Dysregulated monocyte compartment in PACS patients

Area of Science:

• Immunology
• Virology
• Hematology

Background:

• Post-acute sequelae of COVID-19 (PACS) affect 1-5% of patients, causing persistent symptoms like fatigue and cognitive dysfunction.
• Immune dysregulation, involving monocytes and cytokines, is implicated in PACS pathogenesis.
• Understanding monocyte subpopulation changes is crucial for elucidating PACS mechanisms.

Purpose of the Study:

• To investigate the impact of PACS on peripheral blood monocyte subpopulations.
• To identify specific monocyte subset alterations associated with PACS symptoms.

Main Methods:

• Flow cytometry was used to analyze monocyte subpopulations in peripheral blood.
• Hematological parameters and blood gas analysis were performed.
• PACS patients were compared with healthy donors.

Main Results:

• PACS patients exhibited increased intermediate and CD56+ monocyte counts compared to healthy controls.
• Total, classical, and non-classical monocyte counts were not significantly different overall.
• Cognitive dysfunction in PACS patients correlated with elevated non-classical monocyte numbers.

Conclusions:

• A disturbed homeostasis of monocyte subsets is present in PACS patients.
• Specific monocyte alterations may be linked to particular PACS symptoms, such as cognitive dysfunction.