AUTHOR=Lim Jackwee , Puan Kia Joo , Wang Liang Wei , Teng Karen Wei Weng , Loh Chiew Yee , Tan Kim Peng , Carissimo Guillaume , Chan Yi-Hao , Poh Chek Meng , Lee Cheryl Yi-Pin , Fong Siew-Wai , Yeo Nicholas Kim-Wah , Chee Rhonda Sin-Ling , Amrun Siti Naqiah , Chang Zi Wei , Tay Matthew Zirui , Torres-Ruesta Anthony , Leo Fernandez Norman , How Wilson , Andiappan Anand Kumar , Lee Wendy , Duan Kaibo , Tan Seow-Yen , Yan Gabriel , Kalimuddin Shirin , Lye David Chien , Leo Yee-Sin , Ong Sean W. X. , Young Barnaby E. , Renia Laurent , Ng Lisa F. P. , Lee Bernett , Rötzschke Olaf TITLE=Data-Driven Analysis of COVID-19 Reveals Persistent Immune Abnormalities in Convalescent Severe Individuals JOURNAL=Frontiers in Immunology VOLUME=12 YEAR=2021 URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.710217 DOI=10.3389/fimmu.2021.710217 ISSN=1664-3224 ABSTRACT=

Severe SARS-CoV-2 infection can trigger uncontrolled innate and adaptive immune responses, which are commonly associated with lymphopenia and increased neutrophil counts. However, whether the immune abnormalities observed in mild to severely infected patients persist into convalescence remains unclear. Herein, comparisons were drawn between the immune responses of COVID-19 infected and convalescent adults. Strikingly, survivors of severe COVID-19 had decreased proportions of NKT and Vδ2 T cells, and increased proportions of low-density neutrophils, IgA+/CD86+/CD123+ non-classical monocytes and hyperactivated HLADR+CD38+ CD8+ T cells, and elevated levels of pro-inflammatory cytokines such as hepatocyte growth factor and vascular endothelial growth factor A, long after virus clearance. Our study suggests potential immune correlates of “long COVID-19”, and defines key cells and cytokines that delineate true and quasi-convalescent states.