Cord blood study on β-thalassemia and hemoglobin E

We describe hematologic data from 18 newborn infants including follow-up data. Of these, ten were the offspring of patients with β-thal/Hb E disease and the remainder were infants who were found to have a decrease in red cell osmotic fragility during a random cord blood examination. The results of the cord blood study showed that two infants having normal red cell osmotic fragility with about 2% Hb E + Hb A + Hb F at birth represented Hb E heterozygosity. Eleven babies had slightly decreased red cell osmotic fragility, a mild degree of microcytosis and poikilocytosis, and hemoglobin types of Hb A + Hb F with no elevation of Hb A₂ at birth. They subsequently had hematologic findings consistent with the β-thal heterozygosity. The means of hematological values of cord blood in the β-thal trait infants appeared to be statistically different from those in the normal infants only with respect to increased red cell count and reduced MCH. One infant was thought to have the β-thal trait but had a greater degree of thalassemic changes in red cells; subsequently he turned out to have homozygous β-thalassemia. Four newborn infants with hypochromia and numerous target cells had 4-7% Hb E + Hb F without Hb A. Follow-up examination showed two cases of Hb E homozygosity; however, the others, who had obvious microcytosis and poikilocytosis in cord blood, finally developed β-thal/Hb E disease. Thus, a careful study on red cell osmotic fragility, morphology and starch gel electrophoresis at birth allows detection and diagnosis of β- thal heterozygosity, β-thal homozygosity, Hb E heterozygosity, Hb E homozygosity and double heterozygosity for β-thal and Hb E.     

Glutathione and iron at the crossroad of redox metabolism in rats infected by Trypanosoma evansi

The aim of this study was to evaluate the changes in hematological and biochemical parameters of blood during acute Trypanosoma evansi infection in Wistar rats. The end points studied were hematologic parameters, red blood cell fragility, iron content, and glutathione and lipid peroxidation levels. Forty-eight animals were infected with trypomastigotes and distributed into five groups according to the level of parasitemia. Twelve non-inoculated animals were used as control. Parasitemia increased progressively, reaching highest scores at 15 days post-inoculation. At this point, several deleterious effects were observed such as an increase in iron content, in osmotic fragility, and in lipid peroxidation index, while glutathione decreased drastically. These changes were highly correlated to parasitemia (p?<?0.0001) and among each other (p?≤?0.001). Hematological indices (Hb, packed cell volume (PCV), red blood cells (RBC), and mean corpuscular hemoglobin concentration) were also correlated to parasitemia (p?≤?0.0003) but failed to correlate to the other variables. Along with increase in iron, RBC fragility produced a decrease in RBC, PCV, and Hb, but not in mean corpuscular volume. Decrease in glutathione was negatively correlated to the end products of lipid peroxidation, clearly indicating the establishment of a pro-oxidant condition. The results show that the infection causes hematological impairments, increases iron and osmotic fragility, along with marked oxidative stress in red blood cells of rats inoculated with T. evansi.     

Newborn screening for hemoglobin abnormalities. A comparison of methods

Peripheral blood from 1,000 newborn infants of black (641) and Southeast Asian (359) ancestry were screened for hemoglobin variants. Results obtained from the combination of cellulose acetate (CAC) and citrate agar (CAG) electrophoresis were compared with isoelectric focusing (IEF) electrophoresis. There was complete agreement between the two methods on assignment of Hb S trait, Hb C trait, Hb E trait, and homozygous Hb E. IEF identified small amounts of Hb A in two newborn infants with Hb S-beta + thalassemia; the CAC and CAG electrophoretic patterns were indistinguishable from sickle cell anemia. One hundred twenty newborn infants with Hb Bart's were detected by IEF; 51 of these were found on CAC. Although IEF was more sensitive in detecting small amounts of hemoglobin, it is not clear if the improvement in detection warrants adopting this form of electrophoresis for routine screening of newborn infants.     

