Comparison of prothrombin time derived from CoaguChek XS and laboratory test according to fibrinogen level.

BACKGROUND: CoaguChek XS is one of the most widely used point-of-care (POC) devices to evaluate prothrombin time for monitoring oral anticoagulant therapy. Unlike laboratory methods, it detects electrical signals produced by thrombin activity to derive the international normalized ratio (INR). Therefore, we hypothesized that laboratory methods and CoaguChek XS could produce different results according to fibrinogen level. METHODS: We compared INR values obtained from the CoaguChek XS and conventional laboratory method with 91 plasma samples covering a wide range of fibrinogen levels. RESULTS: The samples were stratified into low, mid, and high fibrinogen groups by fibrinogen levels of <130 mg/dl, 130-450 mg/dl, and >450 mg/dl, respectively. The mean INR difference of the low fibrinogen group was significantly different from that of the mid or high fibrinogen group (P < 0.001). In the low fibrinogen group, CoaguChek XS INR showed a negative bias compared with the laboratory INR, while the mid and high fibrinogen groups had positive bias. CONCLUSION: Our results suggest that patient selection according to fibrinogen status should precede the implementation of POC testing using CoaguChek XS. Also, periodic comparisons between CoaguChek XS and laboratory INR results should be continued during the use of CoaguChek XS.

A novel bi-alleleic DDX41 mutations in B-cell lymphoblastic leukemia: case report.

BACKGROUND: The germline mutations of DDX41, also known as DEAD box RNA helicase 41, have been found in about 1.5% of myeloid neoplasms (MNs). Development of MDS/AML is relatively common in germline DDX41 mutations. However, a variety of hematological malignancies (HMs) have been reported. CASE PRESENTATION: We report a novel case of bi-alleleic DDX41 mutations in B-cell lymphoblastic leukemia (B-ALL), with unusual location of DDX41 mutations. The gene expression profile (GEP) of Ph + B-ALL with bi-alleleic DDX41 mutations showed heterogeneously transitional GEP and altered gene expression levels of genes involved in the process essential for red blood cells and myeloid cell differentiation were noted. CONCLUSIONS: We report that DDX41 mutations are unusual but can be an underlying event in Ph + B-ALL and screening DDX41 mutations can be also informative for patients awaiting for haploidentical stem cell transplantation and choosing the therapy.

Immunogenicity of Third-dose BNT162b2 mRNA Vaccine Following Two Doses of ChAdOx1 in Health Care Workers: A Prospective Longitudinal Study.

Following the original severe acute respiratory syndrome coronavirus 2 strain (Wuhan-Hu-1) in December 2019, the Delta variant in May 2021 and the Omicron variant in December 2021 were classified as variants of concern. The pandemic has been ongoing for more than two years, and the three-dose vaccination rate has reached approximately 50% in Korea. We analyzed anti-S antibodies (Abs) and neutralizing Abs (NAbs) in 32 healthcare workers at a university hospital, focusing on the first to third doses of ChAdOx1-ChAdOx1-BNT162b2, which is the most common vaccination regimen in Korea. Antibodies were analyzed at eight time points according to the vaccine regimen. The first to third doses of ChAdOx1-ChAdOx1-BNT162b2 produced high Ab concentrations; NAb concentrations after the third dose were predicted to remain high for a longer period than those after the first and second doses. The effectiveness of a second dose of ChAdOx1 in the real world was demonstrated by analyzing samples collected during an outbreak that occurred in the study period, 4-5 months after the second dose. The relative risk ratio was 88.0%, and the efficacy of the second ChAdOx1 dose was 12.0% (P<0.05). Therefore, maintaining appropriate Ab concentrations through regular vaccination will help protect against coronavirus disease-19.

Empagliflozin suppresses urinary mitochondrial DNA copy numbers and interleukin-1ß in type 2 diabetes patients.

