Total Hemoglobin Research Articles

Efficacy and Safety of Brl-101, CRISPR-Cas9-Mediated Gene Editing of the BCL11A Enhancer in Transfusion-Dependent β-Thalassemia

BACKGROUND: β-Thalassemia is an inherited hemolytic disease that is prevalent worldwide. Over 200 mutations in the HBB gene, which encodes adult hemoglobin (HbA), result in β-thalassemia. Hereditary persistence of fetal hemoglobin (HbF) can alleviate the symptoms of anemia. CRISPR-Cas9-mediated disruption of the BCL11A erythroid enhancer results in the reduction of BCL11A expression and the induction of fetal γ-globin, which is a practicable therapeutic strategy for treating transfusion-dependent β-thalassemia (TDT). METHODS: We obtained mobilized autologous CD34+ cells from 4 TDT patients sponsor initiated in phase I/II clinical trial (NCT05577312) and 6 TDT patients in investigator initiated clinical study（NCT04211480, NCT04205435）respectively. These cells were edited with CRISPR-Cas9 RNP at the +58 erythroid specific enhancer region of the BCL11A gene and then reinfused after the patients had undergone myeloablative busulfan conditioning. We subsequently monitored adverse events, neutrophil and platelet engraftment. Efficacy assessments included proportion of transfusion-independent (TI) subjects, levels of total hemoglobin and HbF, and proportion of red blood cells expressing HbF in peripheral blood. TI was evaluated for elimination of transfusions starting 42 days after the last transfusion and Hb above 90 g/L. RESULTS: Between October 15, 2019 and November 20, 2022, 10 patients with TDT were enrolled and received BRL-101 with a median age of 12.4 years (6-26). Among all the treated patients, 5 patients were β 0/β 0 phenotype, 4 patients were β0/β+ phenotype and 1 patient were β +/β + phenotype. As of July 20, 2023, the median follow- up was 24.6 months (4.3-39.2 m) (Tab.1). All of 10 patients achieved TI. The median duration of TI was 22.1 months (1.3 - 37.2 m). The longest duration of TI was 37.2 months (Fig.1). The levels of HbF ranged from 2.3 to 140.7g/L and the levels of total hemoglobin ranged from 105.7 to 149 g/L (Fig.2). At 6 months after BRL-101 infusion, the proportion of HbF-expressing red blood cells in peripheral blood had reached 96.5%, and then continued to rise and remained around 98-99% (Fig.3). Treatment-related adverse events were typical of those associated with myeloablation and autologous stem-cell transplantation, mainly manifested as hematological toxicities (Tab.2, Tab.3). 3 patients experienced adverse events (AEs) grade ≥ 3 which related to BRL-101. 4 patients experienced serious AEs (SAEs), including decreased platelet count, shock, febrile infection, soft tissue infection, and veno-occlusive liver disease. Only decreased platelet count may related to BRL-101, the others were due to busulfan treatment. All the SAEs were resolved. No study drug-related withdrawals or deaths occurred during treatment. CONCLUSIONS: Whether genotype was β 0/β 0 or non-β 0/β 0, BRL-101 demonstrated clinically meaningful increases in total Hb and HbF which occurred early and have been maintained over time, the safety profile of BRL-101 is generally consistent with that of myeloablative conditioning and autologous hematopoietic stem cell transplant. The updated data with 10 patients reported here are consistent with previous reports and support continued investigation of BRL-101 as a potential functional cure for patients with TDT.

New Insights in Sickle Cell Disease Provided By Intravascular Hemolysis and Total Hb Mass Parameters

