bims-supasi 2023-02-26 papers

bims-supasi

Biomed News

on Sulfation pathways and signalling

Issue of 2023–02–26
thirteen papers selected by
Jonathan Wolf Mueller, University of Birmingham

Synthesis of biotinylated chondroitin sulfate DA and AD tetrasaccharides composed of hetero-type disaccharide units, and their interactions with the mAb MO-225.
Molecular Dynamics-Based Comparative Analysis of Chondroitin and Dermatan Sulfates.
Conditional ablation of heparan sulfate expression in stromal fibroblasts promotes tumor growth in vivo.
Bioinformatics analysis identifies heparan sulfate proteoglycans acting as different progress subtypes of biliary atresia.
Correlation between Saliva Levels and Serum Levels of Free Uremic Toxins in Healthy Volunteers.
Anticoagulant Property of a Sulfated Polysaccharide with Unique Structural Characteristics from the Green Alga Chaetomorpha aerea.
Histone tyrosine sulfation by SULT1B1 regulates H4R3me2a and gene transcription.
DHEAS and nutritional status among Sidama, Ngandu, and Aka children: Effects of cortisol and implications for adrenarche.
Indoxyl sulfate mediates low handgrip strength and is predictive of high hospitalization rates in patients with end-stage renal disease.
Sulfated polysaccharides as multi target molecules to fight COVID 19 and comorbidities.
Development of a new heparan sulfate proteoglycan (HSPG) chromolith LC column to study the pH dependence binding of peptide vaccines to HSPG and role of human serum albumin on its binding.
Monitoring the stability of heparin: NMR evidence for the rearrangement of sulfated iduronate in phosphate buffer.
Monitoring heparin therapy: stability of two different anti-Xa assays using blood samples collected in citrate-containing and CTAD tubes.

Bioorg Med Chem. 2023 Feb 10. pii: S0968-0896(23)00039-1. [Epub ahead of print]81 117191

Synthesis of biotinylated chondroitin sulfate DA and AD tetrasaccharides composed of hetero-type disaccharide units, and their interactions with the mAb MO-225.

Asumi Uemura, Satomi Nadanaka, Hiroshi Kitagawa, Jun-Ichi Tamura.

  Chondroitin sulfate (CS), a linear acidic polysaccharide, exhibits numerous biological activities that are dependent on sulfation patterns. CS oligosaccharides comprise repeating disaccharide units with different (hetero)-type sulfation patterns and are common in nature. We herein report the synthesis of the following biotinylated CS tetrasaccharides: CS-AD [βGalNAc4S(1-4)βGlcA(1-3)βGalNAc6S(1-4)βGlcA2S] and CS-DA [βGalNAc6S(1-4)βGlcA2S(1-3)βGalNAc4S(1-4)βGlcA], in a stereo-controlled manner. We also demonstrated that the CS-d-specific monoclonal antibody MO-225 bound more strongly to CS-DA than to CS-DD or -AD.

Keywords:  Chondroitin sulfate; Glycosylation; Oligosaccharide synthesis; mAb MO-225

DOI:  https://doi.org/10.1016/j.bmc.2023.117191
Biomolecules. 2023 Jan 28. pii: 247. [Epub ahead of print]13(2):

Molecular Dynamics-Based Comparative Analysis of Chondroitin and Dermatan Sulfates.

Marta Pągielska, Sergey A Samsonov.