Sodium-glucose co-transporter 2 (SGLT2) inhibitors improve cardiovascular and renal outcomes in type 2 diabetes mellitus (T2DM) patients. However, the mechanisms by which SGLT2 inhibitors improve the clinical outcomes remain elusive. We evaluated whether empagliflozin, an SGLT2 inhibitor, ameliorates mitochondrial dysfunction and inflammatory milieu of the kidneys in T2DM patients. We prospectively measured copy numbers of urinary and serum mitochondrial DNA (mtDNA) nicotinamide adenine dinucleotide dehydrogenase subunit-1 (mtND-1) and cytochrome-c oxidase 3 (mtCOX-3) and urinary interleukin-1ß (IL-1ß) in healthy volunteers (n = 22), in SGLT2 inhibitor-naïve T2DM patients (n = 21) at baseline, and in T2DM patients after 3 months of treatment with empagliflozin (10 mg, n = 17 or 25 mg, n = 4). Both urinary mtDNA copy numbers and IL-1ß levels were higher in the T2DM group than in healthy volunteers. Baseline copy numbers of serum mtCOX-3 in the T2DM group were lower than those in healthy volunteers. Empagliflozin induced marked reduction in both urinary and serum mtND-1 and mtCOX-3 copy numbers, as well as in urinary IL-1ß. Empagliflozin could attenuate mitochondrial damage and inhibit inflammatory response in T2DM patients. This would explain the beneficial effects of SGLT2 inhibitors on cardiovascular and renal outcomes.

Analytical Performance Evaluation of Automated Coagulation Analyzer CP3000 for Routine and Special Coagulation Assays.

CP3000 coagulation analyzer is a high-throughput, fully automated coagulation analyzer. The objective of this study was to evaluate the analytical performance of CP3000 coagulation system for general and special coagulation analyses. Quality control materials and patient samples were used to evaluate the analytical performance of CP3000 coagulation system. Precision, carryover, linearity, comparability with ACL-TOP 700 coagulation system, and verification of reference range were evaluated or performed according to Clinical and Laboratory Standards Institute guidelines. Within-run and between-run precisions were below 5% for both normal and abnormal ranges. There was no detectable carryover. The linearity of antithrombin and fibrinogen were excellent. The comparability between CP3000 and ACL-TOP 700 coagulation systems was acceptable except for activated partial thromboplastin time and thrombin time due to differences in reagent composition. Reference ranges proposed by the manufacturer were verified to be acceptable. CP3000 coagulation system is a reliable system that can be used to perform routine and special coagulation tests rapidly and accurately. Because of its small footprint as an additional advantage, the implementation of CP3000 coagulation system can be efficient in hospital laboratories of various sizes.

Updated recommendations for the treatment of venous thromboembolism.

Venous thromboembolism (VTE), which includes pulmonary embolism and deep vein thrombosis, is a condition characterized by abnormal blood clot formation in the pulmonary arteries and the deep venous vasculature. It is often serious and sometimes even fatal if not promptly and appropriately treated. Moreover, the later consequences of VTE may result in reduced quality of life. The treatment of VTE depends on various factors, including the type, cause, and patient comorbidities. Furthermore, bleeding may occur as a side effect of VTE treatment. Thus, it is necessary to carefully weigh the benefits versus the risks of VTE treatment and to actively monitor patients undergoing treatment. Asian populations are known to have lower VTE incidences than Western populations, but recent studies have shown an increase in the incidence of VTE in Asia. A variety of treatment options are currently available owing to the introduction of direct oral anticoagulants. The current VTE treatment recommendation is based on evidence from previous studies, but it should be applied with careful consideration of the racial, genetic, and social characteristics in the Korean population.

Fibrinogen Yecheon: congenital dysfibrinogenemia with gamma methionine-310 to threonine substitution.