New biomarkers may provide a better understanding of the complex pathophysiology of sickle cell disease. Anemia is defined as a reduction in the blood concentration of hemoglobin ([Hb]) to < 12 g/dL in females and < 13 g/dL in males. [Hb] will depend not just on the total circulating quantity of hemoglobin (tHbmass), but also on plasma volume (PV) in which it is suspended. Exercise capacity correlates poorly with [Hb], in contrast to tHbmass, as shown by studies comparing elite athletes and sedentary individuals. Similarly, classic parameters of hemolysis (LDH, bilirubin, ASAT) are not very specific for erythrocytes and do not always reflect the intravascular component of hemolysis. Plasma hemoglobin and heme, released by hemoglobin oxidation, are specific biomarkers of RBC destruction in the circulation and have their own deleterious effects on vascular walls, NO bioavailability, and the inflammatory state. In this study, we aimed to analyze the contribution of these biomarkers to cardiac and vascular parameters. Method: We carried out a preliminary analysis of patients included in the HEMOPROVE trial (NCT05199766) a prospective open-label study designed to better understand the effects of Voxelotor. Patients had to be more than one month from a vaso-occlusive crisis, 3 months from a transfusion and on a stable dose of hydroxyurea (HU) for at least 3 months to be included. We extracted and analyzed data from patients who had a pre-treatment Hb mass measurement. Hb mass, plasma volume were determined using the validated oCOR method using medical device Detalo Clinical TM - CO Rebreather (IEC 60601-1 and IEC 62304 for medical devices). Only patients with a HbCO of less than 3% benefited from this measurement; plasma hemoglobin and plasma heme were measured using the technique developed by our team (BET 18P3417). Blood pressure and heart rate were measured during echocardiography. All values were collected within the same week of inclusion in the protocol. Correlations were performed using a Spearman test, paired data comparisons were made with a Wilcoxon test (Graphpad9, PRISM). Results: Fourteen patients were included for blood mass measurement. Median age was 38 years [34.7-50.7], sex ratio F/M was 7/7, 10/14 patients were treated with HU. Median [Hb] was 7.4g/dL [6.6-7.7], tHbmass was 522 g [352-704] corresponding to 8.1 g/kg [6.1-11.7]. [Hb] and tHbmass were strongly correlated (p=0.008, r=0.68), whereas it was weaker with tHbmass/kg (p=0.046, r=0.54). Interestingly, some patients with approximately the same [Hb] had widely varying tHbmass. These results can be explained by significant variability in plasma volume, which was increased in half the patients, with a median increase of +135% [100-215] and a median volume of 5656 ml [4140-6931]. The tHbMass (p=0.01; r=0.64), tHbMass/kg (p=0.05, r=0.52) and above all PV (p=0.004; r=0.73) correlated with the E/E' used to evaluate the left ventricle filing pressure, while there was no correlation with [Hb] (p=0.5). Interestingly, the cardiac index was inversely correlated with plasma Hemoglobin (p=0.003, r=-0.74) with no correlation with [Hb] (p=0.4) or LDH (p=0.90), while mean and diastolic blood pressure were negatively correlated with plasma Heme (respectively p=0.01; r=-0.65 and p=0.001; r=-0.77) with no correlation with [Hb] and LDH (p>0.4). Conclusions: Measurements of total hemoglobin mass and intravascular hemolysis parameters provide a better understanding of the diversity of manifestations that lie behind sickle cell anemia, underpinned by complex mechanisms.

Translating an HPFH-Mechanism into Oral Small Molecule Therapy for Beta-Hemoglobinopathies: Clinical Proof-of-Principle

Introduction: Hereditary persistence of fetal hemoglobin (HPFH) down-modulates co-inherited sickle cell disease (SCD) severity, encouraging characterization of HPFH-mechanisms for interventional reprise. One HPFH mechanism is polymorphisms in DNA methyltransferase 1( DNMT1) that decrease DNMT1 protein stability (Gong et al, Blood 2021), agreeing with biochemical observations that DNMT1 mediates repression of fetal hemoglobin (HbF) genes by BCL11A. Here we describe translation of this HPFH-mechanism into oral therapy for SCD patients at high-risk for early mortality (Steinberg et al, JAMA 2004) despite standard-treatments. Methods and Results: The small molecule decitabine (Dec) contains a pyrimidine ring modification that binds and depletes DNMT1 and a natural deoxyribose that incorporates into DNA without terminating chain synthesis: minimum biologically effective doses of Dec, to deplete DNMT1 without cytotoxicity, can thus be found (reviewed in Zavras et al, Clin Ca Res, 2021). Other key properties of Dec are tropism to hematopoietic precursors, driven by high expression in these cells of deoxycytidine kinase that phosphorylates Dec, and rapid catabolism in vivo by cytidine deaminase (CDA), that severely restricts Dec bioavailability and half-life. We therefore combined Dec with a CDA-inhibitor tetrahydrouridine (THU): dose and schedule of THU/Dec that depleted DNMT1 without cytotoxicity to hematopoietic precursors in vivo were identified in non-human primate studies and Phase 1 clinical trials (Molokie et al, PLoS Med 2017), and here we describe interim results from proof-of-principle study in patients with SCD ( Table 1). Study interventions were oral THU/Dec (~10/0.2 mg/kg) 1X/week with or without oral nicotinamide (vitamin B3) 1 g/day. B3 was studied because it is a direct precursor of NADH, a fundamental antioxidant currency and also a cofactor for epigenetic enzymes that channel hematopoiesis to erythropoiesis vs megakaryopoiesis, to potentially counter an expected side-effect of THU/Dec of increasing platelets. Randomization was to THU/Dec vs B3 for 12 weeks, followed by THU/Dec + B3 for 12 weeks, then option to extend therapy for a further 24 weeks. Standard clinical and laboratory parameters were measured. Six patients enrolled, were randomized equally to THU/Dec or B3, and opted to extend. Dose-limiting toxicities (DLTs), including neutropenia or thrombocytosis, did not occur ( Table 1). In the year preceding study-treatment, 15 vaso-occlusive crises (VOC) requiring hospitalization were documented ( Table 1). By comparison, during 52 weeks on-study (48 weeks on-therapy, 4 weeks follow-up), the grade 3/4 adverse events were VOC hospitalizations x3 (1 during follow-up without therapy, 1 during B3 alone, 1 during B3 + THU/Dec therapy), hyperkalemia x2, and non-cardiac chest pain x1 ( Table 1)(p=0.04, paired t-test 2-sided). THU/Dec dose (7.6/0.15 mg/kg) was below the Phase 1 identified minimum biologically effective dose window (8-12/0.16-0.25 mg/kg, protocol since amended to accommodate high body weights) in one patient (TDN04) who accordingly did not have HbF% or hemoglobin increases ( Fig.1). In the 5 other patients, HbF increases (pre-treatment to maximum) were: 9.4 to 17.3, 5.9 to 11, 3.4 to 9.3, 3.3 to 16.3 and 5.7 to 10 % ( Fig.1). There were corresponding improvements in hemolysis and coagulation pathway parameters (LDH, total bilirubin, D-Dimer), and total hemoglobin increased from 9.9 to 11.5, 8.7 to 10.6, 6.6 to 7.7, 5.7 to 7.1 and 8 to 9.7 g/dL respectively. TDN01 and 06, the two patients with lowest pre-treatment hemoglobin, requested and resumed THU/Dec post-study by Expanded Access. Conclusions: This is the longest-term treatment to date of oral THU/Dec to target DNMT1 in patients with SCD, with or without B3. Subjective and objective improvements were sustained without DLTs in high-risk patients who displayed known negative prediction markers for response to hydroxyurea (HbF% <7.5%, reticulocyte count <300 x10 9/L - Steinberg et al, Blood 1997). The safety and efficacy signals align with scientific target validation data, and together with accessibility, support relevance to SCD patient needs and goals worldwide, bearing in mind major study limitations of single-site enrollment and only 6 patients.

