Current status of testing intervals for antiphospholipid syndrome testing: a 13-year retrospective national data analysis in South Korea

OBJECTIVE

To assess the appropriateness of laboratory testing intervals and antiphospholipid syndrome (APS) incidence.

METHODS

Between January 2010 and August 2022, insurance claims data of patients with disease codes for other thrombophilia (D68.6) and APS (V253) were retrieved in South Korea. Patients who received antiphospholipid antibody tests more than twice were classified as having suspected APS. The interval between the first 2 antiphospholipid antibody tests was evaluated in the patients with suspected APS. Patients with suspected APS who received anticoagulants for >180 days were classified as having APS.

RESULTS

Overall, 8656 patients were classified as having suspected APS. The testing interval for the first 2 tests in patients with suspected APS was <6 and <12 weeks in 11.1% and 20.6% of cases, respectively, in 2010, gradually increasing to 21.0% and 35.4%, respectively, in 2021. Subsequently, 4344 patients were classified as having APS, with 65.0% being female. Only 330 patients were diagnosed with APS in 2021, down from 436 in 2020.

CONCLUSION

This study showed a gradual increase in patients receiving antiphospholipid antibody testing with an inappropriate short-term interval, underscoring the need for laboratory stewardship to ensure an appropriate interval for APS testing.

Increased PD-1 expression of bone marrow T-cells in acute myeloid leukaemia patients after stem cell transplantation, and its association with overall survival

BACKGROUND

Immune checkpoints are involved in mechanisms by which tumours escape from the host immune system. Our aim was to evaluate acute myeloid leukaemia (AML) patients to determine expression levels of checkpoint molecules according to diagnosis and treatments, and to identify optimal candidates for checkpoint blockade.

METHODS

Bone marrow (BM) samples were obtained from 279 AML patients at different disease status and from 23 controls. Flow cytometric analyses of PD-1 and PD-L1/PD-L2 expression were performed.

RESULTS

Programmed death-1 (PD-1) expression levels on CD8+ T-cells at AML diagnosis were increased compared to controls. PD-L1 and PD-L2 expression levels on leukaemic cells at diagnosis were significantly higher in secondary AML than in de novo AML. PD-1 levels on CD8+ and CD4+ T-cells after allo-SCT were significantly higher than those at diagnosis and after CTx. PD-1 expression on CD8+ T-cells increased in the acute GVHD group than in the non-GVHD group. The overall survival of patients with high PD-1 expression on CD8+ T-cells was significantly shorter than that of patients with low PD-1 expression.

CONCLUSIONS

In conclusion, patients who underwent allo-SCT exhibited high PD-1 expression, suggesting that allo-SCT increases PD-1 expression on T-cells, and the patients with high PD-1 expression on CD8+ T-cells after allo-SCT showed the poor prognosis. For these patients, PD-1 blockade could be an immunotherapeutic strategy.

Automated sepsis detection with vancomycin- and allantoin-polydopamine magnetic nanoparticles

Rapid and accurate identification of the bacteria responsible for sepsis is paramount for effective patient care. Molecular diagnostic methods, such as polymerase chain reaction (PCR), encounter challenges in sepsis due to inhibitory compounds in the blood, necessitating their removal for precise analysis. In this study we present an innovative approach that utilizes vancomycin (Van) and allantoin (Al)-conjugated polydopamine (PDA)-coated magnetic nanoparticles (MNPs) for the rapid and automated enrichment of bacteria and their DNA extraction from blood without inducing clumping and aggregation of blood. Al/Van-PDA-MNPs, facilitated by IMS, eliminate the need for preliminary sample treatments, providing a swift and efficient method for bacterial concentration and DNA extraction within an hour. Employing Al/Van-PDA-MNPs within an automated framework has markedly improved our ability to pre-concentrate various Gram-negative and Gram-positive bacteria directly from blood samples. This advancement has effectively reduced the detection threshold to 102 colony-forming unit/mL by both PCR and quantitative PCR. The method's expedited processing time, combined with its precision, positions it as a feasible diagnostic tool for diverse healthcare settings, ranging from small clinics to large hospitals. Furthermore, the innovative application of nanoparticles for DNA extraction holds promising potential for advancing sepsis diagnostics, enabling earlier interventions and improving patient outcomes.

