Immature granulocyte percentage for prediction of sepsis in severe burn patients: a machine leaning-based approach.

BACKGROUND: Of the existing sepsis markers, immature granulocytes (IG) most frequently reflect the presence of an infection. The importance of IG as an early predictor of sepsis and bacteremia is evaluated differently for each study. This study aimed to evaluate the effectiveness of the Sysmex XN series' IG% as an independent prognostic indicator of sepsis using machine learning. METHODS: A total of 2465 IG% results from 117 severe burn patients in the intensive care unit of one institution were retrospectively analyzed. We evaluated the IG% for sepsis using the receiver operating characteristic, logistic regression, and partial dependence plot analyses. Clinical characteristics and other laboratory markers associated with sepsis, including WBC, procalcitonin, and C-reactive protein, were compared with the IG% values. RESULTS: Twenty-six of the 117 patients were diagnosed with sepsis. The median IG% value was 2.6% (95% CI: 1.4-3.1). The area under the receiver operating characteristic curve was 0.77 (95% CI: 0.78-0.84) and the optimal cut-off value was 3%, with a sensitivity of 76.9% and specificity of 68.1%. The partial dependence plot of IG% on predicting sepsis showed that an IG% < 4% had low predictability, but increased thereafter. The interaction plot of IG% and C-reactive protein showed an increase in sepsis probability at an IG% of 6% and C-reactive protein of 160 mg/L. CONCLUSIONS: IG% is moderately useful for predicting sepsis. However, since it can be determined from routine laboratory test results and requires no additional intervention or cost, it could be particularly useful as an auxiliary marker.

Currently Applied Molecular Assays for Identifying ESR1 Mutations in Patients with Advanced Breast Cancer.

Approximately 70% of breast cancers, the leading cause of cancer-related mortality worldwide, are positive for the estrogen receptor (ER). Treatment of patients with luminal subtypes is mainly based on endocrine therapy. However, ER positivity is reduced and ESR1 mutations play an important role in resistance to endocrine therapy, leading to advanced breast cancer. Various methodologies for the detection of ESR1 mutations have been developed, and the most commonly used method is next-generation sequencing (NGS)-based assays (50.0%) followed by droplet digital PCR (ddPCR) (45.5%). Regarding the sample type, tissue (50.0%) was more frequently used than plasma (27.3%). However, plasma (46.2%) became the most used method in 2016-2019, in contrast to 2012-2015 (22.2%). In 2016-2019, ddPCR (61.5%), rather than NGS (30.8%), became a more popular method than it was in 2012-2015. The easy accessibility, non-invasiveness, and demonstrated usefulness with high sensitivity of ddPCR using plasma have changed the trends. When using these assays, there should be a comprehensive understanding of the principles, advantages, vulnerability, and precautions for interpretation. In the future, advanced NGS platforms and modified ddPCR will benefit patients by facilitating treatment decisions efficiently based on information regarding ESR1 mutations.

A comparison of complete blood count reference intervals in healthy elderly vs. younger Korean adults: a large population study.

Background The use of laboratory reference intervals based on younger populations is of questionable validity in older populations. We established reference intervals for 16 complete blood count (CBC) parameters in healthy elderly Koreans aged ≥60 years and compared them to those of individuals aged 20-59 years. Methods Among 64,532 individuals (39,609 men and 24,923 women) aged ≥20 years who underwent medical checkups, 8151 healthy subjects (12.6%, 5270 men and 2881 women, including 675 and 511, respectively, who were ≥60 years of age) were enrolled based on stringent criteria including laboratory, imaging and endoscopy results; previous medical history; and medication history. CBC parameters were measured using an Advia2120i instrument. Results Overall, healthy individuals aged ≥60 years did not require separate reference intervals from those aged <60 years except for red cell distribution width (RDW) and mean corpuscular hemoglobin (MCH) in women. However, subjects aged ≥60 years still required sex-specific reference intervals for red blood cell count, hemoglobin, hematocrit, MCH, monocytes and eosinophils. Separate reference intervals were required for MCH, eosinophils and basophils for certain age subgroups of men aged ≥60 years, and for MCH and RDW in certain age subgroups of women aged ≥60 years, compared to counterparts <60 years of age. Conclusions Healthy elderly Koreans can use the same reference intervals as younger populations. Thus, abnormal CBC results may not necessarily be attributable to physiologic changes but possible underlying diseases that should be investigated.

