Diffuse alveolar damage in patients with dermatomyositis: a six-case series

Differentiation of idiopathic pulmonary hemosiderosis from rheumatologic and autoimmune diseases causing diffuse alveolar hemorrhage: establishing a diagnostic approach

This narrative review provides an overview of diffuse alveolar hemorrhage (DAH) associated with rheumatologic and autoimmune diseases and their differentiation from idiopathic pulmonary hemosiderosis (IPH). Relevant immunologic diseases associated with DAH are discussed, and a diagnostic flowchart is proposed to establish a "definitive" diagnosis of IPH within the spectrum of DAH. IPH is a rare cause of recurrent DAH both in children and adults. In adults, a definitive diagnosis of IPH requires a lung biopsy and histopathologic examination demonstrating intraalveolar hemorrhage, hemosiderin-laden macrophages, and a variable degree of fibrosis in the absence of both capillaritis and cellular inflammation. The presence of small vessel vasculitis points towards immunologic, well-differentiated, or sometimes undifferentiated rheumatologic diseases. However, it is essential to recognize that many rheumatologic diseases may in the initial phase present with DAH without any evidence of capillaritis, thus mimicking IPH. Although not definitely established, it is likely that immunologic processes are involved in IPH, and we, therefore, suggest the consideration of a more suitable term for the disease, e.g., "Immune-mediated Pulmonary Hemosiderosis" to acknowledge the aberrancy in the immune parameters and a positive response to immunosuppressive therapy.

Acute respiratory distress syndrome relapsing in 10 months with an initial manifestation of polymyositis

Autoimmune disorders are an important cause of acute respiratory distress syndrome (ARDS). We report a case of a patient with steroid-responsive ARDS that relapsed in 10 months with an initial manifestation of seronegative polymyositis. ARDS associated with polymyositis may develop earlier than myopathy and may relapse later.

Polymyositis Presenting as Rhabdomyolysis After the Initiation of Omeprazole

Rhabdomyolysis is a clinical syndrome with a wide range of presentations; it results in muscle necrosis and release of intracellular muscle contents into the circulation. Inflammatory myopathies are a rare cause of rhabdomyolysis. We present a case of a 46-year-old male with a two-week history of progressively worsening diffuse muscle pain after he had been prescribed omeprazole one month prior. A creatine phosphokinase (CPK) elevation was noted, which persisted despite treatment with IV fluids, sodium bicarbonate, and close correction of electrolytes. Further workup, including autoimmune and infectious etiologies, was notable for elevated antinuclear antibodies (ANA), erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP). Furthermore, a muscle biopsy showed evidence of endomysial inflammatory cells, consistent with a diagnosis of polymyositis. Steroids were initiated with significant improvement in symptoms and a decrease in CPK levels. The patient was discharged on a tapering dose of steroids and, on follow-up with the rheumatologist, transitioned to methotrexate with control of symptoms. In patients with rhabdomyolysis who do not respond to first-line therapy, obtaining a detailed medication history and screening with ANA and ESR are encouraged. Given the link between medication and autoimmune disease, clinicians should consider autoimmune myopathy in the differential for cases with persistently elevated creatine kinase. Prompt diagnosis with early initiation of immunosuppressive medication may improve outcomes and avoid complications associated with untreated rhabdomyolysis or polymyositis.

Pathological interpretation of connective tissue disease-associated lung diseases

Connective tissue diseases (CTDs) can affect all compartments of the lungs, including airways, alveoli, interstitium, vessels, and pleura. CTD-associated lung diseases (CTD-LDs) may present as diffuse lung disease or as focal lesions, and there is significant heterogeneity between the individual CTDs in their clinical and pathological manifestations. CTD-LDs may presage the clinical diagnosis a primary CTD, or it may develop in the context of an established CTD diagnosis. CTD-LDs reveal acute, chronic or mixed pattern of lung and pleural manifestations. Histopathological findings of diverse morphological changes can be present in CTD-LDs airway lesions (chronic bronchitis/bronchiolitis, follicular bronchiolitis, etc.), interstitial lung diseases (nonspecific interstitial pneumonia/fibrosis, usual interstitial pneumonia, lymphocytic interstitial pneumonia, diffuse alveolar damage, and organizing pneumonia), pleural changes (acute fibrinous or chronic fibrous pleuritis), and vascular changes (vasculitis, capillaritis, pulmonary hemorrhage, etc.). CTD patients can be exposed to various infectious diseases when taking immunosuppressive drugs. Histopathological patterns of CTD-LDs are generally nonspecific, and other diseases that can cause similar lesions in the lungs must be considered before the diagnosis of CTD-LDs. A multidisciplinary team involving pathologists, clinicians, and radiologists can adequately make a proper diagnosis of CTD-LDs.

Anti-MDA5 Antibody Spectrum in Western World

PURPOSE OF REVIEW

Anti-melanoma differentiation-associated gene 5 (anti-MDA5) is a novel and highly specific myositis-associated autoantibody, which defines a unique phenotype among patients with dermatomyositis (DM).

RECENT FINDINGS

Anti-MDA5 was originally characterized in Japan in DM patients with hallmark cutaneous features and no proximal muscle weakness and termed clinically amyopathic DM (CADM). Anti-MDA5 has characteristic cutaneous manifestations which include tender palmar papules and cutaneous ulcerations, along with an increased frequency of interstitial lung disease (ILD) that can be rapidly progressive (RPILD) and fatal. This review will highlight the clinical significance of anti-MDA5 autoantibodies in Caucasian DM patients.

Effective Administration of Rituximab in Anti-MDA5 Antibody-Positive Dermatomyositis with Rapidly Progressive Interstitial Lung Disease and Refractory Cutaneous Involvement: A Case Report and Literature Review

We describe the case of a 48-year-old man with dermatomyositis (DM) who demonstrated rapidly progressive interstitial lung disease (RP-ILD) and refractory cutaneous involvement together with high levels of anti-melanoma differentiation-associated gene 5 antibody (anti-MDA5-Ab). Even after combination immunosuppressive therapy including a corticosteroid, cyclosporine A, and intravenous cyclophosphamide, his respiratory insufficiency and cutaneous involvement progressively worsened. However, the administration of rituximab (RTX) resulted in clinical remission as well as a visible reduction in anti-MDA5-Ab levels, suggesting that RTX could be a useful remedy in cases refractory to conventional immunosuppressive agents, especially those of RP-ILD related to anti-MDA5-Ab–positive DM.