Interstitial Lung Diseases in Developing Countries

Abstract

More than 100 different conditions are grouped under the term interstitial lung disease (ILD). A diagnosis of an ILD primarily relies on a combination of clinical, radiological, and pathological criteria, which should be evaluated by a multidisciplinary team of specialists. Multiple factors, such as environmental and occupational exposures, infections, drugs, radiation, and genetic predisposition have been implicated in the pathogenesis of these conditions. Asbestosis and other pneumoconiosis, hypersensitivity pneumonitis (HP), chronic beryllium disease, and smoking-related ILD are specifically linked to inhalational exposure of environmental agents. The recent Global Burden of Disease Study reported that ILD rank 40th in relation to global years of life lost in 2013, which represents an increase of 86% compared to 1990. Idiopathic pulmonary fibrosis (IPF) is the prototype of fibrotic ILD. A recent study from the United States reported that the incidence and prevalence of IPF are 14.6 per 100,000 person-years and 58.7 per 100,000 persons, respectively. These data suggests that, in large populated areas such as Brazil, Russia, India, and China (the BRIC region), there may be approximately 2 million people living with IPF. However, studies from South America found much lower rates (0.4-1.2 cases per 100,000 per year). Limited access to high-resolution computed tomography and spirometry or to multidisciplinary teams for accurate diagnosis and optimal treatment are common challenges to the management of ILD in developing countries.

Figure 1

Classification of Idiopathic Interstitial Pneumonias. IIP: Idiopathic Interstitial Pneumonia. Adapted from Am J Respir Crit Care Med. 2013, Vol 188, Iss. 6, pp. 733–748 [2].

Figure 2

Mechanisms by which Air Pollution Exposure Could Trigger Intertidal Lung Diseases. Modified from Chest 2015;147(4):1161–1167 [63]. PM_2.5: particulate matter <2.5 um in aerodynamic diameter; PM₁₀: particulate matter <10 um in aerodynamic diameter.