Mean Platelet Volume and Platelet Distribution Width Indicate that Platelets Remain Small for Most of Their Lifespans in Patients with Essential Thrombocythemia.

BACKGROUND: Platelets are large when young and immature and shrink as they age. The mean platelet volume (MPV) and platelet distribution width (PDW) reflect the volume and distribution of platelets, respectively. We compared the MPVs and PDWs of patients with immune thrombocytopenic purpura (ITP) or essential thrombocythemia (ET) to those of healthy individuals to test whether these values can reflect the pathomechanisms of these diseases. METHODS: Platelet counts, MPVs, and PDWs were measured in 153 healthy individuals and in 20 and 34 patients with ITP and ET, respectively, using an XN-3000 instrument. RESULTS: The MPVs and PDWs were significantly higher in ITP patients than in healthy individuals or ET patients. The MPVs were significantly lower in ET patients than in both ITP patients and healthy individuals; however, the PDWs in ET patients were similar to those in healthy individuals. The MPVs and PDWs did not correlate with platelet count in ITP or ET patients. CONCLUSIONS: Our data suggested an increased production of young, large platelets and nondiscriminatory destruction of circulating platelets irrespective of their ages in ITP. Decreased MPVs and unelevated PDWs in ET suggest that clonal process-produced platelets remain small throughout their lifespans.

Central venous catheter tip colonization and associated bloodstream infection in patients with severe burns under routine catheter changing.

BACKGROUND: Although routine changing of central venous catheters (CVCs) is commonly performed in patients with severe burns, information on pathogen colonization of the CVC tip and associated bloodstream infections (BSIs) is limited in those patients. METHODS: The medical records of 214 patients with severe burns who underwent routine CVC changing at 7-day intervals and their results of 686 pairs of CVC tips and concurrent blood cultures were retrospectively reviewed to evaluate the CVC colonization rate and associated BSI pathogens. RESULTS: Of the 686 CVCs, 137 (20.0%) were colonized by pathogens, and 81 (59.1%) of them had BSIs caused by the same pathogen. Nonflame burn (P = .002), total body surface area burn ≥30% (P = .004), femoral catheterization (P = .001), CVC changing during pre-existing BSI (P < .001), and renal replacement therapy (P = .017) were associated with catheter-related BSI in the multivariate analysis. Most BSIs were caused by Gram-negative bacteria (most commonly Acinetobacter baumannii, Klebsiella pneumoniae, and Pseudomonas aeruginosa). CONCLUSIONS: The CVC colonization rate in patients with severe burns and routine CVC changing was not high. Lengthening the CVC duration might be attempted in patients at a lower risk of catheter-related BSI although further prospective studies are necessary.

Clinical performance of the Roche Cobas Liat SARS-CoV-2 & influenza A/B assay: A systematic review and meta-analysis.