Thalassemia minor: routine erythrocyte measurements and differentiation from iron deficiency

The clinical differentiation of the causes of microcytosis is difficult because of the lack of a method for the diagnosis of alpha thalassemia. A number of laboratory tests have been proposed for the differentiation of alpha thalassemia from iron deficiency, including decision functions based on the red blood cell indices generated by electronic cell counters. The accuracy of these screening methods was assessed in 93 patients with microcytosis known to be secondary to either iron deficiency or beta thalassemia minor and, prospectively, in 26 patients with microcytosis in whom globin chain synthesis ratio was used to diagnose thalassemia. The functions evaluated were: RBC volume distribution curve; osmotic fragility; erythrocyte count; discriminant function = MCV - (5 X Hgb) - RBC - 8.4; ratio of MCH/RBC; ratio of MCV/RBC; and 0.01 X MCH X (MCV)2. A simplified method of measuring anisocytosis using the RBC volume distribution curve was significantly more accurate (P less than 0.01) in distinguishing iron deficiency from thalassemia than any of the other decision functions. Analysis of red blood cell volume distribution, although not sufficiently accurate for definitive diagnosis, appears to be a useful technic in the initial screening of patients with microcytosis and in determining which additional testing should be done.     

A microtechnique for measuring red cell osmotic fragility of infants.

Chloramphenicol (D-threo-2-dichloroacetamido-1-p-nitrophenylpropane-1,3-diol) added to blood samples did not alter the observed shift in the red cell osmotic fragility curves as the samples were aged in vitro for 24 hours at 37 degrees C. Nor was the normal rate of loss of 2,3-diphosphoglycerate, ATP, or glutathione from the red cells affected by the presence of chloramphenicol over the same period. Consequently, this bacteriostatic agent can be added to blood samples taken under non-sterile conditions, such as from the heel of an infant, in order to preserve them from the effects of microbial contamination. In this way red cell osmotic fragility results can be obtained on non-sterile samples after their incubation at 37 degrees C for 24 hours. A miniaturisation of the standard osmotic fragility procedure is described, which allows results to be produced from the small, non-sterile samples obtained by heel-prick of infants.     

A novel hemoglobin-adenosine-glutathione based blood substitute: evaluation of its effects on human blood ex vivo

Chemically modified hemoglobin (Hb) solutions are under current investigation as potential red cell substitutes. Researchers at Texas Tech University have developed a novel free Hb based blood substitute product. This blood substitute is composed of purified bovine Hb cross-linked intramolecularly with o-adenosine-5'-triphosphate and intermolecularly with o-adenosine, and conjugated with reduced glutathione (GSH). In this study, we compared the effects of our novel blood substitute and unmodified (U) Hb, by using allogenic plasma as the control, on human blood components: red blood cells (RBCs), platelets, monocytes (Mo), and low-density lipoproteins (LDLs). The pro-oxidant potential of both Hb solutions on RBCs was examined by the measurement of osmotic and mechanical fragility, conjugated dienes (CD), lipid hydroperoxides (LOOH), thiobarbituric acid reactants (TBAR-S), isoprostanes (8-iso PGF2alpha) and intracellular GSH. The oxidative modification of LDLs was assessed by CD, LOOH, and TBAR-S, and the degree of apolipoprotein (apo) B cross-linking. The effects of Hb on platelets have been studied by monitoring their responses to the aggregation agonists: collagen, ADP, epinephrine, and arachidonic acid. Monocytes were cultured with Hb solutions or plasma and tested for TNF-alpha and IL-1beta release, then examined by electron microscopy. Results indicate that native UHb initiates oxidative stress of many blood components and aggravates inflammatory responses of Mo. It also caused an increase in RBC osmotic and mechanical fragility (p < 0.001). While the level of GSH was slightly changed, the lipid peroxidation of RBC increased (p < 0.001). UHb was found to be a stimulator of 8-iso PGF2alpha synthesis, a potent modulator of LDLs, and an effective potentiator of agonist induced platelet aggregation. Contrarily, our novel blood substitute did not seem to induce oxidative stress nor to increase Mo inflammatory reactions. The osmotic and mechanical fragility of RBCs was similar to that of the control. Such modified Hb failed to alter LDLs, increase the production of 8-iso PGF2alpha, but markedly inhibited platelet aggregation. The effect of this novel blood substitute can be linked with the cytoprotective and anti-inflammatory properties of adenosine, which is used as a cross-linker and surface modifier, and a modification procedure that lowers the hemoglobin pro-oxidant potential.     