  Glycosaminoglycans (GAGs) are a class of linear anionic periodic polysaccharides containing disaccharide repetitive units. These molecules interact with a variety of proteins in the extracellular matrix and so participate in biochemically crucial processes such as cell signalling affecting tissue regeneration as well as the onset of cancer, Alzheimer's or Parkinson's diseases. Due to their flexibility, periodicity and chemical heterogeneity, often termed "sulfation code", GAGs are challenging molecules both for experiments and computation. One of the key questions in the GAG research is the specificity of their intermolecular interactions. In this study, we make a step forward to deciphering the "sulfation code" of chondroitin sulfates-4,6 (CS4, CS6, where the numbers correspond to the position of sulfation in NAcGal residue) and dermatan sulfate (DS), which is different from CSs by the presence of IdoA acid instead of GlcA. We rigorously investigate two sets of these GAGs in dimeric, tetrameric and hexameric forms with molecular dynamics-based descriptors. Our data clearly suggest that CS4, CS6 and DS are substantially different in terms of their structural, conformational and dynamic properties, which contributes to the understanding of how these molecules can be different when they bind proteins, which could have practical implications for the GAG-based drug design strategies in the regenerative medicine.

Keywords:  GLYCAM06; chondroitin sulfate; conformational analysis; dermatan sulfate; explicit solvent simulations; glycosaminoglycan sulfation code; modelling glycosaminoglycans; molecular dynamics

DOI:  https://doi.org/10.3390/biom13020247
PLoS One. 2023 ;18(2): e0281820

Conditional ablation of heparan sulfate expression in stromal fibroblasts promotes tumor growth in vivo.

Ayumi Niwa, Toshiaki Taniguchi, Hiroyuki Tomita, Hideshi Okada, Takamasa Kinoshita, Chika Mizutani, Mikiko Matsuo, Yuko Imaizumi, Takahito Kuroda, Koki Ichihashi, Takaaki Sugiyama, Tomohiro Kanayama, Yu Yamaguchi, Shigeyuki Sugie, Nobuhisa Matsuhashi, Akira Hara.

Heparan sulfate (HS) is a glycocalyx component present in the extracellular matrix and cell-surface HS proteoglycans (HSPGs). Although HSPGs are known to play functional roles in multiple aspects of tumor development and progression, the effect of HS expression in the tumor stroma on tumor growth in vivo remains unclear. We conditionally deleted Ext1, which encodes a glycosyltransferase essential for the biosynthesis of HS chains, using S100a4-Cre (S100a4-Cre; Ext1f/f) to investigate the role of HS in cancer-associated fibroblasts, which is the main component of the tumor microenvironment. Subcutaneous transplantation experiments with murine MC38 colon cancer and Pan02 pancreatic cancer cells demonstrated substantially larger subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Additionally, the number of myofibroblasts observed in MC38 and Pan02 subcutaneous tumors of S100a4-Cre; Ext1f/f mice decreased. Furthermore, the number of intratumoral macrophages decreased in MC38 subcutaneous tumors in S100a4-Cre; Ext1f/f mice. Finally, the expression of matrix metalloproteinase-7 (MMP-7) markedly increased in Pan02 subcutaneous tumors in S100a4-Cre; Ext1f/f mice, suggesting that it may contribute to rapid growth. Therefore, our study demonstrates that the tumor microenvironment with HS-reduced fibroblasts provides a favorable environment for tumor growth by affecting the function and properties of cancer-associated fibroblasts, macrophages, and cancer cells.

DOI: https://doi.org/10.1371/journal.pone.0281820
Front Pediatr. 2023 ;11 1065521

Bioinformatics analysis identifies heparan sulfate proteoglycans acting as different progress subtypes of biliary atresia.

Zequan Ding, Wenyu Song, Wei Zhu, Hua Xie, Zhongxian Zhu, Weibing Tang.

