Background: The Clauss assay is widely used to quantify blood fibrinogen levels in clinical laboratories. However, by relying on thrombin as the main reagent, the Clauss assay is susceptible to interference from thrombin inhibitors, such as heparin or direct thrombin inhibitors. Here, we developed an innovative fibrinogen assay utilizing both recombinant batroxobin (rBat) and carboxymethyl chitosan (CMCS). Methods: Various biopolymers were tested to identify a suitable candidate that could enhance rBat-induced fibrin clot formation. Chromogenic substrate hydrolysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis showed that CMCS potentiated rBat activity. Consequently, we formulated a novel fibrinogen assay reagent, ANYFIB.C, comprising rBat and CMCS. We compared ANYFIB.C fibrinogen with an established reagent (HemosIL fibrinogen-C) with 96 clinical samples using an ACL-TOP 700 coagulation analyzer. We also evaluated the interfering effects of thrombin inhibitors on fibrinogen measurements. Results: CMCS significantly enhanced the enzymatic activity of rBat and dose-dependently reduced plasma clotting times. ANYFIB.C fibrinogen levels were comparable with those of HemosIL fibrinogen-C, with the 95% confidence intervals of the Passing–Bablok regres-sion intercept and slope being −7.4797 to 6.0185 and 0.9581 to 1.0116, respectively. Nosignificant interference was observed with heparin concentrations up to 10 U/mL or dabigatran concentrations up to 600 µg/L in the ANYFIB.C fibrinogen assays. In contrast, the HemosIL fibrinogen-C reagent demonstrated inhibitory interference at dabigatran concentrations as low as 150 µg/L. Conclusions Our results suggest that ANYFIB.C (a mixture of CMCS and rBat) can be used to measure blood fibrinogen levels effectively and protect from thrombin inhibitor interference.

Background: Since the clinical application of flow cytometry, many clinical laboratories have utilized this method for diagnosing hematologic malignancies. However, delays in testing can occur due to various reasons.To address this issue, whole blood fixatives are occasionally administered.Hence, this study aimed to determine the impact of applying whole blood fixative on bone marrow specimens. Methods: Nine samples without lymphoma/leukemia bone marrow involvement were examined. Flow cytometry was performed using 17 common markers. The samples were stored at room temperature (RT) and 4°C without fixative treatment, stored at 4°C after TransFix (Cytomark, UK) treatment, and stored at RT after Cyto-Chex (Streck, USA) treatment.Subsequently, the samples were divided into groups and examined. A total of 13 tests were conducted on each sample for up to 5 days. Results: The neutrophil and monocyte fractions improved when the samples were stored at 4°C, while no significant difference was observed in the lymphocyte fractions. The fluorescence intensity of the markers varied depending on the marker and conditions, with the most stable markers observed when stored in TransFix at 4°C, followed by storage at 4°C, CytoChex RT, and RT. Conclusions The use of fixative on bone marrow specimens maintained the stability of markers during delayed testing. Both fixatives are more effective in preserving marker intensity and cell fractions compared with RT storage.Refrigeration and the use of fixatives may be beneficial for examinations delayed beyond 72 hours.

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.

Bone Marrow ; Diagnosis ; Female ; Fluorescence ; Humans ; In Situ Hybridization ; Korea ; Leukemia ; Leukemia, Promyelocytic, Acute ; Male ; Microsatellite Repeats ; Peripheral Blood Stem Cell Transplantation ; Polymorphism, Single Nucleotide ; Stem Cell Transplantation ; Tandem Repeat Sequences ; Tissue Donors ; Y Chromosome

