Alterations in immune function following head injury in children

Area of Science:

• Pediatric critical care medicine
• Immunology
• Neurotrauma research

Background:

• Severe head injury (SHI) can significantly impact a child's immune system.
• Understanding immune responses post-SHI is crucial for predicting outcomes and developing interventions.

Purpose of the Study:

• To investigate cellular and humoral immune responses in children following severe head injury.
• To assess immune function during the acute phase and early recovery period after SHI.

Main Methods:

• Prospective observational study involving 15 children with SHI (Glasgow Coma Score ≤ 7).
• Assessed cellular immunity via skin antigen testing, lymphocyte counts, and mitogen proliferation tests (PHA, ConA, PWM).
• Measured humoral immunity through immunoglobulin concentrations and evaluated plasma effects on T-cell responses.

Main Results:

• Anergy was prevalent, affecting 71% on day 1 and decreasing to 18% by 3 months post-injury.
• Decreased T-cell counts and phytohemagglutinin responses were observed acutely, with elevated B-cell counts and later immunoglobulin increases.
• Patient plasma from day 7 post-injury suppressed normal lymphocyte proliferation, suggesting immunosuppressive factors.

Conclusions:

• Severe head injury in children is linked to significant depression of cell-mediated immunity.
• Immunosuppressive factors in plasma may play a role in the observed T-cell dysfunction after SHI.