Transfusion Practice: Hemolysis Markers After In Vitro Infusion of Packed Red Blood Cells by the Gravitational Method in Peripheral Catheter.

The objective of this study was to compare hemolysis marker levels after in vitro infusion of red blood cells (RBCs) according to storage time, infusion rate, and peripheral intravenous catheter size. This is an experimental study with randomly administered RBCs in quintuplicate, according to storage time shorter than and longer than 14 days, as well as infusion rate (50 mL/h and 100 mL/h) using catheters with calibers of 14-, 18-, and 20-gauge. Aliquots were collected from RBCs (V1), after equipment and catheter (V2) free-flow filling and after controlled infusion through the catheter (V3). The hemolytic markers analyzed were degree of hemolysis (%), hematocrit (Ht) (%), total hemoglobin (THb) (g/dL), free hemoglobin (FHb) (g/dL), potassium (K) (mmol/L), and lactate dehydrogenase (LDH) (U/L), considering a probability of error ≤5%. Sixty experiments were performed with the analysis of 180 aliquots. When RBCs aged <14 days were used, all catheters tended to increase THb, FHb, and K; while >14 days, RBCs presented increased FHb and degree of hemolysis with catheters of 18-gauge and THb levels at 14-gauge. Among the conditions analyzed, only 20-gauge catheters (the smallest) did not influence changes in hemolysis markers, regardless of RBC storage time.

Evaluation of the pleth variability index, perfusion index, and other physiological parameters after COVID-19.

The aim of this study was to observe the changes in pleth variability index (PVI), perfusion index (PI) and other hemodynamic parameters in adult individuals who had had Coronavirus disease 2019 (COVID-19) and were currently living a normal life. A further aim was to draw attention to the fact that some hemodynamic changes after COVID-19 may cause long-term health problems. A total of 174 adult individuals who had had COVID-19 and were currently living a normal life and 56 healthy individuals with similar demographic characteristics who had not had COVID-19 were included in the study. The PI, PVI, oxygen saturation (SpO2), pulse rate (PR), total hemoglobin (Hgb), oxygen reserve index (ORI), and blood pressure values were measured by Masimo Radical 7. The data of individuals who had and did not have COVID-19 before were compared. The mean PVI (p = 0.008) and PI (p < 0.001) were significantly lower in people who had been exposed to COVID-19. Likewise, the mean of ORI, SpO2, and SpOC values was observed to be significantly lower in participants exposed to COVID-19 disease (p < 0.001, p < 0.001, and p = 0.006, respectively). The PVI had a positive correlation with body mass index (BMI) (r = 0.263, p < 0.001) and a negative correlation with SpO2 (r = -0.194, p = 0.003) and PR (r = 0.190, p = 0.004). The PVI, PI, and other physiological parameters could potentially be useful for monitoring COVID-19 patients and evaluating their response to therapy. We believe that people who have been exposed to COVID-19 may be more susceptible to other diseases; therefore, they should be subjected to regular clinical checks.

Efficacy of wearable vibration dressings on full-thickness wound healing in a hyperglycemic rat model.

Local low-frequency vibration promotes blood flow and wound healing in hard-to-heal diabetic foot ulcers (DFUs). However, vibration treatment is challenging in patients with DFUs due to wound management difficulties and low adherence. Consequently, developing wearable self-care devices becomes imperative for effective wound healing. This study introduces a wearable vibration dressing and assesses its impact on wound healing in hyperglycemic rats. Low-frequency vibration at 52 Hz was applied to the wound for 40 min/day in awake rats. Relative wound areas on post-wounding days (PWDs) 4-7 were significantly smaller and the wound closure rate was significantly higher in the vibration group than in the control group (p < 0.05, respectively). The total haemoglobin at baseline and after vibration on post-wounding day 7 was significantly larger in the vibration group than in the control group (p < 0.05). On PWD 7, the thickness of the granulation tissue was significantly higher in the vibration group than in the control group (p < 0.05). Moreover, the number of blood vessels at the wound site and vascular endothelial growth factor A protein expression were significantly higher in the vibration group than in the control group (p < 0.05, respectively). The ratio of (CD68+ /iNOS+ )/(CD163+ ) macrophages in the vibration group was significantly lower than that in the control group (p < 0.05). These results indicate the potential of wearable vibration dressings as new self-care devices that can promote angiogenesis and blood flow, improve inflammation, and enhance wound healing in DFUs.