Respiratory tract infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses are persistent and critical. The Cobas Liat SARS-CoV-2 & influenza A/B assay (Multiplex Liat), the FDA-authorized point-of-care reverse transcriptase polymerase chain reaction (RT-PCR) assay, has a turnaround time of 20 min and high accuracy. This study evaluates the pooled performance of this assay to provide practical information. This meta-analysis was registered in PROSPERO (registration number: CRD42023467579). A systematic literature search was conducted within PubMed, Ovid-EMBASE, and the Cochrane Library for articles evaluating the accuracy of the Multiplex Liat assay through September 2023. A random-effects model was used to calculate the pooled diagnostic values with real-time RT-PCR (rRT-PCR) as a reference test. A total of 4,705 samples from eight studies were included in the primary meta-analysis. The overall pooled sensitivity and specificity of Multiplex Liat were 100.0 % (95 % confidence interval [CI] = 96.7 %-100.0 %) and 99.7 % (95 % CI = 98.7 %-99.9 %), respectively. The presence of variants of concern or in-house rRT-PCR assays as reference standards did not significantly affect the pooled diagnostic performance of the Multiplex Liat. When 5,333 samples from nine studies were assessed for sensitivity, the pooled sensitivity was 100.0 % (95 % CI = 85.8 %-100.0 %) without a significant difference. This meta-analysis demonstrates the usefulness of Multiplex Liat for the detection of SARS-CoV-2 based on pooled diagnostic values. These practical findings may facilitate appropriate settings for the diagnosis and management of patients with respiratory tract infections.

Trends in the detection of viruses causing gastroenteritis over a 10-year period and impact of nonpharmaceutical interventions.

BACKGROUND: Viral gastroenteritis continues to be a leading cause of death in low-income countries. The impact of nonpharmaceutical interventions (NPIs) on the transmission of gastroenteritis-causing viruses during the COVID-19 pandemic is understudied. OBJECTIVES: To investigate the 10-year trends of enteric viruses and estimate the impact of implementing and mitigating NPIs. STUDY DESIGN: Data regarding norovirus, rotavirus, adenovirus, astrovirus, and sapovirus detection were collected from five Korean hospitals between January 2013 and April 2023. We compared positivity between the pre-pandemic, pandemic, and post-pandemic periods. The causal effects of implementing and mitigating NPIs were quantified using the Bayesian Structural Time Series (BSTS) model. RESULTS: Norovirus was most frequently detected (9.9 %), followed by rotavirus (6.7 %), adenovirus (3.3 %), astrovirus (1.4 %), and sapovirus (0.6 %). During the pandemic, the positivity of all five viruses decreased, ranging from -1.0 % to -8.1 %, with rotavirus showing the greatest decrease. In the post-pandemic period, positivity rebounded for all viruses except for rotavirus. The BSTS model revealed that NPI implementation negatively affected the detection of all five viruses, resulting in reductions ranging from -73.0 % to -91.0 % compared to the prediction, with rotavirus being the least affected. Conversely, NPI mitigation positively affected the detection of all viruses, ranging from 79.0 % to 200.0 %, except for rotavirus. CONCLUSIONS: Trends observed over 10 years show that NPIs have had a major impact on changes in enteric virus detection. The effect of vaccines, in addition to NPIs, on rotavirus detection requires further investigation. Our findings emphasize the importance of NPIs in infection control and prevention.

Evaluation of the BD Phoenix CPO Detect Panel for Detection and Classification of Carbapenemase Producing Enterobacterales.

Carbapenem-resistant Enterobacterales (CRE) pose a serious public health threat due to their resistance to most antibiotics. Rapid and correct detection of carbapenemase producing organisms (CPOs) can help inform clinician decision making on antibiotic therapy. The BD Phoenix™ CPO detect panel, as part of antimicrobial susceptibility testing (AST), detects carbapenemase activity (P/N) and categorizes CPOs according to Ambler classes. We evaluated a CPO detect panel against 109 carbapenemase producing Enterobacterales (CPE) clinical isolates from Korea. The panel correctly detected carbapenemases production in 98.2% (n = 107/109) isolates and identified 78.8% (n = 26/33) class A, 65.9% (n = 29/44) class B, and 56.3% (n = 18/32) class D carbapenemase producers as harboring their corresponding Ambler classes. Specifically, the panel correctly classified 81.3% (n = 13/16) of K. pneumoniae KPC isolates to class A. However, the panel failed to classify 40.0% (n = 4/10) IMP and 63.6% (n = 7/11) VIM isolates to class B. Despite 27.5% (n = 30/109) CPE not being assigned Ambler classes, all of them tested carbapenemase positive. Our results demonstrate that the CPO detect panel is a sensitive test for detecting CPE and classifying KPC as class A, helping with antibiotics selection, but one-third of CPE remained unclassified for Ambler classes.

