment in these patients is appropriate. We advocate that ANCA antibody testing be performed as a baseline evaluation in patients presenting with idiopathic interstitial pneumonia. Suggested treatment of ANCA-ILD includes immunosuppression and/or antifibrotic agents, though supporting data and clinical trials to substantiate use of these therapies are needed.

Prognostic value of radiological findings indeterminate for UIP pattern and anterior upper lobe honeycomb-like lesion in chronic fibrosing interstitial lung disease associated with MPO-ANCA

Background

Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) is often positive in patients with interstitial lung disease (ILD), which is also often present in patients with microscopic polyangiitis (MPA). A possible association between MPO-ANCA, MPA, and idiopathic ILD remains unclear. The objective of this study was to determine whether high-resolution computed tomography (HRCT) classification based on recent idiopathic pulmonary fibrosis guideline and specific CT findings can obtain new knowledge of prognostic factors in all MPO-ANCA-positive patients with ILD including both idiopathic ILD and MPA-ILD.

Methods

We analyzed 101 consecutive MPO-ANCA-positive patients with respiratory disease. We assessed the diagnostic accuracy of CT findings, HRCT pattern, and specific radiological signs. Prognostic predictors were determined using Cox regression models.

Results

Subjects with chronic ILD included 22 patients with MPA-ILD and 39 patients with ILD but without MPA. A quarter of the patients were radiological indeterminate for usual interstitial pneumonia (UIP) pattern, which resulted in a better prognosis than that for UIP pattern. “Increased attenuation around honeycomb and traction bronchiectasis” and “anterior upper lobe honeycomb-like lesion” were found to be highly frequent radiological findings (39% and 30%, respectively). In addition, the latter finding was a significant negative prognostic factor.

Conclusions

Radiological indeterminate for UIP was a useful HRCT classification in MPO-ANCA-positive patients with ILD. In addition, anterior upper lobe honeycomb-like lesion was found to be specific radiological finding that was a significant prognostic factor. The present results might aid in the assessment of appropriate strategies of diagnosis in these patients.

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.

Diagnosis and management of connective tissue disease-associated interstitial lung disease in Australia and New Zealand: A position statement from the Thoracic Society of Australia and New Zealand

Pulmonary complications in CTD are common and can involve the interstitium, airways, pleura and pulmonary vasculature. ILD can occur in all CTD (CTD-ILD), and may vary from limited, non-progressive lung involvement, to fulminant, life-threatening disease. Given the potential for major adverse outcomes in CTD-ILD, accurate diagnosis, assessment and careful consideration of therapeutic intervention are a priority. Limited data are available to guide management decisions in CTD-ILD. Autoimmune-mediated pulmonary inflammation is considered a key pathobiological pathway in these disorders, and immunosuppressive therapy is generally regarded the cornerstone of treatment for severe and/or progressive CTD-ILD. However, the natural history of CTD-ILD in individual patients can be difficult to predict, and deciding who to treat, when and with what agent can be challenging. Establishing realistic therapeutic goals from both the patient and clinician perspective requires considerable expertise. The document aims to provide a framework for clinicians to aid in the assessment and management of ILD in the major CTD. A suggested approach to diagnosis and monitoring of CTD-ILD and, where available, evidence-based, disease-specific approaches to treatment have been provided.

Myeloperoxidase anti-neutrophil cytoplasmic antibody-associated vasculitis with a unique imaging presentation of organizing pneumonia: A case report

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) constitutes a group of blood vessel inflammation diseases of autoimmune origin. Myeloperoxidase (MPO) ANCA is closely related to ANCA associated AAV. The MPO-ANCA positive AAV patients have lung involvement at high rates; however, there are only a few reported cases with organizing pneumonia (OP). A 78-year-old man was presented to our hospital due to a fever of 38 °C despite a whole month of antibiotics treatment. Chest computed tomography image revealed restricted consolidations visible in the middle lobe of the right lung and the upper lobe of the left lung, which suggested an OP pattern. MPO-ANCA and urine occult blood tests were positive. Histopathological examination of the transbronchial biopsy revealed OP and mucus plug. Histological findings on renal biopsy showed necrotizing glomerulonephritis related to AAV. The patient was diagnosed with MPO-ANCA positive AAV and was treated with systemic corticosteroid therapy, from which he recovered rapidly. Thus, when diagnosing OP, the possibility of AAV should be considered by ordering patients’ serum ANCA and occult hematuria tests.

