Plasma and Erythrocyte Folate in Iron Deficiency and Folate Deficiency

Erythrocyte and plasma folate levels were studied before treatment in 20patients with iron deficiency anemia and in 23 patients with megaloblasticanemia due to folate deficiency. Fourteen of the cases of iron deficiency anemiawere also studied after treatment with oral iron alone. Fifty-seven normalpersons were used as controls.

The mean erythrocyte folate (ng./ml. packed cells) was significantly increased in iron deficiency anemia and significantly depressed in folate deficiency anemia. After treatment with oral iron alone, the mean erythrocytefolate level fell to normal in the iron deficiency anemia group. The mean corpuscular folate (ng. x 108^-8) was also significantly raised in iron deficiency:in eight of 10 cases this fell after treatment, but the overall fall was not significant. The plasma folate rose in iron deficiency anemia after oral irontreatment.

Submitted on August 8, 1969 Accepted on November 17, 1969     

Hereditary Nonspherocytic Hemolysis With Erythrocyte Phosphofructokinase Deficiency

Hereditary nonspherocytic hemolysisassociated with abnormal erythrocytephosphofructokinase activity was demonstrated in a young man. Enzymeactivity in the propositus, his mother,and maternal grandmother was approximately 60% of normal controls. Therewas markedly increased lability ofenzyme activity on in vitro storage.Kinetic studies revealed increased sensitivity to adenosine triphosphate inhibition. Erythrocyte adenosine triphosphate levels were depressed. Theabsence of muscle disease and thepresence of normal in vivo lactateproduction following ischemic exercisedifferentiated this kindred from thosewith Type VII glycogen storagedisease.

Submitted on July 16, 1971 Revised on August 24, 1971 Accepted on August 31, 1971     

Erythrocyte Pyrimidine 5‘-Nucleotidase Deficiency

We present 2 Norwegian siblings who we believe to be the first cases of pyrimidine 5′-nucleotidase deficiency diagnosed in the Scandinavian countries. In addition to the features presented by previously published cases, our patients exhibited signs of intravascular haemolysis with haemoglobinuria and increased loss of iron in the urine. The loss of iron has made iron medication necessary from time to time. A kidney biopsy from the oldest patient revealed accumulation of iron in the epithelium of the proximal tubuli. The kidneys were considerably enlarged in both patients, but with normal function tests.     

Erythrocyte Populations in Pyruvate Kinase Deficiency Anaemia Following Splenectomy

S ummary . Light and scanning electron microscopic examination of fresh erythrocytes from the blood of four patients splenectomized for severe pyruvate kinase (PK) deficiency haemolytic anaemia has revealed three morphologically different cell populations. Most striking in these patients was the presence of crenated red cells (30–50% of total) which fit current criteria for definition as cchinocytes, but also with unusual surface retraction compatible with the existence of intracellular shrinkage, a phenomenon known to occur after incubation of PK deficient red cells in vitro. Additional cell types include immature reticulocytes (7–8% of total) and thin macrocytic discocytes (45–65% of total) none of which are considered specific for the disease. These morphological findings are in sharp contrast with the paucity of red cell shape abnormalities usually described in PK deficient patients before splenectomy and may provide insight into the mechanisms leading to accelerated erythrocyte destruction in this disease.     

Distribution of Erythrocyte Nucleotides in Pyrimidine 5''-Nucleotidase Deficiency

In pyrimidine 5'-nucleotidase deficiency, erythrocytes contain elevated levels of pyrimidine nucleotides. The composition of this nucleotide pool was examined by ion exchange chromatography on Dowex formate columns using a linear ammonium formate elution gradient. In contradistinction to normal erythrocytes, adenine nucleotides accounted for only 32% of the nucleotide pool. The remainder consisted of 50% cytidine and 16% uridine nucleotides. The remaining 2% was not identified. The most abundant compound appeared to be UDP glucose whilst high levels of CTP, CMP and an unidentified cytidine compound less polar than CMP accounted for most of the cytidine nucleotide pool. The possibility that the abnormal nucleotides were due to an elevated reticulocyte count was excluded and it was also shown that erythrocytes from subjects heterozygous for pyrimidine 5'-nucleotidase deficiency did not have detectable levels of the abnormal nucleotides.     

