Background: TP53 mutations are associated with poor prognosis in myelodysplastic neoplasm (MDS) and AML. The updated 5th WHO classification and International Consensus Classification (ICC) categorize TP53-mutated MDS and AML as unique entities. We conducted a multicenter study in Korea to investigate the characteristics of TP53-mutated MDS and AML, focusing on diagnostic aspects based on updated classifications. Methods: This study included patients aged ≥ 18 yrs who were diagnosed as having MDS(N = 1,244) or AML (N = 2,115) at six institutions. The results of bone marrow examination, cytogenetic studies, and targeted next-generation sequencing, including TP53, were collected and analyzed. Results: TP53 mutations were detected in 9.3% and 9.2% of patients with MDS and AML, respectively. Missense mutation was the most common, with hotspot codons R248/ R273/G245/Y220/R175/C238 accounting for 25.4% of TP53 mutations. Ten percent of patients had multiple TP53 mutations, and 78.4% had a complex karyotype. The median variant allele frequency (VAF) of TP53 mutations was 41.5%, with a notable difference according to the presence of a complex karyotype. According to the 5th WHO classification and ICC, the multi-hit TP53 mutation criteria were met in 58.6% and 75% of MDS patients, respectively, and the primary determinants were a TP53 VAF > 50% for the 5th WHO classification and the presence of a complex karyotype for the ICC. Conclusions Collectively, we elucidated the molecular genetic characteristics of patients with TP53-mutated MDS and AML, highlighting key factors in applying TP53 mutation-related criteria in updated classifications, which will aid in establishing diagnostic strategies.

Background: The direct method for reference interval (RI) estimating is limited due to the requirement of resources, difficulties in defining a non-diseased population, or ethical problems in obtaining samples. We estimated the RI for inflammatory biomarkers using an indirect method (RII). Methods: C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and presepsin (PSEP) data of patients visiting a single hospital were retrieved from April 2009 to April 2021. Right-skewed data were transformed using the Box-Cox transformation method. A mixed population of non-diseased and diseased distributions was assumed, followed by latent profile analysis for the two classes. The intersection point of the distribution curve was estimated as the RI. The influence of measurement size was evaluated as the ratio of abnormal values and adjustment (n×bandwidth) of the distribution curve. Results: The RIs estimated by the proposed RII method (existing method) were as follows: CRP, 0–4.1 (0–4.7) mg/L; ESR, 0–10.2 (0–15) mm/hr and PSEP, 0–411 (0–300) pg/mL. Measurement sizes ≥2,500 showed stable results. An abnormal-to-normal value ratio of 0.5 showed the most accurate result for CRP. Adjustment values ≤5 or >5 were applicable for a measurement size <25,000 or ≥25,000, respectively. Conclusions The proposed RII method could provide additional information for RI verification or estimation with some limitations.

Transfusion support for hematopoietic stem cell transplantation (HSCT) is an essential part of supportive care, and compatible blood should be transfused into recipients. As leukocyte antigen (HLA) matching is considered first and as the blood group does not impede HSCT, major, minor, bidirectional, and RhD incompatibilities occur that might hinder transfusion and cause adverse events. Leukocyte reduction in blood products is frequently used, and irradiation should be performed for blood products, except for plasma. To mitigate incompatibility and adverse events, local transfusion guidelines, hospital transfusion committees, and patient management should be considered.

In healthy peripheral blood stem cell (PBSC) donors, rare cases of transient thrombocytopenia have been reported due to the administration of granulocyte colony-stimulating factor (G-CSF) or the apheresis itself. Meanwhile, differentiating pseudothrombocytopenia induced by anticoagulants is crucial, as it can result in false low platelet counts. This study aimed to investigate the causes of thrombocytopenia in healthy PBSC donors. We investigated PBSC donors who experienced thrombocytopenia during transplantation at St. Mary’s Hospital, Seoul. Three donors were identified and donor workup studies were within the normal limits. After G-CSF administration prior to transplantation, the donors experienced a significant reduction in platelet counts. Apheresis resulted in lower levels, yet platelet counts returned to normal levels approximately two weeks later. In donor 3, thrombocytopenia was seen during the donor workup and ethylenediaminetetraacetic acid (EDTA)-induced pseudothrombocytopenia was identified after the supplementation of amikacin. For donor 3, we investigated whether his recipient’s sample showed EDTA-induced pseudothrombocytopenia through a review of any platelet clumping in the apheresis product and the presence of immunoglobulin M (IgM) or IgG antiplatelet antibodies in the recipient’s peripheral blood. In conclusion, the risk of severe thrombocytopenia with G-CSF administration in PBSC donors should be considered and accurate differentiation of pseudothrombocytopenia is imperative.

