Secondary cardiac involvement in anti-SRP-antibody-positive myopathy: an 87-year-old woman with heart failure symptoms as the first clinical presentation

Abstract

Background: Necrotizing myopathy (NM) is defined by the dominant pathological feature of necrosis of muscle fibers without substantial lymphocytic inflammatory infiltration. Anti-signal recognition particle (SRP)-antibodypositive myopathy is related to NM. Anti-SRP-antibody-positive myopathy can comorbid with other disorders in some patients, however, comorbidity with malignant tumor and myopericarditis has still not been reported. Case presentation: An 87-year-old woman with dyspnea on exertion and leg edema was referred to our hospital because of suspected heart failure and elevated serum creatine kinase level. Upon hospitalization, she developed muscle weakness predominantly in the proximal muscles. Muscle biopsy and immunological blood test led to the diagnosis of anti-SRP-antibody-positive myopathy. A colon carcinoma was also found and surgically removed. The muscle weakness remained despite the tumor resection and treatment with methylprednisolone. Cardiac screening revealed arrhythmia and diastolic dysfunction with pericardial effusion, which recovered with intravenous immunoglobulin (IVIg) treatment. Conclusions:We reported the first case of anti-SRP-positive myopathy comorbid with colon carcinoma and myopericarditis. This case is rare in the point that heart failure symptoms were the first clinical presentation. The underlying mechanism is still not clear, however, physicians should be carefully aware of the neoplasm and cardiac involvement in anti-SRP-antibody positive-myopathy patients and should consider farther evaluation and management.

Immunotherapy reversed myopathy but not cardiomyopathy in a necrotizing autoimmune myopathy patient with positive anti-SRP and MDA-5 autoantibodies

“…Cardiac abnormalities had been observed in patients with anti-SRP-positive NAM [ 6 , 9 , 10 , 14 – 17 ] and previous study had suggested preferential involvement of the cardiac conduction system in anti-SRP-positive patients [ 14 ]. Even though anti-MDA5 antibodies were also identified in the patient, there was a lack of correlation between anti-MDA5 antibodies and cardiac involvement [ 11 ].…”

“…Why the autoimmunity in the skeletal muscles responded well to immunotherapy but the cardiac damage was independent and unresponsive simultaneously in this case? There has been two reported cases with anti-SRP antibodies who suffered acute congestive heart failure responded well to prednisone, tacrolimus, and intravenous immunoglobulins or prednisone, plasma exchanges, and rituximab [ 8 , 9 ]. In this case, the fact that the patient developed chronic heart failure with steroid and immunosuppressants may be due to the more complex mechanisms underlying cardiac damage mediated by autoimmunity.…”

Case Report: Immune Mediated Necrotizing Myopathy With IgG Antibodies to 3-Hydroxy-3-Methylglutaryl-Coenzyme a Reductase (HMGCR) May Present With Acute Systolic Heart Failure

“…Cardiac involvement is a well-known feature of other immune myopathies, such as polymyositis, dermatomyositis (PM & DM), and anti-SRP antibody necrotizing myopathy ( 5 , 9 ). PM and DM can exhibit a wide spectrum of cardiac abnormalities, including pericarditis, myocarditis, conduction system abnormalities and mitral valve prolapse ( 10 ).…”

“…PM and DM can exhibit a wide spectrum of cardiac abnormalities, including pericarditis, myocarditis, conduction system abnormalities and mitral valve prolapse ( 10 ). Cardiomyopathy with heart failure is the most common cardiac abnormality in PM, it is one of the main prognostic factors for this condition and can cause death in 10–20% of patients ( 9 , 11 ). The existing literature suggests that cardiomyopathy is not a typical feature of anti-HMGCR myopathy ( 2 ).…”

Clinical Characteristics of Immune-Mediated Necrotizing Myopathy with Autoantibodies Recognizing the Signal Recognition Particle: A Retrospective Study of a Chinese Cohort

“…Therefore, ILD in the 11 patients we reported was most likely associated with anti-SRP antibody. In previous reports, anti-SRP myositis patients may also have cardiac involvement, including cardiac rhythm or conduction abnormalities as well as cardiac insu ciency in 13%-16% 21,23,24 . However, we did not observe obvious cardiac involvement in this anti-SRP-positive Chinese cohort.…”