Immune-checkpoint proteins, cytokines, and microbiome impact on patients with cervical insufficiency and preterm birth.

Background: Microenvironmental factors, including microbe-induced inflammation and immune-checkpoint proteins that modulate immune cells have been associated with both cervical insufficiency and preterm delivery. These factors are incompletely understood. This study aimed to explore and compare interactions among microbiome and inflammatory factors, such as cytokines and immune-checkpoint proteins, in patients with cervical insufficiency and preterm birth. In particular, factors related to predicting preterm birth were identified and the performance of the combination of these factors was evaluated. Methods: A total of 220 swab samples from 110 pregnant women, prospectively recruited at the High-Risk Maternal Neonatal Intensive Care Center, were collected between February 2020 and March 2021. This study included 63 patients with cervical insufficiency receiving cerclage and 47 control participants. Endo- and exocervical swabs and fluids were collected simultaneously. Shotgun metagenomic sequencing for the microbiome and the measurement of 34 immune-checkpoint proteins and inflammatory cytokines were performed. Results: First, we demonstrated that immune-checkpoint proteins, the key immune-regulatory molecules, could be measured in endocervical and exocervical samples. Secondly, we identified significantly different microenvironments in cervical insufficiency and preterm birth, with precise cervical locations, to provide information about practically useful cervical locations in clinical settings. Finally, the presence of Moraxella osloensis (odds ratio = 14.785; P = 0.037) and chemokine CC motif ligand 2 levels higher than 73 pg/mL (odds ratio = 40.049; P = 0.005) in endocervical samples were associated with preterm birth. Combining M. osloensis and chemokine CC motif ligand 2 yielded excellent performance for predicting preterm birth (area under the receiver operating characteristic curve = 0.846, 95% confidence interval = 0.733-0.925). Conclusion: Multiple relationships between microbiomes, immune-checkpoint proteins, and inflammatory cytokines in the cervical microenvironment were identified. We focus on these factors to aid in the comprehensive understanding and therapeutic modulation of local microbial and immunologic compositions for the management of cervical insufficiency and preterm birth.

Prognostic impacts of soluble immune checkpoint regulators and cytokines in patients with SARS-CoV-2 infection.

Coronavirus disease 2019 (COVID-19) has been a pandemic for the past two years. Predicting patient prognosis is critical. Although immune checkpoints (ICs) were shown to be involved in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, quantitative studies of ICs in clinical practice are limited. In this study, various soluble ICs (sICs) and cytokine levels in patients with SARS-CoV-2 infection at different time points were compared between survivors and deaths; we also examined whether sICs are useful for predicting prognosis. sICs and cytokines were measured in serum samples from 38 patients diagnosed with COVID-19 in the first and second week post-diagnosis. All assays were performed by bead-based multiplexed immunoassay system using Luminex Bio-Plex 200 system. The correlation of sICs and cytokines with laboratory markers was evaluated, and the levels of sICs in survivors were compared with those in deaths. Among the sICs, the second-week levels of soluble cluster of differentiation (sCD27, p = 0.012), sCD40 (p< 0.001), cytotoxic T-lymphocyte-associated protein 4 (sCTLA-4, p< 0.001), herpes virus entry mediator (sHVEM, p = 0.026), and T-cell immunoglobulin and mucin-domain containing-3 (sTIM-3, p = 0.002) were significantly higher in deaths than in survivors. The levels of nine cytokines assessed in the second week of deaths were significantly higher than those in survivors. The sICs sCD27, sCD40, sCTLA-4, and sTIM-3 and cytokines chemokine CC motif ligand 2 (CCL2), GM-CSF, IL-10, and IL-8 showed significant positive correlations with the levels of C-reactive protein (CRP) and procalcitonin and were negatively correlated with the absolute lymphocyte count and platelet values. Increased levels of sICs including sCD27, sCD40, sCTLA-4, and sTIM-3 and cytokines were significant factors for poor prognosis. sICs, together with cytokines and inflammatory markers, may be useful as prognostic stratification markers in SARS-CoV-2-infected patients.

