Spectrum of interstitial lung diseases and their association with pulmonary hypertension

Interstitial lung diseases (ILDs) are an intriguing group of pulmonary disorders, which still require the study of epidemiological, genetic, pathophysiological, clinical, and radiological parameters. Pulmonary hypertension (PH) is an underreported complication in interstitial lung diseases which is associated with worse outcome. In our study, we have reported the spectrum of ILDs and estimated the prevalence of pulmonary hypertension among these subjects at a tertiary care centre. A cross-sectional study was performed in which demographical, clinical, radiological, and histological data of subjects with ILD, attending the department of Respiratory Medicine in the University was collected from 1^st September 2018 to 31^st August 2019. Serological tests were done wherever indicated. Standard criteria along with multidisciplinary opinion were needed to arrive at the final diagnosis. All subjects were screened for pulmonary hypertension via 2-D echocardiography. Mean pulmonary artery pressure ≥20 mmHg was used to define PH. In the defined period, 239 subjects were enrolled (58% females, n=141; mean age 52.38±13.40 years). A tissue diagnosis was obtained in 34% cases.  The most common ILD was hypersensitivity pneumonitis (32.2%), followed by autoimmune-ILD (31.4%), idiopathic pulmonary fibrosis (IPF) (15.9%) and sarcoidosis (12.6%), non-IPF idiopathic interstitial pneumonitis (2.1%) and rest 21 (5.9%) subjects were diagnosed as other types of ILD.  Pulmonary hypertension was seen in 46.0% of subjects.

Selman M. Hypersensitivity pneumonitis. In: Interstitial lung disease, 5th ed. Schwarz M, and King TE Jr, editors. Shelton, CT: People’s Medical Publishing House-USA; 2011. pp. 597-625.

Raghu G, Collard HR, Egan JJ, et al. An official ATS/ERS/JRS/ALAT statement: idiopathic pulmonary fibrosis: evidence- based guidelines for diagnosis and management. Am J Respir Crit Care Med 2011;183:788. DOI: https://doi.org/10.1164/rccm.2009-040GL

American Thoracic Society, European Respiratory Society. American Thoracic Society/European Respiratory Society International Multidisciplinary Consensus Classification of the Idiopathic Interstitial Pneumonias. This joint statement of the American Thoracic Society (ATS), and the European Respiratory Society (ERS) was adopted by the ATS board of directors, June 2001 and by the ERS Executive Committee, June 2001. Am J Respir Crit Care Med 2002;165:277. DOI: https://doi.org/10.1164/ajrccm.165.2.ats01

King TE Jr, Pardo A, Selman M. Idiopathic pulmonary fibrosis. Lancet 2011;378:1949. DOI: https://doi.org/10.1016/S0140-6736(11)60052-4

Travis WD, Hunninghake G, King TE Jr, et al. Idiopathic nonspecific interstitial pneumonia: report of an American Thoracic Society project. Am J Respir Crit Care Med 2008;177:1338. DOI: https://doi.org/10.1164/rccm.200611-1685OC

Bradley B, Branley HM, Egan JJ, et al. Interstitial lung disease guideline: the British Thoracic Society in collaboration with the Thoracic Society of Australia and New Zealand and the Irish Thoracic Society. Thorax 2008;63:v1-58. DOI: https://doi.org/10.1136/thx.2008.101691

Cottin V, Hirani NA, Hotchkin DL, et al. Presentation, diagnosis and clinical course of the spectrum of progressive-fibrosing interstitial lung diseases. Eur Respir Rev 2018;27:180076. DOI: https://doi.org/10.1183/16000617.0076-2018

Singh S, Sharma BB, Bairwa M, et al. Management of interstitial lung diseases: A consensus statement of the Indian Chest Society (ICS) and National College of Chest Physician (NCCP). Lung India 2020;37:359-78.

Behr J, Ryu J. H. Pulmonary hypertension in interstitial lung disease. Eur Respir J 2008;31:1357-67. DOI: https://doi.org/10.1183/09031936.00171307

Maimon N, Salz L, Shershevsky Y, et al. Sarcoidosis-associated pulmonary hypertension in subjects with near-normal lung function. Int J Tuberc Lung Dis 2013;17:406-11. DOI: https://doi.org/10.5588/ijtld.12.0428

Oliveira RK, Pereira CA, Ramos RP, et al. A haemodynamic study of pulmonary hypertension in chronic hypersensitivity pneumonitis. Eur Respir J 2014;44:415-24. DOI: https://doi.org/10.1183/09031936.00010414

Koschel DS, Cardoso C, Wiedemann B, et al. Pulmonary hypertension in chronic hypersensitivity pneumonitis. Lung 2012;190:295-302. DOI: https://doi.org/10.1007/s00408-011-9361-9

Yan W, Peng LY, Ban CJ, et al. Incidence and clinical characteristics of pulmonary hypertension in subjects with idiopathic pulmonary fibrosis. Chin Med J (Engl) 2015;128:896-901. DOI: https://doi.org/10.4103/0366-6999.154284

Cottin V, Le Pavec J, Prévot G, et al. Pulmonary hypertension in subjects with combined pulmonary fibrosis and emphysema syndrome. Eur Respir J 2010;35:105-11. DOI: https://doi.org/10.1183/09031936.00038709

Hatano S, Strasser T, World Health Organization. Primary pulmonary hypertension: report on a WHO meeting, Geneva, 15-17 October 1973. World Health Organization; 1975.