Association of blood donor characteristics with hemoglobin content in leukoreduced packed red blood cells.

A complex relationship exists between donor characteristics and red blood cell quality which remains partly explored. The present study aimed to determine the correlation of donor characteristics with the hemoglobin (Hb) content of leukoreduced packed red blood cells (PRBC). This prospective cross-sectional study was conducted on 100 blood donors. A pre-donation sample was collected for hemoglobin and hematocrit estimation. Whole blood was collected in quintuple blood bags and packed red cells were prepared. Sample from each packed red cell unit was estimated for hemoglobin and hematocrit. The volume, total Hb, actual total Hb, volume and Hb lost during processing, mathematical total Hb and hematocrit of each PRBC unit was calculated using formulas. The donor characteristics were analysed for correlation with Hb content of PRBC. The mean age of the 100 donors enrolled in the study was 36.3±9.9years. Majority of the donors were vegetarian, non-alcoholic, non-smokers, and had a pre-donation hemoglobin level of more than 14g/dl. The mean pre-donation Hb of the donors was 14.8±1.5g/dl. There was a strong positive correlation of donor pre-donation hemoglobin with total Hb (r=1.000, p=0.000), actual Hb (r=0.518, p=0.000) and mathematical hemoglobin (r=0.951, p=0.000) using the Pearson correlation test. A strong positive correlation was observed between the total and actual hemoglobin (r=0.518, p=0.000) of the units. There was no association of other donor characteristics with Hb content of leukoreduced PRBC. Donor pre-donation hemoglobin showed a strong positive correlation with the actual hemoglobin content of leukoreduced packed red blood cells.

Hemoglobin Mass and Blood Volume in Swimming: A Comparison Between Highly Trained, Elite, and World-Class Swimmers.

Total hemoglobin mass (tHbmass) and blood volume (BV) are important determinants of maximal oxygen uptake and endurance capacity. Higher-caliber endurance athletes usually possess higher tHbmass and BV values. This study aimed to compare tHbmass and BV among swimmers of diverse competitive calibers and distances. Thirty swimmers (16 female and 14 male) participated in the study: 3 were tier 5, world class (869 [59] FINA points); 15 were tier 4, elite/international (853 [38] points); and 12 were tier 3, highly trained/national (808 [35] points). They specialized in competition distances ranging from 200m to open-water 10km. Between February 2019 and February 2020, all swimmers had their tHbmass and BV measured by carbon monoxide rebreathing 1 to 6 times and participated in multiple competitions and race events. Relative tHbmass and BV were not different (P > .05) between tiers among women or among men (pooled tHbmass values 14.5 [0.5], 12.5 [1.5], 12.6 [2.3]g/kg for tier 5, tier 4, and tier 3, respectively). No differences were observed in relative tHbmass (P = .215) and BV (P = .458) between pool and open-water swimmers or between 200-, 400-, and 1500-m specialists (P > .05). No significant correlations were found between the highest measured absolute or relative tHbmass and BV and the highest FINA points scored over the follow-up period (R = -.42-.17, P = .256-.833), irrespective of competition distance. tHbmass and BV values did not differ between swimmers of different calibers or among competition distances. Furthermore, these values did not correlate with FINA points, either in males or in females. The present results indicate that hematological characteristics may have a lesser impact on swimming performance than on land-based endurance sports.

High-Density Functional Near-Infrared Spectroscopy and Machine Learning for Visual Perception Quantification.

The main application scenario for wearable sensors involves the generation of data and monitoring metrics. fNIRS (functional near-infrared spectroscopy) allows the nonintrusive monitoring of human visual perception. The quantification of visual perception by fNIRS facilitates applications in engineering-related fields. This study designed a set of experimental procedures to effectively induce visible alterations and to quantify visual perception in conjunction with the acquisition of Hbt (total hemoglobin), Hb (hemoglobin), and HbO2 (oxygenated hemoglobin) data obtained from HfNIRS (high-density functional near-infrared spectroscopy). Volunteers completed the visual task separately in response to different visible changes in the simulated scene. HfNIRS recorded the changes in Hbt, Hb, and HbO2 during the study, the time point of the visual difference, and the time point of the task change. This study consisted of one simulated scene, two visual variations, and four visual tasks. The simulation scene featured a car driving location. The visible change suggested that the brightness and saturation of the car operator interface would change. The visual task represented the completion of the layout, color, design, and information questions answered in response to the visible change. This study collected data from 29 volunteers. The volunteers completed the visual task separately in response to different visual changes in the same simulated scene. HfNIRS recorded the changes in Hbt, Hb, and HbO2 during the study, the time point of the visible difference, and the time point of the task change. The data analysis methods in this study comprised a combination of channel dimensionality reduction, feature extraction, task classification, and score correlation. Channel downscaling: This study used the data of 15 channels in HfNIRS to calculate the mutual information between different channels to set a threshold, and to retain the data of the channels that were higher than those of the mutual information. Feature extraction: The statistics derived from the visual task, including time, mean, median, variance, extreme variance, kurtosis, bias, information entropy, and approximate entropy were computed. Task classification: This study used the KNN (K-Nearest Neighbors) algorithm to classify different visual tasks and to calculate the accuracy, precision, recall, and F1 scores. Scoring correlation: This study matched the visual task scores with the fluctuations of Hbt, Hb, and HbO2 and observed the changes in Hbt, Hb, and HbO2 under different scoring levels. Mutual information was used to downscale the channels, and seven channels were retained for analysis under each visual task. The average accuracy was 96.3% ± 1.99%; the samples that correctly classified the visual task accounted for 96.3% of the total; and the classification accuracy was high. By analyzing the correlation between the scores on different visual tasks and the fluctuations of Hbt, Hb, and HbO2, it was found that the higher the score, the more obvious, significant, and higher the fluctuations of Hbt, Hb, and HbO2. Experiments found that changes in visual perception triggered changes in Hbt, Hb, and HbO2. HfNIRS combined with Hbt, Hb, and HbO2 recorded by machine learning algorithms can effectively quantify visual perception. However, the related research in this paper still needs to be further refined, and the mathematical relationship between HfNIRS and visual perception needs to be further explored to realize the quantitative study of subjective and objective visual perception supported by the mathematical relationship.