Prevalence and Clinical Significance of Antineutrophil Cytoplasmic Antibodies in North American Patients With Idiopathic Pulmonary Fibrosis

BACKGROUND

Antineutrophil cytoplasmic antibodies (ANCAs) have been reported to occur in 7% to 10% of patients with idiopathic pulmonary fibrosis (IPF), but their clinical relevance remains unclear. The aim of this study was to estimate the prevalence of ANCAs in a North American population with IPF and evaluate their clinical significance.

METHODS

This was a retrospective study of two independent cohorts of patients diagnosed with IPF at the University of California San Francisco (discovery cohort) and the University of Chicago (replication cohort). Myeloperoxidase (MPO) and proteinase 3 (PR3) ANCAs were measured in all patients. Prevalence and associations of ANCAs with clinical characteristics and transplant-free survival were evaluated.

RESULTS

A total of 14 of 353 (4.0%; 95% CI, 2.2-6.5) and 20 of 392 (5.1%; 95% CI, 3.1-7.8) patients with IPF were positive for ANCAs at the time of diagnosis in the discovery and replication cohorts, respectively. Among those positive for MPO antibodies, two of six (33%) in the discovery cohort and three of 12 (25%) in the replication cohort developed vasculitis. None of the patients who were PR3-positive developed vasculitis. Patients who were ANCA-positive were more likely to be women than patients who were ANCA-negative, and were more likely to have some ground-glass opacities on CT scan. In the combined cohort of 745 patients, median transplant-free survival was not significantly different in patients who were ANCA-positive vs ANCA-negative (P = .57).

CONCLUSIONS

ANCA positivity is uncommon in North American patients with IPF and not associated with baseline disease severity or transplant-free survival; however, a significant proportion of patients who are MPO-positive with IPF develop clinical vasculitis.

Clinical features and prognosis of microscopic polyangiitis with usual interstitial pneumonia compared with idiopathic pulmonary fibrosis

INTRODUCTION

Pulmonary involvement in microscopic polyangiitis (MPA) is common, little is known about the clinical features of MPA with interstitial pneumonia (MPA-IP).

OBJECTIVES

This study aimed to explore the prevalence of microscopic polyangiitis associated usual interstitial pneumonia (UIP)(MPA-UIP) and compare its clinical features and prognosis with those of MPA-non-UIP and idiopathic pulmonary fibrosis (IPF).

METHODS

A total of 73 patients with MPA-IP were identified and divided into MPA-UIP patients and MPA-non-UIP patients. The clinical characteristics and survival of MPA-UIP patients were analysed and compared with those of MPA-non-UIP patients and 68 patients with IPF.

RESULTS

The results showed that 34/73 (47%) MPA-IP patients were classified as MPA-UIP patients. Compared with MPA-non-UIP patients, MPA-UIP patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the initial presentation. However, they were less likely to have proteinuria and/or hematuria. Compared with IPF patients, MPA-UIP patients usually had multisystem damage, positive anti-neutrophil cytoplasmic autoantibodies and elevated levels of nonspecific inflammatory markers. MPA-UIP death was concentrated mainly in the first 3 months after diagnosis and resulted in a higher early mortality compared with IPF.

CONCLUSION

UIP is the most frequent type of MPA-IP. These patients tend to have longer duration of symptoms prior to diagnosis and usually have pulmonary involvement as the first presentation. However, they are less likely to have proteinuria and/or hematuria. MPA patients with UIP can be differentiated from IPF patients through comprehensive analysis of clinical and laboratory findings.

