Low RBC Research Articles

Prestorage WBC filtration of RBC units with soft-shell filters: filtration performance and impact on RBCs during storage for 42 days.

The introduction of universal WBC filtration of RBCs prior to storage is currently under consideration in many countries, as it is thought to minimize the incidence of transfusion-associated adverse effects. Centrifugation of blood containers with newly developed soft-shell WBC filters is more convenient, and so of great interest. Two different quadruple blood pack systems with integrated soft-shell WBC filters were compared (Sepacell OptiPure RC, Baxter Biotech, vs. LCR 5, Maco Pharma). Buffy coat-depleted RBC units were investigated from whole-blood donations that were held for 2 to 3 hours before centrifugation and subsequent filtration at 22 degrees C (Group 1, OptiPure RC, 450 mL; Group 2, LCR 5, 450 mL; Group 3, OptiPure RC, 500 mL; Group 4, LCR 5, 500, mL, n = 12 per group). Filtration performance was analyzed, and the impact of WBC filtration on hemolysis rate, Hb content, pH, supernatant potassium, ATP, and 2,3 DPG was investigated weekly during storage for 42 days. Filtration reduced the WBC count by 4.4 to 5.1 log. Mean +/- SD Hb content was 44.7 +/- 3.0, 41.2 +/- 3.3, 53.1 +/- 5.0, and 51.5 +/- 6.3 g per unit, respectively, with a corresponding mean RBC recovery after filtration of 71.0 +/- 3.0, 68.3 +/- 3.3, 76.6 +/- 1.7, and 68.9 +/- 4.5 percent. WBC filtration resulted in a significant reduction of Hct (0.10-0.14) in all four groups. Investigation of all RBC storage variables revealed acceptable values throughout the storage for 42 days. WBC filtration with two newly developed soft-shell filters showed acceptable WBC-reduction efficacy without any difference between filter types in buffy coat-depleted RBCs from 450- and 500-mL whole-blood donations. However, the application of both filters resulted in an unacceptably low RBC recovery after filtration, which was particularly evident with the LCR5 filter. Our findings raise concern that WBC reduction with these filters may result in the production of RBCs with an inappropriately low Hb concentration.

The expression and changes of heat shock protein 70, MDA and haemorheology in rat cortex after diffuse axonal injury with secondary insults

In the present study the role of heat shock protein 70 (HSP70) expression, changes of malonyldialdehyde (MDA) in rat cortex and haemorheology with time after diffuse axonal injury (DAI) only and DAI with secondary insults (SI) were studied. The rat DAI and DAI with SI model were made according to our previous work and animals were divided into a control and another five injury groups with time after injury. Immunohistochemical assay was used to detect the neuronal expression of HSP70 at 0.5h, 3h, 12h, 24h, 72h after DAI or DAI with SI. In the meantime, the high (ηh ) and low whole blood viscosity (ηL ), haematocrit (HCT) and RBC aggregation index (AI = ηL/ηh ) were also detected and calculated. MDA in the homogenised brain tissue was assayed by thiobarbituric acid (TBA) reaction. The results showed that HSP70 positive neurons were not detected at 30 minutes, but the number of HSP70 positive neurons begin to increase obviously at 3 hours, reach a peak at 24 hours (P< 0.01), and decrease at 72 hours (P= 0.05) after brain injury. The trend of expression of HSP70 was alike for both DAI only or DAI with SI. Meanwhile, MDA, ηh, ηL , HCT and AI changes showed the same tendency. Compared with DAI only group, MDA and blood viscosity indexes in DAI with SI were significantly higher at respective time points (P< 0.01). It is concluded that HSP70 expression, MDA and haemorheology indices increased after brain injury and brain injury with SI. Free radicals and haemorheological changes play an important role in the aggravation of brain damage and HSP70 expression upregulation.

An amino acid substitution in the putative second extracellular loop of RBC band 3 accounts for the Froese blood group polymorphism.

