Hand-mirror lymphocytes in infectious mononucleosis

Area of Science:

• Immunology
• Hematology
• Cell Biology

Background:

• Infectious mononucleosis (IM) is a common viral illness.
• Morphologically unique lymphocytes have been observed in IM patients.
• Understanding lymphocyte subsets in IM is crucial for diagnosis and prognosis.

Purpose of the Study:

• To identify and characterize a unique lymphocyte morphology in infectious mononucleosis.
• To quantify the prevalence of hand-mirror lymphocytes (HML) in IM patients.
• To determine the cellular lineage and potential function of HML in IM.

Main Methods:

• Peripheral blood smears from IM patients and controls were examined.
• Wright staining and differential counts were performed.
• E-rosette separation and cytochemistry were used to identify T-cells.
• Electron microscopy was employed for ultrastructural analysis.

Main Results:

• Patients with IM showed significantly higher percentages of HML (mean 9.2%) compared to controls (2.7%).
• HML counts increased during the recovery phase of IM (mean 12.1%).
• HML were predominantly found within the T-cell population (approx. 25% of T-cells) in IM patients.

Conclusions:

• Hand-mirror lymphocytes are a distinct feature of infectious mononucleosis.
• HML are primarily T-cells and their numbers increase during recovery.
• The unique ultrastructure of HML suggests a role in cellular attachment and cytotoxicity.