The lung in polymyositis

[Pulmonary manifestations in collagen vascular diseases]

CLINICAL/METHODICAL ISSUE

Pulmonary complications are frequent in patients with collagen vascular diseases (CVD). Frequent causes are a direct manifestation of the underlying disease, side effects of specific medications and lung infections.

STANDARD RADIOLOGICAL METHODS

The standard radiological procedure for the work-up of pulmonary pathologies in patients with CVD is multidetector computed tomography (MDCT) with thin-slice high-resolution reconstruction.

PERFORMANCE

The accuracy of thin-slice CT for the identification of particular disease patterns is very high. The pattern of usual interstitial pneumonia (UIP) representing the direct pulmonary manifestation of rheumatoid arthritis (RA) can be identified with a sensitivity of 45 % and a specificity of 96 %.

ACHIEVEMENTS

Both direct pulmonary manifestations, drug-induced toxicity and certain infections can have a similar appearance in thin-slice MDCT in various forms of CVD. Knowledge of the patterns and causes contributes to the diagnostic certainty.

PRACTICAL RECOMMENDATIONS

At first diagnosis of a CVD and associated pulmonary symptoms thin-slice MDCT is recommended. Clinical, lung function and imaging follow-up examinations should be performed every 6-12 months depending on the results of the MDCT. In every case the individual CT morphological patterns of pulmonary involvement must be identified. The combination of information on the anamnesis, clinical and imaging results is a prerequisite for an appropriate disease management.

Connective Tissue Disease-associated Interstitial Lung Disease: A review

Interstitial lung disease (ILD) is commonly encountered in patients with connective tissue diseases (CTD). Besides the lung parenchyma, the airways, pulmonary vasculature and structures of the chest wall may all be involved, depending on the type of CTD. As a result of this so-called multi-compartment involvement, airflow limitation, pulmonary hypertension, vasculitis and extrapulmonary restriction can occur alongside fibro-inflammatory parenchymal abnormalities in CTD. Rheumatoid arthritis (RA), systemic sclerosis (SSc), poly-/dermatomyositis (PM/DM), Sjögren's syndrome (SjS), systemic lupus erythematosus (SLE), and undifferentiated (UCTD) as well as mixed connective tissue disease (MCTD) can all be associated with the development of ILD. Non-specific interstitial pneumonia (NSIP) is the most commonly observed histopathological pattern in CTD-ILD, but other patterns including usual interstitial pneumonia (UIP), organizing pneumonia (OP), diffuse alveolar damage (DAD) and lymphocytic interstitial pneumonia (LIP) may occur. Although the majority of patients with CTD-ILD experience stable or slowly advancing ILD, a small yet significant group exhibits a more severe and progressive course. Randomized placebo-controlled trials evaluating the efficacy of immunomodulatory treatments have been conducted only in SSc-associated ILD. However, clinical experience suggests that a handful of immunosuppressive medications are potentially effective in a sizeable portion of patients with ILD caused by other CTDs. In this manuscript, we review the clinical characteristics and management of the most common CTD-ILDs.

Thoracic manifestations of collagen vascular diseases

Collagen vascular diseases are a diverse group of immunologically mediated systemic disorders that often lead to thoracic changes. The collagen vascular diseases that most commonly involve the lung are rheumatoid arthritis, progressive systemic sclerosis, systemic lupus erythematosus, polymyositis and dermatomyositis, mixed connective tissue disease, and Sjögren syndrome. Interstitial lung disease and pulmonary arterial hypertension are the main causes of mortality and morbidity among patients with collagen vascular diseases. Given the broad spectrum of possible thoracic manifestations and the varying frequency with which different interstitial lung diseases occur, the interpretation of thoracic images obtained in patients with collagen vascular diseases can be challenging. The task may be more difficult in the presence of treatment-related complications such as drug toxicity and infections, which are common in this group of patients. Although chest radiography is most often used for screening and monitoring of thoracic alterations, high-resolution computed tomography can provide additional information about lung involvement in collagen vascular diseases and may be especially helpful for differentiating specific disease patterns in the lung. General knowledge about the manifestations of thoracic involvement in collagen vascular diseases allows radiologists to provide better guidance for treatment and follow-up of these patients.

Review series: Aspects of interstitial lung disease: connective tissue disease-associated interstitial lung disease: how does it differ from IPF? How should the clinical approach differ?

