A 43-year-old man with antisynthetase syndrome presenting with acute worsening of dyspnea

Effectiveness and safety of mycophenolate mofetil and rituximab combination therapy for immune idiopathic myopathies

INTRODUCTION

Idiopathic inflammatory myopathies (IIM) represent a rare and heterogenous group diseases, and their treatment is not fully defined yet. According to previous small case series, the combination of mycophenolate mofetil (MMF) and rituximab (RTX) may be effective in controlling difficult-to-treat patients. Our aim was to further explore the efficacy and safety of this combined approach in patients with IIM.

METHODS

Patients with IIM treated with the RTX/MMF combination in our Center were retrospectively identified. After the start of combination therapy, the efficacy was evaluated at 12 months (T12) according the 2016 ACR/EULAR response criteria for IIM. Cardiac imaging and pulmonary function tests were used to monitor disease activity in patients with myocarditis and interstitial lung disease, respectively. Adverse events were recorded over the follow-up period.

RESULTS

Among the 20 patients (median age 61 years; 70% female) included in the study, anti-synthetase syndrome was the most prevalent IIM subgroup (60%). At treatment start, muscle, heart, and lung were the most commonly actively affected organs. After 12 months, a moderate or major response was observed in all patients, and creatine kinase was significantly decreased (p-value = 0.012). Cardiac imaging and enzymes monitoring showed a reduction of heart inflammation, while pulmonary function tests improved in patients with lung involvement. No severe side effects were observed.

CONCLUSION

Our data show that combination of RTX and MMF is effective and safe in patients with severe and refractory IIM. Therefore, this combined treatment might represent a feasible approach for difficult-to-treat IIM cases.

Pulmonary histopathology of interstitial lung disease associated with antisynthetase antibodies

BACKGROUND

We aimed to determine if antibody type is an indicator of pulmonary histopathology, using antisynthetase antibody positive interstitial lung disease (ILD) cases with lung biopsy or autopsy findings.

METHODS

We conducted a comprehensive review of the English language literature in PubMed to identify ILD histopathology results for cases with antibodies against anti-aminoacyl-transfer RNA (tRNA) synthetases (anti-ARS antibodies), including Jo1, PL-12, PL-7, KS, ES, and OJ. We additionally identified patients who had ILD, anti-ARS antibodies, and a lung biopsy between 2015 and 2020 at Beth Israel Deaconess Medical Center. For each case, we documented the specific anti-ARS antibody and major histopathologic patterns identified on biopsy or autopsy, including usual interstitial pneumonia (UIP), nonspecific interstitial pneumonia (NSIP), organizing pneumonia (OP), and acute lung injury (ALI). To determine if histopathology varied by antibody type, we compared the proportion of each of four major patterns by antibody type using the Fisher's Exact test.

RESULTS

We identified 310 cases with pathology findings and anti-ARS antibody positivity, including 12 cases from our institution. The proportion of NSIP differed significantly across antibody type, found in 31% of Jo1 (p < 0.01), 67% of EJ (p < 0.01), and 63% of KS (p < 0.01) cases. OP was common in Jo1 (23%, p = 0.07), but rare in EJ (4%, p = 0.04) and KS (4%, p = 0.04). UIP was common in PL-12 alone (36%, p = 0.03).

CONCLUSION

The frequency of histopathologic findings in ILD with anti-ARS positivity varies significantly by antibody type, and NSIP occurs in less than half of all cases.

Efficacy and safety of mycophenolate mofetil in the treatment of rheumatic disease-related interstitial lung disease: a narrative review

Mycophenolate mofetil (MMF) is an antimetabolite with a potent inhibitory effect on proliferation of T and B lymphocytes used since the early 1990s for the prevention of acute allograft rejection after organ transplant. MMF is also widely used for the treatment of a variety of rheumatic diseases (RDs) and their pulmonary involvement. Interstitial lung disease (ILD) is a heterogeneous group of progressive fibrotic diseases of the lung, which is often secondary to RD and represents a major cause of morbidity and mortality. MMF is considered the main alternative to cyclophosphamide as a first-line agent to treat RD-related ILD or as possible maintenance therapy after cyclophosphamide, with a lower rate of side-effects. However, as for other immunosuppressive agents, the use of MMF in RD-ILD is supported by poor scientific evidence. In this narrative review, we describe the available data and recent advances on the effectiveness and safety of MMF for the treatment of ILD related to RD, including rheumatoid arthritis, systemic sclerosis, primary Sjögren syndrome, systemic lupus erythematosus, idiopathic inflammatory myopathies, undifferentiated connective tissue disease, interstitial pneumonia with autoimmune features and antineutrophil cytoplasmic antibody-associated vasculitis.

A misdiagnosed case of antisynthetase syndrome complicated by myocarditis: when the cardiologist deals with rheumatology

We report a case of a 56-year-old woman with an alleged diagnosis of an acute coronary syndrome that was later correctly identified in our Cardiology Unit as antisynthetase syndrome (AS) with inflammatory cardiac involvement. In this case report, we focus on clinical features of this rare autoimmune disease aiming to provide useful tips to achieve correct differential diagnosis according to updated international guidelines and recommendations, especially in cases of concurrent disease-related myocarditis.