Low-dose dietary L-arginine increases plasma interleukin 1 alpha but not interleukin 1 beta in patients with diabetes mellitus.

Oral high-dose arginine supplementation is used for the experimental immunotherapy of tissue trauma and sepsis. Yet the adequate dosage required for immunomodulation has to be established and the toxicity of high-dose arginine has not been fully elucidated. Following a protocol for the treatment of diabetic long-term complications (oral daily doses of 30 mg/kg BW; blind, placebo-controlled prospective study with crossing-over design) we studied plasma levels of interleukins 1 alpha (IL-1 alpha) and 1 beta reflecting immunostimulation. Arginine supplementation in 29 patients with diabetes mellitus prompted a 2-fold increase of IL-1 alpha from baseline levels (P < 0.001) while IL-1 beta was unaffected. Implications for the treated panel of diabetic patients could be a reduction of collagen accumulation by enhanced collagenolysis and clearance of advanced-stage non-enzymatic glycosylation products. Based upon our data, low-dose arginine protocols for further immunotherapeutical studies should be discussed.