The lung is frequently involved in connective tissue diseases (CTDs), although the frequency of lung manifestations varies according to the type of CTD. Interstitial lung diseases (ILD) are frequently seen in CTDs, particularly systemic sclerosis (SSc), polymyositis/dermatomyositis (PM/DM) and rheumatoid arthritis (RA), accounting for a significant proportion of deaths. A large percentage of patients with CTD-associated ILD has limited and stable disease, not requiring treatment. However, a significant minority has severe and/or progressive disease, necessitating prompt initiation of treatment. CTD-ILD histological patterns include non-specific interstitial pneumonia (NSIP), usual interstitial pneumonia (UIP), organizing pneumonia (OP), diffuse alveolar damage (DAD) and lymphocytic interstitial pneumonia (LIP). NSIP is the most common pattern in all CTDs, except for RA, characterized by a higher frequency of UIP. ILD can present acutely or chronically, with acute presentations being more common in systemic lupus erythematosus and PM/DM. Idiopathic pulmonary fibrosis (IPF) is a progressively worsening ILD characterized by inflammation and fibrosis. The characteristic histological pattern of IPF is UIP. Interestingly, a UIP pattern is associated with a significantly better survival in CTD-related disease compared to the idiopathic variety. Prognosis in IPF is dismal, with a median survival since diagnosis of 2-3 years. No treatment regimen has been shown to improve survival in IPF. By contrast, although there have been only two randomized placebo-controlled trials investigating the effect of immunosuppressive treatment in SSc-associated ILD, clinical experience suggests that immunosuppressive drugs in CTD-related ILDs are capable of benefiting a significant proportion of patients, particularly those with certain histological patterns of disease. This review will essentially focus on CTD-associated ILD and will compare aspects of clinical presentation and management to those of IPF.

Clinical value of 18F-fluorodeoxyglucose positron emission tomography in patients with connective tissue disease

Connective tissue diseases represent a heterogeneous group of immunologically mediated inflammatory disorders with a large variety of affected organs other than the lung. (18)F-fluorodeoxyglucose positron emission tomography ((18)F-FDG PET) is widely used in oncology but may also be valuable in patients with infections or inflammatory disease. The purpose of this article was to assess the clinical value of (18)F-FDG PET in patients with connective tissue disease. Our experience demonstrates that (18)F-FDG PET is a unique imaging technique for assessing the metabolic activity throughout the body in those with a connective tissue disease. The technique appears to be a promising imaging modality for detecting coexistent neoplastic diseases and other autoimmune disorders.

Characterization and peripheral blood biomarker assessment of anti-Jo-1 antibody-positive interstitial lung disease

OBJECTIVE

Using a combination of clinical, radiographic, functional, and serum protein biomarker assessments, this study was aimed at defining the prevalence and clinical characteristics of interstitial lung disease (ILD) in a large cohort of patients with anti-Jo-1 antibodies.

METHODS

A review of clinical records, pulmonary function test results, and findings on imaging studies determined the existence of ILD in anti-Jo-1 antibody-positive individuals whose data were accumulated in the University of Pittsburgh Myositis Database from 1982 to 2007. Multiplex enzyme-linked immunosorbent assays (ELISAs) for serum inflammation markers, cytokines, chemokines, and matrix metalloproteinases in different patient subgroups were performed to assess the serum proteins associated with anti-Jo-1 antibody-positive ILD.

RESULTS

Among the 90 anti-Jo-1 antibody-positive individuals with sufficient clinical, radiographic, and/or pulmonary function data, 77 (86%) met the criteria for ILD. While computed tomography scans revealed a variety of patterns suggestive of underlying usual interstitial pneumonia (UIP) or nonspecific interstitial pneumonia, a review of the histopathologic abnormalities in a subset of patients undergoing open lung biopsy or transplantation or whose lung tissue was obtained at autopsy (n = 22) demonstrated a preponderance of UIP and diffuse alveolar damage. Analysis by multiplex ELISA yielded statistically significant associations between anti-Jo-1 antibody-positive ILD and elevated serum levels of C-reactive protein (CRP), CXCL9, and CXCL10, which distinguished this disease entity from idiopathic pulmonary fibrosis and anti-signal recognition particle antibody-positive myositis. Recursive partitioning further demonstrated that combinations of these and other serum protein biomarkers can distinguish these disease subgroups at high levels of sensitivity and specificity.