Combined pulmonary fibrosis and emphysema with myeloperoxidase-antineutrophil cytoplasmic antibody positivity that resolved upon smoking cessation

Myeloperoxidase antineutrophil cytoplasmic autoantibody (MPO-ANCA) is well-known as a serological marker for small-vessel vasculitis. However, when a smoker with interstitial lung disease (ILD) exhibits serum ANCA positivity without systemic vasculitis, diagnosis is a matter of debate; the relationship between smoking and ANCA is unknown. We report a case of combined pulmonary fibrosis and emphysema (CPFE) with elevated MPO-ANCA. Surgical lung biopsy showed emphysema and fibrotic interstitial pneumonia without vasculitis. The MPO-ANCA level decreased after smoking cessation, and no vasculitis or progression was observed during 3 years of follow-up. This suggested that smoking cessation was related to normalization of MPO-ANCA and corresponding disease activity.

Clinical significance of myeloperoxidase-anti-neutrophil cytoplasmic antibody in idiopathic interstitial pneumonias

Objective

Although a possible association among myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA), microscopic polyangiitis (MPA), and idiopathic pulmonary fibrosis (IPF) has been suggested, the clinical significance of MPO-ANCA in idiopathic interstitial pneumonias (IIPs), including IPF and non-IPF, remains unclear. We aimed to investigate the frequency of MPO-ANCA positivity, as well as MPA incidence and risk factors for development in patients initially diagnosed with IIP.

Methods

We retrospectively analysed 305 consecutive patients who were initially diagnosed as IIP and had MPO-ANCA results available.

Results

Of the 305 patients, 26 (8.5%) were MPO-ANCA-positive. Baseline characteristics were similar between the MPO-ANCA-positive and -negative patients. The cumulative 5-year MPA incidence was 24.3% in the MPO-ANCA-positive patients and 0% in the -negative patients (P < 0.0001). MPO-ANCA was positive in 15 of 133 (11.3%) patients initially diagnosed with IPF and in 11 of 172 (6.3%) patients initially diagnosed with non-IPF (P = 0.56), with cumulative 5-year MPA incidence of 6.2% and 1.0%, respectively (P = 0.10). Multivariate analysis revealed that UIP pattern on HRCT (HR = 3.20, P < 0.01) and no treatment for IIP (HR = 3.52, P < 0.01) were independently associated with MPA development in MPO-ANCA-positive patients.

Conclusion

MPO-ANCA positivity was uncommon, but was associated with subsequent MPA development in patients initially diagnosed with IIP, including both IPF and non-IPF cases. The study suggested that attention should be paid to MPA development in MPO-ANCA-positive IIP patients with UIP pattern on HRCT and those without treatment for IIP.

Pleuroparenchymal fibroelastosis with positive MPO-ANCA diagnosed with a CT-guided percutaneous needle biopsy

A 67-year-old woman was referred to our hospital because of gradually increasing dyspnoea on exertion for 6 months. Chest CT scan showed subpleural parenchymal fibrotic opacities with traction bronchiectasis in the bilateral upper lung fields. Serum rheumatoid factor and myeloperoxidase-antineutrophil cytoplasmic antibody (MPO-ANCA) were positive. There was no evident reason to suspect connective tissue disease such as ANCA-associated vasculitis or rheumatoid arthritis. We performed a CT-guided percutaneous needle biopsy of the subpleural lesion that showed slight uptake on the fluorodeoxyglucose-positron emission tomography (FDG-PET) CT scan. This specimen showed subpleural fibrosis as evidenced by an abnormal increase of elastic tissue and minimal collagen deposition, which indicated pleuroparenchymal fibroelastosis (PPFE). Although PPFE can be associated with a variety of causes, its association with MPO-ANCA is unknown. A CT-guided transthoracic lung biopsy caused no adverse events and was useful in the diagnosis of PPFE in our patient.

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.