   Background: Biliary atresia (BA) is a life-threatening disorder, which is characterized by the obliteration of biliary tracts. Heparan sulfate proteoglycans (HSPGs) are important regulators in liver diseases. Whether HSPGs participate in the development of BA is poorly understood.
Methods: RNA-seq dataset GSE122340, including 171 BA and 7 normal liver tissue, was integrated for bioinformatic analysis. R function "wilcox.test" was used to compare HSPGs expression levels, and "cor.test" was used to evaluate the correlation analysis. MCPcounter was used to assess the abundance of immunocytes. Molecular subtypes of BA were clustered via NMF clustering and LASSO regression was applied to screen hub HSPGs genes in BA clusters. RT-PCR analysis was used to assess the expression of hub HSPGs in BA liver. Immunohistochemical staining and immunofluorescence assay were used to evaluated the location and expression of hub HSPGs in BA liver tissue.
Results: Majority of HSPGs was up-regulated in BA and correlated with liver fibrosis and ductular reaction markers. The abundance of immunocytes was higher in BA and associated with HSPGs. Based on the expression of HSPGs, BA patients were classified into 3 subtypes (C1, C2, and C3). Pathway enrichment analysis revealed C1 subtype had severe liver injury with SDC4 identified as the hub gene, while C3 subtype presented relatively normal liver condition with GPC3 identified as the hub gene. RT-PCR analysis demonstrated the expression levels of 2 hub genes in BA liver tissue with different jaundice clearance standards. Immunohistochemical staining and immunofluorescence assay showed that SDC4 was mostly expressed in ductular reaction area, while GPC3 was mostly expressed in hepatocytes.
Conclusion: Majority of HSPGs are aberrant expressed in BA. The subtype hub gene SDC4 and GPC3 might be used as a potential indicator for different types of prognosis.

Keywords:  biliary atresia; ductular reaction; heparan sulfate proteoglycan; immunocytes infiltration; liver fibrosis; molecular classification

DOI:  https://doi.org/10.3389/fped.2023.1065521
Toxins (Basel). 2023 Feb 13. pii: 150. [Epub ahead of print]15(2):

Correlation between Saliva Levels and Serum Levels of Free Uremic Toxins in Healthy Volunteers.

Nicolas Fabresse, Islam Amine Larabi, Emuri Abe, Elodie Lamy, Claire Rigothier, Ziad A Massy, Jean-Claude Alvarez.

  The objective of the present study was to investigate the putative correlation between the saliva concentration and free serum concentration for 10 uremic toxins (UTs; eight protein-bound solutes: 3-carboxy-4-methyl-5-propyl-2-furanpropanoic acid (CMPF), hippuric acid (HA), indole-3-acetic acid (3-IAA), indoxyl sulfate (I3S), kynurenic acid (KA), kynurenine (KYN), p-cresyl glucuronide (pCG), and p-cresyl sulfate (pCS); two free, water-soluble, low-molecular weight solutes: phenylacetylglutamine (PAGN) and trimethylamine N-oxide (TMAO); and three precursors: tyrosine (Tyr), phenylalanine, and tryptophan). Saliva samples and blood samples were collected simultaneously from 18 healthy volunteers. After the addition of internal standards, 50 µL of saliva or serum were precipitated with methanol. UTs and precursors were quantified using a validated LC-MS/MS method. The saliva-serum correlation was statistically significant (according to Spearman's coefficient) for six UTs (TMAO, HA, I3S, pCS, 3-IAA, and CMPF). Tyr presented a weak saliva-serum correlation (p = 0.08), whereas the other two precursors did not show a saliva-serum correlation. For three UTs (KYN, KA and pCG), we were unable to test the correlation since the saliva or serum levels were too low in many of the volunteers. The present study is the first to report on the saliva concentrations of TMAO, KYN, HA, PAGN, pCG, and 3-IAA.

Keywords:  indoxyl sulfate; mass spectrometry; p-cresyl sulfate; saliva; uremic toxins

DOI:  https://doi.org/10.3390/toxins15020150
Mar Drugs. 2023 Jan 26. pii: 88. [Epub ahead of print]21(2):

Anticoagulant Property of a Sulfated Polysaccharide with Unique Structural Characteristics from the Green Alga Chaetomorpha aerea.

Ling Qin, Yajing Yang, Wenjun Mao.

