The pathologic spectrum of pulmonary lesions in patients with anti-neutrophil cytoplasmic autoantibodies specific for anti-proteinase 3 and anti-myeloperoxidase

Three Diseases Mediated by Different Immunopathologic Mechanisms-ANCA-Associated Vasculitis, Anti-Glomerular Basement Membrane Disease, and Immune Complex-Mediated Glomerulonephritis-A Common Clinical and Histopathologic Picture: Rapidly Progressive Crescentic Glomerulonephritis

Immune mechanisms play an important role in the pathogenesis of glomerulonephritis (GN), with autoimmunity being the main underlying pathogenetic process of both primary and secondary GN. We present three autoimmune diseases mediated by different autoimmune mechanisms: glomerulonephritis in vasculitis mediated by anti-neutrophil cytoplasmic antibodies (ANCAs), glomerulonephritis mediated by anti-glomerular basement membrane antibodies (anti-GBM antibodies), and immune complex-mediated glomerulonephritis. Some of these diseases represent a common clinical and histopathologic scenario, namely rapidly progressive crescentic glomerulonephritis. This is a severe illness requiring complex therapy, with the main role being played by therapy aimed at targeting immune mechanisms. In the absence of immune therapy, the crescents, the characteristic histopathologic lesions of this common presentation, progress toward fibrosis, which is accompanied by end-stage renal disease (ESRD). The fact that three diseases mediated by different immunopathologic mechanisms have a common clinical and histopathologic picture reveals the complexity of the relationship between immunopathologic mechanisms and their clinical expression. Whereas most glomerular diseases progress by a slow process of sclerosis and fibrosis, the glomerular diseases accompanied by glomerular crescent formation can progress, if untreated, in a couple of months into whole-nephron glomerulosclerosis and fibrosis. The outcome of different immune processes in a common clinical and histopathologic phenotype reveals the complexity of the relationship of the kidney with the immune system. The aim of this review is to present different immune processes that lead to a common clinical and histopathologic phenotype, such as rapidly progressive crescentic glomerulonephritis.

Concomitant pleuritis and pericarditis developing during glucocorticoid therapy: a case report on granulomatosis with polyangiitis

Granulomatosis with polyangiitis is an anti-neutrophil cytoplasmic antibody-associated vasculitis that manifests in various ways by affecting the small-sized vessels in multiple organs. Acute pleuritis and pericarditis are both rare among the different manifestations of granulomatosis with polyangiitis. The symptoms in each of the organs are often apparent at the time of diagnosis and tend to diminish with treatment. Organ damage and progression of the disease during treatment are uncommon. We encountered a patient with granulomatosis with polyangiitis who, after starting intravenous methylprednisolone pulse therapy, concurrently developed acute pleuritis and pericarditis. The patient was a 47-year-old Japanese man with myalgia in whom kidney dysfunction, proteinase 3-anti-neutrophil cytoplasmic antibody positivity, and a lung mass were detected. Granulomatosis with polyangiitis was diagnosed pathologically from a lung and a kidney biopsy. Acute pleuritis and pericarditis, which developed after the first course of intravenous methylprednisolone pulse therapy, both resolved following the second course. The present report indicates that secondary serositis such as pleuritis and pericarditis can develop in patients with granulomatosis with polyangiitis even during glucocorticoid therapy.

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.

Pulmonary Vasculitides: A Radiological Review Emphasizing Parenchymal HRCT Features

Vasculitides represent a heterogeneous group of immune-mediated disorders, characterized by a systemic inflammatory destructive process of the blood vessels resulting either in ischemia or hemorrhage. The organ involved and vessel size influence the pattern of presentation of the pathology. The lung is commonly involved in systemic vasculitides, with heterogeneous clinical, radiological, and histopathological presentations. Primary vasculitides most commonly associated with lung parenchymal involvement include small-vessel antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides, such as granulomatosis with polyangiitis (GPA), eosinophilic granulomatosis with polyangiitis (EGPA), and microscopic polyangiitis (MPA). Several studies have reported cases of interstitial lung diseases (ILDs) associated with systemic vasculitis, particularly those positive for ANCA associated vasculitis/vasculitidis: AAV. We have selected from our case series different radiological features of pulmonary vasculitis (i.e., solitary or multiple nodules, cavitary lesions, nodules with centrilobular or peribronchial distribution, airspace consolidations, “crazy paving” appearance, interstitial disease), including cases with interstitial lung alterations. Therefore, the aim of this review is to describe the typical clinical manifestations of vasculitides and their main radiologic features (especially AAV).

