Spectrum of Diffuse Parenchymal Lung Diseases in Bangladesh: Institutional-based Cross- sectional Study

Background The definite patterns of Diffuse Parenchymal Lung Diseases (DPLD) are not known in Bangladesh. This is the first study in our country aimed at evaluating the frequency and clinical spectrum of various types of DPLDs. Methods This cross-sectional study was conducted at the Department of Respiratory Medicine, Bangladesh Medical University (BMU) in Bangladesh over one year. DPLD was diagnosed based on clinical, radiological, pulmonary function tests, and/or histopathological background. Patients with a diagnosis of chronic lung disease like tuberculosis, lung malignancy, asthma, chronic obstructive pulmonary disease (COPD), bronchiectasis, chronic heart disease like chronic heart failure, or valvular heart disease were excluded from this study. Results Seventy-seven participants were included in this study. Connective tissue disease-associated DPLD (CTD-DPLD) was the most common entity (n = 25, 32.4%), followed by non-specific interstitial pneumonia (NSIP) (n = 23, 29.9%), and idiopathic pulmonary fibrosis (IPF) (n = 16, 20.8%). The mean age was 53.16 ± 15.56 years, and females were predominant (58.4%). Age, sex, and occupation were significantly associated with DPLD (p < 0.05). The most common symptom was coughing (97.4%), followed by shortness of breath (96.1%). Clubbing (87.5%) and Gastroesophageal reflux disease (GERD) (62.5%) were most frequent in IPF, and extra-pulmonary manifestations in CTD-DPLD. Clubbing, arthralgia, Raynaud's, joint deformity, and GERD were significantly associated with DPLD. Bilateral (95%), subpleural (75.0%) involvement, and honeycombing (68.7%) were more frequent in IPF. On pulmonary function tests, most of them have restrictive lung disease. Conclusions DPLD encompasses a group of diseases with a wide range of causes that have various presentations and prognoses. We found CTD-DPLD, IPF, and NSIP were the most common causes. CTD-DPLD typically occurs in younger individuals with a higher prevalence of extrapulmonary manifestations.