Validation of High-sensitivity Flow Cytometry for Reliable Immune Cell Analysis in Real-world Laboratory Settings

The adoption of high-sensitivity flow cytometry (HSFC) in routine laboratory settings has been slow owing to concerns regarding the reliability and reproducibility of results. Validation is an essential prerequisite for conducting assays, and implementing the CLSI guidelines has been confusing, primarily because many aspects are not yet established. We aimed to validate an HSFC protocol for detecting follicular helper T (Tfh) cells in a real-world laboratory environment. The analytical validity of the Tfh cell panel was ensured through rigorous testing, including evaluations of precision, stability, carryover, and sensitivity, following the CLSI H62 guidelines. We found that Tfh cells, present in very small numbers in the blood, could be sufficiently detected through HSFC, and concerns about the reliability and reproducibility of the results in real-world laboratories could be solved through systematic validation. Establishing the lower limit of quantification (LLOQ) is a critical step in HSFC evaluations. By selecting an appropriate sample, for example, collecting residual cells from CD4 isolation in our experiment and using them as low-level samples, the LLOQ could be accurately established. The strategic validation of flow cytometry panels can facilitate the adoption of HSFC in clinical laboratories, even with limited resources.

Development and Assessment of a Multi-Purpose Knowledge-Based Planning Model (RapidPlan) for Prostate Radiation

PURPOSE/OBJECTIVE(S)

RapidPlan (RP) is a knowledge-based planning (KBP) tool to improve plan quality, planning speed, and reduce inter-patient plan variability. For small to medium institutions, it is difficult to find sufficient patient numbers to configure a reliable KBP-RP model. This study aimed to build a multi-purpose KBP-RP model for prostate cancers.

MATERIALS/METHODS

A total of 124 prostate plans from 2018-2022 at our institution were selected to configure the initial RP model. After model training, outliers were removed. 77 patients were used for the final RP model. Three fine-tuned RP sub-models with different optimized constraints corresponding to prostate bed, prostate + seminal vesicles (SV), and prostate boost plans were generated. RP models were validated by comparing plan quality with the original manually optimized plans (MP). 54 independent plans were selected to validate the RP models. Validation included: dose to 99% and 2% of PTV (D99%, D2%), PTV conformity index (CI); for organs at risk (OARs), volume receiving >70Gy and >60Gy (V70Gy, V60Gy) to bladder and rectum, maximum dose (Dmax) to femur heads (FHs) and small bowel. Statistical t-test analysis was performed with a significance of p<0.05.

RESULTS

A total of 48/54 model-based plans were clinically approved after single RP optimization. 6/54 failed plans were prostate bed plans and were deemed acceptable after additional minor constraint adjustments. For PTV, D99%, D2%, and CI were comparable (p>0.05) to MP. Bladder and rectum V70Gy were comparable (p>0.05), and V60Gy were significantly lower to MP (p<0.05), with an average Dmean of 23.21±14.58Gy and 16.41±10.63Gy vs 26.36±16.89Gy and 18.24±12.81Gy for RP and MP. RP significantly reduced Dmax to FHs and small bowel (p<0.05), with average Dmax of 34.95±6.06Gy and 35.62±18.99Gy vs 36.81±7.05Gy and 38.14±17.81Gy, respectively.

CONCLUSION

Multi-purpose prostate RP model was configured and approved plans were generated after single optimization. Prostate RP plans had equivalent PTV coverage with better or comparable OAR constraints.

Effective and Practical Complete Blood Count Delta Check Method and Criteria for the Quality Control of Automated Hematology Analyzers

Background

Delta checks increase patient safety by identifying automated hematology analyzer errors. International standards and guidelines for the complete blood count (CBC) delta check method have not been established. We established an effective, practical CBC delta check method and criteria.

Methods

We assessed five delta check methods for nine CBC items (Hb, mean corpuscular volume, platelet count, white blood cell [WBC] count, and five-part WBC differential counts) using 219,804 blood samples from outpatients and inpatients collected over nine months. We adopted the best method and criteria and evaluated them using 42,652 CBC samples collected over two weeks with a new workflow algorithm for identifying test errors and corrections for Hb and platelet count.

Results

The median delta check time interval was 1 and 21 days for inpatients and outpatients (range, 1-20 and 1-222 days), respectively. We used delta values at 99.5% as delta check criteria; the criteria varied among the five methods and between outpatients and inpatients. The delta percent change (DPC)/reference range (RR) rate performed best as the delta check for CBC items. Using the new DPC/RR rate method, 1.7% of total test results exceeded the delta check criteria; the retesting and resampling rates were 0.5% and 0.001%, respectively.

Conclusions

We developed an effective, practical delta check method, including RRs and delta check time intervals, and delta check criteria for nine CBC items. The criteria differ between outpatients and inpatients. Using the new workflow algorithm, we can identify the causes of criterion exceedance and report correct test results.