Erythrocyte Phosphoglycerate Kinase Deficiency: Enzymatic and Oxygen Binding Studies

Summary Enzyme and oxygen transport studies have been made on seven members of a kindred with red cell deficiency of phosphoglycerate kinase (PGK), an enzyme known to be linked to the X-chromosome. The two affected males were children, had little detectable PGK activity and had severe neurological damage. Both had moderate haemolytic anaemia complicated by the occurrence of haemolytic crises. Red cell ATP levels were substantially decreased in both subjects. However, they had more than double the normal level of 2,3-diphosphoglycerate (2,3-DPG) in their ted cells, associated with a rightward shift in their oxygen-haemoglobin equilibrium curves. This shift in the curve was sufficient to permit oxygen delivery to most body tissues, including the brain, at better tensions than normal, except during a haemolytic crisis.
Two of the three known heterozygotes were aged over 70. They had moderate haemolytic anaemia, considerable reduction of red cell PGK activity (19% and 35% of normal, respectively), and considerable increase in red cell 2,3-DPG with rightward shifting of the oxygen-haemoglobin equilibrium curve. The other known heterozygote was aged 22 and showed little abnormality in her blood oxygen transport.     

N-Acetylneuraminic Acid Deficiency in Erythrocyte Membranes: Biophysical and Biochemical Correlates

The electrochemical and rheologic behaviors of red blood cells (RBCs) from apatient with acquired polyagglutinabilitywere studied. The N-acetylneuraminic acidcontent of the RBCs averaged less thanone-half normal. The majority of thepatient’s RBCs (over 90%) showed a reduction in electrophoretic mobility and adecrease in binding of positively chargedcolloid with a widening of the charge-freeareas, but a small population exhibitednormal surface charge density. Dextran 40,which does not induce significant aggregation of normal RBCs, caused thepatient’s RBCs to form rouleaux. Dextran80 induced a stronger aggregation of thepatient’s RBCs than that of normal RBCs.The increased tendency of the patient’sRBCs to be aggregated by macromoleculeswas associated with an elevation of bloodviscosity. This study on a clinical patient hasprovided evidence for the conclusions previously derived from experimental studiesthat the stability of RBC aggregation depends upon a balance between macromolecular bridging force and electrostaticrepulsive force and that alterations in RBCsurface charge may affect cell aggregationand blood viscosity.

Submitted on June 5, 1973 Revised on August 2, 1973 Accepted on August 7, 1973     

Chronic Haemolytic Anaemia in Two Patients Heterozygous for Erythrocyte Pyruvate Kinase Deficiency

Two patients with mild chronic haemolytic anaemia, a mother and her son, were found to be heterozygous for erythrocyte pyruvate kinase deficiency. In the red blood cells the enzymatic activity was reduced by about 50 % and the residual PK had normal kinetic properties, stability and electrofocusing pattern. The PK antigen concentration was also decreased by half, so that the ratio of the enzymatic activity to the immunological reactivity (i.e. the molecular specific activity) was normal. In the son's liver PK enzymatic activity was slightly reduced and, above all, an abnormal active form, more anodic than normal PK, was detected by electrofocusing. The propositus's liver PK was also slightly thermo-unstable. It is suggested that the patients were heterozygous for an unstable PK variant which is found in liver, nucleated tissue actively synthesizing proteins, but which disappeared from the erythrocytes because of its unstability.     

Erythropoiesis: Erythrocyte Deformability is Reduced and Fragility increased by Iron Deficiency

Hypochromic and microcytic erythrocytes, resulting from absolute iron deficiency, have a shortened survival due to ineffective production coupled with accelerated reticuloendothelial cell sequestration once released into the circulation. To explore the contribution of diminished deformability and increased fragility to these in vivo phenomena, iron status was correlated with the corresponding in vitro measurements using ektacytometry on whole erythrocytes or resealed ghost membranes. Compared to normal controls (Group 1: n = 15), those with iron deficiency of unknown origin (Group 2: n = 15), or when associated with primary proliferative polycythemia (Group 3: n = 20), were significantly less deformable and more fragile, whereas the latter category of patients, who were not anaemic (Group 4: n = 33), occupied an intermediate position. These observations support the contention that shortened intramedullary and extramedullary lifespan is contributed to by the altered physical characteristics of the red cell membrane. This observation is therapeutically important since the lesion can be readily corrected by oral iron supplementation which, at the same time, reverses the symptoms of the anaemia and prevents the development of paradoxical hyperviscosity. Additionally, it is speculated that the risk of thrombotic events in the polycythemic group may be reduced, since these appear to occur more frequently in the face of depleted body iron stores.     