  Sulfated polysaccharides from marine algae have attracted a great amount of attentions for the development of marine drugs due to their unique structural features, and they are great potential sources of naturally occurring anticoagulant agents. The genus Chaetomorpha is one of the largest genera in green algae and has a worldwide distribution. In the present study, a homogeneous polysaccharide from Chaetomorpha aerea, designated as PCA, was obtained by alkali extraction, anion-exchange and size-exclusion chromatography. Based on the results of chemical and spectroscopic analyses, PCA was a sulfated galactoarabinan which was mainly constituted of a backbone of →4)-β-l-Arap-(1→ unit, partially sulfated at C-3 of →4)-β-l-Arap-(1→ and C-4 of →6)-α-d-Galp-(1→. The side chains consisting of →6)-α-d-Galp-(1→ and →5)-α-l-Araf-(1→ residues were in C-2 of →4)-β-l-Arap-(1→ unit. PCA had a strong anticoagulant activity in vitro as evaluated by the assays of activated partial thromboplastin time, thrombin time and fibrinogen level. The obvious anticoagulant activity in vivo of PCA was also found. PCA significantly inhibited the activities of the intrinsic coagulation factors XII, XI, IX and VIII, and exhibited weak inhibition effects on the common coagulation factors II and X. The anticoagulant mechanism of PCA was attributed to strong thrombin inhibition potentiated by heparin cofactor II or antithrombin III, and it also possessed an apparent inhibition effect on coagulation factor Xa mediated by antithrombin III. The investigation demonstrated that PCA could be a promising anticoagulant agent for health promotion and the treatment of thrombotic diseases.

Keywords:  anticoagulant activity; coagulation factor; structural characteristics; sulfated polysaccharide

DOI:  https://doi.org/10.3390/md21020088
Nat Chem Biol. 2023 Feb 20.

Histone tyrosine sulfation by SULT1B1 regulates H4R3me2a and gene transcription.

Weixing Yu, Runxin Zhou, Nan Li, Zhi-Chao Lei, Dingyuan Guo, Fei Peng, Yan Li, Xue Bai, Shan Feng, Yu Wang, Jie He, Sibi Yin, Xiao Zeng, Leya He, Yuan Gao, Mingchang Li, Yusong R Guo, Ke Liu, Yugang Wang.

Tyrosine sulfation is a common posttranslational modification in mammals. To date, it has been thought to be limited to secreted and transmembrane proteins, but little is known about tyrosine sulfation on nuclear proteins. Here we report that SULT1B1 is a histone sulfotransferase that can sulfate the tyrosine 99 residue of nascent histone H3 in cytosol. The sulfated histone H3 can be transported into the nucleus and majorly deposited in the promoter regions of genes in chromatin. While the H3Y99 residue is buried inside octameric nucleosome, dynamically regulated subnucleosomal structures provide chromatin-H3Y99sulf the opportunity of being recognized and bound by PRMT1, which deposits H4R3me2a in chromatin. Disruption of H3Y99sulf reduces PRMT1 binding to chromatin, H4R3me2a level and gene transcription. These findings reveal the mechanisms underlying H3Y99 sulfation and its cross-talk with H4R3me2a to regulate gene transcription. This study extends the spectrum of tyrosine sulfation on nuclear proteins and the repertoire of histone modifications regulating chromatin functions.

DOI: https://doi.org/10.1038/s41589-023-01267-9
Am J Hum Biol. 2023 Feb 19. e23881

DHEAS and nutritional status among Sidama, Ngandu, and Aka children: Effects of cortisol and implications for adrenarche.

Courtney Helfrecht, Hui Wang, Samuel J Dira, David DeAvila, Courtney L Meehan.