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.

Classification of ANCA-associated vasculitis: differences based on ANCA specificity and clinicopathologic phenotype

The classification of vasculitis according to a schema with universal acceptance is challenging, given the heterogeneous and protean nature of these diseases. Formal nomenclature and classification criteria for anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have suffered several changes since their first description; none provides comprehensive diagnostic and classification criteria. Different factors account for the difficulties in the classification of vasculitis, including the incomplete understanding of the pathogenesis, the multisystemic nature of the disease, the non-specific patterns of vascular involvement, the overlap between entities, and the presence of various classification systems. The present article reviews the classification of AAV considering different points of view, including clinical, serologic, pathogenetic, organ predilection, therapeutic, and prognostic factors, and provides perspectives on future challenges in the understanding of AAV. There is an unmet need for a unifying view of the disease spectrum that considers the constantly evolving paradigms.

Pathology of Granulomatous Pulmonary Diseases

CONTEXT.—

Because granulomas are represented in almost every disease category, the number of clinically and pathologically important granulomatous pulmonary diseases is large. Their diagnosis by pathologists is particularly challenging because of their nonspecificity. A specific diagnosis can be achieved only when a granuloma-inciting agent(s) (eg, acid-fast bacilli, fungi, foreign bodies, etc) are identified microscopically or by culture; this does not occur in most cases. Furthermore, a specific diagnosis cannot be reached in a high percentage of cases. Although sarcoidosis and infectious diseases account for approximately half of pulmonary granulomatous diseases worldwide, there is significant geographic variation in their prevalence.

OBJECTIVES.—

To present updated information to serve as a guide to pathologic diagnosis of pulmonary granulomatous diseases, to address some commonly held misconceptions and to stress the importance of multidisciplinary coordination. Presentation of basic aspects of granulomas is followed by discussion of specific disease entities, such as tuberculous and nontuberculous Mycobacterial infections, fungal, bacterial, and parasitic infections, sarcoidosis, necrotizing sarcoid granulomatosis, berylliosis, hypersensitivity pneumonitis, hot tub lung, rheumatoid nodule, bronchocentric granulomatosis, aspirated, inhaled, and embolized foreign bodies, drug-induced granulomas, chronic granulomatous disease, common variable immunodeficiency, and granulomatous lesions associated with various types of cancer.

DATA SOURCES.—

Review of pertinent medical literature using the PubMed search engine and the author's practical experience.

CONCLUSIONS.—

Although the diagnosis of granulomatous lung diseases continues to present significant challenges to pathologists, the information presented in this review can be helpful in overcoming them. The importance of multidisciplinary coordination in cases where morphologic diagnosis is not possible cannot be overstated.

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

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

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.

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.

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.

Pulmonary disorders that are potentially associated with anti- neutrophilic cytoplasmic antibodies: A brief review

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis frequently manifests with involvement of the lungs and kidneys, and it also may affect other anatomic sites. This article presents the patterns of pulmonary injury in which ANCA-associated vasculitis is included in the differential diagnosis, with a discussion of antineutrophil cytoplasmic antibody testing methods. The histologic features of non-vasculitic, potentially-ANCA-associated pulmonary lesions are reviewed briefly as well.

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.

