Red cell fragility

Premature infants and children with chronic cholestasis may develop spontaneous vitamin E deficiency. In premature infants, the deficiency manifests itself as increased red cell fragility and mild hemolytic anemia. It has been claimed, but not established, that these infants respond to administration of vitamin E. The anemia is not prevented by vitamin E, and only small improvements in red cell indices follow vitamin E treatment. A role has been claimed for vitamin E in prophylaxis of retrolental fibroplasia and bronchopulmonary dysplasia, two types of oxygen-induced tissue injury that occur in premature infants treated aggressively with oxygen. 

Oxygenation Complete blood count, clinical color (pallor, ruddiness, cyanosis) Red blood cell number, hemoglobin/hematocrit, membrane lipids, fragility, reticulocyte count, red cell fragility... 

A normocytic or microcytic, hypochromic anemia is most frequently observed, but macrocytosis has been seen in the final stages of GD (Feinberg and Quigley 1946, Reich et al. 1951). The life span of the red cells has been found shortened in the few cases so examined (Motulsky et al. 1958). Usually osmotic resistance is normal (Pick 1933, Burger 1934), but a hemolytic component with increased red cell fragility may exist (Sobel and Kaye 1942). Hemoglobinuria was observed in... 

Hematological Methods. Hematological analyses can Include the determination of the total hemoglobin concentration (In g%), the packed cell volume (PCV In %), the red blood cell count (In 10 /mm ) and reticulocytes count (In %), calculation of the red cell Indices, examination of a blood film, tests to demonstrate the presence of Inclusion bodies and of sickle cells, tests to evaluate the distribution of fetal hemoglobin (Hb-F) Inside the red cells, the red cell osmotic fragility, the concentration of serum Iron (SI), total Iron binding capacity (TIBC), and the survival time of the red cells. Details of all... 

Decreased. red-cell acetylcholinesterase and increased osmotic fragility (no effect at 0.25 ppm)... 

Rare Red blood cell fragility leads to hemolytic anemia None Benefits of supplementation not established in controlled trials... 

Vitamin E (a-tocopherol) has as its active form any of several tocopherol derivatives. It functions as an antioxidant. Vitamin E deficiency is rarely seen, but can lead to red blood cell fragility that leads to hemolytic anemia. It has no known toxicity. 

The most important diagnostic features of HS are as follows (1) congenital hemolytic anemia (2) microspherocytosis on the peripheral blood film (3) increased osmotic fragility, particularly in incubated red cells and (4) negative antiglobulin (Coombs) test. 

The osmotic fragility test is the most sensitive and useful test for the diagnosis of HS (Fig. 6-2). Although the fresh red cells of about 20% of HS patients have a normal or near-normal osmotic fragility, the test performed in cells incubated at 37°C for 24 hours is more often positive in association with an increased rate of spontaneous hemolysis (autohemolysis). 

HS was first described in 1871 by Vanlair and Masius (Vanlair and Masius, 1871). They reported a young woman who had repeated attacks of abdominal pain and jaundice and found that some of her erythrocytes were spherical and much smaller than normal. In 1907, Chauf-fard (Chauffard, 1907) demonstrated increased osmotic fragility of erythrocytes as the hallmark of the disease. A membrane lesion was first suggested by the observation of Bertles in 1957 (Bertles, 1957) that HS red cells are unusually permeable to sodium ions. Since then, many abnormalities have been reported in HS red cells, but it is now clear that HS is a consequence of heterogeneous defects in the red cell membrane proteins. 

Homozygosity for this type of thalassemia results in a complete suppression of 8 chain production, and thus in a complete absence of Hb-A2 (F5, 02). Heterozygotes have decreased levels of Hb-A (1.2-1.6%). Subjects with this anomaly are free of clinical symptoms, have a normal red cell morphology, and a normal osmotic fragility of the erythrocytes. 

Detailed hematological studies of several hundred obligatory adult heterozygotes for a-thalassemia suggest that this condition is often associated with a normal blood picture (P23). The hemoglobin concentration varies between 10 and 13 g/100 ml with MCV values of 60-80 and MCH of 22-30 pg per cell hypochromia is not prominent and reticulocytosis is hardly observed. Osmotic fragility of red cells is usually reduced. 

The major symptom of vitamin E deficiency in humans is an increase in red blood cell fragility. 

The intricate interactions of the spectrin-protein 4.1-actin complex may be of central importance in maintaining the structural integrity of the red cell membrane. Two genetic disorders affecting the red cell membrane skeleton are hereditary spherocytosis and hereditary elliptocytosis. The former, the most common congenital form of hemolytic anemia in persons of northern European descent, exhibits an autosomal dominant inheritance pattern. The red blood cells are spherical, osmotically fragile, and considerably reduced in life span. They undergo... 

Low levels of G-6-PD in combination with a high level of oxidized GSH cause high oxidative stress. Without antioxidant protection, red cell membranes become fragile, a condition that eventually causes hemolytic anemia. 

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