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.