Effect of changes in lymphocyte subsets at diagnosis in acute myeloid leukemia on prognosis: association with complete remission rates and relapse free survivals

We prospectively investigated whether the characteristics of lymphocyte subsets at diagnosis in acute myeloid leukemia (AML) patients are different from healthy controls and affect treatment outcomes. A total of 91 AML patients classified into 3 genetic risk subgroups (favorable/intermediate/poor) according to 2022 NCCN guidelines were enrolled. We measured lymphocyte subsets by flow cytometry with peripheral blood samples at diagnosis and compared results with healthy controls. Influences of lymphocyte subsets on complete remission (CR) rates and survivals were also evaluated. AML patients had significantly lower numbers and proportions of CD56dimCD16+ natural killer (NK) cells, central memory T cells, and regulatory T cells than healthy controls. Higher proportion of helper/inducer T cells, CD4+CD31+ naïve T cells, and decreased proportion of NK cells significantly increased CR rates in 65 non-promyelocytic leukemia patients (P = 0.034, 0.027, and 0.019, respectively), and it was also significant in multivariable analysis with age/risk adjusted (P = 0.014, 0.016, and 0.045, respectively). NK cells < 4.8% of lymphocytes demonstrated significantly shorter relapse free survivals (RFS) in both univariate and multivariate analyses with risk adjusted (P = 0.006 and 0.037, respectively). AML patients showed significant lower numbers of CD56dimCD16+ NK cells, central memory T cells, and regulatory T cells than healthy controls at diagnosis. Higher proportion of helper/inducer T cells and CD4+CD31+ naïve T cells and decreased proportion of NK cells at diagnosis were independent factor of increasing probability of CR, and proportion of NK cells < 4.8% at diagnosis had adverse impact in RFS.

Lupus anticoagulants as a prospective independent predictor in COVID-19 patients

OBJECTIVE

Lupus anticoagulant (LA) are commonly detected during SARS-CoV-2 infection. However, the relationship between LA and clinical significance is still unclear.

METHODS

A retrospective chart analysis was performed on COVID-19 patients who were tested for LA at our hospital from March 2020 to November 2021. We analyzed the patient's characteristics based on the result of the LA test. In addition, subgroup analysis performed the LA-positive group who had undergone serial LA tests.

RESULTS

A total of 219 COVID-19 patients were enrolled in the study, 148 patients (67.6%) were positive for LA test. The LA-positive group received more treatment of high flow nasal cannula (LA-positive 73.0%, LA-negative 57.7%, p = 0.024). The LA-positive group showed prolonged aPTT, higher levels of CRP and fibrinogen (all p's < 0.05). Among 148 LA-positive patients, 127 patients (86.5%) were found to be LA-positive within 10 days of SARS-CoV-2 positive, and LA-positive group confirmed a median time to LA loss of 10 days. However, there was a group that was negative for LA in the early stages of infection and became positive about 13 days later. A subgroup analysis showed that these patients had different characteristics due to their longer hospital stays and higher D-dimer levels.

CONCLUSIONS

In COVID-19 patients, LA is expected to be associated to disease severity. Since the clinical significance of LA is different depending on the onset time of LA positivity, the LA test is suggested to be done at diagnosis of SARS-CoV-2 infection, even if LA is negative, follow-up test should be considered within 10 days.

Evaluation of laboratory diagnostic tests for light-chain clonality and bone marrow findings in AL amyloidosis

Background

Light-chain amyloidosis (AL) is the most common form of systemic amyloidosis. This study aimed to evaluate the usefulness of laboratory tests for light-chain clonality and bone marrow (BM) findings in AL amyloidosis.

Methods

We retrospectively enrolled patients newly diagnosed with AL amyloidosis on pathological examination who underwent a BM biopsy. Laboratory test data for light-chain clonality were collected and compared. Amyloid deposits were identified with H&E, Congo red, and PAS stains.

Results

We reviewed 98 patients with AL amyloidosis. Light chain clonality (λ, 64 cases; κ, 34 cases) was detected by serum immunofixation electrophoresis (IFE) (63.3%), urine IFE (70.8%), serum protein electrophoresis (PEP) (44.9%), urine PEP (44.8%), serum free light chain (SFLC) ratio (79.5%), and BM immunohistochemistry (IHC) (85.7%). Flow cytometric (FCM) assay identified aberrant BM plasma cells in 92.9% of cases. BM amyloid deposits were identified in 35 of the 98 cases (35.7%); 71.4% (25/35) were Congo red-positive, and 100.0% (35/35) were PAS-positive.

Conclusion

Laboratory tests for detecting light-chain clonality in AL amyloidosis in order of sensitivity include FCM assay for aberrant plasma cells, IHC for light chains on BM biopsy or clot section, SFLC ratio, and serum and urine IFE. Congo red staining of BM samples remains an important tool for identifying amyloid deposits in BM. Periodic acid-Schiff (PAS) staining can be useful in diagnosing some cases of Congo red-negative amyloidosis.

The Impact of Communication Information on the Perceived Threat of COVID-19 and Stockpiling Intention

This article investigates the role of diverse nudging communication strategies on perceived threat and stockpiling intention. Across three studies, the authors examined the various effects of “nudging” on consumer behavior. Study 1 demonstrates that a commonly used picture has a stronger impact on perceived threat than a less frequently exposed picture regardless of its accuracy. Study 2 shows that the perceived threat of COVID-19, in terms of severe health consequences, is lower when using an indirect (vs. direct) explanation of the virus, as well as when reducing the amount of information about the virus. Study 3 investigates the impact of salient negative information and childhood socioeconomic status (SES). Findings reveal that negative information about deaths associated with the virus increases the level of perceived threat and stockpiling intention, especially among people of low childhood SES.

