Minor Hemoglobin Research Articles

Prognostic impact of in-hospital hemoglobin decline in non-overt bleeding ICU patients with acute myocardial infarction

BackgroundThe prognostic value of in-hospital hemoglobin drop in non-overt bleeding patients with acute myocardial infarction (AMI) admitted to the intensive care unit (ICU) remains insufficiently investigated.MethodsA retrospective analysis was performed based on the Medical Information Mart for Intensive Care (MIMIC)-IV database. 2,334 ICU-admitted non-overt bleeders diagnosed with AMI were included. In-hospital hemoglobin values (baseline value on admission and nadir value during hospitalization) were available. Hemoglobin drop was defined as a positive difference between admission and in-hospital nadir hemoglobin. The primary endpoint was 180-day all-cause mortality. The time-dependent Cox proportional hazard models were structured to analyze the connection between hemoglobin drop and mortality.Results2,063 patients (88.39%) experienced hemoglobin drop during hospitalization. We categorized patients based on the degree of hemoglobin drop: no hemoglobin drop (n = 271), minimal hemoglobin drop (< 3 g/dl; n = 1661), minor hemoglobin drop (≥ 3 g/dl & < 5 g/dl, n = 284) and major hemoglobin drop (≥ 5 g/dl; n = 118). Minor (adjusted hazard ratio [HR] = 12.68; 95% confidence interval [CI]: 5.13–31.33; P < 0.001) and major (adjusted HR = 13.87; 95% CI: 4.50-42.76; P < 0.001) hemoglobin drops were independently associated with increased 180-day mortality. After adjusting the baseline hemoglobin level, a robust nonlinear relationship was observed in the association between hemoglobin drop and 180-day mortality, with 1.34 g/dl as the lowest value (HR = 1.04; 95% CI: 1.00-1.08).ConclusionIn non-overt bleeding ICU-admitted patients with AMI, in-hospital hemoglobin drop is independently associated with higher 180-day all-cause mortality.

Abstract 78: A Single Center Comparison Of Transradial And Transfemoral Approaches For Carotid Angioplasty And Stent Placement

Context: Transradial access has been increasingly utilized for neurointerventional procedures including carotid angioplasty and stent placement (CAS) over the past decade. At our center, we adopted transradial approach as the preferred approach in 2020. Objective: To compare the results of transradial approach with transfemoral approach for CAS as part of a quality assurance initiative. Methods: We analyzed data collected for all non-urgent CAS procedures performed at our institute in the last 24 months by same interventionalists to minimize inter-operator variability. We looked at the rates of technical failure; hemorrhagic complications classified as major (hemoglobin decrease &gt;5 g/dL or intracranial hemorrhage with deficits), minor (hemoglobin decreases 3-5 g/dL or intracranial hemorrhage without residual deficits), or insignificant; and any stroke and/or death within 1-month post procedure. Results: A total of 182 non-urgent CAS procedures were performed at our institution; 116 (64%) were initiated using transfemoral approach and 66 (36%) were initiated using transradial approach. The median age was similar between the two group (66.5 years versus 66.7 years). There were 6 (3%) CAS procedures initiated using transradial approach but later converted to transfemoral due to anatomical and/or technical difficulties. One (0.6%) CAS procedure initiated using transfemoral approach was converted to transradial approach due to severe iliofemoral atherosclerosis. The rates of any stroke and/or death were 1.6% (n=1) and 3.3%% (n-=4) in patients undergoing CAS using transradial and transfemoral approaches, respectively. The rate of major hemorrhagic complications were 1.6% (n=1) and 5.7% (n-=7) in patients undergoing CAS using transradial and transfemoral approaches, respectively. Conclusions: The rates of major hemorrhagic complications were lower among patients who underwent CAS via transradial approach compared with CAS using transfemoral approach although the rates of technical failure remain relatively high with transradial approach.

