Effect Of Hematocrit Research Articles

Quantitation of meropenem in dried blood spots using microfluidic-based volumetric sampling coupled with LC-MS/MS bioanalysis in preterm neonates

Meropenem, a carbapenem antibiotic, has been used for empirical and definitive therapy of severe infections for many years. Therapeutic drug monitoring (TDM) plays an indispensable role in the individualization of meropenem particularly in the preterm neonates, a population in which adjusting proper dosages has always been one of the most challenging tasks for their growth changes. In this report, a simple and accurate method for the quantitative analysis of meropenem in dried blood spot (DBS) samples by LC-MS/MS was developed. The traditional DBS drawbacks were conquered in this study by combining microfluidic-based volumetric sampling, shorten drying procedure, and sensitive detection. Moreover, the on-card stability of meropenem was improved obviously. The DBS-based method validation included hematocrit (Hct) effect, selectivity, carry-over, linearity, accuracy, precision, matrix effect, recovery and stability (high temperature and humidity). The calibration linear range of meropenem was 0.3–100 µg/mL. The acceptance criteria of accuracy (relative error < 4.53 %) and precision (coefficient of variation < 8.63 %) were met in all levels of quality control samples. The DBS samples was stable at 40 °C for 12 h, room temperature for 1 day, 4 °C for 7 days, −20 °C for 14 days and −40 °C for 30 days, respectively. A good correlation was observed between DBS concentration and plasma concentration of meropenem. There was 93.4 % of the samples between estimated plasma concentration and plasma concentration within 20 % of the mean of concentration, and no significant Hct effect was observed on the quantification. It has been successfully applied to samples derived from preterm neonates with severe infections. The supported data indicated that the DBS-based method using microfluidic-based volumetric sampling could be an alternative strategy to carry on TDM of meropenem in preterm neonates, with satisfactory performance and logistics advantages.

Increased reliability of CT-imaging signs of bleeding into soft tissue in patients with COVID-19 for planning transarterial embolization.

Spontaneous bleeding into the soft tissues of the abdominal and thoracic wall is described as complication of anticoagulant therapy. Computed tomography (CT) allows to detect the presence of extravasation of the contrast agent into a hematoma, which is indicated as a sign of ongoing bleeding. Other specific CT signs of such coagulopathic bleeding have been described earlier. To evaluate the significance of specific coagulopathic CT signs for predicting the dynamics of spontaneous bleeding into soft tissues in patients with COVID-19. A retrospective study included 60 patients with COVID-19 with spontaneous bleeding into soft tissues and extravasation of a contrast agent on CT. In addition to extravasation, a "hematocrit effect" was detected in 43 patients on CT. Of these, 39 had extravasation in the form of a "signal flare." All patients underwent transarterial catheter angiography (TCA). To assess the prognostic value of CT signs, the results of CT and TCA compared. The absence of extravasation on the TCA more often corresponded to stopped bleeding. Extravasation on TCA found in 27 (45%) patients. The presence of the "hematocrit effect" or the combination of this sign with the phenomenon of a "signal flare" on CT (n = 43) led to more frequent confirmation of extravasation on TCA than in their absence (n = 17): 23.5% vs. 53.4% (p = 0.028). The presence of a fluid level and the phenomenon of a "signal flare" on CT in the structure of spontaneous hematomas of the soft tissues of the abdominal and thoracic wall in COVID-19 patients more often corresponded to ongoing bleeding on the TCA. The absence of coagulopathic CT signs more often corresponded to stopped bleeding.

Therapeutic Drug Monitoring of Tacrolimus Based on Volumetric Absorptive Microsampling Technique (VAMS) in Renal Transplant Pediatric Recipients-LC-MS/MS Method Development, Hematocrit Effect Evaluation, and Clinical Application.

