Alterations in T-helper and T-suppressor lymphocyte populations after multiple injuries.

Fifteen patients with multiple injuries and an Injury Severity Score (ISS) ranging from 2 to 57 (median 25) were studied for variations in lymphocyte populations on the day of injury and the three following days. Nine of the patients had an ISS above 16. In all patients the total number of lymphocytes fell during the first 24 hours after the injury (P less than 0.01), mainly due to a reduction in the number of circulating T-lymphocytes from a median of 1.8 to 0.6 x 10(9) cells/l (P less than 0.01). No reduction in the T-helper/T-suppressor cell ratio could be demonstrated for the group as a whole, but in the 9 patients with an Injury Severity Score (ISS) of more than 16 a significant reduction in ratio from median 1.5 to 0.8 was found. Due to clinical observations patients with an ISS of more than 16 are considered severely injured and at risk of developing complications such as infection and septicaemia. The fall in T-helper/T-suppressor ratio indicates impaired immunity in these patients.