Alveolar Hemorrhage

Alveolar hemorrhage (AH) is a clinical syndrome with diverse etiologies both immune and nonimmune. The defining pathological feature of AH is the presence or absence of pulmonary capillaritis. The antineutrophil cytoplasmic antibody (ANCA) related vasculitis and systemic lupus erythematosus are the commonest causes of immune AH with pulmonary capillaritis, whereas Goodpasture's syndrome and idiopathic pulmonary hemosiderosis are common causes of immune AH without pulmonary capillaritis. The major nonimmune causes of AH are primarily drug induced, or due to hematological malignancy and disorders of coagulation. Clinical features of AH include: dyspnea, fever, hemotypsis, bilateral crackles and pallor. Hypoxemia and bilateral diffuse airspace disease on the chest radiograph with relative sparing of the bases and apices which most often clears within 48 hours after its onset further characterize this syndrome. The major clinical implications of this syndrome are its potential to cause respiratory failure in severe cases and its sequelae of pulmonary fibrosis with associated morbidity and disability. In addition, AH may be the initial manifestation of a systemic immune disorder which can be managed optimally if recognized early. The diagnosis of AH is confirmed by bronchoalveolar lavage by demonstrating a progressively bloody return on successive aliquots of instilled saline or hemosiderin laden macrophages in the bronchoalveolar lavage fluid. The open lung biopsy remains the gold standard for the diagnosis of AH but is reserved for inapparent cases in whom corticosteroids and immunosuppressive therapy may be life saving. Serologic testing and examination of the urine sediment are useful adjuncts to the diagnosis. The treatment of AH is primarily supportive while an attempt is made to determine its etiology and initiate specific therapy. Glucocorticoids and cyclophosphamide are the cornerstones of therapy in immune AH with adjunctive plasmapheresis in life-threatening cases.

Myeloperoxidase Anti-Neutrophil Cytoplasmic Antibody-Positive Interstitial Pneumonia Associated with Granulomatosis with Polyangiitis Diagnosed by Surgical Lung Biopsy

Granulomatosis with polyangiitis (GPA) is a rare systemic vasculitis that often involves the lung. However, interstitial pneumonia (IP) is rarely seen in GPA patients. We herein report 3 cases of IP associated with GPA diagnosed by surgical lung biopsy. High-resolution CT showed uniform subpleural reticular opacity with traction bronchiectasis. Biopsies from all 3 patients revealed neutrophilic capillaritis, microabscesses with giant cells, and coexisting histological findings of usual IP pattern or fibrosing nonspecific IP pattern. All 3 patients had elevated levels of serum myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), but not proteinase 3-ANCA. We diagnosed GPA and treated with corticosteroid and cyclophosphamide. Follow-up CT showed improvement of the lesions in all patients. Surgical lung biopsy specimens which revealed GPA enabled us to conduct the most suitable therapy. This report indicates the importance of surgical lung biopsy for differentiating idiopathic IPs from GPA-associated IP and suggests a relationship between MPO-ANCA and IP in GPA.

Elevated serum levels of two anti-neutrophil cytoplasmic antibodies in a lung cancer patient: A case report

A 71-year-old woman with arthralgia and lung fibrosis was referred to Mito Kyodo General Hospital (Mito, Japan) for a mass, which was incidentally observed on a chest radiograph. The chest computed tomography scan demonstrated fibrotic lesions in the lower lobes of the lung and a nodule in the left upper lobe. The serum levels of myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA) and proteinase 3 (PR3)-ANCA were 60.3 and 7.5 U/ml, respectively. A transbronchial biopsy obtained from the nodule in the left upper lobe of the lung revealed a lung adenocarcinoma and the patient underwent standard upper lobectomy of the left lung. Subsequent to the resection, the serum levels of PR3-ANCA and MPO-ANCA returned to 10.0 and <1.0 U/ml, respectively. Notably, titers of antinuclear antibodies were also decreased during the postoperative course. Although elevated serum ANCA levels are rarely seen in lung cancer, they may be associated with the occurrence of lung cancer in certain patients, as observed in the present case.

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.

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.

Pleural vasculitides of microscopic polyangiitis with asbestos-related plaques

A 69‐year‐old man who had been exposed to asbestos for approximately 40 years presented with the complaint of fever and pleuritic chest pain on the right side on deep inspiration. Chest X‐ray films showed pleural effusion in the right side. Initial antibiotic treatment was ineffective. The hyaluronic acid level was high in the pleural effusion but no malignant mesotheliomal cells were seen with blind pleural biopsy. Blood chemistry showed a remarkable high titer of myeloperoxidase anti‐neutrophil cytoplasmic antibody (MPO‐ANCA) and open renal biopsy suggested crescentic glomerulonephritis. The precise pathological examination on the pleura obtained by the open pleural biopsy showed vasculitides and plaque leading to diagnosis of microscopic polyangiitis (MPA). This is a rare case of MPA seen in the pleural arteries.