Development and validation of a deep learning-based protein electrophoresis classification algorithm.

BACKGROUND: Protein electrophoresis (PEP) is an important tool in supporting the analytical characterization of protein status in diseases related to monoclonal components, inflammation, and antibody deficiency. Here, we developed a deep learning-based PEP classification algorithm to supplement the labor-intensive PEP interpretation and enhance inter-observer reliability. METHODS: A total of 2,578 gel images and densitogram PEP images from January 2018 to July 2019 were split into training (80%), validation (10%), and test (10.0%) sets. The PEP images were assessed based on six major findings (acute-phase protein, monoclonal gammopathy, polyclonal gammopathy, hypoproteinemia, nephrotic syndrome, and normal). The images underwent processing, including color-to-grayscale and histogram equalization, and were input into neural networks. RESULTS: Using densitogram PEP images, the area under the receiver operating characteristic curve (AUROC) for each diagnosis ranged from 0.873 to 0.989, and the accuracy for classifying all the findings ranged from 85.2% to 96.9%. For gel images, the AUROC ranged from 0.763 to 0.965, and the accuracy ranged from 82.0% to 94.5%. CONCLUSIONS: The deep learning algorithm demonstrated good performance in classifying PEP images. It is expected to be useful as an auxiliary tool for screening the results and helpful in environments where specialists are scarce.

Prevalence and Clinical Impact of Coinfection in Patients with Coronavirus Disease 2019 in Korea.

Coinfection rates with other pathogens in coronavirus disease 2019 (COVID-19) varied during the pandemic. We assessed the latest prevalence of coinfection with viruses, bacteria, and fungi in COVID-19 patients for more than one year and its impact on mortality. A total of 436 samples were collected between August 2020 and October 2021. Multiplex real-time PCR, culture, and antimicrobial susceptibility testing were performed to detect pathogens. The coinfection rate of respiratory viruses in COVID-19 patients was 1.4%. Meanwhile, the rates of bacteria and fungi were 52.6% and 10.5% in hospitalized COVID-19 patients, respectively. Respiratory syncytial virus, rhinovirus, Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans were the most commonly detected pathogens. Ninety percent of isolated A. baumannii was non-susceptible to carbapenem. Based on a multivariate analysis, coinfection (odds ratio [OR] = 6.095), older age (OR = 1.089), and elevated lactate dehydrogenase (OR = 1.006) were risk factors for mortality as a critical outcome. In particular, coinfection with bacteria (OR = 11.250), resistant pathogens (OR = 11.667), and infection with multiple pathogens (OR = 10.667) were significantly related to death. Screening and monitoring of coinfection in COVID-19 patients, especially for hospitalized patients during the pandemic, are beneficial for better management and survival.

Performance of a Machine Learning-Based Methicillin Resistance of Staphylococcus aureus Identification System Using MALDI-TOF MS and Comparison of the Accuracy according to SCCmec Types.

The prompt presumptive identification of methicillin-resistant Staphylococcus aureus (MRSA) using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) can aid in early clinical management and infection control during routine bacterial identification procedures. This study applied a machine learning approach to MALDI-TOF peaks for the presumptive identification of MRSA and compared the accuracy according to staphylococcal cassette chromosome mec (SCCmec) types. We analyzed 194 S. aureus clinical isolates to evaluate the machine learning-based identification system (AMRQuest software, v.2.1, ASTA: Suwon, Korea), which was constructed with 359 S. aureus clinical isolates for the learning dataset. This system showed a sensitivity of 91.8%, specificity of 83.3%, and accuracy of 87.6% in distinguishing MRSA. For SCCmec II and IVA types, common MRSA types in a hospital context, the accuracy was 95.4% and 96.1%, respectively, while for the SCCmec IV type, it was 21.4%. The accuracy was 90.9% for methicillin-susceptible S. aureus. This presumptive MRSA identification system may be helpful for the management of patients before the performance of routine antimicrobial resistance testing. Further optimization of the machine learning model with more datasets could help achieve rapid identification of MRSA with less effort in routine clinical procedures using MALDI-TOF MS as an identification method.

