Cimetidine enhances delayed-type hypersensitivity responses and serum interleukin ( IL)-2,-10,-12, and IL-17 levels after burn injury in an animal model

The immunosuppression that occurs after burn injury causes an increase in susceptibility to infection. The aim was to investigate time-related alterations in various cytokines following thermal injury and to modulate cytokines by use of an immunomodulant, cimetidine. Male Balb/c mice were anesthetized and given a 10% total body surface area full-thickness burn by submerging in 90 C water for 9 s. Time-dependent changes in delayed type hypersensitivity (DTH) and serum levels of the cytokines IL-2, IL-10, IL-12, IL-17 and TGF beta were then assessed at various post-burn day (PBD) timepoints. Effects of 10 mg cimetidine/kg on DTH responses and cytokine levels were evaluated up to PBD 14. In comparison to healthy non-burned control mice, levels of IL-2 and IL-17 significantly decreased at PBD 3, 5, 10, and 14, those of IL-10 at PBD 1, 3, 5, and 10, and those of IL-12 at PBD 1, 3, 5, 10, and 14. Administration of cimetidine significantly augmented the levels of IL-2 (at PBD 3, 5, and 10), IL-10 (at PBD 1 and 5), IL-12 (at PBD 3, 5, 10, and 14), and IL-17 (at PBD 3 and 14) as compared to those in burned counterparts who did not receive drug. In comparison to healthy mice, biphasic alterations were observed regarding TGF beta levels; values were significant decreased and increased at PBD 3 and PBD 14, respectively. Cimetidine significantly diminished the elevated TGF beta levels at PBD 14. Cimetidine also significantly augmented DTH responses at PBD 5, 10, and 14 as compared to responses in non-drug-treated burned hosts. Taken together, the results here showed significant time-dependent changes in serum cytokines levels after burn injury and that cimetidine was able to significantly augment IL-2, IL-10, IL-12, and IL-17 levels as well as DTH responses that are normally suppressed following thermal trauma.