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.

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.

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.

Nonarteriosclerotic vascular disease

Thromboangiitis obliterans, or Buerger disease, is a chronic nonatherosclerotic endarteritis manifesting as inflammation and thrombosis of distal extremity small and medium-sized arteries resulting in relapsing episodes of distal extremity ischemia. Takayasu arteritis is a rare syndrome characterized by inflammation of the aortic arch, pulmonary, coronary, and cerebral vessels, presenting with cerebrovascular symptoms, myocardial ischemia, or upper extremity claudication in young, often female, patients. Kawasaki disease is a small- and medium-vessel acute systemic vasculitis of young children, with morbidity and mortality stemming from coronary artery aneurysms. Microscopic polyangiitis, Churg-Strauss syndrome, and Wegener granulomatosis are systemic small-vessel vasculitides, affecting arterioles, capillary beds and venules, and each presenting with variable effects on the pulmonary, renal and gastrointestinal systems.

Pulmonary involvement in ANCA-associated vasculitis from the view of the pulmonologist

Microscopic polyangiitis (MPA), granulomatosis with polyangiitis (GPA), and eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) are conditions classified under the general heading of antinuclear cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). Lung lesion is a very common and important clinical feature in AAV. In MPA, diffuse alveolar hemorrhage and pulmonary fibrosis (PF) are the most frequent manifestations. High-resolution computed tomography (HRCT) chest findings associated with MPA in PF patients demonstrate a high frequency of usual interstitial pneumonia (UIP), fibrotic-nonspecific interstitial pneumonia (F-NSIP), and combined PF and emphysema (CPFE) pattern with honeycombing, traction bronchiectasis, ground-glass opacity, and emphysema. In most of these cases, the histologic pattern of PF has been classified as UIP and/or fibrotic NSIP. In addition, a high incidence of histological findings, such as extensive interstitial fibrosis, lymphoid hyperplasia, and bronchiolitis, are characteristics observed in PF associated with collagen vascular diseases and which are not observed in idiopathic PF (IPF). In some cases, PF precedes the development of MPA. Indeed, there are some cases of pulmonary-limited MPA in this group. Therefore, clinicians should be aware of MPA as an underlying feature of PF in order to avoid overlooking and misdiagnosing this condition as IPF. The median survival time (MST) in UIP pattern/MPA is comparable with that of IPF. In GPA, almost all patients have either upper airway or lower respiratory tract lesions. Solitary or multiple nodules (frequently cavitated) and masses are the most common findings on chest images. Asthma is a cardinal symptom of Churg-Straus syndrome, often preceded by allergic rhinitis. To induce remission, a severity-based regimen was given to patients according to the appropriate protocol of the Japanese patients with myeloperoxidase (MPO)-ANCA-associated vasculitis (JMAAV) study group: low-dose corticosteroid and, if necessary, cyclophosphamide or azathioprine in patients with mild form; high-dose corticosteroid and cyclophosphamide in those with severe form; severe-form regimen plus plasmapheresis in those with the most severe form.

Granulomatous lung disease: an approach to the differential diagnosis

CONTEXT

Granulomas are among the most commonly encountered abnormalities in pulmonary pathology and often pose a diagnostic challenge. Although most pathologists are aware of the need to exclude an infection in this setting, there is less familiarity with the specific histologic features that aid in the differential diagnosis.

OBJECTIVE

To review the differential diagnosis, suggest a practical diagnostic approach, and emphasize major diagnostically useful histologic features. This review is aimed at surgical pathologists who encounter granulomas in lung specimens.

DATA SOURCES

Pertinent recent and classic peer-reviewed literature retrieved from PubMed (US National Library of Medicine) and primary material from the institutions of both authors.