Impact of COVID-19 on Antimicrobial Consumption and Spread of Multidrug-Resistance in Bacterial Infections.

The spread of COVID-19 pandemic may have affected antibiotic consumption patterns and the prevalence of colonized or infected by multidrug-resistant (MDR) bacteria. We investigated the differences in the consumption of antibiotics easily prone to resistance and the prevalence of MDR bacteria during the COVID-19 pandemic (March 2020 to September 2021) compared to in the pre-pandemic period (March 2018 to September 2019). Data on usage of antibiotics and infections caused by methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB), and carbapenem-resistant Pseudomonas aeruginosa (CRPA) were obtained from hospitalized patients in four university hospitals. The consumption of penicillin with ß-lactamase inhibitors (3.4% in ward, 5.8% in intensive care unit (ICU)), and carbapenems (25.9% in ward, 12.1% in ICU) increased during the pandemic period. The prevalence of MRSA (4.7%), VRE (49.0%), CRE (22.4%), and CRPA (20.1%) isolated in clinical samples from the ward and VRE (26.7%) and CRE (36.4%) isolated in clinical samples from the ICU were significantly increased, respectively. Meanwhile, only the prevalence of CRE (38.7%) isolated in surveillance samples from the ward increased. The COVID-19 pandemic is associated with increased consumption of antibiotics and has influenced the prevalence of infections caused by MDR isolates.

Genotypic Distribution and Antimicrobial Susceptibilities of Carbapenemase-Producing Enterobacteriaceae Isolated From Rectal and Clinical Samples in Korean University Hospitals Between 2016 and 2019.

BACKGROUND: The emergence of carbapenemase-producing Enterobacteriaceae (CPE) represents a major clinical problem. Recently, the occurrence of CPE has increased globally, but epidemiological patterns vary across region. We report the trends in the genotypic distribution and antimicrobial susceptibility of CPE isolated from rectal and clinical samples during a four-year period. METHODS: Between January 2016 and December 2019, 1,254 nonduplicated CPE isolates were obtained from four university hospitals in Korea. Carbapenemase genotypes were determined by multiplex real-time PCR. Antimicrobial susceptibility was profiled using the Vitek 2 system (bioMérieux, Hazelwood, MO, USA) or MicroScan Walkaway-96 system (Siemens West Sacramento, CA, USA). The proportions of carbapenemase genotypes and nonsusceptibility were analyzed using Pearson's chi-square test. RESULTS: Among the 1,254 CPE isolates, 486 (38.8%), 371 (29.6%), 357 (28.5%), 8 (0.6%), 8 (0.6%), and 24 (1.9%) were Klebsiella pneumoniae carbapenemase (KPC), oxacillinase (OXA)-48-like, New Delhi metallo-ß-lactamase (NDM), imipenemase (IMP), Verona integron-encoded metallo-ß-lactamase (VIM), and multiple producers, respectively. The predominant species was K. pneumoniae (72.6%), followed by Escherichia coli (6.5%). More than 90% of the isolates harboring KPC, NDM, and OXA-48-like were nonsusceptible to cephalosporins, aztreonam, and carbapenems. CONCLUSIONS: The impact of CPE is primarily due to KPC-, NDM-, and OXA-48-like-producing K. pneumoniae isolates. Isolates carrying these carbapenemase are mostly multidrug-resistant. Control strategies based on these genotypic distributions and antimicrobial susceptibilities of CPE isolates are required.

Epidemiologic Trends of Thalassemia, 2006-2018: A Nationwide Population-Based Study.

