OPA5 CLINICAL OUTCOMES AND PROGNOSTIC FACTORS IN MYOSITIS-ASSOCIATED INTERSTITIAL LUNG DISEASE: INSIGHTS FROM FIVE-YEAR MULTICENTRE STUDY

Yen Shen Wong1, Noorul Afidza Muhammad2, Chen Yong Tan2, Shoban Raj Vasudayan2, Fatimah Zaharah Rosli2, Karamjit Kaur Sarban Singh2, Haly Rozie Ahmad2, Sumithra appava2, Nuruliman Dashuki1, Chun Hau Lam3, Jen Lye Wan3, Shereen Suyin Ch’ng3, Jamalul Azizi Abdul Rahman, Aisya Natasya Musa1
1Faculty Of Medicine, University Teknologi Mara (UiTM) Sg Buloh, Selangor, Malaysia
2Respiratory Department, Sultan Idris Shah Serdang Hospital, Selangor, Malaysia
3Medical Department, Hospital Selayang, Selangor, Malaysia

Introduction: 

Myositis-associated interstitial lung disease (ILD) is a rare complication of idiopathic inflammatory myopathies (IIMs). 

Objectives: 

This retrospective study aims to evaluate the clinical features and factors linked to mortality among patients diagnosed with myositis-associated ILD.

Methodology: 

This is a multicenter retrospective study across three ILD centers in Selangor, Malaysia. We identified 41 patients who was diagnosed over a period of five years.

Results: 

The mean age at diagnosis was 57 years, with a majority of female patients (61%). A significant proportion presented without proximal myopathy or skin manifestations (66%), while 73% exhibited normal creatine kinase levels. Radiologically, organizing pneumonia (OP) (25%) and fibrotic nonspecific interstitial pneumonia (NSIP) (19.5%) were common pattern. A higher population was positive for Anti-melanoma Differentiation-associated protein 5 antibody (27%). Approximately 26.8% of patients were at risk of progressive pulmonary fibrosis. The 5-year survival rate was 85%, with mortality significantly associated with advancing age, Indian ethinicty, elevated oxygen requirement at diagnosis, fibrotic NSIP radiological pattern, absence of mycophenolate mofetil (MMF) therapy, and frequency of ILD exacerbation (P = 0.013, 0.016, 0.001, 0.019, 0.048 and 0.001 respectively). 

Conclusion: 

The subtle nature of myositis-associated ILD without myopathy or dermatological signs highlights the need to screen NSIP/OP patients for myositis antibodies. Combination immunosuppressive therapy with MMF or rituximab offers benefit in preventing PPF and improving survival.