Osmotic fragility test in heterozygotes for alpha and beta thalassaemia.

This study shows that the combination of heterozygous beta thalassaemia and deletion heterozygous (-alpha/alpha alpha) or homozygous (-alpha/-alpha) alpha+ thalassaemia may result in the production of erythrocytes which have normal mean volume and haemoglobinisation but decreased osmotic fragility. Based on this finding and previous studies, which have shown that beta thalassaemia screening by the osmotic fragility test may miss a significant proportion of beta thalassaemia heterozygotes, we conclude that beta thalassaemia screening in a population in which both alpha and beta thalassaemia are prevalent should combine the one tube osmotic fragility test with electronic measurement of red blood cell indices in the initial screening process.     

Preservation of erythrocytes of heterozygous SC sickle cell patients]

In order to evaluate the feasibility of the autologous transfusion in an alloimmunized sickle cell patient, changes in the hematologic and biochemical characteristics of erythrocytes stored for 42 days from two patients with sickle cell SC anemia were compared with control subjects' (Hb A) red blood cells. Erythrocytes were stored in Saline Adenosine Dextrose Mannitol at +4 degrees C. The cryopreservation storage was made and 51Cr red cell survival was measured in one patient. No significant difference in the hematologic and biochemical parameters of the SC red blood cells and the control subjects was observed during the storage at +4 degrees C. Red cell survivals determined in fresh cells, cells stored for 42 days at +4 degrees C and thawed cells from one patient demonstrate much shorter half-life values than those of normal red blood cells. Before application, our results need to be confirmed by the same protocol with another patient with sickle cell SC.     

23809例育龄人群地中海贫血筛查与血液学分析

目的了解育龄人群中地中海贫血（地贫）携带情况及其血液学特点,为地贫出生干预及筛查方法的完善提供依据。方法 23 809例育龄人群进行地贫初筛,对红细胞脆性或（和）平均容积低于正常值者进行血红蛋白电泳分析,根据初筛及电泳结果进行基因诊断。结果 23 809例育龄人群中,地贫初筛阳性5147例,血红蛋白分析筛出可疑α地贫3523例、β地贫1624例。地贫基因检测确诊α地贫2435例,包括合并β地贫103,1877例α地贫-1,462例α地贫-2,96例HbH病;β地贫1492例,包括HbE61例,249对夫妇可能生育中、重型地贫儿。少数地贫者血红蛋白水平正常,部分HbH和HbCS病血红蛋白电泳无特殊区带,β地贫合并α地贫双重杂合子表现为β地贫特点,各类地贫间血红蛋白水平、MCV、血红蛋白电泳结果及RBC脆性比较差异均有统计学意义（P〈0.05）。结论掌握地贫患者血液学特点,选择合理的筛查模式对育龄人群进行常规筛查,对高危者进行基因检测是干预重症地中海贫血患儿出生的有效措施。     

