Microscopic polyangiitis presenting as a “pulmonary-muscle” syndrome: Is subclinical alveolar hemorrhage the mechanism of pulmonary fibrosis?

ANCA-associated vasculitis with muscle involvement mimicking polymyalgia rheumatica

We report a case of a woman in her early 80s with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis presented as myalgia mimicking polymyalgia rheumatica (PMR). She had positive results for the Neer and Hawkins-Kennedy impingement tests, and a normal serum creatine kinase (CK) concentration. At first, we suspected PMR; however, the patient did not strictly meet the classification criteria. Electromyography revealed an abnormal myogenic pattern, and muscle MRI revealed intramuscular and fascial hyperintensity. Moreover, chest CT revealed interstitial lung disease, and test results for ANCAs were positive. We diagnosed the patient with ANCA-associated vasculitis based on the criteria and treated her with corticosteroids and rituximab. Thus, ANCA-associated vasculitis can cause muscle involvement without elevation of the CK concentration and mimic PMR.

Antineutrophil cytoplasmic antibody-associated vasculitis with predominant truncal muscle weakness: a retrospective case series

Introduction

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) frequently leads to mononeuritis multiplex, which are characterized by distal weakness associated with sensory disturbances. Although AAV has also been reported to be associated with myopathy, the pathogenesis and characteristics remain unclear. We aimed to show the clinical and laboratory findings in AAV-associated myopathy.

Methods

This retrospective single-center study included patients with the diagnosis of AAV who had been admitted to the neurology department and had biopsy specimens of muscle and/or nerve tissue.

Results

We identified four patients with a distinct clinical presentation of muscle weakness in the trunk and proximal limbs. The weakness resembled that of inflammatory muscle disease. These patients denied symptoms associated with neuropathy, and had normal serum creatine kinase (CK) levels. Needle electromyography (needle EMG) showed spontaneous electrical activity at rest, and results of magnetic resonance imaging (MRI) suggested inflammatory myopathy. Muscle biopsy specimens from all four patients revealed vasculitis and inflammation in proximity to the affected vessels, without any discernible characteristics of other myopathies. The patients also complained of symptoms affecting other organs, such as the ears and kidneys, which is typical of AAV cases. Remission induction therapy, such as cyclophosphamide pulse therapy in addition to oral prednisolone, were effective for all four patients. However, relapses occurred in two patients during maintenance therapy and two patients died of aspiration pneumonia.

Discussion

The clinical course of our patients might represent a subtype of AAV that is characterized by muscle weakness of the trunk and proximal extremities and arises from vasculitis within the muscles. The clinical manifestations of our patients were similar to those of patients with inflammatory myopathy with regard to the distribution of muscle weakness, MRI and needle EMG findings. However, there are notable differences between AAV associated myopathy vs. inflammatory myositis like dermatomyositis; (1) the absence of elevated CK levels, (2) the presence of complications in other organs, (3) distinct pathological findings, and (4) severe outcomes. Awareness that AAV patients with muscle involvement could have a subtype of AAV that seriously affects various organs is critical for an accurate diagnosis and effective therapeutic management.

Long-term clinical course and outcomes of patients with microscopic polyangiitis-associated interstitial lung disease

Background: Interstitial lung disease (ILD) is a significant complication associated with microscopic polyangiitis (MPA) that has a poor prognosis. However, the long-term clinical course, outcomes, and prognostic factors of MPA-ILD are not well defined. Hence, this study aimed to investigate the long-term clinical course, outcomes, and prognostic factors in patients with MPA-ILD. Methods: Clinical data of 39 patients with MPA-ILD (biopsy proven cases, n = 6) were retrospectively analyzed. High resolution computed tomography (HRCT) patterns were assessed based on the 2018 idiopathic pulmonary fibrosis diagnostic criteria. Acute exacerbation (AE) was defined as the worsening of dyspnea within 30 days, with new bilateral lung infiltration that is not fully explained by heart failure or fluid overload and that does not have identified extra-parenchymal causes (pneumothorax, pleural effusion, or pulmonary embolism). Results: The median follow-up period was 72.0 months (interquartile range: 44-117 months). The mean age of the patients was 62.7 years and 59.0% were male. Usual interstitial pneumonia (UIP) and probable usual interstitial pneumonia patterns on high resolution computed tomography were identified in 61.5 and 17.9% of the patients, respectively. During the follow-up, 51.3% of patients died, and the 5- and 10-year overall survival rates were 73.5% and 42.0%, respectively. Acute exacerbation occurred in 17.9% of the patients. The non-survivors had higher neutrophil counts in bronchoalveolar lavage (BAL) fluid and more frequent acute exacerbation than the survivors. In the multivariable Cox analysis, older age (hazard ratio [HR], 1.07; 95% confidence interval [CI], 1.01-1.14; p = 0.028) and higher BAL counts (HR, 1.09; 95% CI, 1.01-1.17; p = 0.015) were found to be the independent prognostic factors associated with mortality in patients with MPA-ILD. Conclusion: During the 6 years-follow-up, about half of patients with MPA-ILD died and approximately one-fifth experienced acute exacerbation. Our results suggest that older age and higher BAL neutrophil counts mean poor prognosis in patients with MPA-ILD.