Clinical features of usual interstitial pneumonia with anti-neutrophil cytoplasmic antibody in comparison with idiopathic pulmonary fibrosis

BACKGROUND AND OBJECTIVE

Myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) is occasionally positive in patients with usual interstitial pneumonia (UIP). However, the differences from idiopathic pulmonary fibrosis (IPF/UIP) have not been well documented. We aimed to clarify the clinical, radiological and pathological features of UIP associated with MPO-ANCA (ANCA/UIP).

METHODS

We retrospectively reviewed the medical records of 12 consecutive ANCA/UIP patients not manifesting microscopic polyangiitis and 108 IPF/UIP patients with no autoantibodies, both diagnosed by surgical lung biopsy.

RESULTS

There was no significant difference in clinical background, laboratory results and pulmonary function tests between ANCA/UIP patients and IPF/UIP patients except for the percentage of bronchoalveolar lavage neutrophils. HRCT showed subpleural reticulation in both groups. Increased attenuation around honeycombing and cysts was significantly observed in ANCA/UIP. Pathologically, ANCA/UIP had more prominent inflammatory cell infiltration, lymphoid follicles with germinal centres and cellular bronchiolitis. During the disease course, three of 12 patients (25%) developed microscopic polyangiitis. Immunosuppressive treatment tended to be more effective in ANCA/UIP patients, and the survival time in ANCA/UIP patients tended to be longer than those with IPF/UIP.

CONCLUSION

ANCA/UIP may be distinguishable from IPF/UIP with a combination of HRCT findings of increased attenuation around honeycombing and cysts and some of the characteristic pathological findings. In contrast to IPF/UIP, immunosuppressive treatment could be a therapeutic option for ANCA/UIP.

Clinical Implication of Proteinase-3-antineutrophil Cytoplasmic Antibody in Patients with Idiopathic Interstitial Pneumonias

PURPOSE

The clinical significance of proteinase-3-antineutrophil cytoplasmic antibody (PR3-ANCA) positivity is not well established in idiopathic interstitial pneumonia (IIP) patients. We aimed to determine the clinical features of PR3-ANCA-positive IIP patients.

METHODS

We retrospectively reviewed 377 consecutive IIP patients; of these, 360 patients had PR3-ANCA and myeloperoxidase-antineutrophil cytoplasmic antibody test results available. The clinical features of PR3-ANCA-positive IIP patients and control ANCA-negative idiopathic pulmonary fibrosis patients (ANCA-negative IPF) were compared.

RESULTS

Sixteen patients (4.4 %) were PR3-ANCA-positive IIP and 94 (26 %) were ANCA-negative IPF. The median age at diagnosis (72 vs. 70 years, P = 0.17) and proportion of males (75 vs. 89 %, P = 0.12) in PR3-ANCA-positive IIP and ANCA-negative IPF patients, respectively, were not significantly different. Radiologically, the HRCT patterns of PR3-ANCA-positive IIP patients varied (UIP, n = 3, 18.8 %; possible UIP, n = 3, 18.8 %; NSIP, n = 5, 31.3 %; unclassifiable CT pattern, n = 5, 31.3 %) more than those of ANCA-negative IPF patients (UIP, n = 69, 73.4 %; possible UIP, n = 25, 26.6 %; P < 0.001). No PR3-ANCA-positive IIP patients developed ANCA-associated vasculitis. The 5-year survival rate was 50 % in PR3-ANCA-positive IIP patients and 52 % in ANCA-negative IPF patients with no significant difference (P = 0.96 by log-rank test).

CONCLUSIONS

The HRCT patterns of PR3-ANCA-positive IIP patients varied more than those of the IPF patients, but the clinical features of high IIP-onset age and male predominance were similar between the groups. Furthermore, PR3-ANCA-positive IIP patients had a poor prognosis similar to that of IPF patients.

Organizing pneumonia associated with myeloperoxidase anti-neutrophil cytoplasmic antibody

Organizing pneumonia (OP) is a clinicopathological entity that occurs idiopathically or in association with several conditions, but there are few reports about myeloperoxidase anti‐neutrophil cytoplasmic antibody (MPO‐ANCA)‐associated OP. We describe a patient with OP whose clinical conditions improved spontaneously. Moreover, serum MPO‐ANCA titers paralleled the clinical activity of the disease, which disappeared in association with disease quiescence. Based on these findings, a subset of patients may have OP related to MPO‐ANCA. ANCA testing should be considered in the work‐up of patients with suspected OP.