小于胎龄儿脐血脂联素水平测定及其临床意义

目的探讨小于胎龄儿（SGA）脐血脂联素（APN）水平变化及其对新生儿的影响。方法研究对象为SGA和适于胎龄儿（AGA）各30例。采用放射免疫分析法测定脐血和产妇血脂联素水平。用免疫比浊法测定三酰甘油（TG）,总胆固醇（TCH）,低密度脂蛋白胆固醇（LDL-C）,高密度脂蛋白胆固醇（HDL-c）水平。并分析脐血脂联素水平与母血脂联素,体质量指数（IBM）,胎盘重量和血脂水平的相关性。结果1.SGA脐血脂联素水平低于AGA差异有显著性（P〈0.01）;SGA血TG,TCH,LDL-c,HDL-c水平与AGA比较差异均无显著性（P〉0.05）。2.SGA血清脂联素水平与新生儿身长,新生儿体质量指数BMI,胎盘重量,脐血TG呈显著正相关（r=0.386,0.431,0.365,0.231,P〈0.05）,与母血脂联素水平,孕前和分娩时产妇IBM无相关性（P〉0.05）。结论小于胎龄儿具有较低血清脂联素水平,测定脐血脂联素水平有助于判断SGA的发展趋势。     

A second Australian family with hemoglobin North Shore (beta 134 Val----Glu)

A second Australian family is reported with Hemoglobin North Shore (beta 134 Val----Glu), an unstable hemoglobin, causing no clinical symptoms. All affected family members showed only mild reticulocytosis and microcytosis on the blood film, despite the strongly positive isopropanol test for Hb (hemoglobin) stability and numerous red cell inclusions. Hb North Shore constituted 31-38% of the total hemoglobin and migrated on the anodal side of Hb A at pH 8.9. The association of a mildly raised Hb A2 level and thalassemic phenotype with Hb North Shore previously reported, is confirmed in this study.     

Heterozygous beta-thalassemia in a large German family

This report deals with a large German family in which 12 carriers of the trait had the characteristic hematologic abnormalities of thalassemia minor. Among these are increased red cell count, decreased hemoglobin content, microcytosis and marked hypochromia in the presence of normal or increased serum iron levels. Thalassemia should always be considered if these hematologic abnormalities are found. It probably occurs more often in central Europe than thought of hitherto.     

Value of nucleated red blood cells in predicting severity and outcome of perinatal asphyxia

The objective of the study was to assess nucleated red blood cell counts in cord blood in a group of asphyxiated infants, and to determine its predictive value for short-term outcome. A prospective case control study was undertaken on cord blood samples collected from fifty six term neonates with perinatal asphyxia and an equal number of normal appropriately matched controls for cord blood pH and nucleated RBC counts. Babies were followed up in nursery till discharge. Statistical analysis employed were ANOVA test, logistic and linear regression analysis. There was a significant increase in the number of nucleated red blood cells in cases as compared to controls. Low Apgar, cord blood pH and neonatal outcome correlated well with nucleated RBC counts. Nucleated red blood cell count at birth is a useful predictor of severity and short-term outcome of perinatal asphyxia.     

脐带不同结扎方式对新生儿影响的研究进展

延迟脐带结扎或挤压脐带可通过胎盘输血增加新生儿血容量、增加婴儿铁储备,减少贫血及输血,减少早产儿脑室内出血、增加血氧饱和度,早产儿在出生时进行脐带挤压可以减轻窒息和降低机械通气的需求。但临床上也有DCC或UCM可使新生儿黄疸加重的情况出现,而产科医生更加关注DCC或UCM对产妇产时出血风险的影响。有研究表明,脐带延迟结扎并不影响小儿的黄疸和抢救风险。目前,生后立即结扎脐带依然是大多数国家一直沿用的临床措施,对胎盘输血的利与弊及脐带结扎的方式需进一步研究讨论。     

Lymphocyte subpopulations in the blood of newborn infants

Assays of lymphocyte subpopulations and function have been applied to cells from the cord blood of twenty-four infants. The results are compared with those obtained in healthy adults. T cells, assayed by spontaneous rosette formation with sheep red blood cells (E rosettes) were present in lower proportion in cord (53%) than in adult blood (65%). There was a higher proportion of lymphocytes bearing stainable immunoglobulin in cord (32%) than in adult blood (22%). From the blood lymphocyte counts it was calculated that both T and B lymphocytes are present in greater numbers in the newborn infants' blood than in adults. Comparison of DNA synthesis showed that cord blood leucocytes had a higher spontaneous rate, but there were only minor differences in the lymphocyte mitotic response to phytohaemagglutinin (PHA). The response of cord blood lymphocytes was slightly lower to a submaximal stimulus and higher to a maximal stimulus. There was a correlation between the submaximal response and the proportion of E rosetting cells.