The low incidence RBC antigen Fr(a) has been excluded from 17 of the 25 established blood group systems. Previous genetic analysis assigned the gene controlling Fr(a) expression to the same chromosomal region as the solute carrier family 4, anion exchanger member 1 gene (SLC4A1). Because SLC4A1 encodes RBC band 3 and controls the expression of Diego blood group system antigens, the possible relationship of Fr(a) to the Diego blood group system was investigated by molecular analysis of SLC4A1. Blood samples were obtained from the members of two unrelated Mennonite kindreds segregating for Fr(a). DNA was extracted, amplified by PCR using intronic primer sets flanking exons 11-20 of SLC4A1, and screened by single-strand conformation polymorphism (SSCP) analysis. Those exons displaying SSCPs were subjected to DNA sequence analysis. An exon 13 SSCP mobility shift was observed in the DNA from all Fr(a+) persons that was not seen in the DNA from Fr(a-) family members or control subjects. Linkage between the exon 13 SSCP and FR:(a) was established, with peak lods = 3.62 at theta = 0.00 for combined paternal and maternal meioses. DNA sequencing revealed a GAG --> AAG mutation that underlies a Glu480Lys substitution in RBC band 3. A point mutation in exon 13 of SLC4A1 accounting for a Glu480Lys substitution in band 3 controls Fr(a) expression. On the basis of these our results, the International Society of Blood Transfusion Working Party on Terminology for Red Cell Surface Antigens has assigned Fr(a) to the Diego blood group system, with the designation DI20.

Anemia and macrocytosis in the prediction of serum folate and vitamin B12 status, and treatment outcome in major depression

Background: Folate and B12 deficiencies may result in macrocytic anemia, and are common in major depression; hypofolatemia may result in poorer antidepressant response. We wished to determine whether anemia or macrocytosis predict hypofolatemia, low B12, or refractoriness to antidepressants. Methods: After obtaining serum folate, B12, and hematological indices, 213 depressed adults were treated with fluoxetine 20 mg/day. Amelioration of depressive symptoms was measured. Results: Neither macrocytosis nor anemia predicted low serum folate/B12, or antidepressant refractoriness. Among 39 patients with hypofolatemia, none had macrocytosis; 28% had low HCT; 41% had low RBC. Among 25 patients with low B12, none had macrocytosis; 24% had low HCT; 28% had low RBC. Among non-responders, 3% had macrocytosis; 24% had low HCT; 25% had low RBC. Conclusion: Anemia and macrocytosis should not be used to predict folate or B12 deficiencies, or refractoriness to antidepressants. Measurement of folate and B12 should be considered when evaluating treatment refractoriness.

Influence of rheologic changes and platelet-neutrophil interactions on cell filtration in sepsis.

We examined the role of erythrocyte (red blood cell; RBC) aggregation and deformability, neutrophil (polymorphonuclear neutrophil; PMN) deformability, whole-blood viscosity, and platelet-neutrophil interactions on cell filtration in subjects who were critically ill with sepsis (CIS), critically ill noninfected subjects (CINS), and healthy controls (C). We assessed cell deformability by filtration through filters of 5-microm pore size. Whole blood, RBC, PMN, and combinations of PMN and RBC were studied. Viscometry was done on isolated RBC. Platelet-PMN interactions were assessed with monoclonal antibodies to CD41 and activated CD63 platelet receptors, and to CD66b PMN receptors. Filtration pressure (Pi) for CIS was significantly greater than for C and CINS at both high and low PMN and RBC concentrations. Viscometry confirmed decreases in RBC deformability and demonstrated significant increases in RBC aggregation in CIS. Increments in Pi were significantly greater with PMN and PMN-RBC combinations suspended in platelet rich plasma (PRP) than in platelet poor plasma (PPP) for CIS as compared with CINS or C. Flow cytometry confirmed significantly greater platelet activation in CIS than in CINS or C (mean fluorescence: 39 +/- 9 lfu versus 18.7 +/- 4.0 lfu and 17.1 +/- 2.3 lfu, respectively) and greater platelet-PMN aggregation (mean fluorescence: 44.7 +/- 3.6 lfu versus 23 +/- 4.1 lfu, respectively) in CIS than in C. We conclude that decreased filtration of whole blood in CIS is related to decreases in RBC and PMN deformability, increases in RBC aggregation, and increased platelet-PMN interactions. Of these, the formation of platelet-PMN aggregates appeares to have the greatest effect in impairing cell filtration. These rheologic abnormalities may contribute to impaired microvascular blood flow in patients with sepsis.