Abstract P516: A Comparison of Transradial and Transfemoral Approaches for Performance of Carotid Angioplasty and Stent Placement

Context: Over the past few decades, transradial access has been increasingly utilized for neurointerventional procedures including carotid angioplasty and stent placement (CAS). Objective: To compare the outcomes of CAS performed via transradial approach with those performed using transfemoral approach within the same institution. Methods: We analyzed all the elective CAS procedures performed at our institute in the last 48 months and divided the procedures based on initial approach (transradial or transfemoral). Both approaches were used by same interventionalists to minimize inter-operator variability. We compared the rates of technical failure; hemorrhagic complications classified as major (hemoglobin decrease &gt;5 g/dL or intracranial hemorrhage with deficits), minor (hemoglobin decreases 3-5 g/dL or intracranial hemorrhage without residual deficits), or insignificant; and any stroke and/or death within 1-month post procedure. Results: A total of 120 elective CAS procedures were performed at our institution; 84 patients (70%) were initiated as transfemoral and 36 patients (30%) were initiated as transradial approach. There were 6 (16%) CAS procedures initiated as trans-radial but later switched to transfemoral due to anatomical and/or technical difficulties. Similarly, 1(1.2%) procedure was switched to transradial from transfemoral. So finally, 89 (74%) patients had transfemoral approach and 31 (26%) patients had transradial approach to CAS. The median age was similar between the two groups (66.5 years versus 67.3 years).The rates of major hemorrhagic complications were 2 (2.2 %) and 0 (0%) in CAS performed using tranfemoral and tranradial approaches, respectively. The rate of any stroke and/or death within 30 days post procedure was 5 (5.6 %) and 1 (3.2 %) in CAS performed using transfemoral and transradial approaches, respectively.The median fluoroscopy time was 36.1 minutes and 34.4 minutes using transfemoral and transfemoral approaches, respectively (p =0.72). Conclusions: Transradial approach is comparable to transfemoral approach for performance of CAS in regard to clinical endpoints although the rates of technical failure remain relatively high in patients in whom CAS was initiated from transradial approach.

Inositol Hexakisphosphate Increases The Transition Constant And The Affinity Of Horse Aquomethemoglobin for 5,5′‐dithiobis(2‐nitrobenzoate)

CysF9[93]β exists in two tertiary conformations, r and t, which are in dynamic equilibrium. The equilibrium constant, Kequ, for the reaction of 5,5′‐dithiobis(2‐nitrobenzoate) — DTNB — with the CysF9[93]β sulfhydryl group of each hemoglobin was determined at 25°C as a function of pH. The reactivity of CysF9[93]β is affected by allosteric effectors such as the proton (H+) and inositol hexakisphosphate (inositol‐P6). The major and minor haemoglobins in horse haemolysate were separated using a column of Whatman's carboxymethylcellulose (CMC 52). The absorbance of the product of DTNB reaction, 5‐thio‐2‐nitrobenzoate, at different concentrations of DTNB and 50 μmol (haem) dm−3 was read at 412 nm. The absorbance was then substituted into an appropriate equation derived for the determination of the equilibrium constant, Kequ, for the reaction. Kequ decreased the orders of magnitude between pH 5.6 and 9.0 in the absence and presence of inositol‐P6. Inositol‐P6 increased the affinity of the major and minor Hb for DTNB but decreased the affinity of the minor aquomet‐Hb. The results show that inositol‐P6 increases the relative population of the t tertiary conformation. So, it increases the affinity of CysF9[93]β by changing the relative distribution of two protein conformations.Study objectiveThe study also seeks to find the equilibrium between the r and t isomers in the reaction of DTNB with CysF9[93]β sulphydryl group of the horse aquomethemoglobins. The relative populations of these two conformations from the pH dependence of equilibrium and kinetic parameters and the effect of inositol‐P6 on these relative populations were determined.MethodsPreparation and separation of horse hemoglobin had been described in Omotosho et al., 2017. Preparation and determination of aquomethemoglobin concentration: Aquomethemoglobin was prepared by the addition of a two‐fold excess of potassium ferricyanide, K3Fe(CN)6, to oxyhemoglobin of a known concentration. An approximately 1 mol dm−3 K3Fe(CN)6 solution was prepared by dissolving 0.33 g of the reagent in 1 cm3 of distilled water. The volume of the K3Fe(CN)6, v cm3, added to V cm3 of hemoglobin to give a two‐fold excess is related to the concentration of the hemoglobin solution.ResultsDomestic horse contains two hemoglobin types: A, the fast hemoglobin, and B, the slow hemoglobin. The two haemoglobins have identical α chains. Horse hemoglobin consists of two electrophoretically distinct components. From Figs. 1 and 2 it is seen that inositol‐P6 increases the affinity of CysF9[93]β of each haemoglobin for DTNB by about three orders of magnitude throughout the pH range 5.6 to 9.2.ConclusionFigs. 1 and 2 report the dependence of Kequ, the equilibrium constant of the reaction of DTNB with CysF9[93]β, on pH. The values of Kequ decrease by about two orders of magnitude for slow aquomet hemoglobin over the range 5.6 ≥ pH ≤ 9.0 whereas there in the fast hemoglobin, the values of Kequ increases by about six orders of magnitude and there is an increase in the affinity for the aquomet derivative. This shows that there is more insight on the nature of the tertiary structure transition in both T and R state hemoglobin.Support or Funding InformationWe appreciate Covenant University Centre for Research, Innovation and Development for the financial support.

