Improving the hepatitis C virus care cascade with the in-hospital Reflex tEsting ALarm-C (REAL-C) model.

BACKGROUND: The World Health Organization (WHO) has set targets to eliminate viral hepatitis, including hepatitis C virus (HCV) infection, by 2030. We present the results of the in-hospital Reflex tEsting ALarm-C (REAL-C) model, which incorporates reflex HCV RNA testing and sending alerts to physicians. METHODS: We conducted a retrospective study analysing the data of 1730 patients who newly tested positive for anti-HCV between March 2020 and June 2023. Three distinct periods were defined: pre-REAL-C (n = 696), incomplete REAL-C (n = 515) and complete REAL-C model periods (n = 519). The primary outcome measure was the HCV RNA testing rate throughout the study period. Additionally, we assessed the referral rate to the gastroenterology department, linkage time for diagnosis and treatment and the treatment rate. RESULTS: The rate of HCV RNA testing increased significantly from 51.0% (pre-REAL-C) to 95.6% (complete REAL-C). This improvement was consistent across clinical departments, regardless of patients' comorbidities. Among patients with confirmed HCV infection, the gastroenterology referral rate increased from 57.1% to 81.1% after the REAL-C model. The treatment rate among treatment-eligible patients was 92.4% during the study period. The mean interval from anti-HCV positivity to HCV RNA testing decreased from 45.1 to 1.9 days. The mean interval from the detection of anti-HCV positivity to direct-acting antiviral treatment also decreased from 89.5 to 49.5 days with the REAL-C model. CONCLUSION: The REAL-C model, featuring reflex testing and physician alerts, effectively increased HCV RNA testing rates and streamlined care cascades. Our model facilitated progress towards achieving WHO's elimination goals for HCV infection.

Trends in category and grade for therapeutic plasma exchange in the latest guideline on therapeutic apheresis by the American Society for Apheresis: Hurdles in pursuing evidence-based medicine.

BACKGROUND AND OBJECTIVES: The Writing Committee of American Society for Apheresis released the ninth edition of guidelines for therapeutic apheresis in 2023. Categories have been a part of the guidelines since the first edition, and the grading system was introduced in the fifth edition, with updates in every new edition. In this study, we investigated the category and grade change trends through the latest five editions, focusing on therapeutic plasma exchange, to suggest future directions as part of evidence-based medicine. MATERIALS AND METHODS: Categories and grades for therapeutic plasma exchange (TPE) were collected and analysed from the fifth through ninth editions. We aligned classification changes to the ninth edition's clinical context and compared its categories and grades with those introduced in the guideline. RESULTS: Among 166 total indications in the ninth edition, 118 included TPE procedure, either as a sole treatment or as one of the therapeutic apheresis techniques. The total number of indications changed, but Category III remained predominant throughout the editions. Similarly, Grade 2C consistently emerged as the most prevalent grade. Notably, 24 cases had grade changes. Of the 16 cases with evidence quality changes, the quality weakened in six and improved in 10. Evidence levels were not improved throughout the study period for 102 clinical conditions. CONCLUSION: To address gaps in evidence quality, international collaboration is imperative to establish comprehensive large-scale studies or randomized controlled trials. This will refine the use of therapeutic apheresis, including TPE, to foster evidence-based advancements in clinical practice.

Correlation between remnant thyroid gland I-131 uptake and serum thyroglobulin levels: can we rely on I-131 whole body scans?