Prevalence Of Hyperhomocyste1nemia Among White, Black And Mexican Elderly Over 60 Years Of Age In The Us: Nhanes Id-Phase Two

Elevated serum homocysteine level is the risk factor of the development of cardiovascular diseases. Folate and vitamin BI2 deficiencies are associated with hyperhomocysteinemia for these vitamins being the cofactors in the remethylation reaction of homocysteine to methionine. Data of 1,822 elderly aged over 60 years from NHANES Ill-Phase Two, who had complete records of 24-hour dietary recall, serum concentrations of homocysteine, folate, vitamin B12 and RBC folate were analyzed to study the prevalence of hyperhomocysteinemia and its association with folate and vitamin B12 status. SUDAAN statistical software was used and sample was grouped into six experimental groups; White male (WM), White female (WF), Black male (BM), Black female (BF), Mexican male (MM) and Mexican female (MF) to study the ethnicity and gender differences. For the folate intake, WF had the lowest intake with 57.12% consuming less than 200ug/d followed by BM, MF, BF, MM, and WM. MM had the highest percentage (9.04%) of low serum folate level (<2.6ng/ml) followed by BM (7.00%), BF (5.48%), MF (5.17%). WM (335%) and WF (1.81%), but BM had the highest percentage (14.1%) of low RBC folate (<102.6ng/ml). For the vitamin B12 intake, BF had the lowest intake with 58.96% consuming less than 2.4ug/d. For the serum B12, WM showed the highest percentage (3.60%) of the deficient level (<165pg/ml). For the hyperhomocysteinemia, BM had the highest prevalence (16.57%) of having levels higher than cutoff value of 16.4nmol/ml followed by WM (14.62%), MM (13.57%), BF (11.56%), WF (10.22%) and MF (5.26%). This study showed BM had the highest prevalence of hyperhomocysteinemia which is associated with the low serum and RBC folate levels. All three ethnic male groups had higher prevalence of hyperhomocysteinemia than all female groups.

Early signs of insulin resistance in normotensive offspring of hypertensives with low RBC K content

Early signs of insulin resistance in normotensive offspring of hypertensives with low RBC K content

L007 Low RBC K (Ki): A possible intermediate phenotype for essential hypertension

L007 Low RBC K (Ki): A possible intermediate phenotype for essential hypertension

Red cell lipid peroxidation and antioxidant enzymes in iron deficiency

Whether iron deficient RBC in humans have a reduced, or an increased, susceptibility to lipid peroxidation was studied in the iron deficiency states of primary proliferative polycythaemia and iron deficiency anaemia and related to changes in the activities of iron-dependent and non-iron dependent antioxidant enzymes. Susceptibility of RBCs to lipid peroxidation was increased when expressed per g Hb. However, this was a result of the low RBC Hb giving an increased membrane lipid: Hb ratio in the incubations. Results were normal when expressed either per cell, or per ml, RBC. Glutathione reductase was normal. Increased RBC superoxide dismutase activity in iron deficiency may be explained by the younger RBC population and reductions in glutathione peroxidase and catalase activities by the microcytic hypochromic changes and the lack of availability of iron, respectively. There is no evidence of an increased susceptibility of RBC to lipid peroxidation in iron deficiency.

Sickle cell anemia with few painful crises is characterized by decreased red cell deformability and increased number of dense cells

The frequency and severity of the painful sickle cell crisis vary greatly among affected patients. Aside from a high level of Hb F(greater than 20%) there is no established parameter which may modulate the clinical severity of the disease. In this paper we describe two groups of adult patients with homozygous SS and present their characteristics. The division into these two groups was on the basis of relatively low RBC deformability (less than or equal to 37% of control) and high RBC deformability (greater than 65% of control) in the steady state. None of the patients had alpha-gene deletion and all had Hb F level less than 6.0%. Each patient was followed for a minimum of 3 years. The number of dense cells was quantitated by centrifugation on discontinuous Stractan gradient. RBC deformability index in isotonic medium (DI 290) was determined by ektacytometry and expressed as % of control. The patients with low RBC deformability had significantly less painful crises and more leg ulcers than those patients with high RBC deformability. The average number of dense cells was 22.2% and 9.8% of total circulating cells in the first and second group respectively. Moreover, the group with high red cell deformability had 33% mortality during the study period whereas no deaths occurred in the group with low RBC deformability. The data indicate that there is a subset of patients with SS who have relatively few painful crises despite low Hb F level. We wish to designate these by the acronym MIDDD syndrome: Mild disease as far as painful crises are concerned, increased number of Dense cells, and Decreased red cell Deformability. In addition these patients have high incidence of leg ulcers, have low incidence of urinary tract infection, and less mortality. Cellular factors seem to contribute to the incidence of painful crises.