Reactive Sulphydryl Groups in Horse Carbonmonoxyhaemoglobin

Background and Objective: Reactive sulphydryl groups in haemoglobin has been related with oxygen binding. In this study, the researchers analyzed the reactive sulphydryl groups in horse (Equus ferus caballus) carbonmonoxyhaemoglobin. Materials and Methods: Hemolysate gotten from fresh horse blood was converted to yield the carbonmonoxy derivative. It was then separated via carboxymethylcellulose into major and minor fractions of haemoglobin. These fractions were titrated with Ellmanʼs reagent (DTNB) and p-hydroxymercuri(II)benzoate (p-MB) stock solutions in increasing volumes. Results: Results showed that two sulphydryl groups reacted with DTNB and p-MB in both major and minor haemoglobin fractions. p-MB is known to be more reactive with thiols than DTNB, on the other hand the reactivity is the same with horse carbonmonoxyhaemoglobin. Conclusion: This study will enable a better understanding as regards the kinetics and equilibrium behind this reaction.

General self-efficacy and diabetes management self-efficacy of diabetic patients referred to diabetes clinic of Aq Qala, North of Iran

BackgroundSelf-efficacy is one of the factors involved in successful self-care of diabetic patients. The aim of this study was to evaluate general self-efficacy and diabetes management self-efficacy and to determine their association with glycemic control in diabetic individuals, referred to the diabetes clinic of Aq Qala city, North of Iran.MethodsIn this cross-sectional study, 251 type 2 diabetes mellitus patients were enrolled using census method. Data collection tools consisted of Sherer General Self-Efficacy Scale (SGSES) and Diabetes Management Self-Efficacy Scale (DMSES) with minor demographic adjustments and hemoglobin A1C test. Data were analyzed using descriptive statistics and analytical techniques include independent t-test, Spearman correlation coefficient and linear regression were applied for further data analysis.ResultsThe mean and standard deviation age of subjects was 56.17 ± 10.45 years. The mean level of HbA1C of studied subject was 8.35 ± 2.02%. There was a negative correlation between age and general self-efficacy and diabetes self-efficacy while, there was a positive correlation between general self-efficacy and diabetes self-efficacy (P < 0.001). Results of the regression analysis showed that duration of the disease was the only variable which had a significant effect on the level of hemoglobin A1C (P < 0.001), so that for each year of having the disease, the level of hemoglobin A1C increased by 0.084% (CI 95% = 0.048–0.121).ConclusionsGeneral self-efficacy and diabetes self-efficacy does not affect glycemic control in diabetic individuals. The duration of the disease is the only affecting variable on glycemic control by its worsening in diabetic individuals. Interventions are recommended to help glycemic control in individuals who are having this disease for longer periods. Moreover, further studies on the affecting factors on poor glycemic control of diabetic patients as well as the role of time variable, are recommended.