BACKGROUND: I-131 treatment (RAI) decision relies heavily on serum thyroglobulin (Tg) levels, as higher Tg levels are assumed to be correlated with higher I-131 uptake. Tg elevation, negative iodine scintigraphy (TENIS) definition is becoming more clinically relevant as alternative treatment methods are available. This study examined the correlation between Tg levels with I-131 uptake in remnant thyroid gland to evaluate the reliability of serum Tg levels in predicting I-131 uptake. METHODS: From March 2012 to July 2019, 281 papillary thyroid cancer patients treated with 150 mCi RAI were retrospectively enrolled. Early (2nd day) and Delayed (7th day) post-RAI whole-body scan (WBS) neck counts were correlated with clinical and pathologic findings. Patients with normal neck ultrasound and undetectable level of serum Tg (< 0.2 ng/mL) and thyroglobulin antibody (TgAb) (< 10 IU/mL) were defined as ablation success within 2 years after I-131 ablation. RESULTS: Thyroid gland weight, tumor size and thyroiditis were independent factors of preoperative serum Tg levels. Serum off-Tg levels correlated with Early and Delayed WBS neck counts, and thyroiditis pathology contributed to lower neck counts in both Early and Delayed WBSs. In multivariable analysis, Delayed WBS neck count, serum off-Tg and off-TgAb were significant factors for predicting ablation success. CONCLUSION: I-131 uptake and retention in remnant thyroid gland correlates with serum off-Tg levels, thyroiditis, and ablation success in thyroid cancer patients receiving high-dose I-131 therapy. Semi-quantitative I-131 analysis with Early and Delayed WBSs provides additional information in evaluating ablation success, with the potential application for metastasis treatment response evaluation.

Lateral flow immunoassay based on surface-enhanced Raman scattering using pH-induced phage-templated hierarchical plasmonic assembly for point-of-care diagnosis of infectious disease.

The outbreak of emerging infectious diseases gave rise to the demand for reliable point-of-care testing methods to diagnose and manage those diseases in early onset. However, the current on-site testing methods including lateral flow immunoassay (LFIA) suffer from the inaccurate diagnostic result due to the low sensitivity. Herein, we present the surface-enhanced Raman scattering-based lateral flow immunoassay (SERS-LFIA) by introducing phage-templated hierarchical plasmonic assembly (PHPA) nanoprobes to diagnose a contagious disease. The PHPA was fabricated using gold nanoparticles (AuNPs) assembled on bacteriophage MS2, where inter-particle gap sizes can be adjusted by pH-induced morphological alteration of MS2 coat proteins to provide the maximum SERS amplification efficiency via plasmon coupling. The plasmonic probes based on the PHPA produce strong and reproducible SERS signal that leads to sensitive and reliable diagnostic results in SERS-LFIA. The developed SERS-LFIA targeting severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) antibodies for a proof of concept had <100 pg/mL detection limits with high specificity in serum, proving it as an effective diagnostic device for the infectious diseases. Clinical validation using human serum samples further confirmed that the PHPA-based SERS-LFIA can distinguish the patients with COVID-19 from healthy controls with significant accuracy. These outcomes prove that the developed SERS-LFIA biosensor can be an alternative point-of-care testing (POCT) method against the emerging infectious diseases, in combination with the commercially available portable Raman devices.

Current Status of Flow Cytometric Immunophenotyping of Hematolymphoid Neoplasms in Korea.

Background: Flow cytometric immunophenotyping of hematolymphoid neoplasms (FCI-HLN) is essential for diagnosis, classification, and minimal residual disease (MRD) monitoring. FCI-HLN is typically performed using in-house protocols, raising the need for standardization. Therefore, we surveyed the current status of FCI-HLN in Korea to obtain fundamental data for quality improvement and standardization. Methods: Eight university hospitals actively conducting FCI-HLN participated in our survey. We analyzed responses to a questionnaire that included inquiries regarding test items, reagent antibodies (RAs), fluorophores, sample amounts (SAs), reagent antibody amounts (RAAs), acquisition cell number (ACN), isotype control (IC) usage, positive/negative criteria, and reporting. Results: Most hospitals used acute HLN, chronic HLN, plasma cell neoplasm (PCN), and MRD panels. The numbers of RAs were heterogeneous, with a maximum of 32, 26, 12, 14, and 10 antibodies used for acute HLN, chronic HLN, PCN, ALL-MRD, and multiple myeloma-MRD, respectively. The number of fluorophores ranged from 4 to 10. RAs, SAs, RAAs, and ACN were diverse. Most hospitals used a positive criterion of 20%, whereas one used 10% for acute and chronic HLN panels. Five hospitals used ICs for the negative criterion. Positive/negative assignments, percentages, and general opinions were commonly reported. In MRD reporting, the limit of detection and lower limit of quantification were included. Conclusions: This is the first comprehensive study on the current status of FCI-HLN in Korea, confirming the high heterogeneity and complexity of FCI-HLN practices. Standardization of FCI-HLN is urgently needed. The findings provide a reference for establishing standard FCI-HLN guidelines.