CONCLUSION

In this large cohort of anti-Jo-1 antibody-positive individuals, the incidence of ILD approached 90%. Multiplex ELISA demonstrated disease-specific associations between anti-Jo-1 antibody-positive ILD and serum levels of CRP as well as the interferon-gamma-inducible chemokines CXCL9 and CXCL10, highlighting the potential of this approach to define biologically active molecules contributing to the pathogenesis of myositis-associated ILD.

Long-term outcome of patients with polymyositis/ dermatomyositis and anti-PM-Scl antibody

BACKGROUND

To date, no series has analysed long-term outcome in patients with polymyositis/dermatomyositis (PM/DM) with anti-PM-Scl antibody.

OBJECTIVES

The aims of the present study were: (i) to assess clinical features and long-term outcome, including organ complications, functional course and mortality rate, in patients with isolated PM/DM with anti-PM-Scl antibody; and (ii) to evaluate prevalence, characteristics and long-term outcome of interstitial lung disease (ILD) in patients with isolated PM/DM with anti-PM-Scl antibody.

METHODS

The medical records of 20 consecutive patients with isolated PM/DM with anti-PM-Scl antibody were reviewed.

RESULTS

Two patients (10%) achieved remission of PM/DM, whereas 14 (70%) improved and four (20%) had a worsened clinical status. Short-term recurrences (during tapering of therapy) occurred in nine patients and long-term recurrences (after discontinuation of therapy) in three patients. Moreover, patients with PM/DM with anti-PM-Scl antibody exhibited severe complications, as follows: oesophageal involvement (n = 4) requiring enteral feeding in three cases, ventilatory insufficiency (n = 3) requiring mechanical ventilation in two cases; three other patients had cancer. Interestingly, patients with PM/DM with anti-PM-Scl antibody often presented symptoms that are usually found in antisynthetase syndrome, i.e. hyperkeratotic rhagadiform hand symptoms (n = 2; 10%), Raynaud's phenomenon (n = 8; 40%), arthralgia/arthritis (n = 7; 35%) and ILD (n = 12; 60%). In our cohort, the associated ILD often required combined therapy of steroids and immunosuppressive agents.

CONCLUSIONS

Our series suggests that the presence of anti-PM-Scl antibody is not a good prognostic factor in patients with PM/DM, as there appears to be an association with lung and oesophageal involvement; in addition, anti-PM-Scl antibody may coexist with malignancy in patients with PM/DM. Furthermore, anti-PM-Scl antibody-positive patients with PM/DM often exhibit 'mechanic's hands', Raynaud's phenomenon and joint involvement. Our latter findings raise the possibility that the immunogenetic background influences the autoantibody status of these patients; HLA-DR3 has, in fact, been found in association with antisynthetase syndrome antibodies and with anti-PM-Scl antibodies.

Idiopathic inflammatory myopathies

The idiopathic inflammatory myopathies are a group of systemic autoimmune syndromes characterized by striated muscle inflammation. Here, we discuss the clinical features of this group of conditions and review the recent developments in the understanding of the pathogenesis and immunogenetics of the idiopathic inflammatory myopathies. The role of myositis-specific autoantibodies and their clinical significance and an overview of management are also provided.

Polymyositis–dermatomyositis and infections

In genetically predisposed individuals, viruses, bacteria, or parasitic infectious agents are suspected to induce autoimmunity and/or to exacerbate the disease once the self-tolerance is broken. Although direct evidence for this association is still lacking, numerous data from animal models as well as from humans support the hypothesis of a direct contribution of pathogens to the induction of several autoimmune diseases. This review focused on the possible role of infectious agents as triggers of autoimmunity in polymyositis (PM) and dermatomyositis (DM). Epidemiological studies, clinical and experimental findings that support the hypothesis of infection-induced PM and DM are summarized and discussed. In addition, immune response abnormalities and immunosuppressive medications may be responsible for the high percentage of infectious complications in PM and DM patients. In this review, the increased risk of developing infections in these patients is also underlined and published data are reported.