Influence of cuff stiffness on hemodynamics and perceived cuff pressure in the upper extremities in males and females: implications for practical blood flow restriction training

BackgroundPractical blood flow restriction (pBFR) during exercise is a cost-saving alternative to traditional blood flow restriction using pneumatic cuffs, particularly when exercising in a group setting. Depending on the pBFR technique, several factors (e.g., cuff width, limb circumference) have already been shown to be of importance when applying the pBFR pressure. Given that elastic cuffs are often used for pBFR, the cuff stiffness might be an additional influencing factor. Therefore, the present study compared the acute effects of three elastic cuffs with identical width but different stiffness (high stiffness (HS), medium stiffness (MS), and low stiffness (LS)) on hemodynamic measures and perceived cuff pressure at rest.MethodsIn a randomized, counter-balanced cross-over study, 36 young and normotensive participants completed three experimental trials. After a 10-min rest period in supine position, the cuff was loosely and proximally applied to the right upper arm. Following baseline data recording, the cuff was successively tightened in 10%-increments with respect to the limb circumference (%overlap) until arterial blood flow was occluded. At baseline and during each %overlap, systolic peak blood flow velocity of the brachial artery, rating of perceived cuff pressure, as well as muscle oxygen saturation and total hemoglobin concentration of the biceps brachii muscle were recorded.ResultsThe %overlap required to occlude arterial blood flow was different between the three cuffs (HS: 30.9 ± 3.8%, MS: 43.9 ± 6.1%, LS: 54.5 ± 8.3%). Furthermore, at 30% overlap, systolic peak blood flow velocity was lower when applying the HS (9.0 ± 10.9 cm∙s− 1) compared to MS (48.9 ± 21.9 cm∙s− 1) and LS cuff (62.9 ± 19.1 cm∙s− 1). Rating of perceived cuff pressure at 30% overlap was higher when using the HS (6.5 ± 1.5 arbitrary unit (a.u.)) compared to MS (5.1 ± 1.4 a.u.) and LS cuff (4.9 ± 1.5 a.u.) with no difference between the MS and LS cuff. However, muscle oxygen saturation and total hemoglobin concentration were not different between the three cuffs.ConclusionsThe present study revealed that the cuff stiffness influenced blood flow velocity and arterial occlusion pressure. Therefore, cuff stiffness seems an important factor for the application of pBFR.

Effect of the infection of the mugilid fish Planiliza subviridis with the copepod Ergasilus rostralis: A haematological study

A total of 83 specimens of Planiliza subviridis were collected from Khor Al-Zubair lagoon, northwest Arab Gulf, Iraq. These fishes were found infected with the copepod Ergasilus rostralis Ho, Javarajan &amp; Radhakrishnan, 1992. Blood parameters: total leukocyte count (WBCs), total red blood cells (RBCs), haemoglobin content (Hb%) and haematocrit volume (PCV) were investigated for lightly (1-5 parasites/fish), mildly (6-10 parasites/fish) and heavily (&gt; 10 parasites/fish) infected fish groups in comparison with uninfected fishes. Uninfected fishes had the highest values of all blood parameters, except WBCs. Hb%, PCV and RBCs significantly decreased in all infected groups when compared with the uninfected group. WBCs significantly increased in all infected fish groups in comparison with the uninfected fishes. WBCs insignificantly decreased in heavily infected group when compared with mildly infected fishes.

Effects of Photobiomodulation Therapy on Performance in Successive Time-to-Exhaustion Cycling Tests: A Randomized Double-Blinded Placebo-Controlled Trial.

