Do COVID-19 Infections Result in a Different Form of Secondary Hemophagocytic Lymphohistiocytosis

Area of Science:

• Immunology
• Infectious Diseases
• Hematology

Background:

• The COVID-19 pandemic presents a global health crisis with high morbidity and mortality.
• Severe cases of COVID-19 are linked to a cytokine storm, resembling hemophagocytic lymphohistiocytosis (HLH).
• This similarity suggests potential therapeutic benefits from immunosuppression in severe COVID-19.

Purpose of the Study:

• To review the literature on HLH diagnosis and features, focusing on secondary HLH.
• To identify knowledge gaps concerning a potential COVID-19 associated HLH.
• To evaluate the utility of current diagnostic criteria and novel biomarkers for identifying COVID-19 HLH-like presentations.

Main Methods:

• Literature review of hemophagocytic lymphohistiocytosis (HLH) and COVID-19.
• Analysis of diagnostic criteria for HLH (e.g., HScore, HLH-2004).
• Exploration of potential biomarkers (e.g., soluble CD163, NK cell activity) for COVID-19 associated HLH.

Main Results:

• Existing HLH diagnostic criteria may not be optimal for identifying COVID-19 associated HLH.
• A COVID-19 associated HLH entity requires further clarification.
• Novel biomarkers might offer improved diagnostic accuracy for COVID-19 HLH-like conditions.

Conclusions:

• The precise nature of HLH in severe COVID-19 remains unclear.
• Current diagnostic tools may need refinement for COVID-19 patients.
• Further investigation into biomarkers is crucial for understanding and managing severe COVID-19.