Erythrocyte folate levels: A clinical study

1) To determine if there are significant differences in laboratory parameters and patient characteristics between patients with low erythrocyte (RBC) folate levels and those with normal RBC folate levels; 2) to determine the correlation between serum and RBC folate levels; 3) to determine if the RBC folate level changed the diagnosis, treatment, and outcome of these patients if the serum folate level was available. The study is a retrospective review of all inpatients and outpatients at a public teaching hospital who had an RBC folate level less than or equal to 175 ng/ml (N = 57) over the study period (69 months) and a blindly selected group of patients with RBC folate levels greater than 175 ng/ml (N = 53) during the same period. Patients with low RBC folate levels had higher mean corpuscular volume (MCV) and red cell distribution width (RDW) values and lower serum folate and B12 values than patients with normal RBC folate levels, but there was no difference in degree of anemia, presence of oval macrocytes and/or hypersegmented neutrophils on the peripheral blood smear, LDH, alcohol use, diet, or any other measured clinical parameter. Serum and RBC folate levels were highly correlated and a low RBC folate affected the clinical outcome of three patients (5% of the low RBC folate group). Based upon these retrospective data and a review of the literature, we cannot define significant differences between patients with low RBC folate and randomly selected patients with normal RBC folate that could not have been equally well defined using serum folate values. The sensitivity and specificity of a low RBC folate level in the diagnosis of ill or healthy individuals are undefined, and until prospective studies utilizing some of the newer, more specific biochemical indicators of tissue folate are completed, the interpretation of low RBC folate levels will remain problematic.

Blood viscosity and circulatory shock.

Rheological features of the whole blood and blood components are of potential importance for microcirculatory blood flow in circulatory shock. The relative contribution of vascular geometric and rheological factors to the resistance to blood flow in the various shock states in man, however, are hard to elucidate [73]. Blood viscosity is mainly determined by haematocrit. In low flow states RBC aggregation in the venules might sustain the arrest of flow and hamper reflow. Lowering haematocrit may be beneficial in improving microcirculatory flow in hypovolaemic conditions as haemorrhagic shock. A decrease in RBC deformability is seen in critically ill, septic patients and this may reduce capillary flow. The WBC is likely to contribute to the maldistribution of microcirculatory flow in both hypovolaemic and septic shock and might even block capillary flow. The exact contribution of changes in haematocrit, RBC aggregation, RBC deformability, WBC deformability and plasma viscosity on blood viscosity and thus (micro)circulatory flow in human shock states, especially in septic shock, remains to be elucidated.

Haematology and metabolism of the blood of the little penguin, Eudyptula minor

1. 1. We studied the haematology of the little penguin, Eudyptula minor, and measured red cell enzymes, and the rate of O 2 and glucose consumption and CO 2 and lactate production of whole penguin blood. 2. 2. Little penguins have a very low RBC count (1.66 × 10 121 −1) and very large red cells (MCV = 229 μm 3), resulting in a normal haemoglobin and haematocrit. 3. 3. Despite the lower body temperature of penguins, the rate of O 2 consumption by whole blood is close to that predicted from studies on other birds.

Are 'Indexes' an Index of Physician Performance?

