Immune activation and decreased tryptophan in patients with HIV-1 infection

J Interferon Res. 1990 Dec;10(6):599-603. doi: 10.1089/jir.1990.10.599.


We compared tryptophan, neopterin, and interferon-gamma (IFN-gamma) concentrations in serum and cerebrospinal fluid (CSF) of 22 patients with human immunodeficiency virus type 1 (HIV-1) infection. Tryptophan levels were found to be decreased in CSF and serum of patients whereas neopterin levels in CSF and serum and serum IFN-gamma concentrations were increased compared to healthy HIV-1 seronegatives. Tryptophan concentrations correlated negatively to neopterin concentrations, and serum neopterin concentrations correlated positively to IFN-gamma concentrations. Thus, decrease of tryptophan levels is associated with chronic immune stimulation in patients with HIV-1 infection. From the data it appears that reduced tryptophan in patients may result from induction of indoleamine (2,3)-dioxygenase by IFN-gamma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Biopterin / analogs & derivatives
  • Biopterin / blood
  • Biopterin / cerebrospinal fluid
  • Enzyme Induction
  • HIV Infections / immunology*
  • HIV Infections / metabolism
  • HIV-1*
  • Humans
  • Interferon-gamma / blood
  • Interferon-gamma / cerebrospinal fluid
  • Middle Aged
  • Neopterin
  • Tryptophan / blood*
  • Tryptophan / cerebrospinal fluid
  • Tryptophan Oxygenase / biosynthesis


  • Biopterin
  • Neopterin
  • Interferon-gamma
  • Tryptophan
  • Tryptophan Oxygenase