Wilfried Tillmann

Role of the spleen in congenital stomatocytosis associated with high sodium-low potassium erythrocytes.

SummaryA girl of German origin with severe congenital hemolytic anemia was found to have overhydrated erythrocytes with markedly increased sodium and reduced potassium concentrations. The cells were stomatocytic with increased osmotic fragility and autohemolysis. Their excessively increased energy production was mainly used for active cation transport. The cells were highly vulnerable to metabolic depletion. Their normal deformability was reduced rapidly during deprivation of glucose. In acidic, hypoglycemic environment of the splenic pulp the cells become swollen and lysed. After splenectomy anemia inproved though increased hemolysis persisted.ZusammenfassungDie Erythrozyten eines deutschen Mädchens mit schwerer kongenitaler hämolytischer Anämie hatten einen hohen Wassergehalt, eine stark erhöhte Natrium- sowie eine niedrige Kaliumkonzentration. 40% der roten Blutzellen waren Stomatozyten, deren osmotische Fragilität und Autohämolyse stark erhöht waren. Ihre exzessiv gesteigerte Energiebildung wurde hauptsächlich für den erhöhten aktiven Kationentransport benötigt. Die ursprünglich normale Verformbarkeit der Stomatozyten nahm bei Glucosemangel schnell ab. In saurer, hypoglykämischer Umgebung, also auch in der Milzpulpa, schwellen die Zellen an, und sie werden hämolysiert. Nach der Splenektomie war die Hämolyse weniger stark ausgeprägt und die Anämie besserte sich.

Aggregate formation of erythrocytes and diabetic retinopathy in children, adolescents, and adults with diabetes mellitus (type I)

SummaryIn vitro measurements were carried out to study the aggregation of erythrocytes in 33 children and young adolescents, three older adolescents, and 38 adults with type I diabetes. The aggregate formation of erythrocytes in stasis was increased in adult patients with both “good” and “poor” metabolic control when compared to control values. The aggregation of red cells in all children and the younger adolescents, both those under good and poor metabolic control, did not statistically differ from those of controls. Each of the three older adolescents showed an increased aggregate formation of their erythrocytes compared to controls. All adult patients under poor metabolic control exhibited various stages of diabetic retinopathy as shown by fluorescence angiography. Only one child under poor metabolic control showed an early stage of retinopathy (stage I according to Malone). The three older adolescents showed an increased aggregate formation of their erythrocytes. These patients exhibited also stage I of retinopathy. We suggest that the increased aggregation of erythrocytes of both adult and older adolescent patients may be one of the reasons for the development of diabetic retinopathy. Moreover, the normal erythrocyte aggregation of the diabetic children and younger adolescents could help to explain the rare occurrence of microangiopathies in childhood diabetes.

Erythrocyte pyruvate kinase deficiency: Characterization of a new variant (PK “Aarau”)

SummaryA new PK variant with moderate hemolytic anemia is described. The enzymes of the nonanemic parents show sigmoidal reaction kinetics, with normal kinetic parameters, but differ with respect to nucleotide specificity, thermostability, and the concentrations of the glycolytic intermediates in the erythrocytes.The most characteristic features of the patients (daughter) enzyme are a 30% activity, hyperbolic reaction kinetics and only two bands in the SDS-gel electrophoresis instead of three bands observed with the parental enzymes. Moreover, the pH-optimum is shifted to the acidic range, the affinity for PEP and ADP is decreased, ATP inhibition is negligible and FDP-activation is roughly ten times smaller than with controls. The concentrations of 2.3-DPG, 2-PG and PEP in the erythrocyte are increased, but ATP decreased.As there is no consanguinity in the parents and their enzymes are different this PK mutant can be considered to be compound-heterozygous for two different mutant PK alleles.

Günstige rheologische Eigenschaften der Erythrozyten beim Glucose-6-phosphatdehydrogenase-Mangel

