title: Increased plasma tryptophan in HIV-infected patients treated with pharmacologic doses of nicotinamide.
abstract: OBJECTIVE
  Decreased plasma tryptophan in persons infected with human immunodeficiency virus (HIV) was first reported over a decade ago, and this observation has since been confirmed by many groups. Before this study, only zidovudine (an antiviral medication) had been reported to reverse plasma tryptophan depletion in HIV-infected persons. Starting with the hypothesis that HIV induces a pellagra-like state and that plasma tryptophan in HIV-infected patients is decreased as a known biochemical correlate of pellagra, we predicted that niacin therapy would reverse plasma tryptophan depletion as it does in pellagra.
  
  
  METHODS
  After receiving approval from the institutional review board, we treated HIV-infected patients for 2 mo with high-dose niacin in the form of oral nicotinamide.
  
  
  RESULTS
  There was an average 40% increase in plasma tryptophan (P = 0.01) in the four HIV-infected individuals who completed the 2-mo protocol. This finding was specific in that four other amino acids, which have been shown to have significant plasma concentration alterations during HIV infection (i.e., cystine, methionine, taurine, and lysine), showed no significant change with nicotinamide therapy.
  
  
  CONCLUSIONS
  There were no adverse side effects attributable to this treatment. The effects of high-dose nicotinamide treatment on morbidity or mortality in HIV-infected persons are yet to be determined. This report marks the first successful use of a vitamin to reverse this HIV-induced metabolic abnormality.
authors.affiliation: Department of Medicine, Brigham and Women's Hospital, Harvard University, Boston, Massachusetts, USA. mfmurray@bics.bwh.harvard.edu
authors.forename: M F
authors.initials: MF
authors.lastname: Murray
authors.forename: M
authors.initials: M
authors.lastname: Langan
authors.forename: R R
authors.initials: RR
authors.lastname: MacGregor
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D015658:HIV Infections / Q000097:blood* / Q000150:complications / Q000188:drug therapy; D006801:Humans; D009525:Niacin / Q000172:deficiency*; D009536:Niacinamide / Q000008:administration & dosage / Q000627:therapeutic use*; D014364:Tryptophan / Q000097:blood* / Q000187:drug effects*
chemical_list: D000596:Amino Acids; D009536:Niacinamide; D009525:Niacin; D014364:Tryptophan