Clinical presentation and long-term outcome of 144 patients with microscopic polyangiitis in a monocentric German cohort

OBJECTIVE

To evaluate the clinical presentation and long-term outcome of a vasculitis centre cohort of patients with microscopic polyangiitis (MPA) with respect to organ manifestations, treatment, chronic damage and mortality.

METHODS

We performed a retrospective chart review at our vasculitis referral centre. MPA patients admitted between 1991 and 2013 classified by a modified European Medicines Agency algorithm were diagnosed and treated according to a standardized interdisciplinary approach.

RESULTS

Comprehensive data from standardized interdisciplinary workups was available for 144 patients (median follow-up 72 months). The overall standardized mortality ratio was 1.40 (95% CI 0.91, 2.07; P = 0.13). We observed a higher mortality [hazard ratio (HR) 4.04 (95% CI 1.21, 13.45), P = 0.02] in 17 patients with MPA-associated fibrosing interstitial lung disease (ILD) and 56 patients with peripheral nervous system involvement [HR 5.26 (95% CI 1.10, 25.14), P = 0.04] at disease onset. One hundred and fifteen patients (79.9%) responded to the initial treatment. Sixty-one (42.3%) achieved complete remission and 54 (37.5%) achieved partial remission. Twenty (13.9%) showed a refractory disease course.

CONCLUSION

MPA patients at our tertiary rheumatology referral centre seemed to have a less severe phenotype resulting in a less severe disease course and better outcome than reported in other cohorts. Fibrosing ILD was significantly associated with mortality in this cohort.

Pathological and radiological correlation in an autopsy case of combined pulmonary fibrosis and emphysema

We report an educational autopsy case of combined pulmonary fibrosis and emphysema. Radiological patterns of the upper lung were considered as mostly emphysema, but pathological observation revealed significant interstitial fibrosis of usual interstitial pneumonia as a major pathology. The patient eventually developed acute exacerbation of background interstitial pneumonia. Careful radiological and pathological correlation of the current case indicates that regions with distal acinar emphysema on computed tomography image may possess histologically marked dense fibrosis of lethal interstitial pneumonia.

Microscopic polyangiitis preceded by combined pulmonary fibrosis and emphysema

A 73-year-old male metalworker was admitted to our hospital with a 3-year history of progressive dry cough. Chest high-resolution computed tomography revealed emphysematous changes and reticular lesions, which is referred to as combined pulmonary fibrosis and emphysema (CPFE). Surgical lung biopsy specimens revealed unclassified interstitial pneumonia, including a nonspecific interstitial pneumonia pattern and usual interstitial pneumonia pattern. Two years after his first admission he developed rapid progressive renal dysfunction with an elevated level of myeloperoxidase-antineutrophil cytoplasmic antibody (428 EU). A renal biopsy specimen revealed interstitial nephritis and glomerulonephritis. Consequently, microscopic polyangiitis preceded by CPFE was diagnosed. Despite transient exacerbation of renal involvement, his general condition remained mostly stable during a 2-year period of corticosteroid treatment. He ultimately died from severe pneumococcal pneumonia associated with acute lung injury.

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

BACKGROUND

Pulmonary involvement is one of the hallmark lesions of anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV) as well as rapidly progressive glomerulonephritis (RPGN). However, the pulmonary involvement of AAV patients seems to differ between Europe and Japan, as does the ANCA serotype.

METHODS

This retrospective and prospective multicenter cohort study collected the clinical data of the features and outcomes of 1772 RPGN patients treated from 1989 to 2007 in Japan. Based on this nationwide RPGN survey, we analyzed the cases of 1147 AAV patients.

