The number of circulating CD26 expressing cells is decreased in critical COVID-19 illness

We evaluated the number of CD26 expressing cells in peripheral blood of patients with COVID-19 within 72 h of admission and on day 4 and day 7 after enrollment. The majority of CD26 expressing cells were presented by CD3(+)CD4(+) lymphocytes. A low number of CD26 expressing cells were found to be associated with critical-severity COVID-19 disease. Conversely, increasing numbers of CD26 expressing T cells over the first week of standard treatment was associated with good outcomes. Clinically, the number of circulating CD26 cells might be a marker of recovery or the therapeutic efficacy of anti-COVID-19 treatment. New therapies aimed at preserving and increasing the level of CD26 expressing T cells may prove useful in the treatment of COVID-19 disease.

Automated summary

The study showed that the number of CD26 expressing cells in the peripheral blood of COVID-19 patients is associated with disease severity and treatment outcomes. CD3(+)CD4(+) lymphocytes are the main cell type expressing CD26, and a low number of CD26 expressing cells is associated with critical disease, while an increasing number of CD26 expressing T cells during the first week of treatment is associated with good outcomes.