Hb A2 Episkopi – a novel δ-globin chain variant [HBD:c.428C>T] in a family of mixed Cypriot–Lebanese descent

ABSTRACTObjectives: Thalassaemia is a potentially lethal inherited anaemia, caused by reduced or absent synthesis of globin chains. Measurement of the minor adult haemoglobin Hb A2, combining α- with δ-globin, is critical for the routine diagnosis of carrier status for α- or β-thalassaemia. Here, we aim to characterize a novel δ-globin variant, Hb A2 Episkopi, in a single family of mixed Lebanese and Cypriot ancestry with mild hypochromic anaemia and otherwise normal globin genotype, which also presents with a coincidental 0.78-Mb sequence duplication on chromosome 1 (1q44) and developmental abnormalities.Methods: Analyses included comprehensive haematological analyses, cation-exchange high-performance liquid chromatography (CE-HPLC), cellulose acetate electrophoresis (CAE), Sanger sequencing and structure-based stability predictions for Hb A2 Episkopi.Results: The GCT > GTT missense mutation, underlying Hb A2 Episkopi, HBD:c.428C > T, introduces a cd142 codon change in the mature protein, resulting in reduced normal Hb A2 amounts and a novel, less abundant Hb A2 variant (HGVS: HBD:p.A143V), detectable as a delayed peak by CE-HPLC. The latter was in line with structure-based stability predictions, which indicated that the substitution of a marginal, non-helical and non-interface residue, five amino acids from the δ-globin chain carboxy-terminus, was moderately destabilizing.Discussion: Detection of the new variant depends on the diagnostic set-up and had failed by CAE and on an independent CE-HPLC system, which, in unfavourable circumstances, may lead to misdiagnoses of β-thalassaemia as α-thalassaemia. Given the mixed background of the affected family, the ethnic origin of the mutation is unclear, and this study thus suggests awareness for possible detection of Hb A2 Episkopi in both the Cypriot and the Lebanese populations.

Higher minor hemoglobin A2 levels in multiple sclerosis patients correlate with lesser disease severity.

ObjectiveTo define whether minor adult hemoglobin A2 (HbA2, α2δ2) exerts any protective activity in multiple sclerosis (MS).MethodsHbA2 levels were measured in 146 MS patients with high performance liquid chromatography and association with MS Severity Scores (MSSS) were determined. HbA2 associations with blood count parameters were also studied using blood counts evaluated on the same day of high performance liquid chromatography sampling. Routine biochemical parameters were also determined to rule out elusively influential factors, such as anemia and thyroid disorders.ResultsHbA2 levels negatively correlated with MSSS (Spearman correlation, R: −0.186, P=0.025). Exclusion of confounding factors with a generalized linear model revealed an even stronger negative correlation between HbA2 and MSSS (P<0.001). HbA2 positively correlated with red blood cells (RBCs) (R=0.350, P<0.001) and in turn, RBCs negatively correlated with MSSS (R=−0.180, P=0.031). Average HbA2 levels were highest among patients treated with interferon β1a.ConclusionRBC fragility is increased in MS, and recent data suggest that circulating free Hb contributes to neural injury in MS. HbA2 and its oxidative denaturation product hemichrome A2 enhance RBC membrane stability to a greater extent than do major HbA or hemichrome A. Reductions in ischemic cerebrovascular vascular events are reported in β-thalassemia carriers and HbA2 levels are considerably higher in this population. Episodic declines of cerebral blood flow were shown in bipolar disorder, and we have recently shown a protective role of HbA2 against postpartum episodes in females with bipolar disorder. HbA2’s erythroprotective functions may reduce free Hb and long-term neural injury in MS.

