Changes in lymphocyte response to phytohaemagglutinin and serum immunosuppressive activity after thermal injury

The present study consisted of two parts. In part one, 14 cases were divided into an invasive infection group (4 cases) and a non-invasive infection group (10 cases). A total of 68 assays for lymphocyte responses to PHA stimulation were carried out. The invasive infection group showed a significantly suppressed lymphocyte response, which occurred during invasive infection but neither before nor after the infection. The extent of third-degree burns was statistically significant between these two groups (P less than 0.05), but no significance was found between the total body surface area burned. In part two, 18 burn patients were studied for serum immunosuppressive activity. Both invasive infection cases and non-invasive infection cases showed serum immunosuppression during the course of the study and no significant difference was found between these two groups (P greater than 0.05). It is concluded that the extent of third-degree burn and the complicated systemic infection contribute to the impairment of lymphocyte responses to PHA stimulation, while the post-burn serum immunosuppression is unrelated to the occurrence of systemic infection.