Natural Killer Cell Activity Test Helps to Suspect Aggressive Natural Killer Cell Leukemia - Diagnostic Challenge

Aggressive natural killer cell leukemia (ANKL) is a rare disease with an aggressive clinical course. We aimed to assess the clinicopathological characteristics of the difficult to diagnose ANKL. During ten years, nine patients with ANKL were diagnosed. All the patients exhibited aggressive clinical course and underwent the BM study to rule out lymphoma and hemophagocytic lymphohistiocytosis (HLH). BM examination showed varying degrees of infiltration of neoplastic cells, which were mainly positive for CD2, CD56, cytoplasmic CD3 and EBV in situ hybridization. Five BM aspirates showed histiocytic proliferation with active heomphagocytosis. Normal or increased NK cell activity test results were obtained from 3 patients who were available for testing. Four had multiple BM studies until diagnosis. An aggressive clinical course and positive EBV in situ hybridization, often with associated secondary HLH, should raise the suspicion of an ANKL. Conducting additional supplementary tests such as NK cell activity and NK cell proportion would be helpful for the diagnosis of ANKL.

Clinical implications and genetic features of clonal cytopenia of undetermined significance compared to lower-risk myelodysplastic syndrome

Clonal cytopenia of undetermined significance (CCUS) is characterized by persistent cytopenias with genetic aberrations, which do not meet the diagnostic criteria for myelodysplastic syndrome (MDS). We aimed to compare the clinical and genetic characteristics of CCUS with lower-risk MDS and identify patients with CCUS with a high risk of progression. We performed targeted sequencing of bone marrow (BM) samples from patients with idiopathic cytopenia of undetermined significance (ICUS) (n = 139) and MDS (n = 226). Overall survival (OS) of patients with CCUS (n = 78) was worse than non-clonal ICUS (n = 61) and superior to lower-risk MDS (n = 99). Patients with CCUS showed similar characteristics to those with lower-risk MDS, except for higher haemoglobin, lower BM cellularity, and less frequent SF3B1 mutations. Lower haemoglobin, DDX41 (biallelic germline and somatic), ETV6, and RUNX1 mutations were independent prognostic factors for worse OS. Lower haemoglobin and DDX41 mutations were also associated with lower progression-free survival. Patients with CCUS with high-risk features showed similar or worse OS than patients with lower-risk MDS. Our findings suggest that patients with CCUS having certain clinical or genetic features should be regarded and treated as lower-risk MDS despite lacking significant dysplasia or MDS-associated chromosomal abnormalities.

Clinical Application for Diagnosis of Myelodysplatic/Myeloproliferative Neoplasm with Ring Sideroblasts and Thrombocytosis

BACKGROUND

Myelodysplastic/myeloproliferative neoplasm with ring sideroblasts and thrombocytosis (MDS/ MPN-RS-T) was newly introduced as a full entity in the 2016 revision of the WHO classification. In this study, we investigated the morphologic, laboratory, and clinical features of MDS/MPN-RS-T.

METHODS

We reviewed the bone marrow and genetic studies of patients whose diagnoses were coded as "refractory anemia with ring sideroblasts (RARS)" or "MDS/MPN, unclassifiable" between January 2008 and April 2018.

RESULTS

A total of 8 cases fulfilled the criteria for a diagnosis of MDS/MPN-RS-T. All of them had no specific symptoms. Half of the cases had less than 450 × 109/L platelet counts by an automated hematology analyzer; however, all platelet counts exceeded 450 × 109/L when performed manually. JAK2 mutation tests were performed in 7 cases, and a heterozygous mutation was detected in 1 case. SF3B1 mutations were present in 3 of the 4 cases tested.

CONCLUSIONS

When RARS is suspected in patients without thrombocytopenia, manual platelet counts should be performed. For patients with suspected essential thrombocythemia, RS evaluation through careful observation of an iron-stained slide is crucial. Since the independent evaluation of RS was reflected in the revised classification, the ambiguous disease classification becomes clearer and more consistent.

Comparison of clinical and laboratory characteristics of nonsecretory multiple myeloma and secretory multiple myeloma in a tertiary care hospital

INTRODUCTION

Nonsecretory multiple myeloma (NSM) is a rare variant of multiple myeloma, accounting for approximately 1%-5% of all reported cases. We compared the characteristics of NSM and secretory multiple myeloma (SM).