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.

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.

Inflammatory muscle involvement in systemic vasculitis: A systematic review

Vasculitis are severe systemic autoimmune diseases which may involve different organs and systems. Conversely, muscles do not represent an organ commonly involved by systemic vasculitis and myositis is not include among any classification or diagnostic criterion of vasculitis. In this regard, we aimed to review the literature in order to report all the available evidence concerning the inflammatory involvement of muscle in patients affected by systemic vasculitis. We collected a total of 108 papers, for a sum of 395 patients affected by muscle vasculitis. Most of them suffered from medium and small vessels vasculitis (mainly polyarteritis nodosa and ANCA-associated vasculitis) or from vasculitis secondary to rheumatoid arthritis. Conversely, muscle involvement in case of large vessel vasculitis occurred seldom, while only few papers reported such occurrence in Kawasaki or Behçet's disease. Histological findings may differ, but the most common ones displayed a necrotizing vasculitis of perimysium vessels, while granulomatous vasculitis was assessed only in case of ANCA-associated vasculitis patients. Creatine kinase were usually within normal range, seldom elevated, while imaging findings were generally undistinguishable from the ones found in idiopathic inflammatory myopathies: magnetic resonance imaging displays signal hyperintensity in T2 and STIR scans, while few data exist for positron emission tomography. The presentation of the disease may be fearsome and severe, sometimes life-threatening, but an overall good response to conventional immunosuppressants and/or glucocorticoids has been reported.

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.

MR imaging findings of musculoskeletal involvement in microscopic polyangiitis: a comparison with inflammatory myopathy

OBJECTIVE

The purpose of this study was to evaluate the importance of MR imaging findings of musculoskeletal involvement of the lower limbs in diagnosing microscopic polyangiitis (MPA) vs polymyositis (PM) or dermatomyositis (DM).

MATERIALS AND METHODS

This study included 13 patients diagnosed with MPA clinically and through histologically, and 38 diagnosed with PM/DM, who underwent MR imaging of the lower limbs prior to treatment. Axial and coronal short tau inversion recovery (STIR) images were reviewed retrospectively.

RESULTS

The sites affected by MPA were the lower legs in six (46%) patients and the thighs in seven (54%). Intramuscular hyperintensity and fascial hyperintensity were observed in all cases of MPA (100%). Fascial hyperintensity was more frequently encountered in MPA than in PM/DM (100% vs. 45%, p < 0.01). As the predominantly involved sites, the fascial regions were more frequently affected by MPA than by PM/DM (77% vs. 18%, p < 0.01). Diffuse subcutaneous fat hyperintensity was more frequently observed in MPA than in PM/DM (100% vs. 16%, p < 0.01). However, no significant differences in intramuscular hyperintensity (100% vs. 97%, p = 0.745) and subcutaneous fat hyperintensity (54% vs. 50%, p = 0.533) were found between MPA and PM/DM.

CONCLUSION

Intramuscular hyperintensity and fascial hyperintensity have always been observed in MPA, and the predominantly affected sites were usually the fascial regions. Compared with PM/DM, fascial hyperintensity and diffuse subcutaneous fat hyperintensity were more frequent in MPA.

Clinical Significance of Interstitial Lung Disease and Its Acute Exacerbation in Microscopic Polyangiitis

BACKGROUND

Presence of interstitial lung disease (ILD) is thought to be associated with mortality in microscopic polyangiitis (MPA); however, evidence on MPA-ILD remains lacking. Acute exacerbation (AE) refers to rapidly progressive, fatal respiratory deterioration that may develop in patients with various ILDs. No study has investigated the clinical significance of AE in MPA-ILD.

RESEARCH QUESTION

We aimed to determine the clinical picture and prognostic factors, the incidence of AE, and the risk factors in patients with MPA-ILD.

STUDY DESIGN AND METHODS

Eighty-four consecutive patients with MPA-ILD and 95 patients with MPA-non-ILD were analyzed. We also compared 80 patients with MPA-ILD and 80 patients with idiopathic interstitial pneumonia without myeloperoxidase-antineutrophil cytoplasmic antibody positivity (ILD alone), who were matched for age, sex, and chest high-resolution CT scan pattern.

RESULTS

The MPA-ILD group had a higher frequency of men and smokers and was associated with higher mortality than the MPA-non-ILD group. The matched MPA-ILD group had a higher mortality rate than the matched ILD alone group. There was no significant difference in AE incidence between the matched MPA-ILD and ILD alone groups (1-year AE cumulative incidence rate, 7.5% and 5.2%, respectively; P = .75). In the MPA-ILD group, a lower percent predicted FVC (%FVC) was independently associated with a higher mortality rate (hazard ratio [HR], 0.96 per 1% increase; P < .01) and a higher AE incidence rate (HR, 0.96 per 1% increase; P = .01). On multivariable Cox regression analysis with time-dependent covariates, developing AE during their clinical course was strongly associated with shorter survival (HR, 17.1; P < .001).