CONCLUSIONS

Most granulomas in the lung are caused by mycobacterial or fungal infection. The diagnosis requires familiarity with the tissue reaction as well as with the morphologic features of the organisms, including appropriate interpretation of special stains. The major noninfectious causes of granulomatous lung disease are sarcoidosis, Wegener granulomatosis, hypersensitivity pneumonitis, hot tub lung, aspiration pneumonia, and talc granulomatosis.

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.

[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.

Respiratory system involvement in antineutrophil cytoplasmic-associated systemic vasculitides: clinical, pathological, radiological and therapeutic considerations

Wegener's granulomatosis (WG), microscopic polyangiitis (MPA) and Churg- Strauss syndrome (CSS) are small-vessel vasculitides that, because of their frequent association with antineutrophil cytoplasmic antibodies (ANCA), are usually referred to as ANCA-associated systemic vasculitides (AASV). The diagnosis of AASV is made on the basis of clinical findings, biopsy of an involved organ and the presence of ANCA in the serum. Lung disease is a very common and important clinical feature of AASV. In WG, almost all patients have either upper airway or lower respiratory tract disease. Solitary or multiple nodules, frequently cavitated, and masses are the most common findings on chest radiography. Asthma is a cardinal symptom of CSS, often preceded by allergic rhinitis. Pulmonary transient and patchy alveolar infiltrates are the most common radiographic findings. In MPA, diffuse alveolar haemorrhage as a result of alveolar capillaritis is the most frequent manifestation of respiratory involvement, and is clinically expressed as haemoptysis, respiratory distress and anaemia. However, diffuse alveolar haemorrhage may also be subclinical and should be suspected when a chest radiograph demonstrates new unexplained bilateral alveolar infiltrates in the context of falling haemoglobin levels. Normal and high-resolution CT have a higher sensitivity than chest radiography for demonstrating airway, parenchymal and pleural lesions. However, many of these radiological findings are nonspecific and, therefore, their interpretation must take into account all clinical, laboratory and pathological data. Therapy of AASV is commonly divided into two phases: an initial 'remission induction' phase, in which more intensive immunosuppressant therapy is used to control disease activity, and a 'maintenance' phase, which uses less intensive therapy, for maintaining disease remission while lowering the risk of adverse effects of immunosuppressant drugs. In patients with AASV refractory to standard therapy with corticosteroids and oral cyclophosphamide, new therapeutic options are now available. Recurrence of pulmonary symptoms suggesting a flare indicates the need for a careful search for an opportunistic lung infection or iatrogenic pulmonary complications. In conclusion, involvement of the respiratory system is a very common and important organ manifestation of AASV. Respiratory system involvement comprises a wide spectrum of clinical features and radiological findings, and because of its frequency and prognostic significance, a complete assessment of the respiratory system should be included in the work-up of all patients with AASV.

Pathological diagnosis of granulomatous lung disease: a review

Granulomas in the lung are common diagnostic problems encountered by pathologists. They occur in a wide range of pulmonary conditions, ranging from common entities to uncommon ones and including both infections and non-infectious diseases. This review summarizes the main histological features that help distinguish various granulomatous lung diseases. It concentrates on the most important and common entities that may be encountered and emphasizes helpful features in the differential diagnosis.

Pulmonary-renal syndromes

Pulmonary-renal syndromes or lung-kidney syndromes are clinical syndromes defined by a combination of diffuse alveolar haemorrhage (DAH) and glomerulonephritis. Pulmonary-renal syndromes are not a single entity, but are caused by a wide variety of diseases, including various forms of primary systemic vasculitis (especially Wegener's granulomatosis and microscopic polyangiitis), Goodpasture's syndrome (associated with autoantibodies to the alveolar and glomerular basement membrane) and systemic lupus erythematosus. The diagnosis rests on the identification of particular patterns of clinical, radiologic, pathologic and laboratory features. Serologic testing is important in the diagnostic work-up of patients presenting with a pulmonary-renal syndrome. The majority of cases of pulmonary-renal syndrome are associated with ANCAs, either c-ANCA or p-ANCA, due to autoantibodies against the target antigens proteinase-3 and myeloperoxidase respectively. The antigen target in Goodpasture's syndrome is type IV collagen, the major component of basement membranes. Diffuse alveolar haemorrhage is characterized by the presence of a haemorrhagic bronchoalveolar lavage (BAL) in serial BAL samples. In the clinical setting of an acute nephritis syndrome, percutaneous renal biopsy is commonly performed for histopathology and immunofluorescence studies. Treatment of generalized ANCA-associated vasculitis consists of corticosteroids and immunosuppressive agents such as cyclophosphamide (as induction therapy) or azathioprine (as maintenance therapy once remission has been achieved). The combination of plasmapheresis with these cytotoxic agents and steroids is effective in patients with Goodpasture's syndrome, especially if instituted early in the course of the disease. Recent evidence suggests that patients with severe ANCA-associated vasculitis, defined by the presence of diffuse alveolar haemorrhage and/or severe renal involvement (creatinine concentration > 5.7 mg/dl), might benefit from plasma exchange in combination with cyclophosphamide and corticosteroids.