SummaryThe rheological properties of erythrocytes of 6 patients with glucose-6-phosphate dehydrogenase deficiency were studied. A method of filtration and measurements of viscosity of erythrocyte suspensions with a hematocrit of 80% were used. The erythrocytes of all patients were more flexible than the erythrocytes of healthy controls. The erythrocytes of the patients passed the polycarbonate filters with a pore diameter of 5 µm more rapidly and showed a lower viscosity of erythrocyte suspensions. The increased flexibility of erythrocytes was due to a lower hemoglobin content which was measured in isolated ghosts. After incubation of the cells with acetylphenylhydrazine, Heinz bodies formed in the erythrocytes of controls. The flexibility of these cells decreased markedly. Though more Heinz bodies were found in the erythrocytes of the patients when the cells were incubated under identical conditions, even these erythrocytes became less rigid than the erythrocytes of controls. From these results we conclude that the more flexible erythrocytes of the patients could pass the splenic sinus even when they contain Heinz bodies.The rheological properties of the erythrocytes explain why splenectomy is not efficient in glucose-6-phosphate dehydrogenase deficiency.ZusammenfassungDie rheologischen Eigenschaften der Erythrozyten von 6 Patienten mit Glucose-6-phosphatdehydrogenase-Mangel wurden mit einer Filtrationsmethode und durch Viskositätsmessungen an Erythrozytensuspensionen mit einem Hämatokrit von 80% untersucht. Die Erythrozyten aller Patienten waren besser verformbar als die Erythrozyten gesunder Kontrollpersonen. Die Zellen der Patienten passierten Polycarbonatfilter mit einer Porengröße von 5 µm rascher. Darüber hinaus waren die Erythrozytensuspensionen der Patienten weniger viskös. Die höhere Flexibilität der Erythrozyten beruht auf einem verminderten Hämoglobingehalt der Erythrozytenmembran. Die Verformbarkeit normaler Erythrozyten sank ab, sobald sich in den mit APH inkubierten Erythrozyten Heinzkörper gebildet hatten. In den Erythrozyten der Patienten bildeten sich unter gleichen Inkubationsbedingungen mehr Heinzkörper. Selbst diese Zellen waren weniger rigide als die inkubierten Kontrollerythrozyten. Aus den in vitro gewonnenen Ergebnissen wird geschlossen, daß die flexibleren Erythrozyten der Patienten, auch wenn sie Heinzkörper enthalten, in vivo die venösen Sinus der Milz passieren können.Die rheologischen Untersuchungen erklären, warum die Splenektomie bei Patienten mit Glucose-6-phosphatdehydrogenase-Mangel nicht wirksam ist.The rheological properties of erythrocytes of 6 patients with glucose-6-phosphate dehydrogenase deficiency were studied. A method of filtration and measurements of viscosity of erythrocyte suspensions with a hematocrit of 80% were used. The erythrocytes of all patients were more flexible than the erythrocytes of healthy controls. The erythrocytes of the patients passed the polycarbonate filters with a pore diameter of 5 micron more rapidly and showed a lower viscosity of erythrocyte suspensions. The increased flexibility of erythrocytes was due to a lower hemoglobin content which was measured in isolated ghosts. After incubation of the cells with acetylphenylhydrazine, Heinz bodies formed in the erythrocytes of controls. The flexibility of these cells decreased markedly. Though more Heinz bodies were found in the erythrocytes of the patients when the cells were incubated under identical conditions, even these erythrocytes became less rigid than the erythrocytes of controls. From these results we condlude that the more flexible erythrocytes of the patients could pass the splenic sinus even when they contain Heinz bodies. The rheological properties of the erythrocytes explain why splenectomy is not efficient in glucose-6-phosphate dehydrogenase deficiency.

Verminderte Flexibilität der Erythrozyten von Neugeborenen

ZusammenfassungDie rheologischen Eigenschaften der Erythrozyten von 10 reifen Neugeborenen wurden mit einer Filtrationsmethode und Viskositätsmessungen an Erythrozytensuspensionen mit einem Hämatokrit von 80% untersucht. Die Erythrozyten der Neugeborenen waren schlechter verformbar als Erythrozyten gesunder Erwachsener. Die Rigidität der Erythrozyten beruht auf einem erhöhten Hämoglobingehalt der Erythrozytenmembranen. Die Verformbarkeit von Erythrozyten Erwachsener sank ab, sobald sich in den mit Acetylphenylhydrazin inkubierten Zellen Heinz-Körper gebildet hatten. In Erythrozyten Neugeborener bildeten sich unter gleichen Inkubationsbedingungen mehr Heinz-Körper. Diese Zellen waren noch rigider als die inkubierten Erythrozyten Erwachsener. Aus den in vitro gewonnenen Ergebnissen wird geschlossen, daß die rigiden Erythrozyten der Neugeborenen, besonders wenn sie Heinz-Körper enthalten, in vivo die venösen Sinus der Milz schlecht passieren können. Die rheologischen Untersuchungen erklären, warum bei Neugeborenen die Überlebenszeit der Erythrozyten verkürzt ist.SummaryThe rheological properties of erythrocytes of 10 full-term infants were studied. A method of filtration and measurements of viscosity of erythrocyte suspensions with a hematocrit of 80% were used. Erythrocytes of newborn infants were less flexible than erythrocytes of healthy adults. Rigidity of erythrocytes was due to an increased hemoglobin content of the erythrocyte membranes which was measured in isolated ghosts. After incubation of the cells with acetylphenylhydrazin Heinz-bodies were formed in the erythrocytes of adults. The flexibility of these cells decreased markedly. More Heinz-bodies were found in the erythrocytes of the newborn infants, when their cells were incubated under identical conditions. These erythrocytes became more rigid than the erythrocytes of adults. From these results we conclude that the more rigid erythrocytes of the newborn infants could not pass the splenic sinus, especially when they contain Heinz-bodies. The rheological properties of the erythrocytes of newborn infants explain the shortened life-span of red cells of newborn infants.