In this issue of theArchives, Hansen and associates 1 present data from a chart audit reflecting physician behavior in the interpretation of RBC indexes. The authors begin with the fact that patients having low mean RBC volumes and high RBC counts relative to those volumes will commonly be found to have thalassemic syndromes if properly examined. Physicians working in areas with large populations of patients from racial stock originating in the Mediterranean basin and large populations of black patients have had to concern themselves with this problem for years. Now the influx of refugees from Southeast Asia increases the numbers of persons at risk and distributes the problem to new regions of this country. Additionally, the need for cost control in medical care increases the incentive to make appropriate clinical decisions based on relatively inexpensive tests such as RBC indexes. Since RBC indexes are routinely provided as part of

Contributions of Red Cells and Plasma to Blood Viscosity in Preterm and Full-Term Infants and Adults

In preterm infants, plasma and red blood cells display several specific properties (eg, RBC size, plasma composition) that could influence blood flow behavior. Hemorheologic properties of blood from 20 preterm infants (24 to 36 weeks of gestation), ten full-term neonates, and ten adults were studied by means of a cone-plate viscometer adapted with a Couette-type chamber allowing viscometry at a wide range of shear rates (1.15 to 230/s). Blood viscosity (at given hematocrit of 60%), plasma viscosity, and RBC aggregation were very low in the smallest preterm infants, increased with gestational age, and reached the highest values in the adults. Whole blood viscosity increased directly with increasing plasma viscosity, plasma fibrinogen, and total plasma protein concentration, with the strongest correlations at the lowest shear rate of 1.15/s. The viscosity of RBCs suspended in a nonaggregating buffer solution was similar in all groups, thereby indicating that RBC deformability is similar in preterm infants, full-term neonates, and adults. Because mixing of neonatal and adult blood components occurs in most small preterm infants as a result of the transfusion of adult blood products, viscosities of cross suspensions (neonatal RBCs in adult plasma and adult RBCs in neonatal plasma) were measured. The exchange of neonatal plasma for adult plasma increased blood viscosity values in the neonates to adult values. On the other hand, the exchange of neonatal RBCs for adult RBCs did not affect blood viscosity. These results indicate that viscosity of blood with given hematocrit is lower in preterm infants than in term neonates and adults as a result of low plasma viscosity and low RBC aggregation, and that neonatal RBCs do not possess specific properties that influence blood viscosity.

Nutrition following gastric operations for morbid obesity.

Nutritional status after 238 gastric operations designed to reduce caloric intake and body weight to within 30% of ideal was assessed by measuring body composition using the multiple isotope dilution technique. Body cell mass (BCM) and body fat were quantitated before and at 24 months after operation. Malnutrition was defined as a total exchangeable sodium (Nae) to total exchangeable potassium (Ke) ratio greater than 1.22. Data were collected on 96 patients. All had lost a mean of 26% of preoperative weight by 24 months. Significant malnutrition occurred in 47 patients whose Nae/Ke ratio ranged from 1.23 to 2.17 (1.45 +/- 0.03). There was a 34% reduction in body fat. The malnourished patients lost 10% more BCM by 24 months than did the normally nourished group. Malnutrition resolved as the stoma enlarged in 19 patients, and dietary counselling helped eight patients. Eighteen patients required reoperation to establish a larger orifice, and endoscopic dilatation was successful in two patients. Administration of a liquid diet via the gastrostomy was required for prolonged periods in some malnourished patients. Seventeen patients who had lost weight rapidly over a short time had low vitamin B12, thiamine, and serum and RBC folate levels. One patient had a markedly decreased serum thiamine level with neuropathy. Symptoms of weakness, easy fatigability, and lassitude were found in the malnourished patients. Low thiamine and serum folate levels were also seen in patients ingesting a liquid diet of 750 kcal with a standard multivitamin supplement. Malnutrition was not seen in these patients. In the 49 patients who remained well nourished, BCM decreased by 19%, but the Nae/Ke remained normal. Weight loss was well tolerated, and no patients required reoperation or supplemental liquid diet to increase caloric or protein intake. The degree of malnutrition in patients after gastric operations is as great as following intestinal bypass but is not associated with liver failure. Malnutrition with vitamin deficiency is a great potential hazard in patients who undergo intake-limiting operations, especially if the goal of the operation is to restore near-normal weight. Current operations are successfully designed to maintain a small orifice size, so that the risks of malnutrition are likely to increase in the future.

