Treatment issues in interstitial lung disease in tropical countries

Spectrum of interstitial lung diseases at a tertiary center in a developing country: A study of 803 subjects

Background

The spectrum of interstitial lung diseases (ILDs) have mainly been reported from the developed countries; data from developing countries is sparse and conflicting. The aim of this study is to describe the distribution of various ILDs from a developing country.

Methods

This is an analysis of prospectively collected clinical, radiological and histological data of consecutive subjects (age >12 years) with ILDs from a single tertiary care medical center. The diagnosis of the specific subtype of ILD was made according to standard criteria for various ILDs.

Results

A total of 803 subjects (mean age, 50.6 years; 50.2% women) were enrolled between March 2015 to February 2017 of which 566 (70.5%) were diagnosed during the study period (incident cases). Sarcoidosis (42.2%), idiopathic pulmonary fibrosis (IPF, 21.2%), connective tissue disease (CTD)-related ILDs (12.7%), hypersensitivity pneumonitis (10.7%), and non-IPF idiopathic interstitial pneumonias (9.2%) were the most common ILDs. The spectrum of ILDs was not significantly different (p = 0.87) between incident and prevalent cases. A histopathological specimen was obtained in 49.9% of the subjects yielding a histologically confirmed diagnosis in 40.6%. A diagnostic procedure was not performed in 402 subjects; the most common reasons were presence of definite usual interstitial pneumonia pattern on high resolution computed tomography and patients’ unwillingness to undergo the procedure.

Conclusion

Sarcoidosis, IPF and CTD-ILDs were the most common ILDs seen at a tertiary center in northern India similar to the spectrum reported from developed countries. More studies are required from developing countries to ascertain the spectrum of ILDs in different geographic locales.

Sarcoidosis in developing countries

Sarcoidosis is seen in different parts of India and other developing countries with almost similar frequency as in the West. It was largely due to lack of awareness and non-availability of investigations for diagnosis that the disease was reported to be rare in the past. A combination of clinical, radiologic, and histologic criteria are used to diagnose sarcoidosis. A confident exclusion of other causes of granuloma formation, especially tuberculosis, is required. Absence of mycobacteria and of caseation in the histologic specimens and presence of skin anergy to tuberculin help make a diagnosis. Transbronchial lung biopsy obtained with the help of fiberoptic bronchoscopy is positive in about 80% of patients. Corticosteroids are used to treat patients with symptoms and those showing active organ involvement. Aggressive treatment is required for patients with acute and severe pulmonary, cardiac, ocular, or neurologic involvements.