A 64-year-old woman with interstitial lung disease and positive antibodies against aminoacyl-transfer RNA synthetases in the absence of myositis: presentation of an anti-PL-12 positive antisynthetase syndrome

Joint and muscle inflammatory disease: A scoping review of the published evidence

OBJECTIVES

Polyarthritis is commonly reported in idiopathic inflammatory myositis patients, but few studies have focused on the overlap of myositis with rheumatoid arthritis which is a difficult diagnosis in the absence of well-defined diagnostic criteria. The primary objective of this scoping review was to map the field of research to explore the potential diagnoses in patients presenting with both myositis and polyarthritis.

METHODS

Two electronic databases (MEDLINE/PubMed® and Web of Science®) were systematically searched using the terms (myositis OR 'inflammatory idiopathic myopathies') AND (polyarthritis OR 'rheumatoid arthritis') without any publication date limit.

RESULTS

Among individual records, 280 reports met inclusion criteria after full-text review. There was heterogeneity in the definition of overlap myositis as well as the characteristics of rheumatoid arthritis. In many studies, key data were lacking; rheumatoid factor status was reported in 56.8% (n=151), anti-citrullinated proteins antibodies status in 18.8% (n=50), and presence or absence of bone erosions in 45.1% (n=120) of the studies. Thirteen different diagnoses were found to associate myositis with polyarthritis: antisynthetase syndrome (29.6%, n=83), overlap myositis with rheumatoid arthritis (16.1%, n=45), drug-induced myositis (20.0%, n=56), rheumatoid myositis (7.5%, n=21), inclusion body myositis (1.8%, n=5), overlap with connective tissue disease (20.0%, n=56), and others (5.0%, n=14).

CONCLUSION

The spectrum of joint and muscle inflammatory diseases encompasses many diagnoses including primitive and secondary myositis associated with RA or arthritis mimicking RA. This review highlights the need for a consensual definition of OM with RA to better individualise this entity from the numerous differential diagnoses.

Anti-Synthetase Syndrome-Related Interstitial Lung Disease With Anti-PL-12 Antibodies

Anti-synthetase syndrome usually comprises interstitial lung disease, myositis, arthralgias, and Raynaud phenomenon. The anti-PL-12 antibody is directed against the enzyme alanyl-tRNA synthetase and has been associated with interstitial lung disease in the absence of inflammatory myositis. We report the case of a 33-year-old woman with complaints of progressive dyspnea, a persistent dry cough, along with intermittent low-grade fever for a few months. A computed tomography (CT) scan of the chest showed the presence of patchy bilateral airspace opacities and infiltrates. It also showed significant mediastinal and hilar lymphadenopathy. Bronchoscopy with transbronchial biopsy was performed, and histopathology changes were consistent with connective tissue disease related to interstitial lung disease. Further workup revealed the presence of anti-PL-12 antibodies. This case illustrates a rare association of interstitial lung disease with the anti-PL-12 antibody.