Objective: To compare short-term treatment outcomes at hospital discharge and hospital length of stay (LOS) in patients with spontaneous intracerebral hemorrhage (sICH) before and after introduction of resident physician work time limit (WTL). Methods: We retrospectively reviewed consecutive patients treated for sICH at our institution between 2016 and 2019. Then we dichotomized these patients into two groups, pre-WTL and post-WTL. We analyzed demographic elements and clinical features, and hospital length of stay (LOS). We evaluated short-term outcome using modified Rankin scale score at hospital discharge and then divided it into “good” and “poor” outcome groups. We subsequently, compared short-term treatment outcome and hospital LOS between the pre-WTL and post-WTL groups. Results: Out of 779 patients, 420 patients (53.9%) were included in the pre-WTL group, and 359 (46.1%) in post-WTL. The mortality rate in sICH patients was higher in the post-WTL group (pre-WTL; 13.6% vs. post-WTL; 17.3%), but there was no statistically significant difference in short-term outcome including mortality (p=0.332) between the groups. The LOS also, was not significantly different between the two groups (pre-WTL; 19.0 days vs. post-WTL; 20.2 days) (p=0.341). The initial Glasgow Coma Scale score, personal stroke history, and mean age were the only independent outcome predicting factors for patients with sICH. Conclusions Some neurosurgeons may expect poorer outcome for sICH after implementation of the WTL of the K-MHW for resident physician however, enforcement of the WTL did not significantly influence the short-term outcome and hospital LOS for sICH in our hospital. Further well-designed multi-institutional prospective studies on the effects of WTL in sICH patient outcome, are anticipated.

BACKGROUND: Flow cytometry analysis of paroxysmal nocturnal hemoglobinuria (PNH) is significantly affected by the methodology used. The lack of data on the effect of age and refrigeration on PNH clone stability motivated us to study these aspects using flow cytometry. METHODS: Peripheral blood was collected from six patients, of which two presented with PNH. All samples were tested immediately and stored at room temperature (RT, 20–25℃) and at 4℃ for re-analysis at 24, 48, 72 hr and 7 days. Anti-CD59-fluorescein isothiocyanate (Beckman Coulter, USA) and anti-CD235a-phycoerythrin (PE; Beckman Coulter) were used to stain red blood cells (RBCs). Fluorescein-labeled proaerolysin (Cedarlane, Canada), anti-CD15-PE (Beckman Coulter), anti-CD24-PE-cyanin 5 (Beckman Coulter), and anti-CD45-PE-cyanin 7 (Beckman Coulter) were used to stain granulocytes. Flow cytometry was performed using a FC500 flow cytometer (Beckman Coulter). The effects of time and temperature were analyzed using generalized estimating equations. RESULTS: No significant differences in the gated percentage of RBCs and PNH clone size of RBCs were observed between the RT and 4℃ groups up to 7 days of testing. The percentage of gated neutrophils decreased with specimen age (P<0.001) and a better correlation with baseline was obtained at 4℃ than at RT (P=0.014). Neutrophil PNH clones were stable until 48 hr and 72 hr at RT and 4℃, respectively, and could not be analyzed at 7 days. CONCLUSIONS: RBC analysis was successfully performed up to 7 days. For neutrophils, testing within 48 hr is recommended, because the number of gated cells decreases significantly with age.
Clone Cells ; Erythrocytes ; Flow Cytometry ; Granulocytes ; Hemoglobinuria, Paroxysmal ; Humans ; Neutrophils ; Refrigeration

Lymphoplasmacytic lymphoma (LPL) is a low-grade B-cell neoplasm, composed of small B lymphocytes, plasmacytoid lymphocytes, and plasma cells, usually involving bone marrow and sometimes lymph nodes or spleen. LPL with bone marrow involvement and an IgM monoclonal gammopathy of any concentration is designated as Waldenström macroglobulinemia (WM). LPL associated with non-IgM monoclonal gammopathy or biclonal gammopathy is rarely observed. LPL diagnosis was based on clinical, morphological, and immunophenotypic findings. Recently, the test for L265P mutation of the myeloid differentiation factor 88 (MYD88) gene has been helpful in the diagnosis of LPL. Here, we reported the first case of LPL/WM with IgM-κ/IgA-λ biclonal gammopathy in Korea.
B-Lymphocytes ; Bone Marrow ; Diagnosis ; Immunoglobulin M ; Korea ; Lymph Nodes ; Lymphocytes ; Lymphoma ; Multiple Myeloma ; Myeloid Differentiation Factor 88 ; Paraproteinemias ; Plasma Cells ; Spleen ; Waldenstrom Macroglobulinemia