Tacrolimus (TAC) is post-transplant pharmacotherapy's most widely used immunosuppressant. In routine clinical practice, frequent uncomfortable venipuncture is necessary for whole-blood (WB) collection to check trough TAC levels. Volumetric absorptive microsampling (VAMS) is an alternative strategy to WB collection. In this study, we aimed to validate and develop a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for TAC quantification in WB and VAMS samples. After extraction with water and protein precipitation, the samples were directly analyzed using LC-MS/MS. Whole-blood and VAMS capillary-blood samples were collected from 50 patients treated with TAC during the follow-up visits. The cross-correlation between the developed methods was evaluated using Passing-Bablok regression and a Bland-Altman bias plot. The matrix effect (ME) and carry-over were insignificant for both scenarios. There was a high correlation between the processes and no significant clinical deviation. LC-MS/MS methods were successfully developed and validated in the 0.5-60 ng/mL calibration range. This study demonstrated and confirmed the utility of VAMS-based TAC monitoring in the pediatric population. This is the first study to directly develop and validate the VAMS LC-MS/MS method for evaluating the hematocrit effect in the pediatric population. The statistical correlation between immunochemical and VAMS-based methods was satisfactory.

Effects of blood hematocrit on performance of endovascular coiling for treatment of middle cerebral artery (MCA) aneurysms: Computational study

Aneurysms with saccular cervical aneurysms are often treated with coiling embolism to prevent rupture and hemorrhage. This study attempted to examine the effects of coiling embolism on blood hemodynamics and bleeding from Middle cerebral artery (MCA) aneurysms. The pulsatile blood stream inside the heart is modeled using computational fluid dynamics by solving Reynolds Average Navier-stocks (RANS) equations. In this study, pressure, oscillatory shear index (OSI), and wall shear stress (WSS) on the sac wall are compared to reveal the high-risk zone at different times during the blood cycle. We also examine the role of coiling porosity in three different conditions of peak systolic blood hematocrit. The WSS value reaches its maximum near the neck of the sac, while the OSI value reaches its maximum near the dome of the aneurysm. Coiling also reduces OSI while having a limited impact on WSS near the neck, according to our results.

A fast and validated LC-MS/MS method to quantify lenvatinib in dried blood spot

A new LC-MS/MS method for the quantification of lenvatinib (LENVA) in venous Dried Blood Spot (DBS) samples has been presented. This method is characterized by a short run time (4 min), requires a volumetric sampling of 10 µL and extraction of the entire spot to avoid hematocrit (Hct) and spot volume effects. The quantification method was successfully validated in the range of 5.00–2000 ng/mL on two different DBS filter papers (Whatman 31 ET CHR and Whatman 903) according to European Medicines Agency (EMA) and Food and Drug Administration (FDA) guidelines, European Bioanalysis Forum (EBF), and International Association of Therapeutic Drug Monitoring and Clinical Toxicology (IATDMCT) recommendations. During the validation process, the following parameters were evaluated: recovery (≥ 77% for both filter papers), absence of matrix effect, process efficiency (close to 72% for Whatman 31 ET CHR and close to 77% for Whatman 903), Hct effect (CV ≤ 6.3% and accuracy within 96–112%), linearity (r ≥ 0.998 for Whatman 31 ET CHR and r ≥ 0.999 for Whatman 903), intra- and inter-day precision (CV ≤ 8.8%) and accuracy (92.8–108%), selectivity and sensitivity, reproducibility with incurred samples reanalysis (ISR), and stability. This method was applied to quantify venous DBS samples from patients with hepatocellular carcinoma treated with LENVA enrolled in a cross-validation study (CRO-2018–83). A good correlation between LENVA plasma concentration determined by standard procedure and the new developed DBS LENVA method (R2 ≥ 0.996) has been observed.

Liquid chromatography-tandem mass spectrometry for therapeutic drug monitoring of immunosuppressants and creatinine from a single dried blood spot using the Capitainer® qDBS device