Erythrocyte Superoxide Dismutase,Catalase and Glutathione Peroxidase in Glucose-6-Phosphate Dehydrogenase Deficiency

Glucose-6-phosphate dehydrogenase (G-6-PD) deficient erythrocytes are particularly sensitive to oxidant stress. In order to evaluate if these cells are protected against oxidant damage, we assayed the antioxidant enzymes superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px) in erythrocytes of G-6-PD deficient (hemizygous and heterozygous) subjects. Normal levels of antioxidant enzymes were found in all subjects examined both with positive and negative histories of haemolytic crisis after fava bean or drug ingestion. In contrast, high levels of catalase and GSH-Px were found in a small group of G-6-PD deficient subjects (hemizygous and heterozygous) with β-thalassaemia trait, probably by reason of the chronically enhanced oxidant stress which is present in β-thalassaemia.     

Diagnosis of Erythrocyte Glucose-6-Phosphate Dehydrogenase Deficiency in the Negro Male Despite Hemolytic Crisis

A simple procedure for the diagnosis of erythrocyte glucose-6-phosphatedehydrogenase deficiency in Negro males experiencing hemolytic crisis isdescribed. By measuring enzyme activity in the persisting older erythrocytes,the deficiency can be recognized without having to wait until the hemolyticepisode and its reticulocyte response have subsided.

Submitted on May 23, 1969 Accepted on July 31, 1969     

Altered Erythrocyte Pyrimidine Activity in Vitamin B12 or Folate Deficiency

The net activity of orotidylic pyrophosphorylase and decarboxylase, sequential enzymes which catalyse the formation of uridine monophosphate from orotic acid in de novo pyrimidine biosynthesis, has been evaluated in erythrocytes of patients with folate or cobalamin deficiency. In patients with normoblastic haemopoiesis and normal cobalamin and folate status a direct relationship exists between the maturity of the peripheral blood erythrocyte population, as indicated by G6PD activity, and net orotidylic activity. In contrast in cobalamin or folate deficiency this co-ordinate relationship is not observed and net orotidylic activity is relatively reduced. Fractionation of erythrocytes by centrifugation demonstrates that this inordinately low orotidylic activity consistently occurs in the young erythrocyte population and is reversed by specific replacement therapy. In vitamin B12 or folate deficiency an impressive array of evidence now exists to implicate altered folate metabolism for the observed alterations in purine and pyrimidine metabolism (Das & Herbert, 1976). Of these changes the cornerstone defect resulting in megaloblastic maturation is impaired methylation of deoxyuridine monophosphate to thymidine monophosphate (Hoffbrand et al, 1976). In this context the reduced serum uridine plus uracil levels in patients with vitamin B12 deficiency (Parry & Blackmore, 1976) and the haematological response of these patients to orotic acid therapy (Rundles & Brewer, 1958) are not readily explicable. Since the conversion of orotic acid to uridine monophosphate depends on the integrity of the coupled activities of orotidylic pyrophosphorylase and decarboxylase, this study has quantitated this capacity in peripheral blood erythrocytes in patients with vitamin B12 or folate deficiency.     

3种脾虚小鼠红细胞膜流动性变化的研究

目的：研究几种脾虚证模型小鼠红细胞（RBC）模流动性（LFU）的变化规律。方法：分别用大黄、番泻叶、利血平制作脾虚模型。用血细胞分析仪检测不同模型小鼠血常规指标的变化，用荧光偏振法检测不同模型小鼠RBC LFU和微粘度（η）的变化。结果：不同造模方法对小鼠血常规指标，除平均血细胞容积外并无明显影响，但均使3种模型小鼠RBV LFU降低，η增加，结论：RBC LFU有可能成为评价脾虚证的一个客观指标。     

A Simple Method for Detection of Erythrocyte Glucose-6-Phosphate Dehydrogenase Deficiency (G-6-PD Spot Test)

A method is described for detection of erythrocyte glucose-6-phosphate dehydrogenase deficiency, based upon the reduction of the tetrazolium dye,MTT, by reduced triphosphopyridine nucleotide. The method is highly reliable and correlates well with established methods of enzyme assay. The testis sufficiently simple to perform that it may be done in any routine clinicallaboratory or physician’s office. The reagents may be prepared in mailable,stable form at minimal expense.

Submitted on May 3, 1962 Accepted on July 21, 1962