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[Intradermal reaction to phytohaemagglutinin. Value in paediatrics (author's transl)]
Insights
A simple skin test using phytohaemagglutinin (PHA) effectively evaluates cellular immunity in children. This test correlates with in vitro immune function, aiding in diagnosing immune deficiencies and other conditions affecting pediatric patients.
Area of Science:
- Immunology
- Pediatrics
Context:
- Cellular immunity deficiencies are prevalent in pediatric populations.
- A simple, rapid diagnostic test for cellular immunity is needed in children.
Purpose:
- To evaluate the intradermal reaction to phytohaemagglutinin (PHA) in 690 children.
- To establish a correlation between the PHA skin test, age, and in vitro immune stimulation (PHA lymphoblastic transformation test).
Summary:
- The study investigated the intradermal PHA reaction in children aged over 1 month.
- A normal reaction involves induration >8 mm and erythema >10 mm at 24 hours, increasing with age up to 15 years.
- An 80% correlation was found between the intradermal reaction and in vitro blastic stimulation.
Impact:
- The PHA skin test is a valuable tool for assessing cellular immunity in pediatric patients.
- Decreased PHA reactions indicate potential issues in viral infections, congenital immune deficiencies, and during specific therapies like corticosteroid or chemotherapy.
- This test aids in the early detection and management of conditions affecting T-cell function in children.
Abstract:
The existence of a deficiency in cellular immunity is common in paediatrics, and hence the need for a simple and rapid test for its evaluation. We thus studied the intradermal reaction to phytohaemagglutinin (PHA) in 690 children and sought to establish a correlation with regard to age and stimulation in vitro (PHA lymphoblastic transformation test). Normally, the injection of 5 g of purified PHA is followed 24 hours later in the child aged over 1 month by an induration more than 8 mm in diameter and erythema larger than 10 mm. These diameters then increase regularly with age up to 15 years. It was possible to establish a correlation between the intradermal reaction and blastic stimulation in vitro in 80% of cases. The intradermal reaction to PHA was found to be decreased in numerous viral infections, foetal diseases, during prolonged corticosteroid therapy, and during chemotherapy, haematological disorders and congenital immune deficiencies affecting T function.