Anémie hémolytique avec déficit en glutathion-peroxydase chez un adulte

Abstract

Résumé. Chez un homme de 67 ans atteint d'une anémie hémolytique chronique avec présence de corps de Heinz, de méthémoglobine et taux de GSH normal, un déficit en glutathion-peroxydase érythrocytaire a été découvert. Le taux d'enzyme était du tiers environ de celui attendu à réticulocytose égale. Les autres systèmes d'oxydoréduction érythrocytaire ont été trouvés normaux. Il n'y avait pas d'hémoglobine instable. L'origine congénitale du déficit est soupçonnée. Les caractéristiques cinétiques de l'enzyme déficient étaient normales.

Erythrocyte Glutathione‐Peroxidase Deficiency

“…Partial GSH-P lack was initially found in newborns with neonatal jaundice and Heinz body anaemia as described by Gross et a1 (1967) and Necheles et a1 (1968). Since then, several additional patients have been reported (Necheles et al, 1969;Boivin et al, 1969;Gharib et al, 1969). Family studies relating to one patient with a homozygous deficiency support the concept that GSH-P deficiency is inherited as an autosomal recessive characteristic.…”

Erythrocyte Glutathione Peroxidase Content and Serum Tocopherol Levels in Newborn Infants

“…Two possible mechanisms for the enzymatic destruction of HzOz within the red cell are by the action of catalase and of GSH-Px, both being present in reduced amounts in newborn infants (Jones & McCance, 1949;Gross et al, 1967). An inherited deficiency of catalase is not usually associated with a haemolytic process, but a true genetically determined deficiency of GSH-Px has been described in three adults in whom haemolysis was exacerbated by ingestion of oxidant drugs (Boivin et al, 1969;Necheles et al, 1969;Steinberg et al, 1970).…”

An Improved Coupled Test Procedure for Glutathione Peroxidase (EC 1.11.1.9.) in Blood

“…The definition of the activity unit takes account of the kinetic properties of the enzyme and allows an easy comparison of the results obtained with the coupled test system with those obtained with the different types of the fixed time assay. The proposed method requires only standard laboratory equipment and may be of great value in the investigation of genetic disorders (12,13,18,20) and selenium deficiency (5,8).…”

“…Though determinations of glutathione peroxidase activity in human red blood cells have been carried out for several years (10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20), no assay for this enzyme activity has been developed, which can generally be accepted. At least two principally different test systems for glutathione peroxidase activity in hemolysate have been employed: 1. a fixed time assay, in which gluathione concentrations are measured at definite time intervals (11,13,15,17), and 2. a coupled test system, in which glutathione reductase (EC 1.6.4.2.)…”

“…is employed for regeneration of GSH. The decrease in NADPH concentration is continuously registrated photometrically (10,12,14,(16)(17)(18)(19).…”