Clinical phenotyping in sarcoidosis management.

Sarcoidosis is a heterogeneous granulomatous disease. Biological markers and clinical features could allow specific phenotypes to be associated with different prognosis, severity and treatment responses. This retrospective multicentre study aims to analyse the clinical and immunological features of sarcoidosis and to identify a routine non-invasive biomarker useful in clinical practice. MATERIALS AND

methods129 Caucasian patients with sarcoidosis (median age IQR, 56 (47-62)) were enrolled retrospectively in the study. Medical history, routine laboratory findings, lung function results and radiological features from the last examination of October 2019 - February 2020 were gathered from the patients' clinical records.

resultsRegardless their clinical status at disease onset, at the last clinical examination we didn't observe any differences in terms of therapeutic management between symptomatic and asymptomatic patients. Stratifying sarcoidosis population according to therapeutic management, the N/L ratio was higher in the treated group than in the non-treated group (p=0.0034). Receiver operating curve (ROC) analysis distinguished these two groups according to N/L ratio with an area under the curve (AUC) of 65.3% and a best cut-off value of 2.21. Peripheral N/L ratio was significantly higher in radiological stages 2-4 than in stages 0-1 (p=0.0090) distinguishing these two groups with an AUC of 64% and a best cut-off value of 2.13. DISCUSSION: In our multicentric cohort study similar periodic follow-up can be suggested for symptomatic and asymptomatic sarcoidosis patients at onset. In the heterogeneous context of this disease, N/L ratio proved to be a useful and simple routine laboratory biomarker related to disease activity and need for treatment.