INTERPRETATION

MPA-ILD represented a distinct phenotype with poor prognosis. Lower %FVC was an independent prognostic factor. Patients with lower %FVC had a risk of developing AE, which was a strong prognostic determinant. The specific management for MPA-ILD and AE should be established.

ANCA-associated vasculitis and severe proximal muscle weakness

ANCA-associated vasculitis is a multiorgan autoimmune inflammatory disease that has a heterogeneous clinical presentation. Our case report provides additional evidence supporting the association between granulomatosis with polyangiitis and myositis. In our patient with proximal muscle weakness and pain, a normal creatine kinase and lack of antibodies to muscular fiber units ruled out primary myositis. Distinct magnetic resonance imaging of the brain within the deep gray matter in addition to positive serologies were consistent with a diagnosis of granulomatosis with polyangiitis. ANCA-associated vasculitis, specifically granulomatosis with polyangiitis, may be overlooked if musculoskeletal manifestations are the presenting symptoms. Prompt and aggressive treatment prevented this patient from experiencing multiorgan failure.

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.

Clinical characteristics of patients with myalgia as the initial manifestation of small and medium-sized vasculitis: a retrospective study

Myalgia is a common symptom in small and medium-sized systemic vasculitis, sometimes occurring as the initial or only clinical manifestation of vasculitis. This study investigated the clinical features and diagnostic process in patients presenting with myalgia as the initial symptom of anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) or polyarteritis nodosa (PAN). We included 93 patients diagnosed with AAV or PAN by retrospectively reviewing their clinical records at the initial diagnosis. Clinical findings and diagnostic methods were assessed in patients with myalgia. Of 93 patients, myalgia was observed in 21 (22.6%) patients, with diagnostic classifications of microscopic polyangiitis (MPA) in 12 (52.4%), granulomatosis with polyangiitis in 2 (9.5%), eosinophilic granulomatosis with polyangiitis in 2 (9.5%), and PAN in 5 (23.8%). Myalgia was present in the lower extremities of all patients; more than 80% of patients had pain in the calf muscle. In 10 patients with myalgia, including 7 with MPA and 3 with PAN, muscle biopsy was performed because myalgia was the main symptom and no other impaired organs were suitable for biopsy. Consequently, 8 patients had necrotizing vasculitis, leading to MPA or PAN diagnosis, although muscle pathology was not evaluated in patients without myalgia. Muscle magnetic resonance imaging was useful in determining the biopsy site. Myalgia, especially in the lower limbs, may be an initial clinical sign of vasculitis, particularly in MPA or PAN patients. Moreover, the histological evidence of muscular vasculitis can contribute to a definite diagnosis especially in patients presenting with myalgia as an early symptom of AAV or PAN.

Severe proximal muscle weakness with normal CK as a presenting feature of ANCA-associated vasculitis

Antineutrophil cytoplasmic antibodies associated vasculitis (AAV) presenting with muscle weakness is rarely reported. We report a case of myeloperoxidase positive vasculitis presenting with severe proximal muscle weakness with normal creatine kinase and no positron-emission tomography uptake. There was a significant delay in the diagnosis of AAV due to atypical presentation. We propose AAV be considered in the differential diagnosis of proximal muscle weakness after excluding the common causes.

Pathogenesis of ANCA-Associated Pulmonary Vasculitis

Antineutrophil cytoplasmic antibodies (ANCAs) are autoantibodies specific for antigens located in the cytoplasmic granules of neutrophils and lysosomes of monocytes. ANCAs are associated with a spectrum of necrotizing vasculitis that includes granulomatosis with polyangiitis, microscopic polyangiitis, and eosinophilic granulomatosis with polyangiitis. Pulmonary vasculitis and related extravascular inflammation and fibrosis are frequent components of ANCA vasculitis. In this review, we detail the factors that have been associated with the origin of the ANCA autoimmune response and summarize the most relevant clinical observations, in vitro evidence, and animal studies strongly indicating the pathogenic potential of ANCA. In addition, we describe the putative sequence of pathogenic mechanisms driven by ANCA-induced activation of neutrophils that result in small vessel necrotizing vasculitis and extravascular granulomatous necrotizing inflammation.

From fibrosis to diagnosis: a paediatric case of microscopic polyangiitis and review of the literature

We herein describe a case of a 6-year-old girl diagnosed with microscopic polyangiitis (MPA) after a long diagnostic process demanding the cooperation of paediatric respiratory medicine specialists, rheumatologists, nephrologists and radiologist. First symptoms of MPA were observed after Mycoplasma pneumoniae infection and included persistent crepitations at the basis of both lungs and mild haematuria. CT imaging showed features of lung fibrosis, renal biopsy was indicative of mesangial proliferative glomerulonephritis, in the skin biopsy features of microscopic polyangiitis were described. In the laboratory tests pANCA antibodies specific for myeloperoxidase (MPO) were present in high titer. MPA with initial features of lung fibrosis is an unusual presentation of this rare disease, usually observed in adult population. This unique case illustrates the diagnostic and therapeutic challenges in paediatric vasculitis patients with an unusual initial presentation in the form of interstitial lung disease. In the manuscript we also discuss the possible aetiology of lung fibrosis in microscopic polyangiitis MPA and provide the review of the current literature on the topic of childhood-onset MPA.