The Landsteiner–Wiener (LW) antigen is a type of red blood cell antigen. Anti-LW appears in various situations, including alloantibodies, autoantibodies, and even transiently occurring antibodies. Anti-LW has similar characteristics to anti-D, so it can interfere with interpreting pre-transfusion tests and finding compatible blood. This paper introduces three cases in whom anti-LW was detected through antibody identification tests. All three cases were examined using the column agglutination technique with ID-DiaPanel (Bio-Rad, Hercules, CA, USA) on a LISS/Coombs card, ID-DiaPanel p (Bio-Rad) on a NaCl/Enzyme card, and ID-DiaPanel (Bio-Rad) on a LISS/Coombs card using red blood cells treated with dithiothreitol. The auto-control test, direct antiglobulin test, and umbilical cord blood test were also performed. In all three cases, the reaction with D-positive panel cells was stronger than that with the D-negative panel cells, and two of them showed a pan-agglutinated reaction in ID-DiaPanel p (Bio-Rad) with NaCl/Enzyme card. They were reported as anti-LW, and as in these cases, anti-LW can occur under a range of conditions and interfere with proper transfusion. Therefore, it is important to identify anti-LW accurately, and if anti-LW is present, the transfusion of D-negative ABO matched blood should be recommended because of the low expression of the LW-antigen. On the other hand, D-positive blood is not a contraindication when an urgent transfusion is needed.

Background: Hepatocellular carcinoma (HCC) is the second-most-common cause of cancer-related deaths worldwide, and an accurate and non-invasive biomarker for the early detection and monitoring of HCC is required. We assessed pathogenic variants of HCC driver genes in cell-free DNA (cfDNA) from HCC patients who had not undergone systemic therapy. Methods: Plasma cfDNA was collected from 20 HCC patients, and deep sequencing was performed using a customized cfDNA next-generation sequencing panel, targeting the major HCC driver genes (TP53, CTNNB1, TERT) that incorporates molecular barcoding. Results: In 13/20 (65%) patients, we identified at least one pathogenic variant of two major HCC driver genes (TP53 and CTNNB1), including 16 variants of TP53 and nine variants of CTNNB1. The TP53 and CTNNB1 variants showed low allele frequencies, with median values of 0.17% (range: 0.06%–6.99%) and 0.07% (range: 0.05%–0.96%), respectively. However, the molecular coverage of variants was sufficient, with median values of 5,543 (range: 2,317–9,088) and 7,568 (range: 2,400–9,633) for TP53 and CTNNB1 variants, respectively. Conclusions Our targeted DNA sequencing successfully identified low-frequency pathogenic variants in the cfDNA from HCC patients by achieving high coverage of unique molecular families. Our results support the utility of cfDNA analysis to identify somatic gene variants in HCC patients.

Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.

BACKGROUND: Hereditary breast and ovarian cancer syndrome (HBOC) is caused by pathogenic variants in BRCA and other cancer-related genes. We analyzed variants in BRCA gene and other cancer-related genes in HBOC patients to evaluate the clinical validity of next-generation sequencing (NGS) multi-gene panel testing. METHODS: The BRCA1/2 NGS testing was conducted for 262 HBOC patients. Multiplex ligation-dependent probe amplification and direct Sanger sequencing were performed for confirmation. Multi-gene panel testing was conducted for 120 patients who did not possess BRCA1/2 pathogenic variants but met the National Comprehensive Cancer Network criteria. RESULTS: Pathogenic variants in BRCA1/2 were detected in 30 HBOC patients (11.5%). Additionally, four out of the 120 patients possessed pathogenic variants by multi-gene panel testing (3.3%): MSH2 (c.256G>T, p.Glu86*), PMS2 (c.1687C>T, p.Arg563*), CHEK2 (c.546C>A, p.Tyr182*), and PALB2 (c.3351-1G>C). All the four patients had a family history of cancer. CONCLUSIONS Multi-gene panel testing could be a significant screening tool for HBOC patients, especially for those with a family history of cancer.

BACKGROUND: DNMT3A mutations occur in approximately 20% of AML cases and are associated with changes in DNA methylation. CDKN2B plays an important role in the regulation of hematopoietic progenitor cells and DNMT3A mutation is associated with CDKN2B promoter methylation. We analyzed the characteristics of DNMT3A mutations including their clinical significance in AML and their influence on promoter methylation and CDKN2B expression. METHODS: A total of 142 adults, recently diagnosed with de novo AML, were enrolled in the study. Mutations in DNMT3A, CEBPA, and NPM1 were analyzed by bidirectional Sanger sequencing. We evaluated CDKN2B promoter methylation and expression using pyrosequencing and RT-qPCR. RESULTS: We identified DNMT3A mutations in 19.7% (N=28) of enrolled patients with AML, which increased to 29.5% when analysis was restricted to cytogenetically normal-AML. Mutations were located on exons from 8–23, and the majority, including R882, were found to be present on exon 23. We also identified a novel frameshift mutation, c.1590delC, in AML with biallelic mutation of CEBPA. There was no significant difference in CDKN2B promoter methylation according to the presence or type of DNMT3A mutations. CDKN2B expression inversely correlated with CDKN2B promoter methylation and was significantly higher in AML with R882H mutation in DNMT3A. We demonstrated that DNMT3A mutation was associated with poor AML outcomes, especially in cytogenetically normal-AML. The DNMT3A mutation remained as the independent unfavorable prognostic factor after multivariate analysis. CONCLUSION We characterized DNMT3A mutations in AML and revealed the association between the DNMT3A mutation and CDKN2B expression and clinical outcome.