T-lymphocytes, the type of white blood cell that plays a key role in fighting infections, are at the center of a recent study on why some patients fare worse than others when infected with the COVID virus. According to research published in a well-known immunology journal, patients with mild or asymptomatic COVID had both higher numbers and better functioning T-cells (aka T-lymphocytes). In fact, patients who fared worse consistently displayed T-cells that were literally exhausted and ceased to function properly. Their T-cells could no longer proliferate (multiply), nor could they properly communicate with other cells, which is one of their main functions – to signal other cells how to respond to pathogens.
A study on 499 patients with confirmed SARS-CoV2 infections showed that COVID patients consistently demonstrated biomarkers associated with dysfunctional T-cells.
In other words, their T-cells were incapable of launching an effective immune response – they neither multiplied in sufficient enough numbers, and the T-cells that did exist didn’t work very well. This led to a two-fold deleterious outcome: low T-cell count and poor T-cell function. In the T-cells that were present, they could not proliferate (due to functional exhaustion), thus confounding the problem of low T-cell count. Clinically, patients with worse prognosis and severe symptoms consistently demonstrated this dysfunctional T-cell state.
An effective immune response depends on activating T cells to do their job, which is to respond against infections. The authors state that “boosting the numbers and function of T cells in COVID-19 patients is critical for successful recovery.” Spectracell measures T-cell function in a test called the Immunidex.
(Frontiers in Immunology, May 2020)