Muscle weakness as a presenting symptom in ANCA-associated vasculitis

Muscle weakness is rarely a presenting symptom of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), although the disease frequently involves the lungs, skin, neurons, and kidneys. Here we describe a case of AAV presenting with muscle weakness in which only muscle biopsy could confirm the diagnosis. The literature review, including three similar cases, suggested that patients with ANCA-associated muscle vasculitis likely had myalgia, normal levels of creatine kinase, pulmonary fibrosis, rheumatoid factor, and muscle edema on MRI.

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.

Prevalence and Responsiveness to Treatment of Lung Abnormalities on Chest Computed Tomography in Patients With Microscopic Polyangiitis: A Multicenter, Longitudinal, Retrospective Study of One Hundred Fifty Consecutive Hospital-Based Japanese Patients

OBJECTIVE

To determine the prevalence of lung abnormalities on chest computed tomography (CT) in patients with microscopic polyangiitis (MPA), to assess the responsiveness of such abnormalities to initial treatment, and to assess associations between these abnormalities and patient and disease characteristics and mortality.

METHODS

We retrospectively identified 167 consecutive hospital-based patients with MPA in 3 hospitals in Japan. We longitudinally collected clinical information for 150 of these patients, for whom CT images obtained before treatment were available. We then determined the presence of 22 imaging components of lung abnormalities in these patients.

RESULTS

The vast majority of patients (97%) had at least 1 lung abnormality on chest CT images, including interstitial lung lesions (66%), airway lesions (66%), pleural lesions (53%), and emphysematous lesions (37%). In multivariate analyses, ground-glass opacity was associated with the Birmingham Vasculitis Activity Score, whereas 3 of 4 airway lesions were associated with myeloperoxidase-antineutrophil cytoplasmic antibodies. Latent class analysis identified a distinct group of patients with airway-predominant lung lesions. Airway lesions such as bronchiolitis and bronchovascular bundle thickening were among the components that showed improvement within 3 months of the initial treatment. An idiopathic pulmonary fibrosis pattern was the only chest CT variable that was independently associated with shorter survival.

CONCLUSION

Abnormalities in a wide range of anatomic areas, including the whole airway, can be identified in the lungs of patients with MPA before treatment. The prevalence, clustering patterns, and responsiveness to treatment of individual lung abnormalities provide groundwork for informing future studies to understand the pathophysiology of MPA.

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.

Intriguing Findings of the Muscle on Magnetic Resonance Imaging in Polyarteritis Nodosa

Polyarteritis nodosa (PAN) confined to the muscle is rare and hard to diagnose. Recently, the utility of magnetic resonance imaging (MRI) for detecting muscle involvement of PAN has been introduced. We herein report the case of biopsy-proven, refractory PAN confined to the lower limb muscles with enhanced MRI demonstrating discretely granular hyperintensities, which was contrary to previous reports. Our results, with those of previous reports, suggest that the MRI findings of muscles in PAN reflect the vessel size involved and disease severity.

Microscopic polyangiitis: Advances in diagnostic and therapeutic approaches

Microscopic polyangiitis (MPA) is an idiopathic autoimmune disease characterized by systemic vasculitis. The disease predominantly affects small-calibre blood vessels and is associated with the presence of antineutrophil cytoplasmic autoantibodies (ANCA). Microscopic polyangiitis was considered to be a disease entity by Savage et al. in 1985. Microscopic polyangiitis has a reported low incidence and a slight male predominance. The aetiology of MPA remains unknown. There is, however, increased evidence that MPA is an autoimmune disease in which ANCAs, particularly those reacting with MPO, are pathogenic. MPA belongs to the systemic vasculitides, indicating that multiple organs can be affected. The major organs involved in MPA are the kidneys and the lungs. As expected for an illness that affects multiple organ systems, patients with MPA can present with a myriad of different symptoms. Ear, nose and throat (ENT) manifestations are not considered to be clinical symptoms of MPA, but in the majority of populations described, ENT involvement was found in surprisingly high percentages. MPA is part of the ANCA-associated vasculitides, which are characterized by necrotizing vasculitis of small vessels. Diagnosis is mainly established by clinical manifestations, computed tomography (TC), ANCA antibody detection and renal and pulmonary biopsy. The introduction of aggressive immunosuppressive treatment has substantially improved the prognosis. The standardized therapeutic regimen is based on cyclophosphamide and corticosteroids. Using this regimen, remission can be achieved in most of the patients. Rituximab may represent an important alternative to cyclophosphamide for patients who may not respond adequately to antimetabolite therapies.