METHODS

We examined clinical and laboratory characteristics of 17 patients diagnosed with NSM and 40 patients diagnosed with SM. NSM was diagnosed based on findings of bone marrow (BM) examination, serum-free light chain (sFLC) assay, flow cytometric (FCM) immunophenotyping, chromosomal analysis, and imaging studies.

RESULTS

No patient with NSM had hypercalcemia or renal insufficiency at diagnosis. Patients with NSM were less anemic (p < .05) but had higher lactate dehydrogenase levels (p < .05) than patients with SM. In addition, patients with NSM had a lower percentage of plasma cells in the BM, confirmed by manual differential count (p < .05) and FCM immunophenotyping (p < .05). The sFLC ratio in patients with NSM was abnormal (15/17, 88.2%) and was lower than that in patients with SM (p < .05). Risk stratification in Revised International Staging System revealed a low-risk tendency in patients with NSM (p = .235).

CONCLUSION

NSM patients showed different clinical and laboratory characteristics from SM patients. FCM immunophenotyping and sFLC assay particularly had differences between NSM patients and SM patients. Thus, they are essential for diagnosing NSM.

Remedying Airbnb COVID-19 disruption through tourism clusters and community resilience

Peer-to-peer (P2P) accommodation markets have been disrupted by the COVID-19 pandemic. However, little attention is paid to how to remedy the disruption in terms of P2P accommodation performance. This study empirically investigates the spatially heterogeneous COVID-19 disruptions in the Airbnb business and offers place-based remedying strategies through local resources, including tourism clusters and community resilience. Using real data on Airbnb operating performance and local resources in Florida, we employ spatial econometric models and visualization techniques to estimate the pandemic-disrupted Airbnb performance model. The results show that leisure and hospitality clusters and three resilience resources-social, community capital, and environmental-had spatially heterogeneous effects on Airbnb revenue and booking performance across Floridian counties during the pandemic. Furthermore, community resilience moderated the effect of tourism clusters on Airbnb performance across individual and subclustered counties. These findings enable P2P accommodation hosts and policymakers to adopt destination-specific remedying strategies to cope with the pandemic.

Microparticle-tagged image-based cell counting (ImmunoSpin) for CD4 + T cells

Affordable point-of-care (POC) CD4 + T lymphocyte counting techniques have been developed as alternatives to flow cytometry-based instruments caring for patients with human immunodeficiency virus (HIV)-1. However, POC CD4 enumeration technologies can be inaccurate. Here, we developed a microparticle-based visual detector of CD4 + T lymphocytes (ImmunoSpin) using microparticles conjugated with anti-CD4 antibodies, independent of microfluidic or fluorescence detection systems. Visual enumeration of CD4 + T cells under conventional light microscope was accurate compared to flow cytometry. Microparticle-tagged CD4 + T cells were well-recognized under a light microscope. ImmunoSpin showed very good precision (coefficients of variation of ImmunoSpin were ≤ 10%) and high correlation with clinical-grade flow cytometry for the enumeration of CD4 + T cells (y = 0.4232 + 0.9485 × for the %CD4 + T cell count, R² = 0.99). At thresholds of 200 and 350 cells/µL, there was no misclassification of the ImmunoSpin system compared to the reference flow cytometry. ImmunoSpin showed clear differential classification of CD4 + T lymphocytes from granulocytes and monocytes. Because non-fluorescence microparticle-tags and cytospin slides are used in ImmunoSpin, they can be applied to an automatic digital image analyzer. Slide preparation allows long-term storage, no analysis time limitations, and image transfer in remote areas.

Immune Checkpoint Programmed Cell Death Protein-1 (PD-1) Expression on Bone Marrow T Cell Subsets in Patients With Plasma Cell Myeloma

Background

Plasma cell myeloma (PCM) is caused by immune dysregulation. We evaluated the expression of immune checkpoint programmed cell death protein-1 (PD-1) on T cell subsets in PCM patients according to disease course and cytogenetic abnormalities. This study aimed to find a target group suitable for therapeutic use of PD-1 blockade in PCM.

Methods

A total of 188 bone marrow (BM) samples from 166 PCM patients and 32 controls were prospectively collected between May 2016 and May 2017. PD-1 expression on BM T cell subsets was measured using flow cytometry.

Results

At diagnosis, the median PD-1 expression on CD4⁺ T cells was 24.6%, which did not significantly differ from that in controls. After stem cell transplantation, PD-1 expression on CD4⁺ T cells was higher than that at diagnosis (P<0.001), regardless of residual disease. PD-1 expression on CD4⁺ T cells in patients with residual disease after chemotherapy was significantly higher than that at diagnosis (P=0.001) and after complete remission following chemotherapy (P=0.044). PD-1 expression on CD8⁺ T cells was higher in PCM patients with cytogenetic abnormalities, including monosomy 13, 1q gain, complex karyotype, and hypodiploidy.