Two distinct clinical types of interstitial lung disease associated with polymyositis-dermatomyositis

Most patients with interstitial lung disease (ILD) associated with collagen vascular diseases (CVD) have a chronic indolent course with a relatively favorable prognosis; however, acute progression has been reported in some polymyositis-dermatomyositis patients. This study evaluated the prevalence, clinical features, and outcome relative to the presentation type of ILD in polymyositis-dermatomyositis (PM-DM). Ninety-nine patients with newly diagnosed polymyositis-dermatomyositis seen at the Asan Medical Center in Korea between January 1990 and December 2004 were enrolled. The clinical, radiological, and pathological findings were retrospectively reviewed. ILD were divided into acute (dyspnea within 1 month before diagnosis) or chronic types. ILD was found on chest radiographs in 33 patients (33.3%), and 11 (33.3%) of these were considered acute. The acute group presented with more severe respiratory symptoms, hypoxemia, and poorer lung function. Patients with an acute presentation had ground glass opacity and consolidation on high-resolution computed tomography (HRCT), in contrast to reticulation and honeycombing in the chronic type. Surgical lung biopsy of one acute-type patient revealed diffuse alveolar damage, whereas biopsies in the chronic type showed usual interstitial pneumonia (UIP) in four cases and nonspecific interstitial pneumonia (NSIP) in another four. Eight acute-type patients (72.7%) died of respiratory failure within 1-2 months despite steroid therapy. The 3-year mortality rate of the chronic-type patients (21.2%) was not statistically significantly different from that of the patients without ILD (10.2%). In polymyositis-dermatomyositis, the acute, severe form of ILD was not infrequent.

Outcome of patients having dermatomyositis admitted to the intensive care unit

Patients having systemic rheumatic diseases constitute a small percentage of admissions to the medical intensive care units (ICUs). Dermatomyositis (DM) is one of the rheumatic diseases that have secondary complications that may lead to a critical illness requiring hospitalization in the ICU. Herein, we present the features, clinical course, and outcome of critically ill patients having DM who were admitted to the ICU. The medical records of six DM patients admitted to the ICU in a large tertiary hospital in a 12-year period were reviewed. The mean age of patients at time of admission to the ICU was 38 (range 16-37). Mean disease duration from diagnosis to admission to the ICU was 1.6 years (range 1 month-8 years), while the main reason for admission to the ICU was acute respiratory failure. Two of six patients died during the hospitalization. The main causes of death were respiratory complications and sepsis. The outcome of DM patients admitted to the ICU was generally not different from the outcome of other patients hospitalized in the ICU. The main reason for hospitalization was acute respiratory failure. As there are many reasons for respiratory failure in DM, an early diagnosis and aggressive appropriate treatment may help to further reduce the mortality in these patients.

Atteintes pulmonaires des polymyosites et dermatopolymyosites

Polymyositis is characterised by an inflammatory reaction in skeletal muscle with a variable degree of muscular weakness and associated with skin lesions in the case of dermatomyositis. Involvement of the muscles of deglutition and the diaphragm may lead to inhalation pneumonia and acute or chronic respiratory failure, often hypercapnic. The other respiratory manifestations are diffuse interstitial pneumonitis (DIP), usually non-specific, and very occasionally pulmonary arterial hypertension. The development of DIP during polymyositis is a grave prognostic factor, respiratory involvement being one of the main causes of morbidity and mortality. The onset of DIP is acute in between 30 and 47% of cases. Anti-synthetase antibodies (particularly anti-JO-1) are positive in about 75% of cases. Treatment is usually with a combination of immunosuppressants and corticosteroids without any immunosuppressants therapy having shown a superiority.

Infections in Systemic Connective Tissue Diseases: Systemic Lupus Erythematosus, Scleroderma, and Polymyositis/Dermatomyositis

In SLE, scleroderma, and PM/DM, infections are important causes of morbidity and mortality. This increased risk for developing infections is the result of immune abnormalities and of organ system manifestations associated with these diseases and their treatments. Common bacteria are responsible for most mild and lethal infections; however, opportunistic microorganisms cause death in some patients, particularly in those receiving high doses of corticosteroid and immunosuppressive therapy. Various viral and fungal infections also contribute to the morbidity and mortality associated with these diseases. Regardless of the cause of infections, adequate and prompt recognition and proper treatment of the infected patient are imperative. Patients who have these diseases, especially when receiving high doses of corticosteroids and immunosuppressive therapy, need to be monitored closely for these infections. This care and concern is necessary to ensure optimal patient outcomes, both in morbidity and mortality.

