Spectrum of interstitial lung disease at a tertiary care centre in India

The available data on the epidemiology of interstitial lung disease (ILD) from India is sparse. Hence, the present study was undertaken with the aim to analyse the demographic profile and clinical, radiological and pathological characteristics along with physiological parameters of various subgroups of ILD patients.

We retrospectively studied 289 patients diagnosed with ILD during the years 2001-2013 at one of the respiratory units of Vallabhbhai Patel Chest Institute.

Mean age at presentation was 44.24 years; females comprised 54.68% of the patients. Prior to presentation at our centre, 14.84% patients had been treated with antituberculous therapy due to misdiagnosis of tuberculosis. In the pool of ILDs analysed, sarcoidosis (37.3%) was found to be the most common subgroup, followed by IPF (27.6%) and NSIP (25.6%). Cough (92.97%) was the most common presenting symptom; exertional dyspnoea was found in 79.2% of patients. Digital clubbing was commonest in IPF, found in 30% of patients. Significant desaturation on six-minute walk test was most frequenty seen (50%) in NSIP patients. The most common pattern on chest roentgenogram was reticular/reticulo-nodular pattern (80.2%) and on HRCT - interstitial fibrosis (49.9%). Mean of predicted total lung capacity (TLC) was 64.3%, the lowest being in the IPF group (58.88%). Mean of predicted DLCO was 50.56%, the lowest being in the IPF group (42.75%). The overall diagnostic yield of bronchoscopic biopsy was 83.04%, the highest yield being among sarcoidosis patients (96.29%).

We found sarcoidosis, IPF and NSIP to be the most common ILDs in northern India. ILDs are still frequently misdiagnosed as TB, and increased awareness, education and diagnostic facilities are required to diagnose ILDs at an early stage.