In recent years, a lot of attention has been given to a more patient-centric therapeutic drug monitoring (TDM) of immunosuppressant drugs (tacrolimus, sirolimus, everolimus and cyclosporin A) by the use of microsampling techniques. By adopting Dried Blood Spots (DBS) after a finger prick, instead of conventional venous blood draws, follow-up can (partially) be established from patients’ homes. Despite the many advantages of DBS, one of the major disadvantages associated with this technique is the well described hematocrit (hct) effect. In order to overcome the hct area bias, different strategies have been proposed, amongst which the use of dried blood sampling techniques based on the volumetric collection of blood.The aim of this study was to evaluate the use of the Capitainer® qDBS (quantitative Dried Blood Spot) device for the combined TDM of four immunosuppressants and creatinine from a single qDBS. The set-up of an adequate sample preparation allowing both immunosuppressants and creatinine quantification was one of the key challenges in the method development due to device-specific interferences. Liquid chromatography tandem-mass spectrometry methods for the quantification of tacrolimus, sirolimus, everolimus, cyclosporin A and creatinine from qDBS (10 μL) were developed and validated based on international guidelines, also taking into account DBS-specific parameters. The methods proved to be accurate and reproducible, with absolute biases below 10% and within-run CVs (%) below 8% over a calibration range from 1 to 50 ng/mL for tacrolimus, sirolimus and everolimus, 20–1500 ng/mL for cyclosporin A, and 15–700 μmol/L for creatinine. Reproducible (CV < 15%) IS-compensated relative recovery values were obtained, showing no hematocrit-dependence (compared to a hct of 0.37), except for cyclosporin A at higher hct values. Application on venous blood left-over patient samples showed good agreement between the results of Capitainer® qDBS and whole blood with 98% (47/48), 93% (41/44), 89% (41/46), 88% (38/43) and 89% (116/131) of the samples lying within 20% of the whole blood result for tacrolimus, sirolimus, everolimus, cyclosporin A and plasma/serum for creatinine, respectively. For creatinine a blood/plasma ratio of 0.85 was found and used to convert qDBS results to plasma/serum results. As a next step, capillary finger prick samples will need to demonstrate the clinical applicability of the method in a real life setting.

A sensitive liquid chromatographic-mass spectrometry method for the quantification of vincristine in whole blood collected with volumetric absorptive microsampling

Vincristine is a well-established cytotoxic drug. In paediatric populations blood collection via venipuncture is not always feasible. Volumetric absorptive microsampling (VAMS) is a less invasive method for blood collection. Furthermore, VAMS lacks the haematocrit effect on the recovery known with dried blood spots. Therefore, a liquid chromatography tandem-mass spectrometry method was developed and validated for the quantification of vincristine in whole blood collected with VAMS devices. Sample preparation consisted of solid-liquid extraction with 0.2% formic acid in water and acetonitrile. The final extract was injected on a C18 column (2.0 ×50 mm, 5 µm). Gradient elution was used and quantification was accomplished with a triple quadruple mass spectrometer operating in the positive mode. The validated concentration range was from 1 to 50 ng/mL with an intra- and inter-accuracy and precision of ± 10.3% and ≤ 7.3%, respectively. This method was able to successfully quantify vincristine concentrations in whole blood collected with VAMS from paediatric oncology patients. Vincristine concentrations in whole blood were non-linearly associated with plasma concentrations, which could be described with a saturable binding equilibrium model.

Modeling and computation for unsteady blood flow and solute concentration in a constricted porous artery

&lt;abstract&gt; &lt;p&gt;We investigated a physical system for unsteady blood flow and solute transport in a section of a constricted porous artery. The aim of this study was to determine effects of hematocrit, stenosis, pulse oscillation, diffusion, convection and chemical reaction on the solute transport. The significance of this study was uncovering combined roles played by stenosis height, hematocrit, pulse oscillation period, reactive rate, blood speed, blood pressure force and radial and axial extent of the porous artery on the solute transported by the blood flow in the described porous artery. We used both analytical and computational methods to determine blood flow quantities and solute transport for different parametric values of the described physical system. We found that solute transport increases with increasing stenosis height, blood pulsation period, convection and blood pressure force. However, transportation of solute reduces with increasing hematocrit, chemical reactive rate and radial or axial distance.&lt;/p&gt; &lt;/abstract&gt;

Volumetric Absorptive Microsampling in Therapeutic Drug Monitoring of Immunosuppressive Drugs-From Sampling and Analytical Issues to Clinical Application.

Miniaturisation and simplification are novel approaches in clinical bioanalysis, especially in therapeutic drug monitoring (TDM). These contemporary trends are related to the sampling, pre-treatment, and analysis of biological fluids. Currently, dried blood spot (DBS), one of the most popular microsampling techniques, is feasible and inexpensive. However, obtaining reliable results with sample homogeneity and volume variability is difficult. Volumetric Absorptive Microsampling (VAMS) has recently enabled the accurate and precise collection of a fixed blood volume. It reduced the hematocrit effect, improved volumetric accuracy, and generated results correlating with the dose and drug exposure from wet blood. This review focuses on VAMS-Mitra™ devices, which have become increasingly important since 2014, mainly for TDM and toxicology studies. First, the current literature has been reviewed based on immunosuppressants and their determination in samples obtained using Mitra™. Second, the critical points, weaknesses, and strengths have been characterized in contrast to classic venipuncture and other microsampling methods. Finally, we indicate the points of attention according to the perspective of Mitra™ as well as its usefulness in clinical practice. VAMS is currently state-of-the-art in microsampling and seems to be a good instrument for improving adherence to immunosuppressive therapy, especially in the pediatric population.

