[Intra-leukocyte cystine in cystinosis treated with cysteamine]

Ann Biol Clin (Paris). 1991;49(9):482-6.
[Article in French]

Abstract

Data on cystine leukocyte content are analyzed in cystinotic patients receiving cysteamine as a depleting agent of cellular cystine. During 2 years, 63 measurements of cystine leucocyte content were performed in 15 cystinotic patients, aged 20 months to 22 years, taking daily 40 to 65 mg/kg of cysteamine. An original method was used to measure leukocyte cystine: a binding protein assay with a specific cystine-binding protein from E. coli. Results were taken individually because of various clinical situations in patients. In 8 patients taking cysteamine regularly, 6 hours after a dose, cystine leukocyte content was between 1 and 2 nmol 1/2 cystine/mg protein, about 10 times less than basal values without treatment and 5 to 10 times more than control subjects. In less compliant patients, cystine leukocyte content was close to basal values without treatment (3 to 25 nmol/mg). Some variability was observed between individuals receiving cysteamine: pharmacokinetic parameters may need further investigation. This sensitive and specific assay helped in controlling compliance and adjusting dosage regimen in each patient. The aim was to maintain a minimum effective dosage in order to avoid toxic side effects of cysteamine.

Publication types

  • English Abstract

MeSH terms

  • Adolescent
  • Adult
  • Binding, Competitive
  • Child
  • Child, Preschool
  • Cysteamine / administration & dosage
  • Cysteamine / therapeutic use*
  • Cystine / blood*
  • Cystinosis / blood*
  • Cystinosis / drug therapy*
  • Drug Administration Schedule
  • Female
  • Humans
  • Infant
  • Leukocytes / chemistry*
  • Male
  • Patient Compliance
  • Radioimmunoassay

Substances

  • Cystine
  • Cysteamine