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

Microscopic polyangiitis (MPA) may present with a syndrome that resembles idiopathic pulmonary fibrosis (IPF). We describe an MPA patient with the clinical presentation of a "pulmonary-muscle" syndrome in which interstitial lung disease antedated the onset of myopathy. Identification of vasculitis on muscle biopsy was instrumental in recognizing clinical, radiographic, and histopathologic features that were more characteristic of MPA than of IPF. Institution of glucocorticoid and cyclophosphamide therapy led to the induction of a complete remission. The histologic findings in this case implicate subclinical episodes of alveolar hemorrhage as the mechanism of interstitial lung disease in MPA.

Pharmacological therapy for Wegener's granulomatosis

Wegener's granulomatosis (WG) is the most common pulmonary granulomatous vasculitis and was a uniformly fatal disease prior to the identification of efficacious pharmacological regimens. The pathogenesis of WG remains elusive but proteinase 3-specific anti-neutrophil cytoplasmic antibodies may be involved. Histologically, WG is defined by the triad of small vessel necrotising vasculitis, 'geographic' necrosis and granulomatous inflammation. Organ involvement characteristically includes the upper and lower respiratory tracts and kidney, but virtually any organ can be involved. The severity of the disease varies, ranging from asymptomatic disease to fulminant, fatal vasculitis. Similarly, the degree of organ involvement is highly variable; WG may be limited to a single organ (typically the lungs or upper respiratory tract), or may be systemic. Currently, a regimen consisting of daily cyclophosphamide and corticosteroids, which induces complete remission in the majority of patients, is considered standard therapy. Since approximately 50% of patients experience a relapse following discontinuation of therapy, alternative regimens designed to maintain remissions after using cyclophosphamide and corticosteroids are usually necessary. This 'induction maintenance' approach to treatment has emerged as a central premise in planning therapy for patients with WG.A number of trials have evaluated the efficacy of less toxic immunosuppressants (e.g. methotrexate, azathioprine, mycophenolate mofetil) and antibacterials (i.e. cotrimoxazole [trimethoprim/sulfamethoxazole]) for treating patients with WG, resulting in the identification of effective alternative regimens to induce or maintain remissions in certain sub-populations of patients. Given the efficacy of methotrexate (for early systemic WG) and cotrimoxazole (in WG limited solely to the upper airways) to induce remissions, and the relatively decreased associated morbidity compared with cyclophosphamide, these alternative regimens are preferred in appropriate patients. Similarly, therapeutic options to maintain disease remission that are less toxic than cyclophosphamide should be offered following induction of remission unless a specific contraindication exists. By following this premise, the development of cyclophosphamide-induced morbidities (e.g. haemorrhagic cystitis, uroepithelial cancers and prolonged myelosuppression) may be minimised. Recent investigation has focussed on other immunomodulatory agents (tumour necrosis factor-alpha inhibitors [infliximab and etanercept] and anti-CD20 antibodies [rituximab]) for treating patients with WG. However, the current data are conflicting and difficult to interpret. As a result, these newer agents cannot be recommended for routine use until vigorous clinical study confirms their efficacy.