Microsampling tools for collecting, processing, and storing blood at the point-of-care.

In the wake of the COVID-19 global pandemic, self-administered microsampling tools have reemerged as an effective means to maintain routine healthcare assessments without inundating hospitals or clinics. Finger-stick collection of blood is easily performed at home, in the workplace, or at the point-of-care, obviating the need for a trained phlebotomist. While the initial collection of blood is facile, the diagnostic or clinical utility of the sample is dependent on how the sample is processed and stored prior to transport to an analytical laboratory. The past decade has seen incredible innovation for the development of new materials and technologies to collect low-volume samples of blood with excellent precision that operate independently of the hematocrit effect. The final application of that blood (i.e., the test to be performed) ultimately dictates the collection and storage approach as certain materials or chemical reagents can render a sample diagnostically useless. Consequently, there is not a single microsampling tool that is capable of addressing every clinical need at this time. In this review, we highlight technologies designed for patient-centric microsampling blood at the point-of-care and discuss their utility for quantitative sampling as a function of collection material and technique. In addition to surveying methods for collecting and storing whole blood, we emphasize the need for direct separation of the cellular and liquid components of blood to produce cell-free plasma to expand clinical utility. Integrating advanced functionality while maintaining simple user operation presents a viable means of revolutionizing self-administered microsampling, establishing new avenues for innovation in materials science, and expanding access to healthcare.

HPLC-DAD quantification of favipiravir in whole blood after extraction from volumetric absorptive microsampling devices

Favipiravir is a prodrug of T-1105 made by modifying the pyrazine group as a COVID-19 therapy. During the pandemic, a safe and comfortable biosampling technique is needed for the subject or patient. Volumetric Absorptive Microsampling (VAMS) is a biosampling technique with a small blood volume and minimum hematocrit effect. The aims of this study were to develop and validate an analytical method for quantifying favipiravir extracted from VAMS using High Performance Liquid Chromatography – Photodiode Array with remdesivir as an internal standard. Analysis of favipiravir was performed using a C18 column (Waters, Sunfire™ 5 µm; 250 × 4.6 mm), with injection volume of 50 µL, flow rate of 0.8 mL/min, column temperature 30 ℃, and wavelength 300 nm. The separation was conducted under gradient elution with mobile phase consists of acetonitrile-0.2 % formic acid-20 mM sodium dihydrogen phosphate pH 3.5 and run time 12 min. Sample preparation was carried out using a protein precipitation method with 500 µL of methanol as precipitating agent. Samples were mixed on vortex for 30 s, sonicated for 15 min, and centrifuged at 10,000 rpm for 10 min. Lower Limit of Quantification (LLOQ) obtained was 0.5 µg/mL and the calibration curve ranged from 0.5 to 160 µg/mL. Sensitivity, linearity, selectivity, carry-over, accuracy, precision, recovery, and stability were validated by the guideline from Food and Drug Administration 2018. The method developed has successfully met the full validation requirements by FDA 2018 with the LLOQ obtained was 0.5 µg /mL.

Hematocrit level effect on diastolic blood pressure more than systolic blood pressure

The objective of the study: is to study the effect of hematocrit (PCV) on diastolic and systolic blood pressure and assert the effect of PCV on blood pressure especially on isolated diastolic blood pressure.&#x0D; Design: cross-sectional study of two groups of patients with isolated diastolic and isolated systolic hypertension and normal healthy controls.Setting: Al- Karama teaching Hospital Department of medicine in Al- Kut city, Iraq. Patients and Method:-This cross-sectional study included inpatients and outpatients with hypertension from (February 2013 to December 2013) in Al- karama Teaching Hospital Department of medicine. The samples were divided into three groups, group 1 (normal healthy controls), group 2(patients with isolated diastolic hypertension) and group 3(patients with isolated systolic hypertension). The level of PCV was measured in each group.Results: Patients with isolated diastolic hypertension have positive relation with increased level of PCV, frequency of patients with PCV&gt;51% is 28% (mean 48.04), more than that in individuals with isolated systolic hypertension, frequency of PCV&gt;51% is 16% (mean 45.70), and normal healthy controls frequency of PCV&gt;51%is 6% (mean PCV 41.34).Hematocrit level remained as statistical significance for patients with isolated diastolic hypertension (P&lt;0.0005), and also in patients with isolated systolic hypertension (Mean PCV 45.70) in compare to normal individuals (P&lt;0.0005)Conclusions: increased level of PCV is a risk factor or marker that affect blood pressure specially patients with isolated diastolic hypertension more than patients with isolated systolic hypertension

