Abstract: The present invention relates to the treatment of an impaired human immune response or to reduction of the severity of degradation of the human immune response by the administration of arginine or ornithine, or a functional analog of arginine or ornithine, or mixtures thereof, to humans suffering from an impaired immune response or at risk of suffering an impaired immune response. Such treatment is provided by enterally administering compositions supplemented with arginine or ornithine, or functional analogs of arginine or ornithine, or parenterally administering amino acid solutions supplemented with arginine or ornithine, or functional analogs of arginine or ornithine, to the patient.

Abstract: Amino acid formulations for administration to human patients with liver disease comprise mixtures of essential amino acids combined in novel relative proportions, and preferably also include non-essential amino acids. In particular, the combined molar proportions of isoleucine, leucine, and valine are from 40 to 300 times the molar proportion of tryptophan and from 15 to 135 times the molar proportion of phenylalanine, or phenylalanine and tyrosine. The formulations may be adapted for either intravenous or oral administration, but the preferred method of administration is by hyperalimentation infusion. The formulations and method can be utilized to provide nutritional support for liver diseased patients while reducing the incidence and severity of hepatic encephalopathy, and/or as primary therapy for treatment of hepatic encephalopathy.