Retrospective Study of Factors Potentially Influencing Occurrence of Cough in Slovak Patients with Sarcoidosis

INTRODUCTION: Sarcoidosis is a multisystem granulomatous disease of unknown aetiology, commonly involving the lungs. Cough is a frequent and troublesome symptom of sarcoidosis that reduces patients' quality of life. AIM: Retrospective analysis of different factors—smoking history, Scadding stage, results of lung function testing, calcium metabolism, endobronchial finding, CD4+/CD8+ T-cell ratio in bronchoalveolar lavage fluid (BALF), and other sarcoidosis symptoms in relationship to presence/absence of cough in sarcoidosis patients. METHODS: We retrospectively studied sarcoidosis patients diagnosed at the Clinic of Pneumology and Phthisiology of Martin University Hospital between 1998 and 2018. Patients with a history of cough-relevant comorbidities were excluded from the study. GraphPad Prism 7.0 software was used to perform statistical analysis. RESULTS: 101 sarcoidosis patients were included to the study: 65 patients reporting from cough and 36 without cough. The cough was slightly more frequent in nonsmokers (p=0.166) and in women (p=0.688). Cough was associated with dyspnoea (p=0.0007), fever (p=0.0324), and chest pain (p=0.0206) and did not associate with arthralgia (p=0.317) and erythema nodosum (p=0.505). Patients with cough had significantly a lower average value of calciuria (p=0.0014) and lower MEF25 (p=0.0304), MEF50 (p=0.0061), FEV1 (p=0.0025), and FVC (p=0.0025) in % of predicted values, and more often positive endobronchial finding (p=0.0206), compared to patients without cough. Calcemia, FEV1/FVC, DLCO, and CD4+/CD8+ T-cell ratio in BALF and occurrence of cough did not differ between different stages of the disease. CONCLUSIONS: We found significant differences between sarcoidosis patients with/without cough regarding symptoms, results of lung function tests, endobronchial finding, and calcium metabolism. Further research is needed to understand the etiopathogenesis of cough in sarcoidosis patients.