Atteinte pulmonaire au cours des polymyosites et des dermatomyosites

Interstitial lung disease is a serious complication of polymyositis/dermatomyositis and leads to death from chronic respiratory insufficiency in 30 to 66% of cases. It is a criterion of poor prognosis in these disorders. Its onset occurs at variable points in the course of polymyositis/dermatomyositis, and precedes them in half of all cases. Presentation may also vary: acute (25%), insidious (60%), or infraclinical, discovered fortuitously (15%). The examinations of choice for early screening are high-resolution computed tomography (CT) and pulmonary function tests, which should be performed during the initial work-up and during ongoing surveillance. Moreover, high-resolution CT also makes it possible to determine the type of histologic lesions in the interstitial lung disease. Today, diagnosis of this disease does not generally require histological confirmation; nonspecific interstitial lung disease seems to be the most common histologic form of lung damage in polymyositis/dermatomyositis (40 to 80%). Anti-Jo1 antibodies are a sensitive marker of interstitial lung disease during polymyositis/dermatomyositis, and close surveillance of lung function is recommended in patients with these autoantibodies. Systematic testing for them is also justified in patients with apparently idiopathic interstitial lung disease, to rule out underlying polymyositis/dermatomyositis. No clear treatment protocols have been established for interstitial lung disease during polymyositis/dermatomyositis. Corticosteroid treatment is the first choice. Its combination with cyclophosphamide may be most effective in corticosteroid-resistant forms of polymyositis/dermatomyositis, especially when begun early; it may also be appropriate to begin corticosteroids as soon as factors predicting poor prognosis are detected.

Interstitial lung disease in polymyositis and dermatomyositis

PURPOSE OF REVIEW

The purpose of this review is to discuss current concepts regarding management of interstitial lung disease in polymyositis and dermatomyositis.

RECENT FINDINGS

Interstitial lung disease seems to be a more frequent manifestation in patients with polymyositis and dermatomyositis than previously reported. Modern technology, including high-resolution computerized tomography in combination with pulmonary function tests provides sensitive tools to detect early signs of interstitial lung disease. By systematic use of these investigations in newly diagnosed polymyositis and dermatomyositis, up to two thirds of patients were discovered to have signs of interstitial lung disease in a recent study. Clinical symptoms such as cough and dyspnea may not be sensitive enough to detect interstitial lung disease. Awareness of this complication in patients with myositis is important, because early diagnosis and management of interstitial lung disease may prevent development of chronic pulmonary fibrosis and thereby prolong patient survival and improve quality of life. Treatment recommendations of interstitial lung disease in polymyositis and dermatomyositis are still limited by absence of controlled trials and could only be based on experiences from small case series and case reports. At least some patients with interstitial lung disease improve with immunosuppressive treatment, but data are limited, and longitudinal studies are needed.

SUMMARY

Interstitial lung disease seems to be a common manifestation in patients with polymyositis and dermatomyositis already at diagnosis of the muscle disease. When present, interstitial lung disease has a major effect on morbidity and mortality and should be looked for in these patients using high-resolution computerized tomography and pulmonary function tests early in the disease course, because immunosuppressive treatment may change the course of the lung disease.

Polymyositis/dermatomyositis-associated lung disease: analysis of a series of 81 patients

The objective of this study was to assess the prevalence, clinical, histological and immunological characteristics, and the long-term outcome of polymyositis- (PM) and dermatomyositis- (DM) associated lung disease, and to define subgroups of lung-associated inflammatory myopathies. This retrospective study included 81 consecutive patients diagnosed with PM/DM. Pulmonary involvement was systematically investigated in relation to clinical symptoms by chest radiography, high resolution computed tomography and pulmonary function testing. Anti-synthetase autoantibodies (ASA) were analysed by ELISA and confirmed by protein and RNA immunoprecipitation methods. Statistical analyses were done with the Student t-test and Fisher exact test. Cumulative survival probabilities were estimated by the Kaplan-Meier method and Cox regression analysis. Fifty patients (61%) presented pulmonary involvement. Thirty-two (39%) had interstitial lung disease and five of them had devastating acute interstitial pneumonia with pneumomediastinum and an unfavorable prognosis. Histology showed diffuse alveolar damage in this subgroup and ASA were negative. Eighteen patients (22%) presented restrictive myopathic lung disease; in three of them respiratory muscles could not maintain ventilation. ASA were positive in 17 of the 50 patients (34%) and were significantly associated with interstitial lung disease (OR: 4.5 [95% CI: 1.3-15.3]), arthritis (OR: 6.0 [95% CI: 1.3-29.2]) and 'mechanic hands' (OR: 8.5 [95% CI: 1.7-41.4]); the presence of these autoantibodies did not imply worse survival prognosis. We concluded that clinical and immunological characteristics allowed the grouping of patients into different types of PM/DM lung-associated disease. Presence of ASA did not affect survival. ASA-negative patients with acute interstitial pneumonitis and pneumomediastinum had an unfavorable prognosis.

