A new study from the Huazhong University of Science and Technology in Wuhan, China has found that a combination of low killer T-cells and high neutrophils significantly increases the risk of severe COVID-19 symptoms. This is especially true for individuals with pre-existing conditions, the elderly, and those who are overweight. The study, published in the journal EBioMedicine, analyzed health data from 40 COVID-19 patients treated in a Wuhan hospital. The research found that killer T-cells with the surface marker (CD8) can predict the severity of the disease by killing virus-infected cells and inhibiting the replication of the SARS-CoV-2 virus. Patients with low levels of these cells are at a higher risk of developing severe symptoms such as pneumonia or blood clotting disorders. Additionally, the study found that neutrophils, which are typically used to fight bacteria, can also suppress T-cell function and increase the risk of severe COVID-19 symptoms.
According to Ulf Dittmer, Director of the Institute of Virology at the University Hospital Essen and co-author of the study, patients with pre-existing conditions that decrease T-cell counts, such as cancer patients undergoing chemotherapy or seniors with age-related T-cell decline, are particularly vulnerable to severe COVID-19 symptoms. The study also confirmed previous research that found a link between obesity and severe COVID-19 symptoms, as overweight individuals tend to have weaker and fewer T-cells. The researchers suggest that stimulating killer T-cells at the onset of infection could boost the body’s natural defenses against the virus, which can be achieved through certain vaccines or vitamins A and C. For transplant patients, reducing the dosage of immunosuppressive drugs can also lower the risk of severe COVID-19 symptoms.
While the study’s findings are promising, Michael Lohoff, Director of the Institute of Medical Microbiology and Hospital Hygiene at the University of Marburg, notes that the sample size is small and further research is needed to confirm the results. He suggests that a reliable test that can predict the severity of COVID-19 symptoms would be helpful in identifying high-risk patients and providing early treatment. However, Dittmer notes that conducting extensive studies in Germany has become difficult due to the decreasing number of patients with severe COVID-19 symptoms being admitted to hospitals.
