Interstitial Lung Disease in India. Results of a Prospective Registry.

RATIONALE: Interstitial lung disease (ILD) is a heterogeneous group of acute and chronic inflammatory and fibrotic lung diseases. Existing ILD registries have had variable findings. Little is known about the clinical profile of ILDs in India. OBJECTIVES: To characterize new-onset ILDs in India by creating a prospective ILD using multidisciplinary discussion (MDD) to validate diagnoses. METHODS: Adult patients of Indian origin living in India with new-onset ILD (27 centers, 19 Indian cities, March 2012-June 2015) without malignancy or infection were included. All had connective tissue disease (CTD) serologies, spirometry, and high-resolution computed tomography chest. ILD pattern was defined by high-resolution computed tomography images. Three groups independently made diagnoses after review of clinical data including that from prompted case report forms: local site investigators, ILD experts at the National Data Coordinating Center (NDCC; Jaipur, India) with MDD, and experienced ILD experts at the Center for ILD (CILD; Seattle, WA) with MDD. Cohen's κ was used to assess reliability of interobserver agreement. MEASUREMENTS AND MAIN RESULTS: A total of 1,084 patients were recruited. Final diagnosis: hypersensitivity pneumonitis in 47.3% (n = 513; exposure, 48.1% air coolers), CTD-ILD in 13.9%, and idiopathic pulmonary fibrosis in 13.7%. Cohen's κ: 0.351 site investigator/CILD, 0.519 site investigator/NDCC, and 0.618 NDCC/CILD. CONCLUSIONS: Hypersensitivity pneumonitis was the most common new-onset ILD in India, followed by CTD-ILD and idiopathic pulmonary fibrosis; diagnoses varied between site investigators and CILD experts, emphasizing the value of MDD in ILD diagnosis. Prompted case report forms including environmental exposures in prospective registries will likely provide further insight into the etiology and management of ILD worldwide.

Hypersensitivity pneumonitis: Clinical manifestations - Prospective data from the interstitial lung disease-India registry.

CONTEXT: Multiple environmental factors are associated with development of hypersensitivity pneumonitis (HP), and diagnostic algorithms for the diagnosis of HP have been proposed in recent perspectives. AIMS: We analyzed the data of patients with HP from interstitial lung disease (ILD)-India registry. The analysis was performed to (1) find the prevalence of HP, (2) reclassify HP as per a recently proposed classification criterion to assess the level of diagnostic certainty, and (3) identify the causative agents for HP. SETTING AND DESIGNS: This was a prospective multicenter study of consecutive, consenting adult patients with new-onset ILD from 27 centers across India (March 2012-April 2015). MATERIALS AND METHODS: The diagnoses were based on prespecified working clinical criteria and multidisciplinary discussions. To assess strength of diagnosis based on available clinical information, patients with HP were subclassified into definite HP, HP with high level of confidence, and HP with low level of confidence using a recent classification scheme. RESULTS: Five hundred and thirteen of 1084 patients with new-onset ILD were clinically diagnosed with HP and subclassified as HP with high level of confidence (380, 74.1%), HP with low level of confidence (106, 20.7%), and definite HP (27, 5.3%). Exposures among patients with HP were birds (odds ratios [OR]: 3.52, P < 0.001), air-conditioners (OR: 2.23, P < 0.001), molds (OR: 1.79, P < 0.001), rural residence (OR: 1.64, P < 0.05), and air-coolers (OR: 1.45, P < 0.05). CONCLUSIONS: About 47.3% of patients with new-onset ILD in India were diagnosed with HP, the majority of whom were diagnosed as HP with a high level of confidence. The most common exposures were birds, cooling devices, and visible molds.