OPA3 SURVIVAL ACROSS DIFFERENT AETIOLOGIES OF INTERSTITIAL LUNG DISEASE (ILD) AND ITS BASELINE PREDICTORS IN A TERTIARY CENTRE IN MALAYSIA

Authors:

Leng Cheng Sia1, Yong-Kek Pang1, Chee Kuan Wong1, Wai Ling Leong2
1Department of Medicine, University Malaya Medical Centre (UMMC), Kuala Lumpur (KL), Malaysia.
2Department of Radiology, UMMC, KL, Malaysia.

Introduction

ILD encompasses a range of heterogenous disorder, characterised by inflammatory and fibrotic changes in the lung parenchyma, with aetiologies including autoimmune disease, exposure-related factors, sarcoidosis, idiopathic causes, cystic lung disease, and others. Classifying these aetiologies aids in management and prognosis. Data on comparative mean survival across different ILD aetiologies is limited.

Objectives

We aimed to evaluate survival across various ILD aetiologies and identify baseline factors affecting ILD survival.

Methodology

ILD cases were retrospectively identified between the visit from 1 January 2010 to 31 May 2023 via hospital database using ICD-10. After excluding patients without baseline forced vital capacity (FVC) and high-resolution computed tomography, 283 patients were included. Survival analysis employed the Kaplan-Meier method, while Cox proportional hazard regression identified mortality-affecting factors.

Results

Among  283 patients, the mean age at diagnosis was 61.5±14.3 years ; 66.8% were female (n=189); 45.9% were Indian (n=130). Autoimmune comprised 42.8% of the cohort. Baseline mean predicted FVC was 54.0±20.8. Kaplan Meier survival curve showed significant survival difference across different groups of ILD, with idiopathic pulmonary fibrosis (IPF) and hypersensitivity pneumonitis (HP) demonstrating the poorest survival (mean survival 5.6 and 6.1 years, respectively; Chi-square =29.118, log-rank<0.001). Autoimmune-ILD, sarcoidosis and miscellaneous (e.g., cystic lung disease and organizing pneumonia) were less associated with mortality compared to idiopathic ILD (HR 0.43, p= 0.016; HR= 0.21, p=0.04). Age at diagnosis of ≥ 50 was associated with 3.79-fold risk of mortality  (p-value 0.014) whereby baseline predicted FVC <60% doubled the mortality risk. (HR=2.05, p= 0.028)

Conclusions

Prognosis of HP is as poor as IPF. Early diagnosis and intervention are crucial to improve the trajectory.