Reactive Sulphydryl Groups present in Horse (Equus Ferus Caballus) Carbonmonoxyhaemoglobin by Titrating with 5, 5′‐Dithiobis‐2‐Nitrobenzoate (DTNB)

This research was carried out to determine the number of reactive sulphydryl groups in horse (Equus ferus caballus) haemoglobin. Haemolysate was prepared from the horse blood. The haemoglobin was separated into major and minor fractions using carboxymethyl cellulose (CMC‐52). Each haemoglobin fraction, in phosphate buffer pH 7.6, was accurately measured into several clean, dry test tubes. Increasing volumes of stock 5,5′‐dithiobis‐2‐nitrobenzoate (DTNB) were added to the different test tubes and left to equilibrate for 3 hours. Absorbance of each solution in each test tube was read at 412 nm. A graph of change in absorbance against the volume of DTNB was plotted; maximum change in absorbance was obtained at the point where the graph levels off. The ratios of 5‐thio‐2‐nitrobenzoate (TNB) concentration to the concentration of haemoglobin tetramer (Hb4) were calculated and plotted against the volume of DTNB. The number of sulphydryl groups reacting with DTNB was found to be two in both the major and minor haemoglobin.Support or Funding InformationCovenant University, Ota.

Functional characterisation of the haemoglobins of the migratory notothenioid fish Dissostichus eleginoides

This study addresses the primary structure, the oxygen-binding properties and the CO-rebinding kinetics of the haemoglobins of the Patagonian toothfish Dissostichus eleginoides. D. eleginoides belongs to the family Nototheniidae, the most diversified of the suborder Notothenioidei, mostly exhibiting an Antarctic distribution. Some of its features are typical of Antarctic species, some are not. For instance, D. eleginoides appears not to have functional antifreeze glycoproteins (consistent with its non-Antarctic distribution). In contrast, it has a major and a minor haemoglobin (similar to many Antarctic notothenioids), and their very low oxygen affinity does not follow the trend of other non-Antarctic notothenioids and appears typical of cold-adapted species. Moreover, the amino-acid sequence reveals high identity with the globins of Antarctic notothenioids, arguing in favour of a common origin within notothenioids, and indicates that the primary structure of the major and minor haemoglobins has undergone modifications only to a limited extent. The ligand-rebinding kinetics of the major haemoglobin of D. eleginoides indicate a strong stabilisation of the quaternary T state at lower pH values.

HbA2 : biology, clinical relevance and a possible target for ameliorating sickle cell disease.

HbA2 , a tetramer of α- and δ-globin chains, provides a diagnostic clue to the presence of β-thalassaemia trait. This minor haemoglobin, which forms about 2-3% of the total, has no known physiological role, but has the interesting property of preventing polymerization of deoxy-sickle haemoglobin. If it were possible to increase the level of HbA2 sufficiently it could have a benefit in sickle cell disease similar to that of foetal haemoglobin. Moreover, HbA2 is present in all erythrocytes, an advantage not found with foetal haemoglobin, which is heterocellularly expressed. The molecular basis of HbA2 gene (HBD) expression is partially understood, and with new molecular tools, it might be possible to induce levels of HbA2 that could be clinically important. However, high concentrations of this positively charged haemoglobin might damage the erythrocyte membrane; also, the reciprocal relationship of δ- and γ-globin gene (HBD and HBG1/2, respectively) expression might negate any benefit of increasing transcription of the former.

Abstract W MP28: Safety of Parentral Antiplatelet Regimen Within 24 Hours of Intravenous tPA Administration: Challenging the Conventional Paradigm

Background and Objective: It is considered unconventional to initiate antiplatelet regimen within 24 hours of IV tPa administration in acute ischemic strokes. There has been an increasing amount of literature assessing combination therapy of IV r- tPA and IV Eptifibatide in acute ischemic stroke. Our objectives were to evaluate the safety (hemorrhagic complications) and efficacy (discharge mRS) of administering IV Eptifibatide within the first 24 hours of receiving full dose IV r-tPA respectively. Materials and Methods: All patients that presented to our university affiliated stroke center from 2010-13 with an acute ischemic stroke were included and retrospectively classified into two groups. Group A underwent full dose IV r- tPa (.9 mg/kg) (+/- Endovascular intervention). Group B underwent full dose IV r-tPa (.9mg/kg) and IV Eptifibatide (+/- Endovascular intervention). Epitafibide was administered as a bolus of 135 mcg/kg IV followed by .5 mcg/kg/min for 20 hours. The primary endpoint of bleeding is classified as major (symptomatic intracranial hemorrhage or hemoglobin decrease by &gt;5 mg/dl), minor (asymptomatic intracranial hemorrhage or hemoglobin decrease by 3-5 mg/dl) and insignificant as proposed by TIMI score. The efficacy endpoint was discharge mRS of 0-1 as favorable, with 2 and above being unfavorable. Results: We reviewed 2,016 patients with ischemic stroke, of which 170 received IV tPA. Among the group, 118 received IV r-tPa alone and 52 received combined modalities of IV r-tPa and IV Eptifibatide. In group A, there were 7 patients who had a major complication of symptomatic intracranial hemorrhage, while 1 patient had a minor complication of asymptomatic intracranial hemorrhage. In group B, there were 3 patients who had major complication of symptomatic intracranial hemorrhage and 5 with minor complications of asymptomatic intracranial hemorrhage. In group A , 9% (n=4) had a favorable outcome (OR=2.389, 95% CI 0.6645 to 8.589, p= 0.2217). Of the 52 patients in group B, 18% (n=8) had a favorable outcome. Conclusion: IV Eptifibatide, within the first 24 hours of ischemic stroke in combination with full dose IV r-tPA was found to be safe and efficacious. Further, larger prospective trials are needed to corroborate our findings.