Microcytosis Caused by RBC Fragmentation

ABNORMALLY low RBC size, expressed as low mean corpuscular volume (MCV), most often is due to iron deficiency or one of the thalassemia syndromes. More rarely, low MCV is associated with pyridoxinesensitive anemia, sideroblastic anemia, anemia of chronic disease,¹and hemoglobinopathies such as CC.²Generally in the latter group microcytosis, if present, is not great. We report a case of a patient with severe burns, considerably low MCV, and none of these diseases. Histograms of RBC size distribution (erythrograms) showed that severe RBC fragmentation caused this patient's low MCV. <h3>Report of a Case</h3> A 2-year-old boy was admitted to the Los Angeles County-University of Southern California Burn Center for a 70% total body third-degree scald burn. Despite appropriate intravenous fluids, antibiotics, and topical care, shock became intractable and he died 36 hours later. At admission the hemoglobin level was 14.1 g/dl; hematocrit value, 40.2%; MCV, 63 cuμ; and

659 HERIDITARY ELLIPTOCYTOSIS, RED CELL FRAGMENTATION, AND DECREASED GLUTATHIONE (GSH)

Marked poikilocytosis accompanied by membrane fragmentation and microspherocyte formation have been described in occasional cases of hereditary elliptocytosis. We have studied a healthy 10 year old black male with a compensated hemolytic anemia, elliptocytosis and severe red cell fragmentation. Several parameters known to affect RBC membrane stability were found to be normal: pyruvate kinase activity, RBC ATP content, unstable hemoglobin evaluation, direct and indirect Coomb's tests, membrane thermal sensitivity, RBC calcium and calcium permeability, RBC cholesterol and phospholipid content, and the distribution of membrane phosphatides including phosphatidyl ethanolamine. The only abnormality found was a RBC GSH content approximately 50% of normal (below that seen in most G-6-PD deficiencies). Furthermore, in centrifugally-separated cells, GSH content decreased progressively with increasing cell density. Unlike G-6-PD deficiency the low GSH content was not accompanied by abnormal oxidant sensitivity; GSH was not diminished by incubation with ascorbate-aminotriazole and no methemoglobin or sulfhemoglobin was formed. Enzymes involved in GSH metabolism (GSH reductase, G-6-PD, GSH peroxidase) were slightly elevated. Incubation of RBC with H3-glutamate, with subsequent molecular weight separation of the GSH inermediates, suggests an intact GSH synthetic pathway but diminished H3-glutamate content. The low RBC GSH may be related to the RBC morphologic features and hemolysis.

Serum folic acid and B12 in 272 psychiatric in-patients.

Serum folate and B12 estimations were carried out on 272 admissions to a psychiatric unit during 1972 and 1973. 21.3% had serum folate below 2 ng/ml and 26.1% serum B12 below 150 pg/ml. The organic psychosis patients had a significantly lower mean B12 than the others, and were over-represented among the low B12 group. Low B12 status was also associated with low RBC and WBC. Low folate status was linked with depression, malnutrition, physical illness and low Hb, RBC and WBC. There were more chronic alcoholics than others with serum folate greater than 4-9 ng/ml, low RBC and macrocytosis. The presence of one or more haematological abnormalities (macrocytosis, low Hb, low RBC or low WBC) predicted low folate in 76%, and low B12 in 79%, but these were also found in 40% of the normal folate and 41% of the normal B12 patients. Macrocytosis may prove to be a reliable sign of alcoholic abuse.

Serum and erythrocyte folates in combined iron and folate deficiency

A high incidence of iron and folate deficiency was found in 80 female subjects living in a private institution. Iron therapy in individuals with low serum iron values resulted in a significant increase in hemoglobin levels. An improvement in serum and RBC folate levels was also found following iron therapy but this could not be attributed to treatment since a similar increase was observed in untreated control subjects, probably due to an increased dietary intake of folates during the study period. In subsequent studies small amounts of pteroylglutamic acid were given to all patients and their response to therapy was related to initial serum and RBC folate values. No correlation between serum folate levels and response to folate therapy could be demonstrated. Red cell folate levels on the other hand correlated well with response to therapy. A significant increase in hemoglobin was found following folate therapy in patients with low RBC folates, but not increase in subjects with normal RBC folates. Conversely, the increase in hemoglobin following iron therapy in subjects with normal RBC folates was three times as much as in patients with low RBC folates. Thus, unlike serum folate determinations, RBC folate measurements are a reliable index of tissue folate stores, and useful in the prediction of response to folate therapy in both the iron-deficient and iron-replete states.