Simonneau G, Montani D, Celermajer DS, et al. Haemodynamic definitions and updated clinical classification of pulmonary hypertension. Eur Respir J 2019;53:1801913. DOI: https://doi.org/10.1183/13993003.01913-2018

Haddad F, Zamanian R., Beraud A-S, et al. A novel non-invasive method of estimating pulmonary vascular resistance in subjects with pulmonary arterial hypertension. J Am Soc Echocardiogr 2009;22:523-9. DOI: https://doi.org/10.1016/j.echo.2009.01.021

Currie PJ. Seward JB, Chan KL, et al. Continuous wave Doppler determination of right ventricular pressure: a simultaneous Doppler-catheterization study in 127 subjects. J Am Coll Cardiol 1985;6:750-6. DOI: https://doi.org/10.1016/S0735-1097(85)80477-0

Amsallem M, Sternbach JM, Adigopula S, et al. Addressing the controversy of estimating pulmonary arterial pressure by echocardiography. J Am Soc Echocardiogr 2016;29:93-102. DOI: https://doi.org/10.1016/j.echo.2015.11.001

Saleem SM. Modified Kuppuswamy scale for the year 2018. Papirex Indian J Res 2018;7:217-18.

Jones PW, Adamek L, Nadeau G et al. Comparisons of health status scores with MRC grades in COPD: implications for the GOLD 2011 classification. Eur Respir J 2013;42:647–54. DOI: https://doi.org/10.1183/09031936.00125612

ATS Committee on Proficiency Standards for Clinical Pulmonary Function Laboratories. ATS statement: guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002;166:111–7. DOI: https://doi.org/10.1164/ajrccm.166.1.at1102

Guidelines for the measurement of respiratory function. Recommendations of the British Thoracic Society and the Association of Respiratory Technicians and Physiologists. Respir Med 1994;88:165–94. DOI: https://doi.org/10.1016/S0954-6111(05)80346-4

Moore VC. Spirometry: step by step. Breathe 2012;8:232-40. DOI: https://doi.org/10.1183/20734735.0021711

ATS/ERS Task Force. Standardisation of Lung Fuction testing. Interpretative strategies for lung function tests. Eur Respir J 2005;26:948-58. DOI: https://doi.org/10.1183/09031936.05.00035205

Global Initiative for Chronic Obstructive Lung Disease (GOLD). Global Strategy for the Diagnosis, Management and Prevention of COPD, 2018. Accessed: July 17, 2018. Available from: https://goldcopd.org/gold-reports/

Raghu G, Remy-Jardin M, Myers JL, et al. Diagnosis of idiopathic pulmonary fibrosis- An official ATS/ERS/JRS/ALAT clinical practice guideline. Am J Respir Crit Care Med 2018;198:563–80. DOI: https://doi.org/10.1164/rccm.201807-1255ST

Travis WD, Costabel U, Hansell DM, et al. An official American Thoracic Society/European Respiratory Society statement: Update of the international multidisciplinary classification of the idiopathic interstitial pneumonias. Am J Respir Crit Care Med 2013;188:733–48. DOI: https://doi.org/10.1164/rccm.201308-1483ST

Fischer A, Antoniou KM, Brown KK, et al. An official European Respiratory Society/American Thoracic Society research statement: interstitial pneumonia with autoimmune features. Eur Respir J 2015;46:976-87. DOI: https://doi.org/10.1183/13993003.00150-2015

Rudski LG, Lai WW, Afilalo J, et al. Guidelines for the echocardiographic assessment of the right heart in adults: A report from the American Society of Echocardiography. J Am Soc Echocardiogr 2010;23:685-713. DOI: https://doi.org/10.1016/j.echo.2010.05.010

Mahan G, Dabestani A, Gardin J, et al. Estimation of pulmonary artery pressure by pulsed Doppler echocardiography. Circulation 1983;68:367.

Life in the Fastlane [Internet]. Pulmonary Hypertension Echocardiography. Accessed: 1st July, 2020. Available from: https://litfl.com/pulmonary-hypertension-echocardiography/

Singh S, Collins BF, Sharma BB, et al. Interstitial lung disease in India. Results of a prospective registry. Am J Respir Crit Care Med 2017;195:801-13. DOI: https://doi.org/10.1164/rccm.201607-1484OC

Dhooria S, Agarwal R, Sehgal IS, et al. Spectrum of interstitial lung diseases at a tertiary center in a developing country: A study of 803 subjects. PLoS One 2018;13:e0191938. DOI: https://doi.org/10.1371/journal.pone.0191938

Akhter N, Rizvi NA. Interstitial lung diseases misdiagnosed as tuberculosis. Pak J Med Sci 2018;34:338-41. DOI: https://doi.org/10.12669/pjms.342.14407

Kumar R, Gupta N, Goel N. Spectrum of interstitial lung disease at a tertiary care centre in India. Pneumonol Alergol Pol 2014;82:218-26. DOI: https://doi.org/10.5603/PiAP.2014.0029

Sen T, Udwadia ZF. Retrospective study of interstitial lung disease in a tertiary care centre in India. Indian J Chest Dis Allied Sci 2010;52:207–11.

Karakatsani A, Papakosta D, Rapti A, et al. Epidemiology of interstitial lung diseases in Greece. Respir Med 2009;103:1122–9. DOI: https://doi.org/10.1016/j.rmed.2009.03.001

Alhamad EH. Interstitial lung diseases in Saudi Arabia: A single-center study. Ann Thorac Med 2013;8:33–7. DOI: https://doi.org/10.4103/1817-1737.105717

Musellim B, Okumus G, Uzaslan E, et al. Epidemiology and distribution of interstitial lung diseases in Turkey. Clin Respir J 2014;8:55–62. DOI: https://doi.org/10.1111/crj.12035

Hyldgaard C, Hilberg O, Muller A, Bendstrup E. A cohort study of interstitial lung diseases in central Denmark. Respir Med 2014;108: 93–9. DOI: https://doi.org/10.1016/j.rmed.2013.09.002