Low concentrations of acid-soluble thiol (cysteine) in the blood plasma of HIV-1-infected patients

Biol Chem Hoppe Seyler. 1989 Feb;370(2):101-8. doi: 10.1515/bchm3.1989.370.1.101.


Blood plasma samples from HIV-1-infected persons contain elevated glutamate concentrations up to 6-fold the normal level and relatively low concentrations of acid-soluble thiol (i.e. decreased cysteine concentrations). The intracellular glutathione concentration in peripheral blood-mononuclear cells (PBMC) and monocytes from HIV antibody-positive persons are also significantly decreased. Therapy with azidothymidine (AZT) causes a substantial recovery of the plasma thiol levels; but glutamate levels remain significantly elevated and intracellular glutathione levels remain low. Cell culture experiments with approximately physiological amino-acid concentrations revealed that variations of the extracellular cysteine concentration have a strong influence on the intracellular glutathione level and the rate of DNA synthesis [( 3H]thymidine incorporation) in T cell clones and human and murine lymphocyte preparations even in the presence of several-fold higher cystine and methionine concentrations. Cysteine cannot be replaced by a corresponding increase of the extracellular cystine or methionine concentration. These experiments suggest strongly that the low cysteine concentration in the plasma of HIV-infected persons may play a role in the pathogenetic mechanism of the acquired immunodeficiency syndrome.

MeSH terms

  • Acquired Immunodeficiency Syndrome / blood*
  • Amino Acids / metabolism
  • Cells, Cultured
  • Cysteine / blood*
  • Cystine / blood
  • Female
  • Glutathione / metabolism
  • HIV-1
  • Humans
  • Male
  • Methionine / blood
  • Monocytes / metabolism
  • T-Lymphocytes / metabolism
  • Thymidine / metabolism


  • Amino Acids
  • Cystine
  • Methionine
  • Glutathione
  • Cysteine
  • Thymidine