OBJECTIVE: Adrenarche, the biological event marked by rising production of dehydroepiandrosterone and its sulfate (DHEAS), may represent a sensitive period in child development, with important implications for adolescence and beyond. Nutritional status, particularly BMI and/or adiposity, has long been hypothesized as a factor in DHEAS production but findings are inconsistent, and few studies have examined this among non-industrialized societies. In addition, cortisol has not been included in these models. We here evaluate effects of height- (HAZ), weight- (WAZ), and BMI- (BMIZ) for-age on DHEAS concentrations among Sidama agropastoralist, Ngandu horticulturalist, and Aka hunter-gatherer children.
METHODS: Heights and weights were collected from 206 children aged 2-18 years old. HAZ, WAZ, and BMIZ were calculated using CDC standards. DHEAS and cortisol assays were used to determine biomarker concentrations in hair. Generalized linear modeling was used to examine effects of nutritional status on DHEAS concentrations, as well as cortisol, controlling for age, sex, and population.
RESULTS: Despite the prevalence of low HAZ and WAZ scores, the majority (77%) of children had BMI z-scores >-2.0 SD. Nutritional status has no significant effect on DHEAS concentrations, controlling for age, sex, and population. Cortisol, however, is a significant predictor of DHEAS concentrations.
CONCLUSIONS: Our findings do not support a relationship between nutritional status and DHEAS. Instead, results suggest an important role for stress and ecology in DHEAS concentrations across childhood. Specifically, effects of environment via cortisol may be influential to patterning of DHEAS. Future work should investigate local ecological stressors and their relationship to adrenarche.

DOI: https://doi.org/10.1002/ajhb.23881
Front Med (Lausanne). 2023 ;10 1023383

Indoxyl sulfate mediates low handgrip strength and is predictive of high hospitalization rates in patients with end-stage renal disease.

Yi-Chou Hou, Yueh-Min Liu, Min-Ter Liao, Cai-Mei Zheng, Chien-Lin Lu, Wen-Chih Liu, Kuo-Chin Hung, Shyh-Min Lin, Kuo-Cheng Lu.

   Background and aims: Sarcopenia has a higher occurrence rate in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD) than in the general population. Low handgrip strength-and not sarcopenia per se-is associated with clinical outcomes in patients with CKD, including cardiovascular mortality and hospitalization. The factors contributing to low handgrip strength are still unknown. Accordingly, this study aimed to determine whether uremic toxins influence low handgrip strength in patients with CKD.
Materials and methods: This cohort study lasted from August 2018 to January 2020. The participants were divided into three groups: the control group [estimated glomerular filtration rate (eGFR) ≥ 60 ml/min], an advanced CKD group (eGFR = 15-60 ml/min), and an ESRD group (under maintenance renal replacement therapy). All participants underwent handgrip strength measurement, dual-energy X-ray absorptiometry, and blood sampling for myokines (irisin, myostatin, and interleukin 6) and indoxyl sulfate. Sarcopenia was defined according to the Asian Working Group for Sarcopenia consensus as low appendicular skeletal muscle index (appendicular skeletal muscle/height2 of < 7.0 kg/m2 in men and < 5.4 kg/m2 in women) and low handgrip strength (< 28 kg in men and < 18 kg in women).
Results: Among the study participants (control: n = 16; CKD: n = 17; and ESRD: n = 42), the ESRD group had the highest prevalence of low handgrip strength (41.6 vs. 25% and 5.85% in the control and CKD groups, respectively; p < 0.05). The sarcopenia rate was similar among the groups (12.5, 17.6, and 19.5% for the control, CKD, and ESRD groups, respectively; p = 0.864). Low handgrip strength was associated with high hospitalization rates within the total study population during the 600-day follow-up period (p = 0.02). The predictions for cardiovascular mortality and hospitalization were similar among patients with and without sarcopenia (p = 0.190 and p = 0.094). The serum concentrations of indoxyl sulfate were higher in the ESRD group (227.29 ± 92.65 μM vs. 41.97 ± 43.96 μM and 6.54 ± 3.45 μM for the CKD and control groups, respectively; p < 0.05). Myokine concentrations were similar among groups. Indoxyl sulfate was associated with low handgrip strength in univariate and multivariate logistic regression models [univariate odds ratio (OR): 3.485, 95% confidence interval (CI): 1.372-8.852, p = 0.001; multivariate OR: 8.525, 95% CI: 1.807-40.207, p = 0.007].
Conclusion: Handgrip strength was lower in the patients with ESRD, and low handgrip strength was predictive of hospitalization in the total study population. Indoxyl sulfate contributed to low handgrip strength and counteracted the benefits of myokines in patients with CKD.