Minor hemoglobins other than A2 in iron deficiency.

To determine any difference in levels of minor hemoglobins, other than hemoglobin A2 (HbA2), in patients with iron deficiency. We divided ethylenediaminetetraacetic acid (EDTA)-anticoagulated blood specimens from 188 patients into 2 groups, of which 94 displayed a normal or high ferritin level and the remaining 94 had a low ferritin level. We correlated the red cell indices, hemoglobin levels, and ferritin levels with the percentage of various minor hemoglobins. The Student's t-test was used to assess the statistical significance of the difference between the mean concentrations of minor hemoglobins in the 2 groups. Only hemoglobin HbA1a had a positive correlation (0.33 in iron-deficient and 0.35 in iron-replete specimens) with serum ferritin concentration. Among the minor hemoglobins, HbA1a (P =.008) and HbA2 (P <.001) were significantly different between the 2 groups. HbA1a may be low in iron deficiency, independent of HbA2. This information may be used to predict coexistent iron deficiency in β-thalassemia traits, in which concomitant infection or inflammation leads to normal ferritin levels.

Minor hemoglobins HbA2 and HbF associate with disease severity in bipolar disorder with a likely protective role of HbA2 against post-partum episodes

BackgroundThere exist studies indicating that bipolar disorder (BD) associates with changes in brain blood flow. Human brain with its high demand to oxygen constitutes 2% of the total body weight, while it receives 20% of cardiac output. α and β globin chains of hemoglobin were recently found in neural tissues, yet no study has questioned blood hemoglobins in BD. MethodsA total of 120 euthymic BD patients (40 males and 80 females) were analyzed via high performance liquid chromatography (HPLC) to measure minor hemoglobin levels, which were statistically compared with disease characteristics. ResultsMinor hemoglobins HbA2 and HbF associated positively with episode density as a measure of disease severity in BD. An increased level of HbA2 meant significantly less postpartum episodes in child bearing women. HbF levels were higher in patients with a positive family history of any psychotic disorder. Sum of HbA2 and HbF correlated with episode density with a stronger significance (p<0.001) supporting intermittent hypoxia hypothesis in BD. LimitationsThe study was conducted only on euthymic patients to avoid likely bigger exogenous effects such as electro-convulsive therapy and diverse drug regimes, yet larger comparative studies are needed to support our current findings. ConclusionsHigher HbA2 and HbF in more severe bipolar disorder may be compensations against intermittent hypoxias in BD. HbA2 increases following myocardial angina and in mountain dwellers, which may indicate protective roles in extreme conditions. HbF increase may act more as a maladaptation or emerge via haplotypal associations of BD genes and gamma-globin locus at 11p15.5.

Sickle Cell Trait: Is There an Increased VTE Risk in Pregnancy and the Postpartum?