This case study reports a rare fibrinogen variant, gamma Met310Thr mutation, for the first time in Korea. The case shows a point mutation from T to C in the 1,007th nucleotide of the FGG gene. This report describes a variant fibrinogen, hereinafter called "fibrinogen Yecheon", using the name after the town where the patient was living at the time of diagnosis. Fibrinogen Yecheon has a de novo heterozygous point mutation of FGG resulting in gamma Met310Thr and subsequent extra N-glycosylation at gamma Asn308. Extra N-glycosylated fibrinogen is considered a main inhibitor of normal fibrinogen activity.

Bariatric Surgery Reduces Elevated Urinary Mitochondrial DNA Copy Number in Patients With Obesity.

OBJECTIVE: Obesity is an independent risk factor for chronic kidney disease. Recently, urinary mitochondrial DNA (mtDNA) has been used as a surrogate marker of mitochondrial damage in various kidney diseases. However, there are no data regarding its use in patients with obesity or the change in urinary mtDNA copy number after surgery. DESIGN: We prospectively recruited age- and sex-matched healthy volunteers and patients with obesity (n = 22 in each group: nine men and 13 women). The copy number of urinary and serum mtDNA nicotinamide adenine dinucleotide dehydrogenase subunit-1 (mtND-1) and cytochrome-c oxidase 3 (mtCOX-3) was measured using quantitative PCR. We measured urinary mtDNA and body weight and carried out laboratory tests, 6 months after surgery. RESULTS: Urinary mtND-1 copy number was significantly higher in the obese group than in healthy volunteers. However, urinary mtCOX-3 and serum ND-1 copy numbers in the obese group did not differ from that in the healthy volunteers. When patients with obesity were divided into two groups, according to their baseline mtND-1 copy number, bariatric surgery reduced the mtND-1 copy number (P = 0.006) in the high baseline mtDNA copy-number group. The change in urinary mtND-1 copy number was correlated with a change in urinary albumin (r = 0.478, P = 0.025). CONCLUSIONS: Obesity is associated with elevated urinary mtND-1 copy number. Bariatric surgery reduces the elevated urinary mtND-1 copy number in patients with obesity. This suggests that bariatric surgery could attenuate mitochondrial damage in the kidney cells of patients with obesity.

Further modification of the Hodge test to screen AmpC beta-lactamase (CMY-1)-producing strains of Escherichia coli and Klebsiella pneumoniae.

Cefoxitin-resistant Escherichia coli and Klebsiella pneumoniae are widespread in Korea. Significant proportions of them are considered to be CMY-1 producers. For effective screening of CMY-1 producers, the Hodge test was modified by using a cefoxitin disk and the performance was evaluated. The sensitivity and specifity of the test were 100% and 94.9%, respectively. The test was easier to perform than the three-dimensional extract test. This modified test should be suitable for screening CMY-1-producing strains of E. coli and K. pneumoniae.

Analytical and clinical performance of a new point of care LABGEOIB D-dimer test for diagnosis of venous thromboembolism.

LABGEO(IB) D-dimer Test is a newly developed POC D-dimer assay and the first commercially available POC immunoassay instrument that exploits the disk rotation method for extraction of plasma. Citrate plasma was obtained from 201 apparently healthy subjects and 91 patients suspected for VTE, and their D-dimer level was measured by the LABGEO(IB) D-Dimer Test (LABGEO D-dimer) and HemosIL D-dimer test as a comparative method. To examine the effect of blood cells and anticoagulant, paired blood samples anticoagulated by heparin and citrate were obtained from various postoperative patients. The overall diagnostic performance of LABGEO(IB) D-dimer and HemosIL was comparable with similar area under ROC curve (p=0.79). The cut-off levels recommended by manufacturers (LABGEO D-dimer: 0.45 µg/ml fibrinogen equivalent unit (FEU), HemosIL: 0.23 µg/ml D-dimer unit (DDU)) and those yielding highest diagnostic efficiency (LABGEO D-dimer: 1.41 µg/ml FEU; HemosIL: 0.85 µg/ml DDU), were chosen for the evaluation. For LABGEO D-dimer negative predictive value (NPV), positive predictive value (PPV), sensitivity, specificity, and negative likelihood ratio (LR-neg) were 93-100%, 67-89%, 93-100%, 53-89% and 0.00-0.08. For HemosIL D-dimer, NPV, PPV, sensitivity, specificity and LR-neg were 90 - 100%, 76-95%, 89-100%, 70-96% and 0.00-0.12, all comparable to results for LABGEO D-dimer. LABGEO D-dimer test demonstrated acceptable performance when used for the VTE diagnostic work-up.