Development of the dried blood spot preparation protocol for comprehensive evaluation of the hematocrit effect

The application of dried blood spots (DBS) has gradually increased in different fields because of its several advantages. The hematocrit (Hct) effect is one major analytical challenge that may affect the quantification accuracy of DBS samples and should be investigated when developing a novel DBS method. However, previous studies usually overlooked the Hct-related distribution bias when evaluating the Hct effect. This study aimed to propose an effective DBS preparation protocol for the comprehensive evaluation of the Hct effect. We selected voriconazole and posaconazole as the demonstration drugs. Fifteen microliters of the blood samples were spotted on DBS cards followed by whole spot extraction. An LC-MS/MS method was first developed to quantify voriconazole and posaconazole in DBS samples. The quantitation accuracy for both azole drugs was within 93.5%–111.7%, except for the accuracies of posaconazole at the LLOQ, which were less than 119%. The intra- and interday precision were below 11%. The validated LC-MS/MS method was used to develop the DBS preparation protocol for evaluating the Hct effect. Three critical parameters that may affect the observed Hct effect were investigated. The results showed that using the solid-state of the target analytes, spiking the target analytes before preparing different Hct levels, and allowing enough equilibrium time after spiking target analytes can provide a more holistic Hct effect evaluation. The validity of the proposed new protocol was verified by conversion factors obtained from 71 paired DBS and plasma samples. Conversion factors calculated by clinical samples were consistent with the Hct effect evaluated by manually prepared DBS samples. This new DBS preparation protocol eliminated the common pitfalls in studying the Hct effect and offered a comprehensive strategy to assess the Hct effect for further DBS studies.

Application of non-contact hematocrit prediction technologies to overcome hematocrit effects on immunosuppressant quantification from dried blood spots

Fully automated dried blood spot (DBS) analysis for therapeutic drug monitoring (TDM) of the immunosuppressants tacrolimus, sirolimus, everolimus and cyclosporin A suffers from a so-called hematocrit (hct) effect. This effect is related to the analysis of a partial DBS punch and extractability differences imposed by blood with different hcts. As this is intrinsic to automated DBS analysis, this poses a serious drawback for accurate immunosuppressant quantification. Knowledge of a sample's hct allows to correct the derived immunosuppressant concentrations for this effect. Unfortunately, when using the DBS approach for sampling at patients' homes, this hct will typically not be available. The aim of this study was to investigate the validity of a correction algorithm during fully automated DBS analysis of immunosuppressants, based on knowledge of the DBS′ hct, obtained via two distinct non-contact hematocrit prediction strategies, using either near-infrared (NIR) or ultra-violet/visible (UV/VIS) spectroscopy.For tacrolimus, sirolimus, everolimus, and cyclosporin A, 48, 47, 58 and 48 paired venous whole blood and venous DBS patient samples were collected, respectively, and analyzed using an automated DBS-MS 500 HCT extraction unit coupled to a liquid chromatography tandem mass spectrometry system. Additionally, for all 201 samples the hct of the DBS was predicted based on NIR and UV/VIS spectroscopy. For tacrolimus and cyclosporin A, both hct prediction strategies allowed for adequate correction of the hct effect. Also for sirolimus and everolimus the results greatly improved after hct correction, although a hct bias remained for sirolimus and for everolimus a slightly significant hct effect was observed after NIR- and UV/VIS-based correction. Application of both hct prediction strategies ensured that clinical acceptance limits (i.e. ≥ 80% of the samples within 20% difference compared to whole blood) were met for all analytes.In conclusion, we demonstrated that non-contact hct prediction strategies, applied in tandem with fully automated DBS analysis, can be used to adequately correct immunosuppressant concentrations, yielding a good agreement with whole blood.

