Whole blood immunophenotyping uncovers immature neutrophil-to-VD2 T-cell ratio as an early marker for severe COVID-19
Guillaume Carissimo, Weili Xu, Immanuel Kwok, Mohammad Yazid Abdad, Yi‐Hao Chan, Siew‐Wai Fong, Kia Joo Puan, Cheryl Yi‐Pin Lee, Nicholas Kim‐Wah Yeo, Siti Naqiah Amrun, Rhonda Sin‐Ling Chee, Wilson How, Stephrene Seok Wei Chan, Bingwen Eugene Fan, Anand Kumar Andiappan, Bernett Lee, Olaf Rötzschke, Barnaby Edward Young, Yee‐Sin Leo, David Chien Lye, Laurent Rénia, Lai Guan Ng, Anis Larbi, Lisa F. P. Ng
Abstract
SARS-CoV-2 is the novel coronavirus responsible for the current COVID-19 pandemic. Severe complications are observed only in a small proportion of infected patients but the cellular mechanisms underlying this progression are still unknown. Comprehensive flow cytometry of whole blood samples from 54 COVID-19 patients reveals a dramatic increase in the number of immature neutrophils. This increase strongly correlates with disease severity and is associated with elevated IL-6 and IP-10 levels, two key players in the cytokine storm. The most pronounced decrease in cell counts is observed for CD8 T-cells and VD2 γδ T-cells, which both exhibit increased differentiation and activation. ROC analysis reveals that the count ratio of immature neutrophils to VD2 (or CD8) T-cells predicts pneumonia onset (0.9071) as well as hypoxia onset (0.8908) with high sensitivity and specificity. It would thus be a useful prognostic marker for preventive patient management and improved healthcare resource management.