New paradigm in the treatment of myositis-associated interstitial lung disease

ABSTRACT

Introduction

Interstitial lung disease (ILD) is the leading cause of mortality in idiopathic inflammatory myopathies or myositis. Clinical characteristics, including the course of ILD, rate of progression, radiological and pathohistological morphologies, extent and distribution of inflammation and fibrosis, responses to treatment, recurrence rate, and prognosis, are highly variable among myositis patients. A standard practice for ILD management in myositis patients has not yet been established.

Areas covered

Recent studies have demonstrated the stratification of patients with myositis-associated ILD into more homogeneous groups based on the disease behavior and myositis-specific autoantibody (MSA) profile, leading to better prognoses and prevention of the burden of organ damage. This review introduces a new paradigm in the management of myositis-associated ILD based on research findings from relevant literature selected by a search of PubMed as of January 2023, as well as expert opinions.

Expert opinion

Managing strategies for myositis-associated ILD are being established to stratify patients based on the severity of ILD and the prediction of prognosis based on the disease behavior and MSA profile. The development of a precision medicine treatment approach will provide benefits to all relevant communities.

KEYWORDS:

• Disease behavior
• idiopathic inflammatory myopathy
• interstitial lung disease
• myositis-specific autoantibody
• precision medicine
• risk prediction model

Article highlights

• Interstitial lung disease (ILD) is the leading cause of mortality in idiopathic inflammatory myopathies or myositis. Clinical presentation, disease behavior, response to treatment, and prognosis are highly variable among patients with myositis-associated ILD.

• Although all myositis patients are required to undergo screening for ILD at diagnosis or when myositis is suspected, we should prudently screen for ILD in patients with DM-related rash and myositis-specific autoantibodies (MSAs), including anti-synthetase, anti-melanoma differentiation-associated gene 5 (MDA5), or anti-small ubiquitin-like modifier activating enzyme autoantibodies.

• Lung auscultation, chest X-ray, and pulmonary function testing (PFT), including the forced vital capacity and diffusing capacity of the lungs for carbon monoxide, should be conducted in all myositis patients regardless of the presence or absence of respiratory symptoms.

• The measurement of MSAs is an essential assessment tool for the prediction of clinical course, treatment response, and prognosis. Anti-MDA5 antibody has the most impact on mortality among MSAs in patients with myositis-associated ILD.

• The comprehensive evaluation of ILD by physical examination, PFT, high-resolution computed tomography, and testing for conventional biomarkers is mandatory to evaluate the status of ILD and predict the prognosis in patients with myositis-associated ILD before the initiation of induction therapy.

• A precision medicine treatment approach is being conducted with the procedure of the stratification of mortality risk based on information on the disease behavior of ILD, MSA profile, ILD severity based on pulmonary function and ILD extent.

• Physicians need to control disease activity to prevent the deterioration of pulmonary function and minimize the risk of an acute exacerbation.

• Appropriate management of infection is also critical during intensive immunosuppressive therapy.

• Referral to a transplantation facility is considered for younger patients with advanced or treatment-resistant ILD.

Declaration of interests

T Gono has received speaking fees from Asahi Kasei, Astellas, Boehringer Ingelheim, Bristol-Myers Squibb, Chugai, Eisai, Janssen, MBL, Nippon Shinyaku, Pfizer, and Ono Pharmaceuticals. M Kuwana holds the patent for the anti-MDA5 antibody measurement kit, and received consulting fees, speaking fees, and research grants from AbbVie, argenx, Asahi Kasei, Astellas, AstraZeneca, Boehringer-Ingelheim, Bayer, Chugai, Eisai, Corbus, GSK, Janssen, Kissei, MBL, Mitsubishi Tanabe, Mochida, Nippon Shinyaku, Pfizer, and Ono Pharmaceuticals. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

Reviewer discloses

Peer reviewers on this manuscript have no relevant financial or other relationships to disclose.

Additional information

Funding

This work was supported by Grants-in-Aid for Scientific Research from the Japan Society for the Promotion of Science 22K08553.The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.