Effect of hematocrit, galactose and ascorbic acid on the blood glucose readings of three point-of-care glucometers

Glucometers are commonly used in a variety of healthcare settings and use in critically ill patients should not be assumed without appropriate tool validation. The study objective was to evaluate the accuracy of three point-of-care glucometers (POCGs) to assess glucose concentration in human blood sample. The POCGs tested included three different instruments and utilized three factors (hematocrit [Hct], galactose and ascorbic acid) in glucose measurements to determine the glucometers’ accuracy and compared to the reference laboratory biochemical analyzer (Cobs 8000, Roche, Basal, Switzerland). In this study, the Nova StatStrip glucometer showed no significant variation compared to the laboratory method at high glucose level with various Hct%. ACCU-Chek Inform II overestimated the glucose results at Hct 22% and underestimated at Hct 62%. The Freestyle glucometer showed lower glucose levels compared to the Cobas 8000 at Hct 62%. The ACCU-Check showed significant increase of blood glucose with low Hct% levels when compared to the laboratory method. The Freestyle showed a decreased level of glucose with high Hct 62% interference compared to the Cobas 8000. Galactose interference 100 and 200 mg/dL dramatically affected the accuracy of ACCU-Chek Inform II. Nevertheless, among all three POCGs in this study, the Nova StatStrip showed the most reliable and stable results for glucose level in the presence of interference. Especially, those in critical care units, whereas the Freestyle Precision Pro and ACCU-Chek Inform II were insufficiently accurate for critically ill patients.

ADAPTATION OF “DRIED BLOOD DROP” METHOD FOR THERAPEUTIC DRUG MONITORING

To control the concentration of drugs with a narrow therapeutic range, and to conduct effective and safe treatments, Therapeutic Drug Monitoring (TDM) is carried out. However, to date, the implementation of TDM is associated with various difficulties, for the solution of which more convenient and less invasive methods for collecting biological material are being developed.The aim of the study was to develop protocols for the collection and storage of “dried blood spot” (DBS) samples, as well as protocols for the validation methods for the quantitative determination of drugs in whole blood, using this technology for subsequent therapeutic drug monitoring.Materials and methods. To analyze a “dried blood spot” method in detail and to identify the characteristic features of taking and storing biosamples, a collection and analysis of scientific literature over the past 10 years has been conducted. The search for literature materials has been carried out from open and accessible sources located in the scientific libraries of institutions, in electronic databases and search engines: Elibrary, PubMed, Scopus, Cyberleninka, Medline, ScienceDirect, Web of Science, Google Scholar. Primary protocols for taking, storing and analyzing samples of the “dried blood drop” have been prepared. To obtain the adequate quality samples, the developed protocols have been tested and optimized at the stages of selection and storage. By high-performance liquid chromatography with mass spectrometric detection (HPLC-MS/MS), using a “dried blood drop” as a sample preparation, drug validation protocols have been optimized to ensure that acceptable validation characteristics were achieved, and subsequent Therapeutic Drug Monitoring was performed.Results. The features of the collection, storage and analysis of the “dried blood spot” samples have been revealed. Such characteristics as a spot volume effect, a hematocrit effect, a droplet uniformity, which can affect the results of a quantitative HPLC-MS/MS analysis, have been determined. For a successful use of the new methods, appropriate protocols for taking samples of “dried blood spot” from the finger of adult patients and from the heel of newborns, as well as protocols for validating methods for the quantitative determination of drugs from these samples, have been developed.Conclusion. The application of the “dried blood spot” method using newly developed protocols for taking, storing and analyzing biological samples, relieves the existing constraints in conducting TDM, and can later become a promising method for conducting preclinical and clinical studies.

