Publication:

A study of respiratory system involvement in autoimmune connective tissue diseases: a marker of morbidity

Background The auto-immune connective tissue diseases (AICTD) are polygenic clinical disorders having heterogeneous overlapping clinical features. Certain features like autoimmunity, vascular abnormalities, arthritis/arthralgia and cutaneous manifestations are common to them. Lung involvement can present in AICTDs in form of: pleurisy, acute/ chronic pneumonitis, pulmonary artery hypertension (PAH), shrinking lung syndrome, diffuse alveolar damage, pulmonary embolism (PE), bronchiolitis obliterans organizing pneumonia, pulmonary infections, cardiogenic pulmonary edema, etc. High-resolution computed tomography (HRCT) plays an important role in identifying patients with respiratory involvement. Pulmonary function tests are a sensitive tool detecting interstitial lung disease.

Methods The present study is an observational study carried out on 170 patients of AICTD in department of Dermatology, Venereology and Leprosy at a tertiary care centre during a period of 2 years from October 2017 to August 2019. Detailed history, examination and relevant investigations like chest X-ray, pulmonary function test (PFT), HRCT thorax were done as indicated.

Results The overall incidence of respiratory involvement was 56.7% with maximum involvement in systemic sclerosis cases (82.8% of cases). 45.7% of patients of systemic lupus erythematosus had respiratory involvement, most common being pleural effusion in 11.5%. Impaired PFT’s were seen in 82.8% cases of systemic sclerosis (SSc)  and all cases of UCTD. Interstitial lung disease was seen in 34.7% and 25% cases of SSc and DM respectively. PAH was found in 15.2% cases of SSc and 9.8% cases of mixed connective tissue diseases.

Conclusions AICTD are multisystem disorders in which pulmonary involvement can be an important cause of morbidity to the patient and early detection is necessary for prevention of long-term respiratory complications.