The goal of this study was to investigate the effects of photobiomodulation therapy (PBMT) on performance, oxygen uptake (VO2) kinetics, and lower limb muscle oxygenation during three successive time-to-exhaustions (TTEs) in cyclists. This was a double-blind, randomized, crossover, placebo-controlled trial study. Sixteen cyclists (~23 years) with a cycling training volume of ~460 km/week volunteered for this study. In the first session, cyclists performed a maximal incremental test to determine maximal oxygen uptake and maximal power output (POMAX). In the following sessions, cyclists performed three consecutive TTEs at POMAX. Before each test, PBMT (135 J/thigh) or a placebo (PLA) was applied to both thighs. VO2 amplitude, O2 deficit, time delay, oxyhemoglobin (O2Hb), deoxyhemoglobin (HHb), and total hemoglobin (tHb) were measured during tests on the right vastus lateralis. The PBMT applied before three successive TTE increased performance of the first and second TTE (~10-12%) tests, speed of VO2 and HHb kinetics during the first test, and increased peripheral muscle oxygenation (increase in HHb and tHb) in the first and second exhaustion tests. However, the PBMT effects were attenuated in the third TTE, as performance and all the other outcomes were similar to the ones from the PLA intervention. In summary, PBMT application increased the first and second successive TTEs, speed of VO2, and muscle oxygenation.

Muscle oxygen supply impairment during maximal exercise in patients undergoing dialysis therapy

This study aimed to investigate whether Chronic Kidney Disease (CKD) influences O2 supply including O2 delivery and release to the active muscles during maximal physical exercise. Twelve CKD patients undergoing dialysis therapy (HD group) and twelve healthy adults (CTR group) performed an incremental exercise test to determine maximal oxygen uptake (VO2peak). Throughout the exercise, near-infrared spectroscopy allowed the investigation of changes in oxyhemoglobin (∆O2Hb), deoxyhemoglobin (∆HHb), and total hemoglobin (∆THb) in the vastus lateralis muscle. VO2peak was significantly lower in HD group. In addition, HD patients had impaired changes in muscular oxygenation (∆HHb and ∆O2Hb) and blood volume (∆THb) during the exercise (p < 0.05). Moreover, a positive correlation was observed between VO2peak and muscle blood volume (∆THb) in both groups (p < 0.05). This study provides the first evidence that HD patients displayed lower VO2peak and blunted muscular deoxyhemoglobin increase during exercise. This result supports the hypothesis of an increase in oxygen affinity and/or mitochondrial dysfunction in this population.

Manipulation of affective speech and hemoglobin changes: A case study

Despite the wide use of functional near-infrared spectroscopy (fNIRS) in various cognitive research, it is under-investigated whether fNIRS can offer neural evidence of emotion vocalization, especially in older adults. In this study, an 74-year-old male participant without a cognitive or physical difficulty completed two speech tasks while an fNIRS device recorded Changes in Oxy-hemoglobin (HbO) and total hemoglobin (HbT) levels in the pre-frontal cortex. The three speech tasks were (1) affective speech (i.e., talking about happy and sad life events) and (2) neutral speech (i.e., explaining how to make a peanut butter and jelly sandwich). The speech tasks were audio recorded which was acoustically analyzed using Praat for frequency and amplitude measures. In general, the frequency measures were highest when talking about sad life event while amplitude measures were highest when producing neutral speech. The HbO and HbT levels were positive and highest during the happy speech manipulation. During the other two speech tasks, the HbO levels were all negative with neutral being the lowest. The HbT levels showed a more complex change. More data are needed to confirm the pre-frontal lobe (de)activation associated with manipulation of affective prosody. This case study will facilitate future research in this line.

Development and Validation of a Three-Parameter Scoring System for Monitoring HIV/AIDS Patients in Low-Resource Settings Using Hematological Parameters.

This study aimed to test the validity of a composite score using complete blood count (CBC) for monitoring HIV patients receiving antiretroviral therapy (ART) in the absence of viral load and CD4 count. This retrospective cohort study analyzed the laboratory data of 82 HIV patients who had pre- and post-treatment viral load, CD4 count, and CBC data. Pre- and post-treatment data were pooled to analyze the correlation of CBC parameters with Polymerase Chain Reaction (PCR) ranks and their performance in indicating a CD4 count<200 cells/mm3 using the Operating Characteristics Curve (ROC), with the determination of cutoffs. A score combining the significant parameters was tested to predict a CD4 count of <200. Total lymphocyte count (TLC), percentage (TLP), and hemoglobin concentration (Hb) were the most significant parameters, showing negative correlations with PCR (Spearman's Rho = -0.357 to -0.242). The risk of acquired immunodeficiency syndrome (AIDS) was independently associated with TLC<1345 cells/mm3 (OR=2.92), TLP<29.07% (OR=3.53), and Hb<10.55 mg/dL (OR=3.60). A combined score of 2-3 indicated a CD4 count<200 with an odds ratio of 8.3-86.7. The proposed 3-parameter score combining the use of TLC, TLP, and Hb, is an affordable and practical approach that may have clinical utility in monitoring HIV patients receiving ART in low-resource settings.

Prediction of plasma volume and total hemoglobin mass with machine learning.

