Elevated frequencies of CD14⁺HLA-DR^lo/neg MDSCs in COVID-19 patients

Area of Science:

• Immunology
• Virology
• Critical Care Medicine

Background:

• Immune responses, including hyper-inflammation and immunosuppression, are critical in COVID-19 progression.
• CD14⁺HLA-DR^lo/neg myeloid-derived suppressor cells (MDSCs) possess potent immunosuppressive capabilities.
• Understanding MDSC dynamics in COVID-19 is crucial for assessing disease severity and immune status.

Purpose of the Study:

• To evaluate changes in the frequency of CD14⁺HLA-DR^lo/neg MDSCs in COVID-19 patients.
• To determine the association of these MDSCs with clinical characteristics and laboratory data.
• To assess the potential of CD14⁺HLA-DR^lo/neg MDSCs as a predictor of COVID-19 severity.

Main Methods:

• Flow cytometry was used to quantify CD14⁺HLA-DR^lo/neg MDSCs in 27 COVID-19 patients.
• Analysis included correlations with clinical parameters and laboratory findings.
• Follow-up assessments were conducted after patients tested negative for SARS-CoV-2.

Main Results:

• Elevated frequencies of CD14⁺HLA-DR^lo/neg MDSCs were observed in COVID-19 patients, especially severe cases.
• MDSC levels correlated positively with viral load and hospital stay, and negatively with lymphocyte counts and albumin.
• High MDSC frequencies persisted in some ICU patients even after testing negative for SARS-CoV-2.

Conclusions:

• A high frequency of CD14⁺HLA-DR^lo/neg MDSCs, particularly in severe COVID-19, suggests immunoparalysis.
• These MDSCs serve as a potential biomarker for predicting disease severity and patient prognosis.
• Further research is warranted to explore therapeutic strategies targeting MDSCs in COVID-19.