RESULTS

We found that 52.3% of the AAV patients had pulmonary involvements: 15.4% of the AAV patients had alveolar hemorrhage (AH), 26.2% had interstitial lung disease (ILD), 2.8% had bronchial asthma, 2.4% had pulmonary granuloma and 12.8% had a chest X-ray abnormality without AH, ILD or pulmonary granuloma. Patient survival was significantly different among the following six groups: the 5-year survival rate was 41.5% in the patients with AH, 50.2% in those with ILD, 67.9% in those with bronchial asthma, 62.5% in those with pulmonary granuloma, 55.8% in those with chest X-ray abnormality and 73.3% in those without pulmonary involvement. AH was one of the predictors of 1- and 5-year mortality for patient survival in AAV, and ILD was added as one of the predictors of 5-year mortality.

CONCLUSION

In these AAV patients, not only AH but also ILD was frequently observed. AH was associated with the prognosis, but ILD was associated with the long-term prognosis of AAV.

Antineutrophil cytoplasmic antibody-positive conversion and microscopic polyangiitis development in patients with idiopathic pulmonary fibrosis

Background

Increasing evidence indicates that antineutrophil cytoplasmic antibody (ANCA)-positive conversion occurs in patients initially diagnosed with idiopathic pulmonary fibrosis (IPF) and as a result, some of these patients develop microscopic polyangiitis (MPA). However, the incidence density of these patients is not well known.

Objectives

To explore the incidence of ANCA-positive conversion and development of MPA during the disease course in patients with IPF and to evaluate whether corticosteroid therapy reduces MPA development in patients with IPF with myeloperoxidase (MPO)-ANCA positivity at diagnosis or who later acquire MPO-ANCA positivity.

Methods

We retrospectively analysed the medical records of 504 Asian patients with IPF treated at our institution in Saitama, Japan.

Results

Of the 504 patients with IPF, 20 (4.0%) had MPO-ANCA and 16 (3.2%) had PR-3-ANCA when first evaluated. In 264 of 504 patients with IPF, ANCA was measured repeatedly and seroconversion to MPO-ANCA and PR3-ANCA occurred in 15 (5.7%) and 14 (5.3%) patients, respectively, and 9 of 35 patients who were either MPO-ANCA positive at IPF diagnosis or who subsequently seroconverted developed MPA. None of the nine patients who developed MPA had been previously treated with steroids. The incidence of MPA tended to be lower in patients treated than not treated with corticosteroids although this was not statistically significant.

Conclusions

Some patients with IPF with MPO-ANCA positivity at IPF diagnosis or with MPO-ANCA-positive conversion during follow-up developed MPA. Clinical trials to determine whether corticosteroid therapy can reduce MPA development and prolong survival in MPO-ANCA-positive patients with IPF should be considered.

Microscopic polyangiitis associated with pulmonary fibrosis

Microscopic polyangiitis (MPA) is a systemic necrotizing vasculitis characterised by inflammation of the small blood vessels, the absence of granulommas on histopathological specimens, with few or no immune deposits and the presence of circulating anti-neutrophil cytoplasmic antibodies (ANCAs). The classic pulmonary manifestation is diffuse alveolar haemorrhage (DAH), but its association with pulmonary fibrosis (PF) has been increasingly reported and may be the first manifestation of MPA. Our aim was to evaluate MPA patients with PF and compare their characteristics and evolution to those of MPA patients without PF. We conducted a retrospective review of MPA patients followed in our hospital over a 15-year period. They were divided into two subgroups, with PF (MPA-PF) and without PF (MPA-non PF), and their clinical and functional features were compared. Nine of the 28 patients were classified as MPA-PF (32%). This subgroup showed significantly more respiratory symptoms and higher mortality than MPA-non PF subgroup. The most frequent chest computed tomographic pattern of PF was usual interstitial pneumonia. PF preceded other manifestations of vasculitis in five patients and occurred simultaneously in the remaining four. During the follow-up period, four deaths were reported in the MPA-PF subgroup. No deaths were registered in the MPA-non PF subgroup. We found a high prevalence of MPA-PF patients (32%), most of whom had a poor outcome and PF was often the first manifestation of the disease.