Hemoglobin concentration ([Hb]) is used for the clinical diagnosis of anemia, and in sports as a marker of blood doping. [Hb] is however subject to significant variations mainly due to shifts in plasma volume (PV). This study proposes a newly developed model able to accurately predict total hemoglobin mass (Hbmass) and PV from a single complete blood count (CBC) and anthropometric variables in healthy subject. Seven hundred and sixty-nine CBC coupled to measures of Hbmass and PV using a CO-rebreathing method were used with a machine learning tool to calculate an estimation model. The predictive model resulted in a root mean square error of 33.2 g and 35.6 g for Hbmass, and 179 mL and 244 mL for PV, in women and men, respectively. Measured and predicted data were significantly correlated (p < 0.001) with a coefficient of determination (R2 ) ranging from 0.76 to 0.90 for Hbmass and PV, in both women and men. The Bland-Altman bias was on average 0.23 for Hbmass and 4.15 for PV. We herewith present a model with a robust prediction potential for Hbmass and PV. Such model would be relevant in providing complementary data in contexts such as the epidemiology of anemia or the individual monitoring of [Hb] in anti-doping.

The effect of tumor vascular remodeling and immune microenvironment activation induced by radiotherapy: quantitative evaluation with magnetic resonance/photoacoustic dual-modality imaging.

Tumor radiotherapy combined with immunotherapy for solid tumors has been proposed, but tumor vascular structure abnormalities and immune microenvironment often affect the therapeutic effect of tumor, and multimodal imaging technology can provide more accurate and comprehensive information in tumor research. The purpose of this study was to evaluate the dynamic monitoring of tumor blood vessels and microenvironment induced by radiotherapy by magnetic resonance/photoacoustic (MR/PA) imaging, and to explore its application value in radiotherapy combined with immunotherapy. The tumor-bearing mice were randomly allocated into six groups, which received different doses of radiation therapy (2 Gy ×14 or 8 Gy ×3) and anti-programmed death ligand-1 (PD-L1) antibody for two consecutive weeks. MR/PA imaging was used to noninvasively evaluate the response of tumor to different doses of radiotherapy, combined with histopathological techniques to observe the tumor vessels and microenvironment. The inhibitory effect of high-dose radiotherapy on tumors was significantly greater than that of low-dose radiotherapy, with the MR images revealing that the signal intensity decreased significantly (P<0.05). Compared with those in the other groups, the tumor vascular density decreased significantly (P<0.01), and the vascular maturity index increased significantly in the low-dose group (P<0.05). The PA images showed that the deoxyhemoglobin and total hemoglobin levels decreased and the SO2 level increased after radiation treatment (P<0.05). In addition, the high-dose group had an increased number of tumor-infiltrating lymphocytes (CD4+ T and CD8+ T cells) (P<0.01, P<0.05) and natural killer cells (P<0.001) and increased PD-L1 expression in the tumors (P<0.05). The combination of radiotherapy and immunotherapy increased the survival rate of the mice (P<0.05), and a regimen of an 8 Gy dose of radiation combined with immunotherapy inhibited tumor growth and increased the survival rate of the mice to a greater degree than the 2 Gy radiation dose with immunotherapy combination (P=0.002). Differential fractionation radiotherapy doses exert biological effects on tumor vascular and the immune microenvironment, and MR/PA can be used to evaluate tumor vascular remodeling after radiotherapy, which has certain value for the clinical applications of radiotherapy combined with immunotherapy.

Association of Blood Leukocytes and Hemoglobin with Hospital Mortality in Acute Pulmonary Embolism.

This study aimed to assess the prognostic significance of total leukocyte count (TLC) and hemoglobin (Hb) levels upon admission for patients with acute pulmonary embolism (PE), considering the European Society of Cardiology (ESC) model for mortality risk. 1622 patients from a regional PE registry were included. Decision tree statistics were employed to evaluate the prognostic value of TLC and Hb, both independently and in conjunction with the ESC model. The results indicated all-cause and PE-related in-hospital mortality rates of 10.7% and 6.5%, respectively. Subgrouping patients based on TLC cut-off values (≤11.2, 11.2-16.84, >16.84 × 109/L) revealed increasing all-cause mortality risks (7.0%, 11.8%, 30.2%). Incorporating Hb levels (≤126 g/L or above) further stratified the lowest risk group into two strata with all-cause mortality rates of 10.1% and 4.7%. Similar trends were observed for PE-related mortality. Notably, TLC improved risk assessment for intermediate-high-risk patients within the ESC model, while Hb levels enhanced mortality risk stratification for lower-risk PE patients in the ESC model for all-cause mortality. In conclusion, TLC and Hb levels upon admission can refine the ESC model's mortality risk classification for patients with acute PE, providing valuable insights for improved patient management.

A-142 Comparison of Alinity c Hemoglobin A1c Immunoassay with Premier Hb9210 Automated HPLC Assay: Very Few Patients May be Outside Reportable Range Using Alinity c.