Conclusions

PD-1 blockade might have therapeutic potential in refractory PCM patients after chemotherapy, especially in those with high- or intermediate-risk cytogenetic abnormalities.

Granulocytic and Monocytic Myeloid-Derived Suppressor Cells are Functionally and Prognostically Different in Patients with Chronic Myeloid Leukemia

Myeloid-derived suppressor cells (MDSCs) represent phenotypically heterogeneous populations that suppress tumor-specific T-cell responses. MDSCs are produced from myeloid precursors in emergent states and are increased in several hematologic malignancies. We evaluated the differences in the levels and prognostic significance of MDSCs according to the clinical status of chronic myeloid leukemia (CML). The percentages and numbers of granulocytic (g)MDSCs and monocytic (m)MDSCs in peripheral blood (PB) and bone marrow (BM) aspirates were determined by five-color flow cytometry (HLA-DR/CD11b/CD15/CD33/CD14). The median BM-gMDSC% and PB-gMDSC% of the CML group were lower than those of the complete hematologic response (CHR) and control groups (P<0.001). In the CHR group, patients with major molecular response (MMR) showed higher median BM-gMDSC% than those without MMR (P=0.039). Conversely, the PB-mMDSC number of the CML group was higher than those of the CHR and control groups (P<0.001). Patients with high PB-gMDSC number exhibited superior survival to those with low PB-gMDSC number (P=0.021), and patients with high PB-mMDSC% showed inferior survival to those with low PB-mMDSC%, but there was no statistical significance (P=0.182). Increased gMDSCs at CHR may reflect non-leukemic granulopoiesis, and a high number of PB-gMDSCs suggests better prognosis in CML. However, mMDSCs may be associated with malignant conditions and poor prognosis.

Hydrogel-Based Stamping Technology for Solution-Free Blood Cell Staining

An accurate microscopical analysis of blood smears requires a reproducible and convenient method of staining. Solution-based staining procedures can be cumbersome. Especially in low- and middle-income countries, the lack of skilled technicians and adequate laboratory facilities, as well as insufficient water and reagent quality, often become confounding factors. To overcome these obstacles, we developed a new cell staining method based on sequential stamping of agarose gel patches that contain eosin, methylene blue/oxidized methylene blue, Azure B, and buffer, respectively. Our method, termed "hydrogel staining", provides a simple, reproducible, solution-free, and inexpensive approach to stain blood cells. We have optimized incubation times to achieve the optimal transfer of dyes to fixed blood cells on a glass slide, with outcomes comparable to conventional solution-based methods for white blood cells and malaria-infected red blood cells. This hydrogel staining method does not require special skills to produce excellent quality stained blood film slides. The new method could enhance the accuracy of microscopical examination of blood smears, especially in resource-limited settings.

Measurement of axial phase difference of density fluctuations owing to spontaneously excited waves by using microwave reflectometer on GAMMA 10/PDX

In the GAMMA 10/PDX tandem mirror, plasma with strong ion-temperature anisotropy is produced by using the ion cyclotron range of frequency waves. This anisotropy of ion temperature causes several Alfvén-Ion-Cyclotron (AIC) waves to spontaneously excite in the frequency range just below the ion cyclotron frequency. In addition, difference-frequency (DF) waves are excited in the radial inner region of the plasma by wave-wave coupling among the AIC waves. The radial density profiles were measured at multi-axial positions using a frequency-modulation reflectometer with an axial array of microwave antennas, and an axial variation of the density was found to be significant. In addition, a relative phase difference of the DF wave between axially separated two points was first obtained by finely choosing the probing frequency of the reflectometers with a maximum coherence used as a measure, indicating that the DF wave is a propagating wave, while the pump AIC waves are standing waves in the axial region of measurement.

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.

Unique ethnic features of DDX41 mutations in patients with idiopathic cytopenia of undetermined significance, myelodysplastic syndrome, or acute myeloid leukemia

DDX41 mutations are associated with hematologic malignancies including myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML), but the incidence in idiopathic cytopenia of undetermined significance (ICUS) is unknown. We investigated the incidence, genetic characteristics, and clinical features of DDX41 mutations in Korean patients with ICUS, MDS, or AML. We performed targeted deep sequencing of 61 genes including DDX41 in 457 patients with ICUS (n=75), MDS (n=210), or AML (n=172). The germline DDX41 mutations with causality were identified in 28 (6.1%) patients, of whom 27 (96.4%) had somatic mutations in the other position of DDX41. Germline origins of the DDX41 mutations were confirmed in all of the 11 patients who performed germline-based testing. Of the germline DDX41 mutations, p.V152G (n=10) was most common, followed by p.Y259C (n=8), p.A500fs (n=6), and p.E7* (n=3). Compared with non-mutated patients, DDX41-mutated patients showed male predominance, old age, normal karyotype, low leukocyte count, and hypocellular marrow at diagnosis. Three of the 4 ICUS patients with germline DDX41 mutations progressed to MDS. DDX41 mutations in Korean patients showed a high incidence and distinct mutation patterns, in that p.V152G was a unique germline variant. ICUS harboring germline DDX41 mutations may be regarded as a hereditary myeloid neoplasm. Germline DDX41 mutations are not uncommon and should be explored when treating the patients with myeloid malignancies.