Comparison of total and IgG ABO antibody titers in healthy individuals by using tube and column agglutination techniques.

BACKGROUND: Most immune reactions related to transfusion and transplantation are caused by IgM ABO antibodies. However, IgG also plays an important role in these reactions. Therefore, a method to measure antibodies, including IgG, is necessary. We investigated ABO antibody titers of healthy individuals using a column agglutination technique (CAT) with or without dithiothreitol (DTT) and compared them with titers obtained using a conventional tube method. METHODS: Among healthy adults who underwent a medical examination, 180 individuals (60 with blood group A, 60 with group B, and 60 with group O) were selected. Antibody titrations were performed using the immediate spin (IS) tube, anti-human globulin (AHG) tube, and CAT with or without DTT methods. RESULTS: Higher median values of anti-B and anti-A titers in groups A and B individuals, respectively, were obtained using the IS method than using the AHG method. Higher values for group O individuals were obtained using the AHG method. Higher median titers of anti-B and anti-A in group O individuals were obtained using CAT without DTT than using the AHG method. Median titers of anti-B and anti-A in all blood groups were higher in CAT without DTT than in CAT with DTT, especially for group O individuals. CONCLUSIONS: We recommend CAT with and without DTT for titration of anti-A and anti-B, especially in group O individuals, to provide more sensitive results that include IgG data. Adjustment of insurance coverage of fees associated with antibody titration might be necessary, considering the actual cost of reagents and personnel.

An engineered fibrinogen variant AαQ328,366P does not polymerise normally, but retains the ability to form α cross-links.

A fibrin clot is stabilised through the formation of factor XIIIa-catalysed intermolecular ε-lysyl-γ-glutamyl covalent cross-links between α chains to form α polymers and between γ chains to form γ dimers. In a previous study we characterised fibrinogen Seoul II, a heterozygous dysfibrinogen in which a cross-linking acceptor site in Aα chain, Gln328, was replaced with Pro (AαQ328P). Following on the previous study, we investigated whether the alteration of Gln residues Aα328 and Aα366 affects fibrin polymerisation and α chain cross-linking. We have expressed three recombinant fibrinogens: AαQ328P, AαQ366P, and AαQ328,366P in Chinese hamster ovary cells, purified these fibrinogens from the culture media and performed biochemical tests to see how the introduced changes affect fibrin polymerisation and α chain cross-linking. Thrombin-catalysed fibrin polymerisation of all variants was impaired with the double mutation being the most impaired. In contrast, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis showed α polymer formation with all three engineered proteins. This study demonstrates that AαQ328 and AαQ366 are important for normal fibrin clot formation and in the absence of residues AαQ328 and AαQ366, other Gln residues in the α chain can support FXIIIa-catalysed fibrin cross-linking.

Fibrinogen residue γAla341 is necessary for calcium binding and 'A-a' interactions.