Abstract Background Hemoglobin A1c (HbA1c; glycosylated hemoglobin) is used for diagnosis and monitoring of patients with diabetes. In the clinical laboratory both immunoassays and high-performance liquid chromatography (HPLC) based tests are available for such measurement. We use Premier Hb9210 analyzer (HPLC method; Trinity Biotech, Jamestown, NY) for measuring HBA1c in whole blood. As our laboratory is transitioning to Abbott chemistry systems, we compared HbA1c values obtained by the Alinity c and Premier Hb9210. Methods The Premier Hb9210 analyzer is based on boronate affinity high performance liquid chromatography with output in 66 sec. The analytical measurement range is 3.8 to 18.5% although values as low as 2% can be reported by the analyzer but result may not be accurate. The Alinity c Hemoglobin A1c assay measures both total hemoglobin and HbA1c (enzymatic assay) in whole blood and then calculates %HbA1c. The analytical measurement range of this assay is 4 to 14% of HbA1c. Specimens cannot be diluted for Alinity c HbA1c measurement. Results Alinity c HbA1c has excellent total precision (0.4% at HbA1c of 5.1% and 0.25% at Hb A1c of 9.4%). In contrast, Premier HB9210 has total precision of 1.89% at HbA1c of 5.5% and 1.81% at HbA1c of 8.4%. However, analytical measurement range of Premier HB9219 is slightly wider compared Alinity c assay. Plotting HbA1c results obtained by the Premier Hb9210 analyzer in the x-axis and the corresponding values obtained by the Alinity c assay, we observed the following regression equation: y = 0.9499 x + 0.1108 ( n = 50, 0.99). The 95% confidence interval of the slope was 0.9241 to 0.9757. Rarely, we get specimen where HbA1c is between 3.8 and 4.0% (42 specimens out of 52 803 between 2/7/22 to 2/7/23; 0.08%) or above 14% (174 specimens out of 52 802; same period; 0.33%) and these specimens would not produce any result with Alinity c assay. We recently observed HbA1c result of 2.4 % in a sickle cell patient (reported as &amp;lt;3.8% per our lab policy). Discussion Our result indicates that HbA1c immunoassay on the Alinity c analyzer showed values comparable to HPLC method. However, for very few patients HbA1c may exceed 14% due to uncontrollable diabetes. Because specimen cannot be diluted, real value could not be measured using Alinity c but can be measured by the HPLC method. Conclusions We conclude that HbA1c assay on the Alinity c analyzer is a viable alternative to HPLC for measuring HbA1c in clinical laboratory. However, for very few patients (sickle cell trait, uncontrolled diabetes), HbA1c may be outside the range of Alinity c, requiring HPLC analysis.

A-070 A fully automated HbA1c Assay on the DxC 500 AU Clinical Chemistry Analyser

Abstract Background Diabetes mellitus is a condition characterized by hyperglycemia resulting from the body’s inability to use blood glucose for energy. In Type-1 diabetes, the pancreas no longer makes insulin and blood glucose cannot enter the cells to be used for energy. In Type-2 diabetes, the pancreas does not make enough insulin or the body is unable to use insulin correctly. According to the World Health Organization (WHO), 422 million adults were living with diabetes globally in 2014 with an estimated 1.6 million deaths directly associated with diabetes annually. HbA1c is the major species of glycohemoglobin in human blood. HbA1c formation occurs through a non-enzymatic reaction, called glycation, which occurs between glucose and the n-terminal valine of the hemoglobin â-chain of HbA. A Schiff base intermediate product is formed, which rearranges to form a stable ketoamine in an irreversible reaction. The rate of glycation is proportional to the glucose concentration in the bloodstream and is an accurate reflection of average blood glucose over a period of eight to twelve weeks. HbA1c testing is recommended for the diagnosis of diabetes by the International Expert Committee (IEC), the American Diabetes Association (ADA), and the WHO, who recommended a diagnostic threshold of = 6.5% ( = 48 mmoL/moL) HbA1c and a range for pre-diabetes of 5.7%–6.4% (39–46 mmoL/moL) HbA1c. Methods The HbA1c Advanced assay on the DxC 500 AU* utilizes automatic sample pre-treatment, has batch and random access capability. No manual pre-treatment of the whole blood sample or additional washing steps are required. Firstly the red blood cells are hemolyzed automatically, total hemoglobin and glycated hemoglobin are then measured colorimetrically and immunoturbidimetrically respectively. Results Precision studies were conducted according to CLSI EP15-A3. Commercial controls and four native K2 EDTA whole blood samples ranging from 5.1% to 12.0% HbA1c, were run twice daily, over twenty days using three lots of reagent on three DxC500AU Clinical Chemistry analyzers at a single site. Repeatability ranged from 0.86% to 1.44% CV and Total Precision ranged from 1.55% to 2.43% CV. Linearity studies were conducted according to CLSI EP06-A, and verified an analytical measuring range of 4.0%–15.0% (NGSP) and 20–140 mmol/mol (IFCC). Method comparison and bias estimation was evaluated using CLSI EP09-A3. K2 EDTA patient samples (n = 150) across the analytical range were run vs a Secondary Reference method and yielded a slope of 1.031, intercept −0.147% HbA1c, correlation coefficient R = 0.997 for Weighted Deming regression, and slope 1.000 and intercept 0.06% HbA1c for Passing Bablok regression. Interference studies carried out demonstrated no significant interference from common endogenous interferences, a large panel of drugs, common Hb variants (HbC, HbD, HbE, HbA2 and HbS) and cross reactants (HbA0, HbA1a+b, acetylated hemoglobin, carbamylated hemoglobin, glycated hemoglobin, glycated albumin and labile HbA1c). Conclusion The HbA1c Advanced assay on the DxC 500 AU is a precise and accurate assay, requiring no manual pretreatment and can be used for monitoring and diagnosing diabetes. *Pending clearance by the United States Food and Drug Administration and achievement of CE compliance. Not currently available for in vitro diagnostic use.