Keywords:  chronic kidney disease; frailty; handgrip strength; indoxyl sulfate; irisin; sarcopenia

DOI:  https://doi.org/10.3389/fmed.2023.1023383
Heliyon. 2023 Feb 17. e13797

Sulfated polysaccharides as multi target molecules to fight COVID 19 and comorbidities.

Enrique Javier Carvajal Barriga, R Douglas Fields.

  The majority of research to combat SARS-CoV-2 infection exploits the adaptive immune system, but innate immunity, the first line of defense against pathogenic microbes, is equally important in understanding and controlling infectious diseases. Various cellular mechanisms provide physiochemical barriers to microbe infection in mucosal membranes and epithelia, with extracellular polysaccharides, particularly sulfated polysaccharides, being among the most widespread and potent extracellular and secreted molecules blocking and deactivating bacteria, fungi, and viruses. New research reveals that a range of polysaccharides effectively inhibits COV-2 infection of mammalian cells in culture. This review provides an overview of sulfated polysaccharides nomenclature, its significance as immunomodulators, antioxidants, antitumors, anticoagulants, antibacterial, and as potent antivirals. It summarizes current research on various interactions of sulfated polysaccharide with a range of viruses, including SARS-CoV-2, and their application for potential treatments for COVID-19. These molecules interact with biochemical signaling in immune cell responses, by actions in oxidative reactions, cytokine signaling, receptor binding, and through antiviral and antibacterial toxicity. These properties provide the potential for the development of novel therapeutic treatments for SARS-CoV-2 and other infectious diseases from modified polysaccharides.

Keywords:  Anti-bacterial; Antioxidant; Antiviral saccharides; COVID-19 and comorbidities; Cancer; Diabetes; Heparin; Hypertension; Immunomodulation; Multi-target drugs; Viral infection

DOI:  https://doi.org/10.1016/j.heliyon.2023.e13797
Anal Methods. 2023 Feb 22.

Development of a new heparan sulfate proteoglycan (HSPG) chromolith LC column to study the pH dependence binding of peptide vaccines to HSPG and role of human serum albumin on its binding.

Claire André, Lydie Lethier, Olivier Adotevi, Yves Claude Guillaume.

Heparan sulfate proteoglycan (HSPG) expressed on immune cell surface participate in antitumor T-cell responses generated in the acidic lymph node (LN) microenvironment. In this work, HSPG was immobilized for the first time on a HPLC chromolith support for studying the effect of extra cellular acidosis in LNs on the binding to HSPG of two peptide vaccines (universal cancer peptide UCP2 and UCP4). This home-made HSPG column enabling to work at high flow-rates, was resistance to change in pH, had a long - life time, an excellent repeatability and negligible non-specific binding sites. The performance of this affinity HSPG column was confirmed by the evaluation of recognition assay for a series of known ligand of HSPG. It was shown that at 37 °C, the UCP2 binding to HSPG versus pH described a sigmoidal shape while UCP4 remained relatively constant in the pH range 5.0-7.5 and lower than the one of UCP2. By the use of an HSA HPLC column, it was shown at 37 °C and in acidic conditions a loss of affinity of UCP2 and UCP4 to HSA. It was demonstrated that upon UCP2/HSA binding, the protonation of the histidine residue in the cluster R(arg) Q(Gln) Hist (H) of the UCP2 peptide allowed to expose more favorably than UCP4 its polar and cationic groups to the negative net charge of HSPG on immune cells. Acidic pHs led to the protonation of the UCP2 residue histidine by flipping the His switch to the on position with a concomitant increase in affinity for the negative net charge of HSPG confirming that UCP2 was more immunogenic than UCP4. As well this HSPG chromolith LC column developed in this work could be used in the feature for other protein - HSPG binding studies or for a separative mode.