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.

Pulmonary Limited MPO-ANCA Microscopic Polyangiitis and Idiopathic Lung Fibrosis in a Patient with a Diagnosis of IgA Nephropathy

We present a case of a male patient with chronic renal insufficiency, due to crescentic glomerulonephritis with IgA deposits, who successively developed (idiopathic) thrombocytopenic purpura (ITP) and MPO-ANCA microscopic polyangiitis (MPA) with pulmonary fibrosis. The patient presented with cough, weight loss, and dyspnea on exertion. CT imaging and pulmonary function tests were compatible with interstitial pneumonitis with pulmonary fibrosis. Laboratory results showed high MPO-ANCA titers; the urinary sediment was bland. The patient was treated successfully with cyclophosphamide and methyl-prednisolone. This unique case illustrates the diagnostic and therapeutic challenges of an unusual presentation of microscopic polyangiitis presenting first as isolated kidney disease with recurrence in the form of pneumonitis without renal involvement, in association with renal IgA deposits and ITP as coexisting autoimmune conditions.

Pulmonary fibrosis in antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis: a series of 49 patients and review of the literature

Pulmonary fibrosis (PF) is an uncommon manifestation observed in patients with antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV), particularly microscopic polyangiitis (MPA). While patients with PF associated with AAV seem to have a worse prognosis, these patients have been described only in case reports or small retrospective case series. In this retrospective multicenter study, we report the main features and long-term outcomes of patients with PF associated with AAV, fulfilling the American College of Rheumatology criteria and/or Chapel Hill definitions. Forty-nine patients (30 men [61%]; median age at diagnosis of AAV, 68 [interquartile range, 58-73] years) with PF associated with AAV were identified. Forty (81.6%) patients had MPA and 9 (18.4%) had granulomatosis with polyangiitis. The diagnosis of PF preceded the onset of vasculitis in 22 (45%) patients. Usual interstitial pneumonia was the main radiologic pattern (n = 18, 43%). ANCA were mostly of antimyeloperoxidase specificity (88%). All patients were treated with glucocorticoids as induction therapy, combined with cyclophosphamide (CYC) (n = 36, 73.5%) or rituximab (RTX) (n = 1, 2%). Factors associated with mortality included occurrence of chronic respiratory insufficiency (hazard ratio [HR], 7.44; 95% confidence interval [CI], 1.6-34.5; p = 0.003), induction therapy with glucocorticoids alone (HR, 2.94; CI, 1.05-8.33; p = 0.04), and initial weigh loss (HR, 2.83; CI, 1.05-7.65; p = 0.041). The 3-year survival rate in patients treated with glucocorticoids alone or combined with an immunosuppressant (CYC or RTX) as induction therapy was 64% (95% CI, 41-99) and 94% (95% CI, 86-100), respectively (p = 0.03). After a median follow-up of 48 months [interquartile range, 14-88 mo], 18 (37%) patients died, including 11 related to respiratory insufficiency. PF is a rare manifestation of AAV with a very poor prognosis. Induction therapy with CYC might improve the outcome.

Computed tomography image analysis before and after treatment of anti-neutrophil cytoplasmic antibody-associated pulmonary interstitial fibrosis in 8 patients

PURPOSE

The purpose of this study was to observe the treatment response of anti-neutrophil cytoplasmic antibody (ANCA)-associated pulmonary interstitial fibrosis in 8 patients before and after glucocorticoid or immunosuppressive therapy.

METHODS

The clinical features and computed tomography imaging findings of the 8 patients in our hospital from October 2011 to October 2013, were retrospectively analyzed.

FINDINGS

Mean age of the 8 patients was 72.6 (range 60-80) years. Five patients exhibited cough, sputum, and chest tightness, including 2 patients with fever. One patient developed hemoptysis, 1 patient exhibited abnormal urinalysis and developed renal insufficiency, and 1 patient developed limb pain. Two patients exhibited high urine erythrocytes and 2 patients had renal dysfunction and urinary abnormalities. One of the latter patients, upon renal biopsy, had focal proliferative necrotizing glomerulonephritis (consistent with vasculitis damage) with stage II to III mild nephropathy. Seven cases were anti-myeloperoxidase-ANCA, and 1 case was anti-proteinase 3-ANCA. All 8 cases exhibited streaks and grid shadows in chest imaging; 2 cases exhibited limited ground-glass patches; 1 case displayed multiple large patches of exudative shadows, indicating diffuse alveolar hemorrhage; 2 cases exhibited obvious honeycomb manifestations; and 1 case exhibited significant traction bronchiectasis. The ground-glass opacities disappeared after corticosteroid or immunosuppressive therapy; however, for streaks and grid shadows, no significant changes in the images were observed after treatment from 2 weeks to 10 months.

IMPLICATIONS

ANCA-associated pulmonary interstitial fibrosis most often in elderly patients with many complications. In these patients ground-glass opacities in computed tomography images, corticosteroid or immunosuppressant therapy may be effective. Clinicians should consider the poor efficacy and side effects of these therapies in the fibrosis stage of the disease.