The most striking differences between infant and adult blood lymphocytes were in their cytotoxic activity against homologous target cells (Chang cells). Antibody-dependent cytotoxicity (K-cell activity) was readily detected using cord blood leucocytes, though it was lower than that of adult cells. PHA-induced cytotoxicity was very low in all cord blood samples, and in many cases was almost unmeasurable. This dissociation between the two types of cytotoxic activity is consistent with other evidence that they may be mediated by different cell types.

The assays were also applied to blood samples taken from five mothers of tested infants immediately after delivery. While some differences from normal adults were found with the mothers' lymphocytes they did not mirror those of the cord blood samples. This suggests that the pattern found for cord blood lymphocytes is not due to maternal factors crossing the placenta.

     

Elevated circulating fetal nucleated red blood cells and placental pathology in term infants who develop cerebral palsy

An elevated circulating fetal nucleated red blood cell count has long been recognized as an indicator of significant intrauterine stress. However, the nature of the causative events and their timing remain controversial. In this study, subacute and chronic placental lesions known to be associated with neurodisability were used as surrogates for antenatal stress. Mother-infant pairs with complete blood counts within 2 hours of delivery (n = 81) were drawn from a larger database of 152 term infants with cerebral palsy. An elevated nucleated red blood cell count (2.5 × 10³/mm³) in these infants was associated with a significantly increased prevalence of subacute or chronic placental lesions, whereas clinical findings did not significantly differ. The number of nucleated red blood cells per 10 high-power fields of villous parenchyma was directly correlated with the nucleated red blood cell count, and a threshold of 10 or more nucleated red blood cells predicted a nucleated red blood cell count greater than 2.5 × 10³/mm³. Among individual placental lesions, multiple foci of avascular villi and chronic villitis were significantly associated with an elevated nucleated red blood cell count, whereas meconium-associated vascular necrosis showed a borderline association. Acute chorioamnionitis was the only placental lesion more common in the group without elevated nucleated red blood cell count. The presence of significant placental lesions was associated with an elevated nucleated red blood cell count in infants with or without either acidosis (cord pH <7.0) or birth asphyxia (American College of Obstetrics and Gynecology criteria). Acidosis and birth asphyxia were not significantly related to an elevated nucleated red blood cell count in infants without these placental lesions.     

Incubated osmotic fragility test does not exclude red blood cell membrane disorders! About a case of hereditary elliptocytosis

We report a case of hereditary elliptocytosis in an infant diagnosed a few months after the birth, in a context of regenerative normocytic normochromic anaemia. The investigations, including incubated osmotic fragility, erythrocytic enzymes study and haemoglobin electrophoresis, were not contributive. Only the persistence of elongated (or cigar-shaped) erythrocytes on blood smears was noted. Hereditary elliptocytosis was confirmed by specialized investigations (rheological study and erythrocytic membrane proteins electrophoresis). Investigations in the mother were realized and led to the discovery of a similar biological pattern. Hereditary elliptocytosis is a red blood cell membrane disorder due to the defect in cytoskeleton proteins (spectrin or 4.1), leading to the loss of deformability properties of erythrocytes. This disorder is considered as rare; however, its incidence is probably underestimated because most cases are pauci- or asymptomatic and the discovery is often fortuitous. The absence of detection of this defect by incubated osmotic fragility should not discard the hypothesis of erythrocytes membrane disorders. The persistent observation of elongated erythrocytes on blood smear must encourage the biologist to evocate a hereditary elliptocytosis.     

