Possible neglected transient (T) polyagglutination in critically ill patients with coronavirus disease-2019 (Covid-19)

T-activation polyagglutination can be caused by bacteria or viruses and has been associated with haemolytic anaemia. Coronavirus disease-19 (COVID-19) is also associated with haemolytic anaemia. The presented study aims to determine T activation polyagglutination in critically ill COVID-19 patients. Anti-T Arachis hypogaea lectin was incubated with the red blood cells of the COVID-19 patient and checked for agglutination. Thirty-four percent (34.3%) of COVID-19 patients in the intensive care unit (ICU) had potentially activated T cells and polyagglutinable red blood cells, as demonstrated by their cryptantigen exposure that caused agglutination. The study revealed a high prevalence of anti-T among ICU-admitted COVID-19 patients, suggesting that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may cause transient T activation, polyagglutination in critically ill COVID-19 patients in vitro and possibly haemolysis in vivo.