A case of pulmonary fibrosis associated with rheumatoid arthritis, scleroderma sine scleroderma and ANCA associated vasculitis

Introduction

Diffuse parenchymal lung disease (DPLD) may be idiopathic or may be due to known associations such as autoimmune diseases. The prognosis in cases associated with autoimmune diseases depends on many factors such as histopathology, baseline lung function, auto-antibody level, et cetera. DPLD and its prognosis is worse in patients with overlap syndromes.

Case description

We present a rare case of a 71 year old Caucasian lady with gradually worsening pulmonary fibrosis secondary to an overlap syndrome with rheumatoid arthritis (RA), scleroderma sine scleroderma (SSS) and anti neutrophil cytoplasmic antibody (ANCA) associated vasculitis.

Discussion and Evaluation

In this paper, we share information from review of literature regarding DPLD associated with RA, systemic sclerosis (SSc) and ANCA associated vasculitis. Details of our discussion include prognostic factors, histology and radiographic features of these individual disease entities.

Conclusion

Since pulmonary fibrosis in overlap syndromes has a poor prognosis, extensive work up should be performed even when clinical evidence of only one autoimmune disease is present.

Autopsy analyses in acute exacerbation of idiopathic pulmonary fibrosis

Background

Acute exacerbation of idiopathic pulmonary fibrosis (AE-IPF) is associated with high mortality. However, few studies have so far reviewed analyses of autopsy findings in patients with AE-IPF.

Methods

We retrospectively reviewed 52 consecutive patients with AE-IPF who underwent autopsies at five university hospitals and one municipal hospital between 1999 and 2013. The following variables were abstracted from the medical records: demographic and clinical data, autopsy findings and complications during the clinical course until death.

Results

The median age at autopsy was 71 years (range 47–86 years), and the subjects included 38 (73.1%) males. High-dose corticosteroid therapy was initiated in 45 (86.5%) patients after AE-IPF. The underling fibrotic lesion was classified as having the usual interstitial pneumonia (UIP) pattern in all cases. Furthermore, 41 (78.8%) patients had diffuse alveolar damage (DAD), 15 (28.8%) exhibited pulmonary hemorrhage, nine (17.3%) developed pulmonary thromboembolism and six (11.5%) were diagnosed with lung carcinoma. In addition, six (11.5%) patients developed pneumothorax prior to death and 26 (53.1%) developed diabetes that required insulin treatment after the administration of high-dose corticosteroid therapy. In addition, 15 (28.8%) patients presented with bronchopneumonia during their clinical course and/or until death, including fungal (seven, 13.5%), cytomegalovirus (six, 11.5%) and bacterial (five, 9.6%) infections.

Conclusions

The pathological findings in patients with AE-IPF represent not only DAD, but also a variety of pathological conditions. Therefore, making a diagnosis of AE-IPF is often difficult, and the use of cautious diagnostic approaches is required for appropriate treatment.

A retrospective study of microscopic polyangiitis patients presenting with pulmonary fibrosis in China

Background

Pulmonary involvement is a common feature of MPA. Although alveolar hemorrhage is the most common pulmonary manifestation of MPA, a few recent studies have described instances of MPA patients with pulmonary fibrosis. Pulmonary fibrosis was seen to predate, be concomitant with, or occur after the diagnosis of MPA. The goal of this study was to describe the clinical features and prognosis of microscopic polyangiitis (MPA) patients whose initial respiratory presentation was pulmonary fibrosis.

Methods

We conducted a retrospective analysis of 19 MPA patients who presented with pulmonary fibrosis at Peking Union Medical College Hospital between 1990 and 2012.

Results

Of 67 total MPA cases, 19 patients presented with pulmonary fibrosis. There were 8 males and 11 females, with a median age of 63.6 years. Common clinical manifestations included fever (89.5%), cough (84.2%), dyspnea (78.9%) and velcro rales (84.2%). Eleven patients experienced weight loss, several had kidney involvement, and most had an increased erythrocyte sedimentation rate and C-reactive protein. All were positive for myeloperoxidase-anti-neutrophil cytoplasmic antibody (ANCA), with 6 patients being positive at the time of their initial diagnosis of pulmonary fibrosis. Every patient had typical features of usual interstitial pneumonia on High-resolution CT. All were treated with corticosteroids and cyclophosphamide, which lead to an improvement in twelve cases. One of the remaining patients progressed slowly, whereas six died.

Conclusions

Patients with MPA, who also presented with pulmonary fibrosis in our cohort, were more likely to be older, female, and have extrapulmonic involvement. Most patients had a delayed positive ANCA. Corticosteroids plus cyclophosphamide was the remission-induction treatment scheme for all cases. The current prognosis for MPA patients with pulmonary fibrosis appears to be poor, suggesting that they may be candidates for new therapies.