Bio-conjugated nanoarchitectonics with dual-labeled nanoparticles for a colorimetric and fluorescent dual-mode serological lateral flow immunoassay sensor in detection of SARS-CoV-2 in clinical samples.

Serological detection of antibodies for diagnosing infectious diseases has advantages in facile diagnostic procedures, thereby contributing to controlling the spread of the pathogen, such as in the recent SARS-CoV-2 pandemic. Lateral flow immunoassay (LFIA) is a representative serological antibody detection method suitable for on-site applications but suffers from low clinical accuracy. To achieve a simple and rapid serological screening as well as the sensitive quantification of antibodies against SARS-CoV-2, a colorimetric and fluorescent dual-mode serological LFIA sensor incorporating metal-enhanced fluorescence (MEF) was developed. For the strong fluorescence signal amplification, fluorophore Cy3 was immobilized onto gold nanoparticles (AuNPs) with size-controllable spacer polyethyleneglycol (PEG) to maintain an optimal distance to induce MEF. The sensor detects the target IgG with a concentration as low as 1 ng mL-1 within 8 minutes. The employment of the MEF into the dual-mode serological LFIA sensor shows a 1000-fold sensitivity improvement compared with that of colorimetric LFIAs. The proposed serological LFIA sensor was tested with 73 clinical samples, showing sensitivity, specificity, and accuracy of 95%, 100%, and 97%, respectively. In conclusion, the dual-mode serological LFIA has great potential for application in diagnosis and an epidemiological survey of vaccine efficacy and immunity status of individuals.

Clinical significances and distribution of unexpected antibodies found in infants.

INTRODUCTION: The unexpected antibody test is an essential for ensuring the safety of blood transfusions. In infants, different pre-transfusion tests and transfusion strategies are needed due to their immature antigen/antibody system. This study aims to analyze the pattern of unexpected antibodies and their clinical significance in infants. METHODS: A retrospective analysis was conducted on the results of unexpected antibody identification tests performed on infants under one year of age at Asan Medical Center from 1999 to 2022. Patients' unexpected antibody identification test results and clinical information were investigated. The results of unexpected antibody identification and phenotype of each patient's mother were collected. RESULTS: 45 cases of antibody results were studied. 25 cases were found in infants under 4 months of age, and 18 cases (76%) were associated with hemolytic disease of the fetus and newborn (HDFN). The most common unexpected antibody in infants was anti-M (17 cases). There was one case of severe HDFN caused by anti-M. In 10 cases, anti-E and anti-c were found together, and 9 of these cases were associated with HDFN. There were four cases with a history of previous transfusion. CONCLUSIONS: Non-ABO antibodies found in infants showed a different pattern compared to adults. Interpreting unexpected antibody tests in infants, it is important to consider the clinical status of the infant and the test results of the mother, due to possibility of HDFN. To our knowledge, this is the first study to reveal the distribution and clinical significances of unexpected antibodies found in infants in Korea.

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.

Investigation of variables affecting the immunogenicity of blood group antigens using a calculation formula.

Previous studies on the immunogenicity of blood group antigens have utilized a formula incorporating antigen frequencies and relative frequencies of unexpected antibodies to the corresponding antigens. This study was aimed at investigating other variables potentially affecting the estimation of immunogenicity using this formula. We examined the effect of multiple transfusions, as there are more chance for a recipient to receive repeated transfusions rather than only once; the effect of antigen density, which may vary depending on homozygote/heterozygote; and the effect of unreliability of the observed frequency of rare antibodies and antigens. For multiple transfusions, the expected antibody frequency increased as the number of transfusions increased. For antigen density, the immunogenicity was falsely low for the low-prevalence antigen, and this tendency intensified as the effect of antigen density increased. Expected antibody frequencies were significantly affected by the uncertainties caused by estimation of small numbers. This study showed that the effects of various factors on the immunogenicity of blood group antigens depended on the antigen frequency. Estimating the immunogenicity of blood group antigens requires acknowledging the diverse factors that can affect it and interpreting the findings with caution.

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.

Transfusion thresholds: the need for a patient-centered approach in hematologic disorders that require chronic transfusion therapy.