Thalassemia is the most common form of hereditary anemia. Here, we aimed to investigate the 13-year trend of the epidemiologic profiles and risk of comorbidities in thalassemia using a nationwide population-based registry in Korea. Diagnosis of thalassemia, the comorbidities and transfusion events in patients with thalassemia were identified in the Korean National Health Insurance database, which includes the entire population. The prevalence of thalassemia increased from 0.74/100,000 in 2006 to 2.76/100,000 in 2018. Notably, the incidence rate has nearly doubled in the last 2 years from 0.22/100,000 in 2016 to 0.41/100,000 in 2018. The annual transfusion rate gradually decreased from 34.7% in 2006 to 20.6% in 2018. Transfusion events in patients with thalassemia were significantly associated with the risk of comorbidities (diabetes: odds ratio [OR] = 3.68, 95% confidence interval [CI] = 2.59-5.22; hypertension: OR = 3.06, 95% CI = 2.35-4.00; dyslipidemia: OR = 1.72, 95% CI = 1.22-2.43; atrial fibrillation: OR = 3.52, 95% CI = 1.69-7.32; myocardial infarction: OR = 3.02, 95% CI = 1.09-8.38; stroke: OR = 3.32, 95% CI = 2.05-5.36; congestive heart failure: OR = 2.83, 95% CI = 1.62-4.97; end-stage renal disease: OR = 3.25, 95% CI = 1.96-5.37). Early detection of comorbidities and timely intervention are required for the management of thalassemia.

Currently Used Laboratory Methodologies for Assays Detecting PD-1, PD-L1, PD-L2 and Soluble PD-L1 in Patients with Metastatic Breast Cancer.

Approximately 20% of breast cancer (BC) patients suffer from distant metastasis. The incidence and prevalence rates of metastatic BC have increased annually. Immune checkpoint inhibitors are an emerging area of treatment, especially for metastatic patients with poor outcomes. Several antibody drugs have been developed and approved for companion testing of the programmed death protine-1 (PD-1) axis. We reviewed currently used laboratory methodologies for assays determining PD-1 axis to provide a comprehensive understanding of principles, advantages, and drawbacks involved in their implementation. The most commonly used method is immunohistochemistry (92.9%) for PD-L1 expression using tissue samples (96.4%). The commonly used anti-PD-L1 antibody clone were commercially available 22C3 (30.8%), SP142 (19.2%), SP263 (15.4%), and E1L3N (11.5%). Enzyme-linked immunosorbent assay and electrochemiluminescent immunoassay that target soluble PD-ligand (L)1 were developed and popularized in 2019-2021, in contrast to 2016-2018. Easy accessibility and non-invasiveness due to the use of blood samples, quantitative outputs, and relatively rapid turnaround times make them more preferable. Regarding scoring methods, a combination of tumor and immune cells (45.5% in 2016-2018 to 57.1% in 2019-2021) rather than each cell alone became more popular. Information about antibody clones, platforms, scoring methods, and related companion drugs is recommended for reporting PD-L1 expression.

Immunoglobulin gene rearrangement in Koreans with multiple myeloma: Clonality assessment and repertoire analysis using next-generation sequencing.

