Altered leukocyte delivery to specific and nonspecific inflammatory skin lesions following burn injury.

This study assessed the effect of burn trauma on the in vivo leukocyte cell delivery during the first 24 hr of the delayed type hypersensitivity (DTH) skin test reaction and a bacterial skin abscess. Inbred male Lewis rats sensitized to keyhole limpet hemocyanin (KLH) were given a 30% scald burn or sham burn. Three days later the animals were injected intradermally, at different sites, with 0.3 mg of KLH, 10(8) organisms of S. aureus 502A, and 0.1 cc of saline, at 2 to 24 hr. Leukocytes labelled with Indium111 oxine(leu111) were injected intravenously. In sham rats the peak leu111 influx in the DTH reaction occurred at 2-4 hr while in the abscess it was biphasic with peaks at 3 hr and 6-8 hr. In burn trauma rats there was a markedly increased leu111 peak at 2 hr in both the DTH and abscess reactions followed by a significantly lower than normal leu111 delivery in the late (6-24) hours. This marked early leukocyte influx in burned rats was paralleled by a reduced DTH skin test lesion (8.2 +/- 1.1 mm to 4.2 +/- 1.1 mm) and an increased bacterial abscess (5.1 +/- 1.1 mm to 8.1 +/- 0.9 mm) post burn. There was a direct correlation between leukocyte cell delivery to a DTH reaction and a bacterial abscess (r8 = 0.69, Spearman rank; p less than 0.001). We conclude that burn trauma results in altered leukocyte delivery to inflammatory lesions and the DTH response can be used to assess the ability of a burn trauma host to recruit leukocytes at a site of infection.