Infrared spectroscopy as a predictive tool for the severity of COVID-19 using patient's saliva: A strategy to avoid hyperinflammation

• Published in: Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy Molecular and biomolecular spectroscopy, 2024-09, Vol.317, p.124320, Article 124320
• Main Authors: Borges, Roger, Bandeira, Carla C.S., Zerbinati, Rodrigo M., Palmieri, Michelle, Schwab, Gabriela, Henrique Braz-Silva, Paulo, A. L. Lindoso, José, Martinho, Herculano
• Format: Article
• Language: English
• ISSN: 1386-1425
• DOI: 10.1016/j.saa.2024.124320

[Display omitted] •Discriminate the severity level of COVID-19 is still a challenge.•Saliva sampling represents a non-invasive, of acessible collection, and low risk way of disease discrimination.•Liquid biopsy by FTIR is molecular changes in biofluids like saliva.•Vibrational bands related to IgM and IgA can discriminate healthy from severe individuals.•Second derivative of spectra probed increased levels of IL-6 in the saliva. Discriminate the severity level of COVID-19 disease is still a challenge. Here we investigate the capability of micro-infrared absorption spectroscopy (micro-FTIR) to probe COVID-19 severity level and predict hyperinflammation, correlating the assigned vibrational data to relevant biomolecules related to the immune system. Saliva of 184 patients was analysed by ELISA assay (Hepcidin) and micro-FTIR. Vibrational bands related to IgM and IgA can discriminate healthy from Severe individuals (sensitivity ≥ 0.749, specificity ≥ 0.945) and are less effective in discriminating Mild or Moderate individuals from the Severe group (sensitivity ≥ 0.628, specificity ≥ 0.867). Analysis of the second derivative of spectra probed increased levels of IL-6 in the saliva a key additional information for the degree of severity prediction. Because the model discriminates all the groups regarding the Severe group, it predicts an intense state of inflammation based on FTIR analysis. It is a powerful tool for predicting hyperinflammation conditions related to SARS-CoV-2 infection and may be an ally in implementing drugs or therapeutic approaches to manage COVID-19 in the Severe stage in healthcare facilities.