Incidence of subsequent osteoporotic fractures after distal radius fractures and mortality of the subsequent distal radius fractures: a retrospective analysis of claims data of the Korea National Health Insurance Service

A better understanding of the features of subsequent fractures after distal radius fracture (DRF) is important for the prevention of further osteoporotic fractures. This study found that the cumulative incidence of subsequent osteoporotic fractures in South Korea increased over time and that the mortality rates of subsequent DRFs were lower than those of first-time DRFs.

INTRODUCTION

We examined the incidence of osteoporotic fractures following distal radius fractures (DRFs) and the mortality rate after subsequent DRFs using claims data from the Korea National Health Insurance (KNHI) Service.

METHODS

We identified records for 41,417 patients with first-time DRFs in 2012. The occurrence of osteoporotic fractures of the spine, hip, wrist, and humerus at least 6 months after the index DRF was tracked through 2016. All fractures were identified by specific diagnosis and procedure codes. One-year mortality rates and standardized mortality ratios (SMRs) for initial and subsequent DRFs were calculated for all patients.

RESULTS

The 4-year cumulative incidence of all subsequent osteoporotic fractures was 14.74% (6105/41,417; 9.47% in men, 15.9% in women). The number of associated subsequent fractures was 2850 for the spine (46.68%), 2271 for the wrist (37.2%), 708 for the hip (11.6%), and 276 for the humerus (4.52%). The cumulative mortality rate 1 year after the first-time and subsequent DRF was 1.47% and 0.71%, respectively, and the overall SMR was 1.48 (95% CI: 1.37-1.61) and 0.71 (95% CI: 0.42-1.21), respectively.

CONCLUSION

The cumulative incidence of osteoporotic fractures following DRFs increased over the study period and was higher among women. The cumulative mortality rates and SMRs of subsequent DRFs were lower than those of first-time DRFs at the 1-year follow-up. Given the increasing incidence rate of DRFs, the incidence of subsequent osteoporotic fractures may also increase.

The 2020 revision of the guidelines for the management of myeloproliferative neoplasms

In 2016, the World Health Organization revised the diagnostic criteria for myeloproliferative neoplasms (MPNs) based on the discovery of disease-driving genetic aberrations and extensive analysis of the clinical characteristics of patients with MPNs. Recent studies have suggested that additional somatic mutations have a clinical impact on the prognosis of patients harboring these genetic abnormalities. Treatment strategies have also advanced with the introduction of JAK inhibitors, one of which has been approved for the treatment of patients with myelofibrosis and those with hydroxyurea-resistant or intolerant polycythemia vera. Recently developed drugs aim to elicit hematologic responses, as well as symptomatic and molecular responses, and the response criteria were refined accordingly. Based on these changes, we have revised the guidelines and present the diagnosis, treatment, and risk stratification of MPNs encountered in Korea.

The BTLA and PD-1 signaling pathways independently regulate the proliferation and cytotoxicity of human peripheral blood γδ T cells

Background

B‐ and T‐lymphocyte attenuator (BTLA) and programmed cell death‐1 (PD‐1) inhibit γδ T cell homeostasis and activation. This study aimed to determine whether BTLA and PD‐1 signaling pathways were convergent or independent in human peripheral blood γδ T cells. Herein we demonstrate that the signalings of BTLA and PD‐1 regulated proliferation and cytotoxicity of human γδ T cells, respectively.

Methods

Human peripheral blood γδ T cells were cultured with inactivated Jurkat cells in the presence of interleukin‐2 and zoledronate (Zol) for 14 days. Flow cytometry was performed to evaluate the phenotypes and functions of γδ T cells.

Results

The proliferation of the γδ T cells was increased when PBMCs were cocultured with inactivated herpes virus entry mediator (HVEM)^low Jurkat cells. The cytotoxicity of the expanded γδ T cells was not affected by coculture with inactivated HVEM^low Jurkat cells and was further increased in the presence of anti‐PD‐L1 mAb. These results suggest that the inactivation of the BTLA signaling pathway during expansion could help produce more γδ T cells without compromising γδ T cell function. The inhibition of BTLA or PD‐1 signaling repressed phosphorylation of the src homology region 2‐containing protein tyrosine phosphatase 2 and increased the phosphorylation of protein kinase B in γδ T cells. However, there were no synergistic or additive effects by a combination of BTLA and PD‐1 blockade.