Transfusion is an essential life-sustaining treatment for many patients. However, unnecessary transfusion has been reported to be related to worse patient outcomes. Further, owing to the recent pandemic, blood supply has been more challenging to maintain. Many studies have been conducted to elucidate the optimal transfusion threshold for many clinical conditions, and most suggested that a restrictive transfusion strategy has advantages over a liberal transfusion strategy. Hematologic disorders, which require chronic transfusion in many cases, have not been the main subjects of such studies, and only little evidence is available regarding the optimal transfusion threshold in these patients. According to several recent studies, a liberal transfusion strategy is preferable for patients with hematologic disorders due to their quality of life. A patient-centered approach is needed for proper management of hematologic disorders.

Relative immunogenicity of blood group antigens: First report in a Korean population.

BACKGROUND: The immunogenicity of a blood group antigen is a measure of its likelihood of inducing alloantibodies. Although the immunogenicity of blood group antigens has been analyzed in Caucasian populations, immunogenicity to date has not been analyzed in Asian subjects. The present study therefore evaluated the relative immunogenicity of blood group antigens in a Korean population. STUDY DESIGN AND METHODS: All available data of unexpected antibody identification tests performed at Asan Medical Center between 1997 and 2021 were analyzed. The relative immunogenicity of a blood group antigen relative to K antigen was calculated based on relative numbers of alloantibodies and the probabilities of antigen-negative recipients receiving antigen-positive RBC units. RESULTS: A total of 3898 antibody identification results were included, with 1632 (41.9 %) from male patients. The ranking of antigen immunogenicity was: E > c > e > C > K > Jk(a) > Lu(a) > S > Fy(a) > Fy(b) > Jk(b) > Di(b) > Di(a) in the total population and E > c > e > C > Jk(a) > Fy(a) > Fy(b) > S > K > Lu(a) > Jk(b) > Di(b) > Di(a) in male patients. DISCUSSION: The rank order of immunogenicity for blood group antigens in this study provides information about relative immunogenecity in Koreans. These findings also provide supporting evidence regarding antigen selection for extended antigen-matched transfusions in recipients of multiple transfusions.

Regional lymph node metastasis detected on preoperative CT and/or FDG-PET may predict early recurrence of pancreatic adenocarcinoma after curative resection.

The objective of this study was to evaluate the role of regional lymph node (LN) metastasis detected on preoperative CT and/or 18F-fluoro-2-deoxyglucose-positron emission tomography (FDG-PET) scans in the prediction of early tumor recurrence after curative surgical resection of pancreatic ductal adenocarcinoma (PDAC). This retrospective study included 137 patients who underwent upfront surgery with R0 resection of PDAC between 2013 and 2016. Regional LN metastasis was identified using two criteria: positive findings for regional LN metastasis on either preoperative CT or FDG-PET scans (LNOR), or on both preoperative CT and FDG-PET scans (LNAND). A total of 55 patients had early tumor recurrence within 12 months after curative resection. Univariable and multivariable Cox proportional hazard regression analysis showed that preoperative carbohydrate antigen 19-9 (CA19-9) levels, preoperative locally advanced status, and regional LN metastasis (both LNOR and LNAND criteria) were significant risk factors for early recurrence. Positive LNOR and LNAND showed significantly poorer recurrence-free survival compared to negative regional LN metastasis groups (p = 0.048 and p = 0.020, respectively). Compared with the LNAND criteria, the LNOR criteria provided higher sensitivity (22.4% vs. 15.5%, p = 0.046) and a higher negative predictive value (61.9% vs. 59.8%, p = 0.046). The LNOR definition provided more sensitive and accurate performance in diagnosing preoperative regional LN metastasis.

Nanoparticle-Based Visual Detection of Amplified DNA for Diagnosis of Hepatitis C Virus.

