ACTA FAC MED NAISS 2018;35(3):216-225

Original article

UDC: 616.24-002.7-071

DOI: 10.2478/afmnai-2018-0023

CD4:CD8 Ratio: A Valuable Diagnostic Parameter for Pulmonary Sarcoidosis

Arda Kiani¹, Ian M. Adcock^2,3, Kimia Taghavi⁴, Esmaeil Mortaz⁵, Atosa Doroudinia¹, Seyed Reza Seyedi⁴, Mehdi Kazempour-Dizaji⁶, Atefeh Abedini⁴

¹Tracheal Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
²Cell and Molecular Biology Group, Airways Disease Section, National Heart and Lung Institute, Imperial College London, Dove house Street, London, UK.10
³Priority Research Centre for Healthy Lungs, Hunter Medical Research Institute, The University of Newcastle, Newcastle, New South Wales, Australia
⁴Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
⁵Department of Immunology, Faculty of Medicine, Clinical Tuberculosis and Epidemiology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran
⁶Mycobacteriology Research Center, National Research Institute of Tuberculosis and Lung Diseases (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran

summary

Sarcoidosis is a multi-organ disease and is characterized by sarcoidal noncaseating granuloma comprised of T-helper/inducer (CD4+) lymphocytes and scant cytotoxic (CD8+) T-lymphocytes. CD4+:CD8+ T-cell elevated ratio is a characteristic diagnostic parameter for sarcoidosis. This is the first report from Iran evaluating the CD4:CD8 ratio capability in differentiating pulmonary sarcoidosis from other interstitial lung diseases (ILDs) on a large cohort. Fifty pulmonary sarcoidosis patients and 50 non-sarcoidosis interstitial lung diseases (nsILDs) patients were included in the current study. Bronchoalveolar lavage (BAL) was performed using flexible fiberoptic bronchoscopy and flow cytometer. Non-sarcoidosis group was established by 50 components that were classified into eight subgroups. Fifty-two per cent of sarcoidosis patients and 62% of non-sarcoidosis interstitial lung disease patients had normal spirometric results. The CD4/CD8 ratio was significantly higher in sarcoidosis than in non-sarcoidosis interstitial lung diseases (p < 0.001). The CD4/CD8 ratio was found to be > 3.5 in 33.3%, 2.5–3.5 in 7.1%, 1.5–2.5 in 20.2% and < 1.5 in 39.4% of the entire study population. The best cut off point was 1.1 with the sensitivity of 92% andspecificity of 80% for distinguishing sarcoidosis from other interstitial lung diseases. Performing bronchoalveolar lavage as the safe and rapid first step confirms the diagnosis of sarcoidosis in 92% of cases (current study sensitivity). Hence, performing an invasive procedure was required in a few patients only. Bronchoalveolar lavage flow cytometry in the assessment of clinical and radiological findings supplies an appropriate diagnostic adjunct for discriminating sarcoidosis from non-sarcoidosis interstitial lung diseases.

Key words: sarcoidosis, bronchoalveolar lavage, lymphocyte, CD4+:CD8+ ratio, flow cytometry