Comparison of point-of-care glucometers and laboratory based glucose oxidase test in determining blood glucose levels

Alterations in blood glucose levels are common and an important determinant of a patient's admission outcomes, point-of-care glucometers, which are affected by a variety of factors, are increasingly used in clinical care. In this study we compared blood glucose levels determined by two commonly used glucometers (One Touch® and Accu-check®) with those of a standard laboratory method and determined the effect of haematocrit on glucose readings. Blood glucose levels were measured with One Touch® and Accu-Check® glucometers and the glucose oxidase method at the same time in 295 children aged 0 to 15 years over a 6-month period. Bland-Altman and correlation analysis were used to explore biases among the three methods. For all statistical tests, a p-value of less than 0.05 was considered statistically significant. Most were males (51.2%) and the median (range) age was 1 year (1 day, 12 years). There was a significant correlation between each of the glucometer methods and laboratory blood sugar, and the correlation between the two glucometers was strong and significant. This correlation remained statistically significant even after controlling for haematocrit values. There was an acceptable level of bias (3.9 mg/dL) between the One Touch® and Accu-check® glucometers, but each had a remarkably large bias compared with the glucose oxidase method. The use of a tested glucometer in clinical settings can aid in rapid decision-making, but there is a need to periodically cross-check with the glucose oxidase method in the laboratory to optimise treatment outcomes for children with dysglycaemia.

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

Clinical practice guidelines for endometriosis in Japan (The 3rd edition).

Performance comparison of Westergren modified SRS 100/II and alternate iSED® method for erythrocyte sedimentation rate.

The erythrocyte sedimentation rate (ESR) includes three phases, each prone to different interferences. Due to many disadvantages of the reference Westergren method, modified and alternate methods have been introduced. The aim of this study was to compare the modified Westergren method on SRS 100/II analyzer in citrate blood with the alternate method on iSED® analyzer in EDTA sample. Additionally, possible interfering factors and ESR stability during 6h at room temperature were evaluated. A total of 188 samples were included in the method comparison. Additionally, the effects of inflammation, haematocrit and MCV values on ESR were evaluated. To determine ESR stability in different samples, ESR was evaluated at three time points; within 15 min of blood sampling and after 3 and 6h in different sample types and analyzers (N= 65). Results indicated the constant difference between tested methods with obtained mean bias of 5 mm (95% CI: 3-7). There was higher absolute mean bias in groups with ESR> 40 mm and elevated inflammation markers (p< 0.001). Regarding different MCV and haematocrit groups there was no statistically significant difference in obtained absolute mean biases for MCV (p= 0.087) while there was higher bias in low haematocrit group compared to normal haematocrit (p= 0.004). In addition, there was a significant difference between ESR values at different time points for iSED® (p< 0.001) and no difference for SRS 100/II analyzer (p= 0.406). There are differences in ESR values between tested methods. EDTA sample on iSED® should be analysed as soon as possible to avoid falsely increased ESR.

Hemoglobin normalization outperforms other methods for standardizing dried blood spot metabolomics: A comparative study

Dried blood spot (DBS) metabolomics has numerous applications in newborn health screening, exposomics, and biomonitoring of environmental chemicals in pregnant women and the elderly. However, accurate metabolite quantification is hindered by several challenges: notably the “hematocrit effect” and unknown blood-spotting volumes. Different techniques have been employed to overcome these issues but there is no consensus on the optimal normalization method for DBS metabolomics, and in some cases no normalization is used. We compared five normalization methods (hemoglobin (Hb), specific gravity (SG), protein, spot weight, potassium (K+)) to unnormalized data, and assessed sex-related differences in the DBS metabolome in 21 adults (group 1, n = 10 males, n = 11 females). The performance of each normalization method was evaluated using multiple criteria: (a) reduction of intragroup variation (pooled median absolute deviation, pooled estimate of variance, pooled coefficient of variation, NMDS and principal component analysis), (b) effect on differential metabolic analysis (dendrogram, heatmap, p-value distribution), and (c) influence on classification accuracy (partial least squares discriminant analysis, sparse partial least squares discriminant analysis error rates, receiver operating curve, random forest out of bag error rate). Our results revealed that Hb normalization outperformed all the other methods based on the three criteria and 13 different parameters; the performance of Hb was further demonstrated in an independent group of DBS from 18 neonates (group 2, n = 9 males, n = 9 females). Furthermore, we showed that SG and Hb are correlated in adults (rs = 0.86, p < 0.001), and validated this relationship in an independent group of 18 neonates and infants (group 3) (rs = 0.84, p < 0.001). Using the equation, SG = −0.4814Hb2 + 2.44Hb + 0.005, SG can be used as a surrogate for normalization by Hb. This is the first comparative study to concurrently evaluate multiple normalization methods for DBS metabolomics which will serve as a robust methodological platform for future environmental epidemiological studies.