Rapid, simple, and inexpensive diagnostic point-of-care tests (POCTs) are essential for controlling infectious diseases in resource-limited settings. In this study, we developed a new detection system based on nanoparticle-DNA aggregation (STat aggregation of tagged DNA, STAT-DNA) to yield a visual change that can be easily detected by the naked eye. This simplified optical detection system was applied to detect hepatitis C virus (HCV). Reverse transcription-polymerase chain reaction (RT-PCR) was performed using primers labeled with biotin and digoxigenin. Streptavidin-coated magnetic particles (1 µm) and anti-digoxigenin antibody-coated polystyrene particles (250-350 nm) were added to form aggregates. The limit of detection (LoD) and analytical specificity were analyzed. The STAT-DNA results were compared with those of the standard real-time PCR assay using serum samples from 54 patients with hepatitis C. We achieved visualization of amplified DNA with the naked eye by adding nanoparticles to the PCR mixture without employing centrifugal force, probe addition, incubation, or dilution. The LoD of STAT-DNA was at least 101 IU/mL. STAT-DNA did not show cross-reactivity with eight viral pathogens. The detection using STAT-DNA was consistent with that using standard real-time PCR.

Enhanced Specificity in Loop-Mediated Isothermal Amplification with Poly(ethylene glycol)-Engrafted Graphene Oxide for Detection of Viral Genes.

Loop-mediated isothermal amplification (LAMP) is a nucleic acid amplification method that allows the simple, quick, and low-cost detection of various viral genes. LAMP assays are susceptible to generating non-specific amplicons, as high concentrations of DNA primers can give rise to primer dimerization and mismatched hybridizations, resulting in false-positive signals. Herein, we reported that poly(ethylene glycol)-engrafted nanosized graphene oxide (PEG-nGO) can significantly enhance the specificity of LAMP, owing to its ability to adsorb single-stranded DNA (ssDNA). By adsorbing surplus ssDNA primers, PEG-nGO minimizes the non-specific annealing of ssDNAs, including erroneous priming and primer dimerization, leading to the enhanced specificity of LAMP. The detection of complementary DNAs transcribed from the hepatitis C virus (HCV) RNA was performed by the PEG-nGO-based LAMP. We observed that the inclusion of PEG-nGO significantly enhances the specificity and sensitivity of the LAMP assay through the augmented difference in fluorescence signals between the target and non-target samples. The PEG-nGO-based LAMP assay greatly facilitates the detection of HCV-positive clinical samples, with superior precision to the conventional quantitative real-time PCR (RT-qPCR). Among the 20 clinical samples tested, all 10 HCV-positive samples are detected as positive in the PEG-nGO-based LAMP, while only 7 samples are detected as HCV-positive in the RT-qPCR. In addition, the PEG-nGO-based LAMP method significantly improves the detection precision for the false-positive decision by 1.75-fold as compared to the LAMP without PEG-nGO. Thus, PEG-nGO can significantly improve the performance of LAMP assays by facilitating the specific amplification of target DNA with a decrease in background signal.

A New Trial to Measure ABO Antibodies Using Complement-Dependent Cytotoxicity.

Background and objectives: The ABO antibody (Ab) titration tests are used in monitoring in ABO-incompatible (ABOi) solid organ transplantation (SOT). However, currently developed ABO Ab tests show Ab binding reactions. This study attempted to measure ABO Ab level using complement-dependent cytotoxicity (CDC). Materials and methods: We studied 93 blood group O serum samples from patients who underwent ABOi SOT from January 2019 to May 2021. Patients' sera were incubated with A1 or B cells and added to a human complement solution. Supernatants were collected after centrifugation, and free hemoglobin (Hb) was measured by spectrophotometry. We converted plasma Hb value to hemolysis (%), which were compared with ABO Ab titer. Results: We found a mild correlation between hemolysis and ABO Ab titers. In simple regression analysis, the correlation coefficients were within 0.3660−0.4968 (p < 0.0001) before transplantation. In multiple linear regression analysis, anti-A hemolysis (%) was higher in immunoglobulin M (IgM) (ß = 12.9) than in immunoglobulin G (IgG) (ß = −3.4) (R2 = 0.5216). Anti-B hemolysis was higher in IgM (ß = 8.7) than in IgG (ß = 0.0) (R2 = 0.5114). There was a large variation in hemolysis within the same Ab titer. Conclusions: CDC can be used in a new trial for ABO Ab measurement. Furthermore, IgM rather than IgG seems to play a significant role in vivo activity, consistent with previous knowledge. Thus, this study may help in the development of the ABO Ab titration supplement test for post-transplant treatment policy establishment and pre-transplant desensitization.