Blacks are purported to have a higher venous thromboembolism (VTE) risk than whites. We hypothesized that this might be due, in part, to the greater presence of sickle cell trait (SCT) among blacks. We investigated whether the presence of SCT resulted in a higher VTE incidence in a population predisposed to VTE, the pregnant/postpartum women. Methods: Using a mirrored clinical database that prospectively gathered in- and out-patient information for the years 1998–2008, we collected demographic data, including hemoglobin electrophoreses, on all pregnant/postpartum non-Hispanic women who delivered at a large, diverse, urban hospital. We identified those women who developed VTE either while pregnant or postpartum during those 11 years. Charts initially identified as potential VTE cases were subjected to review to ensure accuracy of VTE coding. Results: Of 12,429 women, 679 non-Hispanic SCT black women, 5,465 non-Hispanic Hemoglobin AA (women with HbA as the only hemoglobin present on electrophoresis, with normal amounts of the minor hemoglobins) black women and 1,162 non-Hispanic HbAA white women were included in the analysis. SCT prevalence was high (11.1%) within this black population as compared to 8.3% in the general non-white population. Proportions with VTE were similar for black SCT and black HbAA groups: 0.44% for the SCT group, 0.49% for non-Hispanic black HbAA women. Black HbAA women had a non-significantly higher proportion of VTE than white HbAA women 0.49% vs 0.26% (RR 1.9, 95%CI:0.6,6.3, p = 0.28). Women with VTE were older than those without VTE (32.2 vs. 27.6 years, p = 0.0002) and the majority of VTE occurred postpartum in all groups, and significantly in the HbAA groups. There was no increase in the incidence of pulmonary emboli in the SCT group. Conclusion: In the largest analysis to date, we could not detect a meaningful difference in peripartum VTE incidence between women with and without sickle cell trait.

Abstract TP123: Open-label Phase I Clinical Study to Assess the Safety and Efficacy of Cilostazol in Patients Undergoing Carotid Artery Angioplasty and Stent Placement

Background: One month dual antiplatelet therapy, with Aspirin and Clopidogrel, following intra- and/or extra-cranial stent placement is the standard of care to prevent in- stent thrombosis. Cilostazol, a novel antiplatelet drug, with vasodilatory effects and smooth muscle cell proliferation inhibition, has recently been demonstrated to be safe and efficacious in secondary stroke prevention and has a safety profile comparable to both Aspirin and Clopidogrel. Objective: To evaluate the safety and clinical efficacy of Cilostazol and Aspirin therapy following internal carotid angioplasty and stent placement prior to and one month post-procedure. Methods: We conducted a Phase I open label, non-randomized single center prospective study. All patients received Aspirin (325 mg/day) and Cilostazol (200 mg/day) for at least 3 days before internal carotid stenting. The two anti-platelet agents were continued for one month after the procedure and then patients were continued on aspirin daily. The primary efficacy end point was the 30-day composite occurrence of death, stroke, TIA, and unplanned endovascular revascularization. The primary safety end point was bleeding. Bleeding complications were classified as major (hemoglobin decrease &gt;5 g/dl), minor (hemoglobin decrease 3-5 g/dl), or insignificant. Results: Twelve patients (mean age 66±12 years; 10 men) were enrolled and underwent internal carotid angioplasty and stent placement. One patient discontinued Cilostazol after the first dose, prior to stent placement, secondary to non-specific dizziness. Another patient did not follow study protocol and continued anticoagulation dose enoxoparin with Aspirin and Cilostazol resulting in symptomatic intracerebral hemorrhage 15 hours following successful stent placement; ultimately leading to withdrawal of care. None of the patients that successfully completed the study, and followed protocol, experienced any complications at 1-month and 3-month follow up. Conclusion: The use of Cilostazol and Aspirin for carotid angioplasty and stent placement appears to be safe but protocol compliance needs to be emphasized. Further studies are required to analyze the effectiveness and role of Cilostazol in neurointerventional procedures.