Co-inheritance of compound heterozygous Hb Constant Spring and a single -alpha(3.7) gene deletion with heterozygous deltabeta thalassaemia: a diagnostic challenge

Haemoglobin Constant Spring (Hb CS) mutation and single gene deletions are common underlying genetic abnormalities for alpha thalassaemias. Co-inheritance of deletional and non-deletional alpha (alpha) thalassaemias may result in various thalassaemia syndromes. Concomitant co-inheritance with beta (beta) and delta (delta) gene abnormalities would result in improved clinical phenotype. We report here a 33-year-old male patient who was admitted with dengue haemorrhagic fever, with a background history of Grave's disease, incidentally noted to have mild hypochromic microcytic red cell indices. Physical examination revealed no thalassaemic features or hepatosplenomegaly. His full blood picture showed hypochromic microcytic red cells with normal haemoglobin (Hb) level. Quantitation of Hb using high performance liquid chromatography (HPLC) and capillary electrophoresis (CE) revealed raised Hb F, normal Hb A2 and Hb A levels. There was also small peak of Hb CS noted in CE. H inclusions was negative. Kleihauer test was positive with heterocellular distribution of Hb F among the red cells. DNA analysis for alpha globin gene mutations showed a single -alpha(-3.7) deletion and Hb CS mutation. These findings were suggestive of compound heterozygosity of Hb CS and a single -alpha(-3.7) deletion with a concomitant heterozygous deltabeta thalassaemia. Co-inheritance of Hb CS and a single -alpha(-3.7) deletion is expected to result at the very least in a clinical phenotype similar to that of two alpha genes deletion. However we demonstrate here a phenotypic modification of alpha thalassemia presumptively as a result of co-inheritance with deltabeta chain abnormality as suggested by the high Hb F level.     

Predictive value of cord blood IgE levels in 'at-risk' newborn babies and influence of type of feeding

Cord serum IgE levels were examined in 101 newborn infants ofatopic parents, and reviewed at the ages of 3, 6, 9, 12, 15, 18, 21 and 24 months, in order to determine any relation with signs and symptoms of allergic rhinitis, bronchial asthma, atopic dermatitis, urticaria and food allergy. Cord blood IgE levels were 1.06+ 1.02 U/ml in the group of infants who developed atopic disease, and 0.34 + 0.79 U./ml in the group of infants who did not develop atopy (P < 0.001). In the breast-fed group 37.5, of the infants with cord blood IgE more than 0.8 U/ml and 11.5% with IgE below 0.8 U/ml had atopic disease. In the soy-fed group 33.3% of the infants with cord blood IgE more than 0.8 U/m! and 15.8% with cord blood IgE less than 0.8 U/ml developed atopy. Ninety percent of the cow's milk-fed infants with cord blood IgE above 0.8 U/ml and 16% with cord blood IgE below 0.8 U/ml showed atopy during the follow-up period. No correlation was found between the IgE levels in maternal and respective cord blood.     

新生儿脐血神经生长因子测定的临床意义

目的探讨新生儿脐血神经生长因子(nerve growth factor,NGF)测定的临床意义。方法采用放射免疫分析法测定200例无缺氧史新生儿、97例有缺氧高危因素足月新生儿脐动脉血中β-NGF表达水平,200例无缺氧史新生儿中足月儿140例,早产儿60例;97例有缺氧高危因素足月新生儿分为3组:重度窒息组25例,子痫组40例,妊娠期糖尿病组32例。结果早产儿脐动脉血β-NGF水平明显低于正常足月产儿(P0.05),有缺氧高危因素足月新生儿脐血中β-NGF水平明显低于无缺氧史足月新生儿(P0.05),β-NGF水平与新生儿性别、体质量及分娩方式无明显关系。结论神经生长因子与胎儿生长发育可能有一定关系,可以客观反映新生儿出生时的状况,对协助判断新生儿预后有指导意义。