Acute respiratory failure due to diaphragmatic weakness revealing a polymyositis

Undifferentiated Connective Tissue Disease With Isolated Diaphragmatic Dysfunction

Undifferentiated connective tissue disease (UCTD) is a rare autoimmune disorder with a prevalence of about two people per 100,000 people per year. Patients present with the features of different connective tissue diseases, including systemic lupus erythematosus, systemic sclerosis, polymyositis, and rheumatoid arthritis, with some positivity in serological markers that is insufficient to fulfill the criteria of any recognized connective tissue disorder. Pulmonary involvement is usually subacute and pleomorphic, which can cause a delay in the diagnosis. A few cases of UCTD involving an isolated diaphragm in the pulmonary system have been reported. We report a case of a 48-year-old female who initially presented with various nonspecific symptoms, including fatigue, polyarthralgia, dry mouth, and Raynaud's phenomenon. Subsequently, she developed significant dyspnea and orthopnea. Laboratory, immunology, and imaging workups were negative for any specific diagnosis. Pulmonary function tests showed severely low maximum inspiratory pressure (MEP) and maximum expiratory pressure, suggesting diaphragmatic dysfunction. A diagnosis of UCTD was considered, and she was treated with hydroxychloroquine and intravenous immunoglobulin (IVIG), which improved her respiratory symptoms and pulmonary function tests.

Shrinking lung syndrome masked by pleuropericarditis: a case report and review of the literature

The purpose of this article is to present an unusual case of shrinking lung syndrome (SLS) masked by pleuropericarditis with a review of the literature. We report a case of SLS in a 44-year-old woman in which the diagnosis was initially confounded by concurrent pleuropericarditis. The English medical literature was comprehensively reviewed for SLS for its presentation, clinical findings, diagnosis, treatment, with specific focus on its pathogenesis. SLS is a rare respiratory complication associated with systemic lupus erythematosus (SLE). The main manifestation of the disease is unexplained dyspnea, chest pain, and orthopnea. Lung volume reduction without parenchymal abnormalities along with restrictive ventilatory defect on pulmonary function test (PFT) is the hallmarks of this condition. Pathogenesis, treatment, and prognosis of SLS are not well described due to the small number of reported cases. The diagnosis of SLS in our patient was made based on imaging, PFT, and the exclusion of other respiratory diseases associated with SLE. Treatment with corticosteroid and intravenous cyclophosphamide was initiated due to simultaneously diagnosed renal involvement. Our case demonstrates the salient features of SLS. It emphasizes that although SLS is a rare disease limited to small subset of patients with SLE, it should be considered in patients with SLE with unexplained dyspnea. Moreover, symptoms of pleuropericarditis can mask and delay the diagnosis of SLS. Prompt diagnosis and treatment can lead to a decrease in morbidity and stabilization of pulmonary function test abnormalities.

Shrinking lung syndrome: recognition, pathophysiology and therapeutic strategy

Shrinking lung syndrome is a rare complication of systemic autoimmune diseases, mainly systemic lupus erythematosus, but also Sjögren's syndrome and polymyositis. It should be suspected in any patient with autoimmune disease presenting with an unexplained dyspnea. Shrinking lung syndrome is characterized by small lung volumes, elevation of the diaphragm and restrictive physiology without parenchymal involvement. Its pathogenesis remains controversial: diaphragm dysfunction, phrenic neuropathy or pleural inflammation. Pleural adhesions and pain probably play a significant role in the pathogenesis. Electrical or magnetic phrenic stimulation is an important method of investigation but it is not widely available. No treatment has been validated. Steroids are proposed as first-line treatment, alone or associated with β2-adrenergic receptor agonists. In refractory cases, immunosuppressors are used. Biotherapies may be beneficial. Long-term prognosis is good, but respiratory failure can occur in some cases.

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.

The respiratory system in connective tissue disorders

The connective tissue disorders (also called collagen vascular diseases) represent an heterogeneous group of immunologically mediated inflammatory disorders with a large variety of affected organs besides the lungs. The respiratory system may be involved in all its components: airways, vessels, parenchyma, pleura, respiratory muscles, etc. The frequency, clinical presentation, prognosis and response to therapy vary, depending on the pattern of involvement as well as on the underlying connective tissue disorders. The subject of this review is to describe the most frequent type of lung disorders observed in patients with connective tissue disease (CTD). We will focus on the most frequent CTD: systemic lupus erythematosus, rheumatoid arthritis, scleroderma, Sjogren's syndrome, dermatopolymyositis and mixed CTD.

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.