[Separation of red blood cells from G6PD-deficient patients in dextran density gradients]. / Trennung roter Blutzellen von G6PD-Mangelträgern im Dextrandichtegradienten.

Red blood cells of 30 patients with G6PD deficiency were separated and characterized by means of isopyknic dextran density gradient centrifugation. The simultaneous determination of G6PD activity and the percentage of NADPH deficiency cells in relation to the maturation parameters of density, reticulocyte share, GOT and PK activity made it possible to recognize differences in the maturation of red blood cells with G6PD deficiency in normal persons as well as within a group of patients. In each case the more or less diminished enzyme activity of the cell suspension was accompanied by a marked enzyme deficiency of the youngest fraction. It is possible that NADPH defect cells are being eliminated at first. In many cases a direct correlation between the percentage of "empty cells" and the in vitro stability tests with and without NADP+ addition could be identified. Decreased maximal speed, changed kinetic behaviour, and instability of these variants are stressed as being the decisive parameters for the life expectation of red blood cells in patients with G6PD deficiency.

[Energy metabolism of erythrocytes in pyruvate kinase enzymopathies]. / Energiestoffwechsel roter Blutzellen bei Pyruvatkinase-Knzymopathien.

Until now pyruvate kinase enzymopathies have been described only for red blood cells. On the basis of these results special structural properties of the erythrocyte PK was assumed, which are not yet totally established. PK defects may cause a nonspherocytic hemolytic anemia. This enzymopathy is characterized by a polymorphism, which is expressed in more than 5 different pathological variants. Up to now 16 cases of PK deficiency have ben diagnozed in the GDR. The following parameters are used for the characterization of the PK: the PEP-dependance, the inhibition by ATP and alanine, the specificity to nucleotides, the stability to temperature and urea and the maturation dependence. Two pathological variants of the PK with a decreased PEP-affinity are described. Furthermore the differences in the energy metabolism of the red blood cells of these two patients under aerobic and anaerobic conditions are discussed.

[Glucose-6-phosphate dehydrogenase deficiency of erythrocytes in the GDR]. / Glukose-6-phosphat-Dehydrogenase-Mangel roter Blutzellen in der DDR.

34 persons with G-6-PD deficiency were diagnosed, and the pathological enzyme-variants of red blood cells were characterized according to the recommendations of WHO. We conclude from the differing residual G-6-PD-activities in red blood cells of the propositi and the differing reactivity of the enzyme in kinetic and physicochemical characterizations that a multiple variety of rare pathological G-6-PD variants exists in the GDR. Using the estimated enzymeparameters it was not possible in all cases to compare directly the newly demonstrated G-6-PD variants with cases already described in the literature. In addition, the differing combinations of parameters render a classification more difficult.