Diaphragmatic dysfunction in patients with idiopathic inflammatory myopathies

Polymyositis, dermatopolymyositis, and inclusion body myositis imply chronic inflammation of skeletal muscles. Pulmonary complications include aspiration pneumonia, interstitial pneumonitis, or respiratory muscle myositis. This study aims at better describing their impact on respiratory muscle. Twenty-three consecutive patients (12 PM, 5 DM, 6 IBM) were studied (static inspiratory and expiratory pressures; diaphragm function in terms of the mouth and transdiaphragmatic pressure responses to bilateral phrenic stimulation). Pulmonary parenchymatous abnormalities were mild (6 cases) or absent. The mouth pressure produced by phrenic stimulation was 6.83+/-3.01 cm H2O, with 18 patients (78%) diagnosed with diaphragm weakness (<10 cm H2O) and lower values in DM (4.35+/-1.48 cm H2O) than in IBM and in PM (P<0.05). Diaphragm weakness is frequent and probably overlooked in inflammatory myopathies. Further studies are needed to delineate the clinical relevance of these results.

Nonspecific interstitial pneumonia: a provisional category of idiopathic interstitial pneumonia

PURPOSE OF REVIEW

Idiopathic interstitial pneumonias (IIP) represent a complex group of relatively rare entities with similar clinical, vaguely similar radiographic and differing histologic features. The recent international multidisciplinary consensus statement produced by the American Thoracic Society/European Respiratory Society aiming to standardize the classification of IIP recognizes nonspecific interstitial pneumonia (NSIP) as a provisional category. While not representing a single disease, but rather a collection of pathologic processes with similar histomorphology, NSIP has been a great source of confusion for pulmonologists, radiologists, and pathologists.

RECENT FINDINGS

Lacking diagnostic clinical or radiographic features, NSIP is an IIP with recognizable and reproducible morphologic patterns different from usual interstitial pneumonia (UIP)-pattern as well as other disease patterns. And while overlap with UIP-pattern can be seen in individuals with multiple biopsy samples, those with either cellular or fibrosing variants of NSIP have a better prognosis than UIP-pattern patients.

SUMMARY

A morphologic diagnosis of NSIP-pattern alerts the clinician to a wide spectrum of potential clinical possibilities and enables researchers to study both this fibrosing interstitial pneumonia pattern and the more common and deadly UIP-pattern separately. Thus, this provisional category is useful to both clinicians and researchers.

Interstitial lung disease, a common manifestation of newly diagnosed polymyositis and dermatomyositis

OBJECTIVES

To estimate the prevalence and predictors of interstitial lung disease in newly diagnosed polymyositis and dermatomyositis.

METHODS

A prospective study in which consecutive patients with newly diagnosed poly- and dermatomyositis, regardless of clinical symptoms of pulmonary disease, were investigated with chest x ray, high resolution computed tomography (HRCT), pulmonary function tests, and biochemical and autoantibody analysis. Patients with inclusion body myositis, malignancy, other defined inflammatory connective tissue diseases (CTDs), or antibody profile indicating other CTDs were excluded.

RESULTS

Between March 1998 and September 2000, 26 new cases of poly- or dermatomyositis were diagnosed; 17 of those patients were included in the study. Interstitial lung disease (ILD), defined as radiological signs on chest x ray examination/HRCT or restrictive ventilatory defect, were found in 11 (65%) patients and were more common in men than in women. Arthritis and occurrence of anti-Jo-1 antibodies were found more often in patients with ILD than in those without. There was no statistically significant association between respiratory symptoms, other serological or laboratory variables and ILD.

CONCLUSIONS

ILD is a common early manifestation in patients with poly- and dermatomyositis and is not always related to clinical symptoms. Chest x ray examination, HRCT, pulmonary function tests, and analysis of anti-Jo-1 antibodies should be included in the initial investigation of patients with myositis regardless of respiratory symptoms.

Infections in systemic connective tissue diseases: systemic lupus erythematosus, scleroderma, and polymyositis/dermatomyositis

In SLE, scleroderma, and PM/DM, infections are important causes of morbidity and mortality. This increased risk of developing infections is the result of immune abnormalities and of organ system manifestations associated with these diseases and their treatments. Common bacteria are responsible for most mild and lethal infections; however, opportunistic microorganisms cause death in some patients, particularly in those receiving high doses of corticosteroid and immunosuppressive therapy. Various viral and fungal infections also contribute to the morbidity and mortality associated with these diseases. Regardless of the cause of infections, adequate and prompt recognition and proper treatment of the infected patient are imperative. Thus, patients with these diseases, especially when receiving high doses of corticosteroids and immunosuppressive therapy, need to be monitored closely for these infections. This care and concern is necessary to ensure optimal patient outcomes, both in terms of morbidity and mortality.