INTRODUCTION: We assessed the applicability of next-generation sequencing (NGS)-based IGH/IGK clonality testing and analyzed the repertoire of immunoglobulin heavy chain (IGH) or immunoglobulin kappa light chain (IGK) gene usage in Korean patients with multiple myeloma (MM) for the first time. METHODS: Fifty-nine bone marrow samples from 57 Korean patients with MM were analyzed, and NGS-based clonality testing that targeted the IGH and IGK genes was performed using IGH FR1 and IGK primer sets. RESULTS: Clonal IGH and IGK rearrangements were observed in 74.2% and 67.7% of samples from Korean patients with kappa-restricted MM, respectively (90.3% had one or both), and in 60.7% and 95.5% of samples from those with lambda-restricted MM, respectively (85.7% had one or both). In total, 88.1% of samples from Koreans with MM had clonal IGH and/or IGK rearrangement. Clonal rearrangement was not significantly associated with the bone marrow plasma cells as a proportion of all BM lymphoid cells. IGHV3-9 (11.63%) and IGHV4-31 (9.30%) were the most frequently reported IGHV genes and were more common in Koreans with MM than in Western counterparts. IGHD3-10 and IGHD3-3 (13.95% each) were the most frequent IGHD genes; IGHD3-3 was more common in Koreans with MM. No IGK rearrangement was particularly prevalent, but single IGKV-J rearrangements were less common in Koreans with kappa-restricted MM than in Western counterparts. IGKV4-1 was less frequent in Koreans regardless of light chain type. Otherwise, the usages of the IGH V, D, and J genes and of the IGK gene were like those observed in previous Western studies. CONCLUSION: NGS-based IGH/IGK clonality testing ought to be applicable to most Koreans with MM. The overrepresentation of IGHV3-9, IGHV4-31, and IGHD3-3 along with the underrepresentation of IGKV4-1 and the differences in IGK gene rearrangement types suggest the existence of ethnicity-specific variations in this disease.

Clinical insights into hematologic malignancies and comparative analysis of molecular signatures of acute myeloid leukemia in different ethnicities using an artificial intelligence offering.

ABSTRACT: Next generation sequencing generates copious amounts of genomics data, causing manual interpretation to be laborious and non-scalable while remaining subjective (even for highly trained specialists). We evaluated the performance of the artificial intelligence-based offering Watson for Genomics (WfG), a variant interpretation platform, in hematologic malignancies for the first time.Next generation sequencing was performed for patients treated for various hematological malignancies at Hallym University Sacred Heart Hospital, South Korea, between December 2017 and August 2020 using a 54-gene panel. Both WfG and expert manual curation were used to evaluate the performance of WfG. Acute myeloid leukemia (AML) molecular profiles were compared between Koreans and other ethnic groups using a publicly available dataset.Seventy-seven patients were analyzed (AML: 45, myeloproliferative neoplasms: 12, multiple myeloma: 7, myelodysplastic syndromes: 6, and others: 7). The concordance between the manual and WfG interpretations of 35 variants in 11 random patients was 94%. Among all patients, WfG identified 39 (51%) with at least 1 clinically actionable therapeutic alteration (i.e., a variant targeted by a United States Food and Drug Administration [US FDA]-approved drug, off-label drug, or clinical trial). Moreover, 46% of these patients (18/39) had genes that were targeted by a US FDA-approved therapy. WfG identified diagnostic or prognostic insights in 65% of the patients with no targetable alterations. In those with AML, FLT3-internal tandem duplications or tyrosine kinase domain mutations were less frequent among Koreans than among Caucasians (6.7% vs 30.2%, P < .001) or Hispanics (6.7% vs 28.3%, P = .005), suggesting ethnic differences.Variant interpretation using WfG correlated well with manually curated expert opinions. WfG provided therapeutic insights (including variant-specific drugs and clinical trials that cannot easily be provided by expert manual curation), as well as diagnostic and/or prognostic information.

A Rare Episode of Extensive Bone Marrow Necrosis in a Chemotherapy-naïve Patient with Multiple Myeloma Exhibiting TP53 and TET2 Mutations.

Bone marrow necrosis (BMN) is a rare life-threatening condition in which the marrow is replaced by necrotic material. Half of BMN occurrences are attributed to chemotherapy or granulocyte-colony stimulating factor treatment in patients with hematolymphoid malignancies. However, we present a patient diagnosed with both multiple myeloma and extensive BMN despite being treatment-naïve. Our patient exhibited a TP53 deletion, TET2 frameshift mutation, and a single TET2 nucleotide change. He is the third such patient reported, but the first to have his cytogenetic and molecular genetic profiles investigated using conventional cytogenetics, fluorescence in situ hybridization, and next-generation sequencing.