Analytical goals for the determination of HbA2

We present a study aimed to define the analytical goals for the determination of hemoglobin A₂, a minor hemoglobin present in human blood normally accounting from 2.5 % to 3.3 % of total hemoglobin, and typically increased up to 6 % – 7 % in subjects carriers of β-thalassemia. The analytical goals have been derived using two approaches, the first one based on biologic variation, and the second one based on the opinion of experts. The data obtained by studying 17 adult non-carrier healthy subjects, from whom we took blood samples every 2 weeks for 2.0 months, indicated a small intraindividual biologic variation (CV I of 0.7 % ), with respect to a larger between-subject variation (CV G of 7.7 % ). The minimum levels for imprecision, bias and total error derived from the analysis of these data were: 0.5 % , 2.9 % and 4.5 % , respectively. The limits derived from the opinion of experts were based on a questionnaire with three clinical cases, which was circulated among two teams of international experts, and on a discussion about the clinical needs. The average total error derived from such surveys ranged between 7.0 % and 9.5 % . The various methods to derive analytical performance goals gave different limits, thus indicating the need for an increased communication between clinicians and laboratory professionals on this matter.

Kinetics of reaction of 5,5′-dithiobis(2-nitrobenzenzoate) with CysF9[93]β sulphydryl group of sheep haemoglobins at neutral and physiological pH ranges

The kinetics of the reaction of 5,5′-dithiobis(2-nitrobenzoate) (DTNB) with CysF9[93]β sulphydryl group of the sheep haemoglobins were studied at neutral and physiological pH (6.8⩽pH⩽7.6) ranges under pseudo first order conditions. Each reaction is of first order with respect to the DTNB concentration. The pH dependence of the observed rate constant of the reaction at neutral and physiological ranges gave a complex trend. The observed rate shows that at neutral pH, the presence of inositol hexakisphossphate (IHP) leads to a relative lowering of the pseudo first order rate constant. Overall, the rate varied among the derivatives as aquomet>oxy>carbomonoxy and the major haemoglobin show a higher reactivity than the minor haemoglobin.

A transgenic mouse model expressing exclusively human hemoglobin E: Indications of a mild oxidative stress

Hemoglobin (Hb) E (β26 Glu→Lys) is the most common abnormal hemoglobin (Hb) variant in the world. Homozygotes for HbE are mildly thalassemic as a result of the alternate splice mutation and present with a benign clinical picture (microcytic and mildly anemic) with rare clinical symptoms. Given that the human red blood cell (RBC) contains both HbE and excess α-chains along with minor hemoglobins, the consequence of HbE alone on RBC pathophysiology has not been elucidated. This becomes critical for the highly morbid β(E)-thalassemia disease. We have generated transgenic mice exclusively expressing human HbE (HbEKO) that exhibit the known aberrant splicing of β(E) globin mRNA, but are essentially non-thalassemic as demonstrated by RBC α/β (human) globin chain synthesis. These mice exhibit hematological characteristics similar to presentations in human EE individuals: microcytic RBC with low MCV and MCH but normal MCHC; target RBC; mild anemia with low Hb, HCT and mildly elevated reticulocyte levels and decreased osmotic fragility, indicating altered RBC surface area to volume ratio. These alterations are correlated with a mild RBC oxidative stress indicated by enhanced membrane lipid peroxidation, elevated zinc protoporphyrin levels, and by small but significant changes in cardiac function. The C57 (background) mouse and full KO mouse models expressing HbE with the presence of HbS or HbA are used as controls. In select cases, the HbA full KO mouse model is compared but found to be limited due to its RBC thalassemic characteristics. Since the HbEKO mouse RBC lacks an abundance of excess α-chains that would approximate a mouse thalassemia (or a human thalassemia), the results indicate that the observed in vivo RBC mild oxidative stress arises, at least in part, from the molecular consequences of the HbE mutation.

First Report of Hb A2-NYU (HBD:c.39T>A) in the Hellenic Population

We report the first heterozygous case of Hb A2-NYU (HBD:c.39T>A) in the Hellenic population. The proband, an adult female from the island of Crete, Greece, was identified during routine family screening. DEAE chromatography of the index case revealed a minor hemoglobin (Hb) fraction preceding the elution of the wild-type Hb A2. DNA sequencing of the entire HBD gene coding regions indicated that the index case was heterozygous for the rare variant Hb A2-NYU. Family studies indicated that this Hb variant was inherited from the mother. This finding underlines the vast genetic heterogeneity of the HBD gene in the Hellenic population.