Interstitial lung disease in polymyositis and dermatomyositis

OBJECTIVES

To assess prevalence, characteristics, and long-term outcome of interstitial lung disease (ILD) in polymyositis (PM) and dermatomyositis (DM). To determine predictive variables of ILD course in PM/DM, and to define both clinical and biochemical features associated with ILD onset in PM/DM.

METHODS

The medical records of 156 consecutive PM/DM patients in 3 medical centers were reviewed.

RESULTS

Thirty-six PM/DM patients (23.1%) developed ILD. We observed that 19.4% of patients with ILD had resolution of pulmonary disorders, whereas 25% experienced ILD deterioration. Morbidity and mortality rates were as high as 13.9% and 36.4%, respectively, in PM/DM patients with ILD. Parameters of PM/DM that related to ILD poor outcome were identified as follows: Hamman-Rich-like pattern, initial diffusing capacity of carbon monoxide <45%, neutrophil alveolitis, and histologic usual interstitial pneumonia. Additionally, for the group with ILD, polyarthritis, higher values of erythrocyte sedimentation rate and C-reactive protein, presence of anti-Jo-1 antibody, and characteristic microangiopathy were significantly more frequent.

CONCLUSION

Our series underlines the high frequency of ILD in PM/DM patients, resulting in increased morbidity and mortality rates. It also indicates that PM/DM patients should routinely be screened for ILD, even those patients without anti-Jo-1 antibody, because 69% of our ILD patients were seronegative for the anti-Jo-1 antibody. Our findings further suggest that PM/DM patients presenting with factors predictive of ILD poor outcome may require more aggressive therapy.

Pulmonary complications of inflammatory myopathy

Pulmonary manifestations contribute significantly to the morbidity and mortality of the idiopathic inflammatory myopathies, ranging from intrinsic lung disease to secondary complications that include aspiration pneumonia, opportunistic infection, congestive heart failure, and hypoventilation. Newer classification schemes for interstitial lung disease have permitted closer correlation between histologic subtype and clinical outcome, while diagnostic techniques such as bronchoalveolar lavage have begun to define the cellular elements responsible for immune-mediated pulmonary dysfunction. Investigators have identified several serum markers correlating with inflammatory disease activity in the lung that should enhance noninvasive monitoring of therapeutic responses to newer regimens involving agents such as cyclosporine and tacrolimus. Taken together, these advances have contributed to better understanding of the immunopathogenesis of myositis-associated interstitial lung disease that should ultimately translate into more effective treatment.

Interstitial lung diseases associated with collagen vascular diseases: radiologic and histopathologic findings

Collagen vascular diseases that demonstrate features of interstitial lung disease include systemic lupus erythematosus, rheumatoid arthritis, progressive systemic sclerosis, dermatomyositis and polymyositis, ankylosing spondylitis, Sjögren syndrome, and mixed connective tissue disease. At histopathologic analysis, interstitial lung diseases associated with collagen vascular diseases are diverse and include nonspecific interstitial pneumonia, usual interstitial pneumonia, bronchiolitis obliterans organizing pneumonia (BOOP), apical fibrosis, diffuse alveolar damage, and lymphocytic interstitial pneumonia. Although proportions of interstitial pneumonias vary, nonspecific interstitial pneumonia accounts for a large proportion, especially in progressive systemic sclerosis, dermatomyositis and polymyositis, and mixed connective tissue disease. The more favorable prognosis in interstitial pneumonia associated with collagen vascular diseases than in idiopathic interstitial pneumonias may be explained by the larger proportion of nonspecific interstitial pneumonia than of usual interstitial pneumonia. High-resolution computed tomography seems to help characterize and determine the extent of interstitial lung disease in collagen vascular diseases.

Neuromuscular disorders in the intensive care unit

Neuromuscular disorders encountered in the ICU can be categorized as muscular diseases that lead to ICU admission and those that are acquired in the ICU. This article discusses three neuromuscular disorders can lead to ICU admission and have a putative immune-mediated pathogenesis: the Guillian-Barré syndrome, myasthenia gravis, and dermatomyositis/polymyositis. It also reviews critical care polyneuropathy and ICU acquired myopathy, two disorders that, alone or in combination, are responsible for nearly all cases of severe ICU acquired muscle weakness.