Extensive pancreatic necrosis in microscopic polyangiitis

We encountered an 84-year-old woman with microscopic polyangiitis who was found to have pancreatitis on autopsy. The patient was admitted to Yamanashi University Hospital because of fever and progressive renal failure. She was diagnosed with anti-myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA)-related microscopic polyangiitis (MPA) and was treated successfully with prednisolone pulse therapy. Two months later, she was found unconscious at home and was transferred to hospital, where she died of cardiac arrest after 6 days. Autopsy revealed systemic vasculitis with fibrinoid necrosis (with the most severe form found in the pancreas), interstitial pneumonia, and crescentic glomerulonephritis. A review of the literature revealed that pancreatic involvement in vasculitis, although rare, is one of the complications of MPA; however, the present study is the first report to focus on the pancreatic involvement of MPA. We recommend that nephrologists consider the possibility of pancreatic involvement in this disease.

Scleroderma associated with ANCA-associated vasculitis

We have recently reported on two cases of scleroderma patients with ANCA-associated vasculitis for the first time in Korea. In order to explore the nature of this disease combination, we pooled together all the previously known cases and statistically analyzed them. Out of the 50 selected cases, survival analysis was done for comparison of the scleroderma disease period and the clinical factors associated with ANCA-associated vasculitis (AAV). Kaplan-Meier analysis revealed that patients having anti-topoisomerase antibody (anti-Scl-70) and, probably, PR-3 ANCA are at a higher risk for developing AAV than patients without both anti-topoisomerase antibody and anti-centromere antibody (ACA), and patients with MPO-ANCA. Multivariate Cox regression analysis revealed having anti-topoisomerase antibody as a risk factor for developing AAV [OR 3.1 (95% CI 1.11-8.55), P=0.031]. We suggest that having anti-topoisomerase antibodies may play a role among scleroderma patients in developing AAV.

Scleroderma associated with ANCA-associated vasculitis

Scleroderma and ANCA-associated vasculitides (AAV), such as microscopic polyangiitis, are distinct disease entities, but are rarely known to coexist with each other. We have reported on two cases of scleroderma patients for the first time in Korea, and these patients were initially known to have only limited type scleroderma with pulmonary fibrosis, but eventually they were found to be ANCA-positive with the associated clinical features of vasculitis. Both were treated with high-dose steroids and cyclophosphamide and remitted without major sequelae. When scleroderma patients exhibit atypical features such as normotensive renal failure with signs of active inflammation, the possibility of AAV should always be considered.

Pulmonary fibrosis in myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitides

OBJECTIVE

The association of pulmonary fibrosis (PF) with myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA)-associated vasculitides has not been well documented. The aim of this study was to assess the clinicopathological characteristics of PF in patients who tested positive for MPO-ANCA.

METHODOLOGY

In this study, 31 patients (17 males and 14 females; mean age, 69 years) diagnosed as having PF with positive MPO-ANCA levels ranging from 10 to 840 EU with a mean of 112.5 EU, were evaluated clinicopathologically.

RESULTS

Among 31 patients with PF, 22 had underlying systemic diseases such as collagen vascular diseases, while nine had unknown aetiology. Evidence of glomerulonephritis was demonstrated in 14 patients. The clinical features were a history of dry cough and/or fine crackles in all 31 patients. Chest CT scans showed honeycombing in the lung bases in 26 patients. The histopathological features of the diseased lung tissues in all 11 autopsied cases were compatible with the usual interstitial pneumonia (UIP) pattern. Vasculitis was confirmed in bronchial arteries and/or pulmonary arterioles in five patients. The mortality was as high as 13 of the 31 patients. The causes of death were: deterioration of PF in five (two of whom were associated with pulmonary haemorrhage), lung cancer in two, pneumonia in four, and digestive tract bleeding in two. The survival rates in PF with MPO-ANCA-negative collagen vascular diseases, cryptogenic fibrosing alveolitis (CFA), and PF with positive MPO-ANCA, were compared. The 5-year survival rate in PF with positive MPO-ANCA was worse than in PF with MPO-ANCA-negative collagen vascular diseases and was the same for CFA.

CONCLUSION

Although there was no correlation between MPO-ANCA titres and the activity of PF, this study demonstrated that the presence of positive MPO-ANCA was an unfavorable prognostic factor in patients with PF.