Decade long unexplained anemia: alert to ANCA associated vasculitis

A 13-year old girl presented with a decade long anemia, diffuse alveolar hemorrhage and interstistial lung disease; was eventually diagnosed as ANCA associated vasculitis. High index of suspicion is thus warranted for alternative diagnosis in chronic anemia, despite increased prevalence of infectious diseases and nutritional anemia.

Diffuse Alveolar Hemorrhage in a 39-year-old Woman: Unusual Initial Presentation of Microscopic Polyangiitis

Microscopic polyangiitis (MPA) is a necrotizing vasculitis involving the small vessels without granulomatous inflammation. Most MPA initially presents with renal involvement without pulmonary involvement. Isolated and initially presenting alveolar hemorrhage is very rare. The patient was a 39-year-old female with a progressive cough, dyspnea, and blood-tinged sputum for the previous 5 days. We determined that her condition was MPA though VATS lung biopsy and renal biopsy. After 2 months of steroid therapy, the chest lesions had improved. We report here a rare case of MPA with isolated and initial involvement of the lung with a review of the literature.

Clinical features and outcome of microscopic polyangiitis under a new consensus algorithm of ANCA-associated vasculitides in Korea

The classification system for antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis and polyarteritis nodosa had its limitations due to numerous overlapping features of these disease entities. The aim of this study is to investigate the clinical features and outcome of patients diagnosed with microscopic polyangiitis (MPA) according to the newly proposed consensus algorithm of ANCA-associated vasculitides and polyarteritis nodosa. Fifty-five cases of MPA, comprised of 33 men and 22 women, diagnosed according to a new consensus algorithm at a single tertiary hospital were identified for analysis. The main clinical features were constitutional symptoms (78.2%), followed by renal involvement (74.5%), musculoskeletal symptoms (67.3%), skin manifestations (50.9%), neurologic involvement (43.6%), and lung involvement (41.8%). P-ANCA and/or anti-myeloperoxidase antibody were present in 69.1%. Five Factor Score and Birmingham Vasculitis Activity Score (BVAS) at diagnosis were 1.1 ± 0.9 and 10.9 ± 4.9, respectively. Forty-four patients were available for a long-term follow-up, and six patients (13.6%) resulted in death. Mortality was associated with BVAS > 9 at the time of diagnosis, age > 60 years, and presence of cardiomyopathy and interstitial lung disease. The survival rate at 1 and 3 years was 93.9 and 89.2%, respectively. Eight patients (14.5%) required dialysis at the time of diagnosis. This is the first study to demonstrate the clinical features in patients with MPA using a new consensus algorithm. Survival rate was higher than previously reported, and interstitial lung disease was a new risk factor for death in patients with MPA.

Interstitial lung disease and ANCA-associated vasculitis: a retrospective observational cohort study

OBJECTIVES

ANCA-associated vasculitis and interstitial lung disease (ILD) are uncommon conditions. The occurrence of both diseases in the same patient is increasingly recognized. Our aim was to ascertain the characteristics and outcomes of patients with ILD and ANCA-associated vasculitis.

METHODS

A retrospective observational cohort study was performed. Patients who presented to the Hammersmith Hospital, London, with ANCA-associated vasculitis [granulomatosis with polyangiitis (Wegener's), microscopic polyangiitis (MPA) or Churg-Strauss syndrome] who also had ILD were included. Following hospital discharge, all patients were followed up in a multi-disciplinary vasculitis clinic. We recorded patient demographics, diagnostic tests, treatment, complications and mortality.

RESULTS

ILD was observed in 2.7% (n = 14) of our patients with ANCA-associated vasculitis (n = 510); all had MPO-ANCA and a clinical diagnosis of MPA, giving a prevalence of 7.2% in patients with MPA (n = 194). There was no significant difference in survival between patients with MPA and ILD and those with MPA alone.

CONCLUSION

It is important that physicians are aware of this clinical association and the presence of ILD should be considered in all patients with ANCA-associated vasculitis, especially those with MPO-ANCA. The possibility that patients with ILD may subsequently develop features of systemic vasculitis should also be remembered.

Conditions in subjects with rheumatic diseases: pulmonary manifestations of vasculitides

Pulmonary involvement is a common complication of vasculitides, especially small vessel vasculitides. This review provides an overview of vasculitic manifestations of the lung as well as of other organs involved in vasculitides. Furthermore, it provides the diagnostic procedures required to asses a patient with vasculitic lung involvement and gives an overview of current treatment strategies.

Pyrexia of unknown origin and pulmonary fibrosis as a presentation of MPO-ANCA associated vasculitis

The authors report the case of a 72-year-old man presenting with chronic dyspnoea and pyrexia of unknown origin (PUO). After extensive investigation, he was found to have pulmonary fibrosis with usual interstitial pneumonia pattern on high-resolution CT imaging and positive myeloperoxidase antineutrophil cytoplasmic antibodies (MPO-ANCA) with no infectious cause or other evidence of vasculitis organ involvement. His pyrexia and symptoms settled with oral systemic corticosteroid treatment. To the authors' knowledge this is the first case of MPO-ANCA positive vasculitis presenting as PUO and pulmonary fibrosis alone. The authors review the recent literature regarding the association of pulmonary fibrosis with ANCA-positive vasculitides with regards to pathogenesis, prognosis and treatment.

