Anti-Signal Recognition Particle Antibody-Associated Severe Interstitial Lung Disease Requiring Lung Transplantation

Abstract

Anti-signal recognition particle (SRP) antibodies are typically associated with immune-mediated necrotizing myopathy. Some patients with anti-SRP antibodies may have extramuscular manifestations including mild respiratory symptoms secondary to interstitial lung disease. We present a case of a 40-year-old female presenting with acute hypoxic respiratory failure secondary to anti-SRP antibody-associated interstitial lung disease with mildly elevated creatinine kinase but without evidence of necrotizing myopathy on muscle biopsy. After a complicated six-month hospitalization, the patient successfully received double lung transplantation and was eventually discharged on room air. Unexplained worsening interstitial infiltrates leading to persistent hypoxic respiratory failure in the setting of nonspecifically elevated creatinine kinase should warrant consideration of an underlying connective tissue disease, including myositis with anti-SRP antibody-associated interstitial lung disease. In rare cases, interstitial lung disease may be severe requiring lung transplantation.