Acute lymphopenia, stress, and plasma cortisol

Area of Science:

• Pediatric Endocrinology
• Clinical Immunology
• Stress Physiology

Background:

• Acute illnesses in children can induce significant physiological stress responses.
• Lymphopenia (low lymphocyte count) and elevated plasma cortisol are known markers of stress.
• The relationship between cortisol levels and lymphocyte counts during acute illness in pediatric populations requires further elucidation.

Purpose of the Study:

• To investigate the dynamic changes in plasma cortisol levels and lymphocyte counts in children hospitalized with acute illnesses.
• To assess the utility of the cortisol level/lymphocyte count ratio as an indicator of acute stress and recovery.
• To determine the temporal relationship between lymphocyte normalization and plasma cortisol levels post-illness.

Main Methods:

• Prospective study involving 51 children admitted to the hospital for acute illnesses.
• Plasma cortisol levels and lymphocyte counts were measured on admission (acute phase) and upon recovery (lymphocyte count normalized).
• Calculation of the cortisol level/lymphocyte count ratio for both phases.

Main Results:

• A significantly higher cortisol level/lymphocyte count ratio was observed during the acute phase of illness compared to the recovery phase.
• This ratio decreased as lymphocyte counts returned to normal levels.
• The findings suggest a clear correlation between illness severity, stress response, and immune cell dynamics.

Conclusions:

• The lymphocyte count serves as a valuable indicator for detecting acute stress conditions in children.
• The cortisol level/lymphocyte count ratio effectively reflects the body's stress response during acute illness.
• Monitoring this ratio aids in assessing the time course of recovery and the normalization of plasma cortisol levels.