Acute respiratory failure due to diaphragmatic weakness revealing a polymyositis

Of the different respiratory disorders that complicate the course of polymyositis, diaphragmatic weakness is one that is seldom described and most often suspected rather than confirmed. We report a case of severe diaphragmatic weakness as a cause of acute respiratory failure revealing a polymyositis. The diaphragmatic involvement was proven by a very low esophageal pressure in response to cervical magnetic stimulation of the phrenic nerve. Corticosteroids and intravenous gammaglobulin, combined with mechanical ventilation, achieved a progressive recovery of diaphragmatic weakness.

High-resolution CT of lung disease related to collagen vascular disease

Although connective tissue diseases may have similar radiographic appearances, a variety of pathologic processes can be seen in the lung of these patients. In such circumstances, early recognition of lung involvement is now easily demonstrated by imaging methods. The development of thin-section and dynamic CT techniques has significantly improved diagnostic accuracy. Moreover, expiratory HRCT is a helpful technique in demonstrating air trapping in these patients. The radiologist plays a significant role in the evaluation of pulmonary manifestations of connective tissue diseases.

[Interstitial lung diseases in polymyositis and dermatomyositis]

PURPOSE

Interstitial lung disease is one of the most common respiratory manifestations in polymyositis and dermatomyositis. It still remains a severe complication of the disease, leading to death related to ventilatory insufficiency in 30-66% of patients.

CURRENT KNOWLEDGE AND KEY POINTS

Time onset of interstitial lung disease is variable, although interstitial lung disease onset precedes initial manifestations of polymyositis/dermatomyositis in roughly half of the patients. Moreover, clinical presentation of interstitial lung disease can be dichotomized, according to patients' pulmonary manifestations, into: 1) both acute and aggressive lung disease similar to Hamman-Rich syndrome; 2) slowly progressive lung disease; and 3) an asymptomatic pattern. The methods of choice adopted for early diagnosis of interstitial lung disease are high-resolution computed tomography scan and pulmonary function tests, which should be performed during both initial evaluation of polymyositis/dermatomyositis and follow-up. Because anti-JO1 antibody is considered to be a marker of interstitial lung disease in polymyositis/dermatomyositis, close pulmonary follow-up of anti-JO1-positive patients with polymyositis is therefore required for early detection of subclinical impairment. Furthermore, histological lung findings provide prognostic data; patients with bronchiolitis obliterans organizing pneumonia (BOOP) indeed appear to have a more favorable outcome than those with usual interstitial pneumonia or diffuse alveolar damage. Finally, as a guide to both the severity and progress of interstitial lung disease, the significance of other investigations, notably bronchoalveolar lavage, remains controversial.

FUTURE PROSPECTS AND PROJECTS

Specific therapy of interstitial lung disease has not yet been clearly established in polymyositis/dermatomyositis patients. Corticosteroid therapy is considered the first line of therapy for polymyositis/dermatomyositis patients with interstitial lung disease. The association of cyclophosphamide and corticosteroids may be the most effective in patients with steroid-resistant interstitial lung disease. Early diagnosis and management of this disease is therefore of the utmost importance.

Pulmonary involvement in juvenile dermatomyositis: a two-year longitudinal study

OBJECTIVE

To investigate the prevalence and features of asymptomatic pulmonary involvement in juvenile dermatomyositis (JDM).

METHODS

Twelve JDM patients underwent pulmonary function tests at baseline, 12 and 24 months. Disease activity, duration, serum lactate dehydrogenase (LDH) values and antinuclear antibody (ANA) titres were also evaluated.

RESULTS

Five patients showed lung impairment at baseline and four at 12 and 24 months. Forced expiratory volume in 1s, forced vital capacity (FVC), carbon monoxide diffusing capacity (DLCO) and alveolar volume were the most frequently altered variables, indicating a restrictive pattern and impairment of diffusion. The prevalence and features of pulmonary alterations did not change during follow-up. FVC values were significantly lower in active JDM patients and were inversely related to LDH. DLCO values were significantly lower in ANA-positive patients. About half of the patients of this small case series of JDM had asymptomatic lung disease.

CONCLUSIONS

We suggest that lung function should be evaluated at disease onset and regularly during follow-up, as pulmonary function tests can detect otherwise unpredictable pulmonary involvement.