Conclusion

These results suggest that BTLA signaling is crucial in regulating γδ T cell proliferation and function and that the BTLA and PD‐1 signaling pathways act independently on the proliferation and cytotoxicity of human peripheral γδ T cells.

Cardiometabolic risk prediction algorithms for young people with psychosis: a systematic review and exploratory analysis

OBJECTIVE

Cardiometabolic risk prediction algorithms are common in clinical practice. Young people with psychosis are at high risk for developing cardiometabolic disorders. We aimed to examine whether existing cardiometabolic risk prediction algorithms are suitable for young people with psychosis.

METHODS

We conducted a systematic review and narrative synthesis of studies reporting the development and validation of cardiometabolic risk prediction algorithms for general or psychiatric populations. Furthermore, we used data from 505 participants with or at risk of psychosis at age 18 years in the ALSPAC birth cohort, to explore the performance of three algorithms (QDiabetes, QRISK3 and PRIMROSE) highlighted as potentially suitable. We repeated analyses after artificially increasing participant age to the mean age of the original algorithm studies to examine the impact of age on predictive performance.

RESULTS

We screened 7820 results, including 110 studies. All algorithms were developed in relatively older participants, and most were at high risk of bias. Three studies (QDiabetes, QRISK3 and PRIMROSE) featured psychiatric predictors. Age was more strongly weighted than other risk factors in each algorithm. In our exploratory analysis, calibration plots for all three algorithms implied a consistent systematic underprediction of cardiometabolic risk in the younger sample. After increasing participant age, calibration plots were markedly improved.

CONCLUSION

Existing cardiometabolic risk prediction algorithms cannot be recommended for young people with or at risk of psychosis. Existing algorithms may underpredict risk in young people, even in the face of other high-risk features. Recalibration of existing algorithms or a new tailored algorithm for the population is required.

Differences in PD-1 expression on CD8+ T-cells in chronic myeloid leukemia patients according to disease phase and TKI medication

Malignant cells can increase in number using immune escape mechanisms such as immune checkpoints. In this study, we evaluated the expression of an immune checkpoint programmed death 1 (PD-1) on T-cell subsets in chronic myeloid leukemia (CML). We obtained bone marrow aspirate samples from CML patients and from individuals without evidence of hematologic malignancies (controls). PD-1 expression on T-cell subsets was measured using flow cytometric analysis. PD-1 expression levels on CD8+ T-cells were significantly lower in complete hematologic response (CHR) than in controls, chronic phase, and blast phase (BP). In CML patients receiving imatinib and dasatinib, PD-1 expression levels on CD8+ T-cells were lower than that at diagnosis. PD-1 expression levels on CD8+ T-cells were positively correlated with quantitative levels of the BCR/ABL fusion gene. PD-1 expression levels on CD4+ T-cells were higher in BP than in CHR. PD-1 expression levels on CD4+ T-cells did not differ significantly according to different medications or quantitative BCR/ABL1 fusion gene levels. Low PD-1 expression on CD8+ T-cells might play a role in maintaining CHR in CML patients. Immune monitoring of PD-1 expression on CD8+ T-cells may predict the disease course. In cases of refractory disease or resistance to imatinib or dasatinib, the use of PD-1 inhibitors would be helpful.

Clinical, Laboratory, and Bone Marrow Findings of 31 Patients With Waldenström Macroglobulinemia

Background

Waldenström macroglobulinemia (WM) is a subset of lymphoplasmacytic lymphoma (LPL) with bone marrow (BM) involvement and an IgM monoclonal gammopathy of any level. We aimed to identify the clinical, laboratory, and BM findings of patients with WM and to evaluate the usefulness of CD154 for the diagnosis and prognosis of WM.

Methods

We reviewed the medical records and BM studies and/or flow cytometric immunotyping of 31 patients with untreated WM. Semiquantitative immunohistochemistry (CD20, CD138, tryptase, and CD154) of BM was performed.

Results

Only six patients presented with symptoms of hyperviscosity syndrome. Eleven patients had solid cancer and/or another hematologic malignancy. Mast cells (MC) increased in all samples, with some in close contact with tumor cells. Tryptase-positive MC (17.1/ high-power fields [HPF], 1.2–72.0/HPF) and CD154-positive MC (8.6/HPF, 0.1–31.1/HPF) were observed. The high CD154-positive MC (≥8.6/HPF) group showed a lower overall five-year survival rate than the low CD154-positive MC (<8.6/HPF) group (71.9% vs. 100.0%; P=0.012). Flow cytometric immunophenotyping of BM aspirates showed increased B lymphocytes and plasma cells with a normal phenotype (CD138⁺/CD38⁺/CD19⁺/CD45⁺/CD56⁻).

Conclusions

Approximately one third of WM patients showed other malignancies and all patients had increased MC. Immunohistochemistry and flow cytometric immunophenotyping are useful for diagnosing WM, and increased CD154-positive MC can indicate poor prognosis.