Serial KL-6 measurements in COVID-19 patients
Miriana d’Alessandro, Laura Bergantini, Paolo Cameli, Giuseppe Curatola, Lorenzo Remediani, David Bennett, Francesco Bianchi, Felice Perillo, Luca Volterrani, Maria Antonietta Mazzei, Elena Bargagli, Siena COVID, Nicola Lanzarone, Francesca Montagnani, Anna Perrone, Federico Franchi, Sabino Scolletta, Serafina Valente, Lucia Migliorini, Barbara Rossetti, Cecilia Vagaggini, Pier Leopoldo Capecchi, Maria Grazia Cusi, Bruno Frediani, Egidio Mastrocinque, Matteo Cameli, Marco Antonio Bellini, Arianna De Lalla, Andrea S. Melani, Nicola De Stefano, Barbara Rita Porchia
Abstract
SARS-CoV2-induced direct cytopathic effects against type II pneumocytes are suspected to play a role in mediating and perpetuating lung damage. The aim of this study was to evaluate serum KL-6 behavior in COVID-19 patients to investigate its potential role in predicting clinical course. Sixty patients (median age IQR, 65 (52-69), 43 males), hospitalized for COVID-19 at Siena COVID Unit University Hospital, were prospectively enrolled. Twenty-six patients were selected (median age IQR, 63 (55-71), 16 males); all of them underwent follow-up evaluations, including clinical, radiological, functional, and serum KL-6 assessments, after 6 (t1) and 9 (t2) months from hospital discharge. At t0, KL-6 concentrations were significantly higher than those at t1 (760 (311-1218) vs. 309 (210-408) p = 0.0208) and t2 (760 (311-1218) vs 324 (279-458), p = 0.0365). At t0, KL-6 concentrations were increased in patients with fibrotic lung alterations than in non-fibrotic group (755 (370-1023) vs. 305 (225-608), p = 0.0225). Area under the receiver operating curve (AUROC) analysis showed that basal KL-6 levels showed good accuracy in discriminating patients with fibrotic sequelae radiologically documented (AUC 85%, p = 0.0404). KL-6 concentrations in patients with fibrotic involvement were significantly reduced at t1 (755 (370-1023) vs. 290 (197-521), p = 0.0366) and t2 (755 (370-1023) vs. 318 (173-435), p = 0.0490). Serum concentrations of KL-6 in hospitalized COVID-19 patients may contribute to identify severe patients requiring mechanical ventilation and to predict those who will develop pulmonary fibrotic sequelae in the follow-up.