Use of muscle biopsies for diagnosis of systemic vasculitides

OBJECTIVE

Few studies have investigated the use of muscle biopsies (MB) for the diagnosis of systemic vasculitides (SV). We aimed to evaluate the diagnostic use of MB in this condition.

METHODS

We reviewed 310 consecutive MB performed in our center between 2000 and 2008 and correlated them with clinical data from the corresponding patients. Thirty-one of the patients, representing a total of 33 MB, were diagnosed with active SV. MB were considered positive when they demonstrated either necrotizing vasculitis or nonnecrotizing vasculitis.

RESULTS

Twenty-two of the 33 MB were positive (sensitivity of 66.7%), with necrotizing vasculitis and nonnecrotizing vasculitis being equally frequent. The SV were antineutrophil cytoplasmic antibody (ANCA)-associated in 22 patients (71%), and ANCA-negative in 9 cases (29%). Neither the type nor the clinical spectrum of the SV was predictive of MB positivity. None of the muscle symptoms (myalgias or biological rhabdomyolysis) were correlated with MB positivity. All the biopsies were performed uneventfully.

CONCLUSION

The feasibility and positive predictive value of MB make it a valuable tool for ruling out a diagnosis of SV. Since no clinical signs could predict its positivity, MB should be considered in all suspected cases of SV. Unlike other biopsies, including kidney biopsy, MB had no prognostic value.

Microscopic polyangiitis

In 1923, Friedrich Wohlwill described two patients with a "microscopic form of periarteritis nodosa," which was distinct from the classical form. This disease, now known as microscopic polyangiitis (MPA), is a primary systemic vasculitis characterized by inflammation of the small-caliber blood vessels and the presence of circulating antineutrophil cytoplasmic antibodies. Typically, microscopic polyangiitis presents with glomerulonephritis and pulmonary capillaritis, although involvement of the skin, nerves, and gastrointestinal tract is not uncommon. Treatment of MPA generally requires use of a cytotoxic agent (such as cyclophosphamide) in addition to high-dose glucocorticoids. Recent research has focused on identifying alternate treatment strategies that minimize or eliminate exposure to cytotoxic agents. This article reviews the history, pathogenesis, clinical manifestations, and treatment of MPA.

Pulmonary fibrosis-an uncommon manifestation of anti-myeloperoxidase-positive systemic vasculitis?

Small vessel vasculitides such as microscopic polyangiitis and Wegener’s granulomatosis commonly involve the kidney and lung, with alveolar haemorrhage being the commonest manifestation of pulmonary involvement. Here we describe a patient who developed acute renal failure and pulmonary haemorrhage with positive autoantibodies against myeloperoxidase 1 year after a diagnosis of usual interstitial pneumonia had been made and we discuss the uncommon association of pulmonary fibrosis and anti-myeloperoxidase positive vasculitis.

A case of ANCA-associated vasculitis presenting with calf claudication

Wegener's granulomatosis (WG), Churg-Strauss syndrome, and microscopic polyangiitis (MPA) are closely related small vessel vasculitides characterized by anti-neutrophil cytoplasmic antibodies (ANCA). Although there were some reports of MPA presenting with claudication, there are very few reports on WG presenting with claudication of calf muscles. We report an unusual case of ANCA-associated vasculitis in a 75-year-old man who presented with bilateral calf claudication. Comprehensive evaluations, including electromyography, nerve conduction study, lower extremity magnetic resonance imaging, and Doppler scan, did not reveal any other cause of bilateral calf claudication. P-ANCA and anti-myeloperoxidase antibody was positive, but the anti-proteinase 3 antibody was negative. Chest computed tomography scan showed subpleural honeycombing and reticulation, predominantly in both basal lung areas. Biopsy of the calf muscle showed granulomatous vasculitis. Kidney biopsy was also performed which revealed focal necrotizing glomerulonephritis. Our patient does not exhibit typical clinical features for WG, but histopathologic findings of necrotizing granulomatous vasculitis in calf muscle biopsy is highly suggestive of WG.

[Pulmonary fibrosis as a presentation of Wegener's granulomatosis]

INTRODUCTION

Pulmonary fibrosis secondary to antineutrophil cytoplasmic antibodypositive vasculitis is rarely reported. Most cases have occurred in association with microscopic polyangiitis.

CASE REPORT

We report the case of an 82-year-old man presenting with pulmonary fibrosis. The CT scan showed honeycombing and traction bronchiectasis with peripheral and basal predominance. The diagnosis of Wegener's granulomatosis was based on the association of positive antineutrophil cytoplasmic antibodies, urinary sediment abnormalities and renal biopsy findings.

CONCLUSION

We emphasize, through this case, the rarity of interstitial fibrosis as a pulmonary manifestation of vasculitis and we discuss the pathogenesis of this association.