Nodular pulmonary vasculitis in a twelve-year-old boy

A 12-year-old boy presented with left shoulder pain during physical exercise and complained of uncommon sweating and fatigue. Diagnostic evaluation revealed a solitary pulmonary nodule in the left upper lobe. All laboratory values were within normal limits, except for an elevated level of antineutrophil cytoplasmic antibodies directed against myeloperoxidase (p-ANCA). Surgery was performed, and pathological examination showed a localized granulomatous vasculitis. Antineutrophil cytoplasmic antibodies directed against affinity purified proteinase 3 (p-ANCA) concentrations returned to baseline within 6 months, and the patient has done well during a follow-up period of 2 years. While nodular vasculitis is known to occur in Wegener's granulomatosis, to the best of our knowledge, this case represents the first c-ANCA negative primary pulmonary vasculitis in childhood.

Antineutrophil cytoplasmic antibody positive alveolar haemorrhage during propylthiouracil therapy for hyperthyroidism

Recently, propylthiouracil (PTU) has been thought to be one of the possible causes of antineutrophil cytoplasmic antibody (ANCA)-associated small vessel vasculitis syndrome, resulting in glomerulonephritis and, infrequently, diffuse alveolar haemorrhage (DAH). The mechanism of ANCA-positive vasculitis during PTU therapy is still unknown. Herein, we describe the case of a 59-year-old woman who developed myeloperoxidase (MPO)- and proteinase 3 (PR3)-ANCA positive DAH, without any other organ system involvement, during PTU therapy. Diminution and discontinuation of PTU resulted in a positive response. To our knowledge, this is the first documentation of both MPO- and PR3-ANCA-positive DAH, without systemic manifestations, developing during PTU therapy.

[Vasculitides: classification, clinical aspects and pathology. A review]

The Consensus Conference of Chapel Hill (1994) laid a common base for a standardized classification of vasculitides which, after a pre-existing historical diversity, enabled a comparison of different studies. The criteria for this classification are foremost anatomico-pathological and are based on the caliber of affected blood vessels. In addition the quality of the inflammatory reaction, and the entirety of clinical symptoms, as well as the results of immunological tests are included. Moreover a unified pathogenetic concept is proposed for all types of vasculitis. The diagnosis of vasculitis of large, medium or small vessels is made primarily by biopsies and examination of HE-stained sections. However, overlap of calibers of vessels affected and lack of specificity of inflammatory reaction with individual vasculitis types have to be paid attention to. Immunohistochemical methods are only rarely routinely applied. In contrast the complete clinical picture and the results of immunological laboratory tests (especially AntiNeutrophilCytoplasmicAntibodies, ANCA) play an important role in the differential diagnosis of various vasculitis types. Definitions, clinical findings and pathology of the various types of vasculitis are described. Also mentioned are secondary vasculitides, e.g concurrent to collagen diseases or infections. Not only the diagnosis of vasculitis but also the recognition of the specific type and, last but not least monitoring by histological controls, may be decisive for an optimal therapy.

Pulmonary interstitial fibrosis as a presenting manifestation in perinuclear antineutrophilic cytoplasmic antibody microscopic polyangiitis

Microscopic polyangiitis (MPA) is one of the vasculitides that is included in the pulmonary renal syndromes. Pathologically, MPA has been defined as necrotizing vasculitis with few or no immune deposits, primarily affecting small vessels including arterioles, venules, or capillaries. Pulmonary interstitial fibrosis (PIF) as an accompanying manifestation in MPA has not been widely appreciated. In the present study, we report six cases of MPA at our institution with radiographic evidence of PIF that was apparent before any treatment was administered. All had biopsy evidence of renal disease that was consistent with MPA as well as positive serum perinuclear antineutrophilic cytoplasmic antibody titers. Hemoptysis was observed in approximately one half of the patients. As determined by CT of the chest, PIF was detected in all of the patients and was often present years before a diagnosis of MPA was made. We conclude that PIF may occur as a pulmonary manifestation of MPA. Further appreciation of this finding may lead to more data with respect to the incidence of PIF in MPA, and to a better understanding of the mechanisms that are involved in the development of this finding.