The fibrinogen γ-module has several important sites relating to fibrinogen function, which include the high affinity calcium binding site, hole 'a' that binds with knob 'A', and the D:D interface. Residue γAla341, which is located in the vicinity of these sites, is altered in three variant fibrinogens: fibrinogen Seoul (γAla341Asp), Tolaga Bay (γAla341Val), and Lyon III (γAla341Thr). In order to investigate the impaired polymerisation of fibrinogens γAla341Asp and γAla341Val to understand the role of γAla341 in fibrin polymerisation and fibrinogen synthesis, we have expressed γAla341Asp and γAla341Val in Chinese hamster ovary (CHO) cells, purified these fibrinogens from the culture media and performed biochemical tests to elucidate their function. Expression in CHO cells was similar for these variants. For both variants the kinetics of thrombin-catalysed FpA release was not different from normal fibrinogen, while FpB release was slower than that of normal. Thrombin-catalysed polymerisation of both variants was dependent on the calcium concentration. At physiologic calcium (1 mM) the variants showed impaired polymerisation with a longer lag period and a slower Vmax than normal fibrinogen. Scanning electron micrographs showed the clots were less organised than normal, having thicker and more twisted fibers, and larger pores. Analysis by SDS-PAGE showed that factor XIIIa-catalysed γ and α chain cross-linking was delayed, and plasmin-catalysed lysis was not reduced by the presence of 5 mM calcium or 5 mM GPRP (Gly-Pro-Arg-Pro). Our data indicate that fibrinogen residue γAla341 is important for the proper conformation of the γ-module, maintaining calcium-binding site and 'A-a' interactions.

Elevated levels of activated and inactivated thrombin-activatable fibrinolysis inhibitor in patients with sepsis.

BACKGROUND: In sepsis, large scale inflammatory responses can cause extensive collateral damage to the vasculature, because both coagulation and fibrinolysis are activated unevenly. Thrombin-activatable fibrinolysis inhibitor (TAFI) plays a role in modulating fibrinolysis. Since TAFI can be activated by both thrombin and plasmin, it is thought to be affected in sepsis. Hence, activated and inactivated TAFI (TAFIa/ai) may be used to monitor changes in sepsis. METHODS: TAFIa/ai-specific in-house ELISA can detect only the TAFIa/ai form, because the ELISA capture agent is potato tuber carboxypeptidase inhibitor (PTCI), which has selective affinity towards only the TAFIa and TAFIai isoforms. TAFIa/ai levels in plasma from 25 patients with sepsis and 19 healthy volunteers were quantitated with the in-house ELISA. RESULTS: We observed increased TAFIa/ai levels in samples from patients with sepsis (48.7±9.3 ng/mL) than in samples from healthy individuals (10.5±5.9 ng/mL). In contrast, no difference in total TAFI concentration was obtained between sepsis patients and healthy controls. The results suggest that TAFI zymogen was activated and that TAFIa/ai accumulated in sepsis. CONCLUSION: The detection of TAFIa/ai in plasma could provide a useful and simple diagnostic tool for sepsis. Uneven activation of both coagulation and fibrinolysis in sepsis could be caused by the activation of TAFI zymogen and elevation of TAFIa/ai. TAFIa/ai could be a novel marker to monitor sepsis and other blood-related disturbances.

[A case of central nervous system myelomatosis with complex chromosome aberrations].

Involvement of the central nervous system is very uncommon in multiple myeloma, observed in approximately 1% of the multiple myeloma patients. We report a case of central nervous system myelomatosis with complex chromosome aberrations in a 62-yr-old female patient, who had previously been diagnosed as multiple myeloma. Fluorescent in situ hybridization revealed 13q deletion, p53 gene deletion and IGH/FGFR3 rearrangement and chromosomal study showed complex chromosome aberrations. After four cycles of chemotherapy, the patient was admitted to the hematology department with severe headache. Plasma cells were found in the cerebrospinal fluid (CSF), and CSF immunoelectrophoresis revealed abnormal precipitin arcs against anti-IgG and anti-lambda antisera. She was given systemic chemotherapy and eight courses of intrathecal chemotherapy, which cleared plasma cells in the CSF. Two months later, she was given autologous stem cell transplantation. Three months after stem cell transplantation, central nervous system myelomatosis progressed to plasma cell leukemia and two months later, the patient expired.