DOI: https://doi.org/10.1039/d3ay00046j
Carbohydr Polym. 2023 May 15. pii: S0144-8617(23)00113-3. [Epub ahead of print]308 120649

Monitoring the stability of heparin: NMR evidence for the rearrangement of sulfated iduronate in phosphate buffer.

Aleksandra M Kozlowski, Edwin A Yates, Johannes P Roubroeks, Kristoffer Tømmeraas, Flemming H Larsen, Alan M Smith, Gordon A Morris.

  Heparin, a major anticoagulant drug, comprises a complex mixture of motifs. Heparin is isolated from natural sources while being subjected to a variety of conditions but the detailed effects of these on heparin structure have not been studied in depth. Therefore, the result of exposing heparin to a range of buffered environments, ranging pH values from 7 to 12, and temperatures of 40, 60 and 80 °C were examined. There was no evidence of significant N-desulfation or 6-O-desulfation in glucosamine residues, nor of chain scission, however, stereochemical re-arrangement of α-L-iduronate 2-O-sulfate to α-L-galacturonate residues occurred in 0.1 M phosphate buffer at pH 12/80 °C. The results confirm the relative stability of heparin in environments like those during extraction and purification processes; on the other hand, the sensitivity of heparin to pH 12 in buffered solution at high temperature is highlighted, providing an important insight for heparin manufacturers.

Keywords:  Alkaline solutions; Heparin; Iduronate rearrangement; NMR; Phosphate buffer

DOI:  https://doi.org/10.1016/j.carbpol.2023.120649
Thromb J. 2023 Feb 20. 21(1): 21

Monitoring heparin therapy: stability of two different anti-Xa assays using blood samples collected in citrate-containing and CTAD tubes.

Marion Gremillet, Laurie Talon, Aurélien Lebreton, Thomas Sinegre.

   BACKGROUND: Anti-factor Xa assays and activated partial thromboplastin time (aPTT) are mainly employed to monitor patients treated with heparins. According to the Clinical and Laboratory Standards Institute and the French Working Group on Haemostasis and Thrombosis, anti-factor Xa activity and aPTT should be tested within 2 h of blood sampling for unfractionated heparin (UFH) monitoring. However, discrepancies exist depending on the used reagents and collecting tubes. The study aim was to determine the stability of aPTT and anti-factor Xa measurements using blood samples collected in citrate-containing or citrate-theophylline-adenosine-dipyridamole (CTAD) tubes and stored for up to 6 h.
METHODS: Patients receiving UFH or low molecular weight heparin (LMWH) were enrolled; aPTT and anti-factor Xa activity were tested using two different analyser/reagent pairs (Stago and reagent without dextran sulfate; Siemens and reagent with dextran sulfate) after 1, 4 and 6 h of sample storage as whole blood or as plasma.
RESULTS: For UFH monitoring, comparable anti-factor Xa activity and aPTT results were obtained with both analyser/reagent pairs when samples were stored as whole blood before plasma isolation. With samples stored as plasma, anti-factor Xa activity and aPTT were not affected up to 6 h after sampling when using the Stago/no-dextran sulfate reagent pair. With the Siemens/dextran sulfate-containing reagent, aPTT was significantly altered after 4 h of storage. For LMWH monitoring, anti-factor Xa activity remained stable (whole blood and plasma) for at least 6 h. Results were comparable with citrate-containing and CTAD tubes.
CONCLUSIONS: Anti-factor Xa activity in samples stored as whole blood or plasma was stable for up to 6 h, regardless of the reagent (with/without dextran sulfate)/collection tube. Conversely, aPTT was more variable because other plasma parameters can influence its measure and complicate the interpretation of its variations after 4 h.

Keywords:  Blood coagulation tests; Drug monitoring; Haemostasis; Heparin; Pre-analytical phase

DOI:  https://doi.org/10.1186/s12959-023-00465-8