Controlled study of enteral arginine supplementation in burned children: impact on immunologic and metabolic status

Objective We compared the effects of an arginine-supplemented diet with those of an isocaloric isonitrogenous diet on immune and metabolic response of children with burns. Methods This was a double-blind, randomized, placebo-controlled trial in a burn treatment center of a pediatric hospital in Santiago, Chile. All children (1–5 y of age) admitted within 48 h of a moderate to deep burn injury covering 10% to 40% of total body surface area were evaluated. Twenty-eight children met the criteria and were randomly assigned to receive an arginine-supplemented diet (AG; n = 14) or an isocaloric isonitrogenous diet (CG; control, n = 14) for 14 d. Samples were collected at admission (baseline) and on days 7 and 14 for lymphoproliferative response to mitogens, plasma interleukins (interleukin-1, interleukin-6, tumor necrosis factor-α), plasma arginine and ornithine levels, serum C-reactive protein, prealbumin, albumin, glucose, and total urinary nitrogen. Results The AG enhanced lymphoproliferative responses (analysis of variance, P < 0.05), which were 72% of normal at baseline in both groups; by day 7 responses increased to 144% in the AG group and decreased to 56% in the CG group; both groups returned to normal by day 14. Baseline interleukin-6 was significantly increased in all children. There were no differences in plasma concentrations of interleukin-1, interleukin-6, tumor necrosis factor-α, C-reactive protein, prealbumin, albumin, or glucose between the AG and CG groups. On day 7 plasma ornithine levels increased significantly in the AG versus CG group (P < 0.05); arginine levels showed no change. Conclusions An exclusively AG improves mitogen-stimulated lymphocyte proliferation in burned children. The benefits of arginine for the immune system do not appear to be related to a metabolic response. The biological significance of this finding remains to be determined.