Current Status of Flow Cytometric Immunophenotyping of Hematolymphoid Neoplasms in Korea

Background@#Flow cytometric immunophenotyping of hematolymphoid neoplasms (FCIHLN) 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, positiveegative 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. Positiveegative 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.

Realistic Estimation of COVID-19Infection by Seroprevalence Surveillance of SARS-CoV-2Antibodies: An Experience From Korea Metropolitan Area From January to May 2022

Background@#Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally, leading to the coronavirus disease 2019 (COVID-19) pandemic. Because a significant proportion of the COVID-19 confirmed cases were concentrated in the capital metropolitan area of South Korea, and a large proportion of the population in the area had been adequately vaccinated against COVID-19, we conducted a seroprevalence surveillance study focusing on the residents of the capital metropolitan area in South Korea. @*Methods@#We used a quota-sampling method to obtain blood samples from 1,000 individuals per round, equally stratified across seven age categories and sexes and regions, from five medical institutions located within the capital metropolitan area of South Korea. During five consecutive months (rounds) between January 2022 and May 2022, a total of 5,000 samples were analyzed for anti-spike (S) and anti-nucleocapsid (N) antibodies. @*Results@#High anti-S seropositivity was observed in all age groups, which corresponded to the vaccine coverage during the study period. Both the cumulative incidence based on polymerase chain reaction (PCR) and the estimated seroprevalence based on anti-N seropositivity increased in the fourth and fifth rounds, which corresponded to April 2022 and May 2022. Seroprevalence coincided with the cumulative incidence during the first three rounds, but exceeded from the fourth survey onwards when infection with omicron variants was increased rapidly in Korea. @*Conclusion@#Seroprevalence confirmed the number of infection cases outside of PCR testing-based surveillance. Seroepidemiological surveillance can help us understand vaccine responses and detect hidden infections, thereby providing appropriate public health guidance for achieving population-level immunity.

Analysis of Antibody Responses After COVID-19 Vaccination in Liver Transplant Recipients: A SingleCenter Study

Background@#Liver transplant (LT) recipients were considered a vulnerable population during the coronavirus disease 2019 (COVID-19) pandemic. The clinical efficacy of the COVID-19 vaccine is unknown in immunocompromised patients. The purpose of this study was to provide evidence of antibody responses after COVID-19 vaccination in LT recipients. @*Methods@#This study enrolled 46 patients who underwent LT at Samsung Medical Center (Seoul, Korea) before implementation of the one-dose vaccine in Korea. Those who completed the two-dose COVID-19 vaccine between August 2021 and September 2021 were included and followed through December 2021. Semiquantitative anti-spike serologic testing was performed using the Roche Elecsys anti-SARS-CoV-2 S enzyme immunoassay (Roche Diagnostics, Rotkereuz, Switzerland) with a positive cutoff of at least 0.8 U/mL. @*Results@#Among all 46 participants, 40 (87%) demonstrated an antibody response after the second dose of a COVID-19 vaccine, while six (13%) had no antibody response after the second dose. Upon univariate analysis, patients with higher antibody titer had longer years since LT (2.3 ± 2.8 vs. 9.4 ± 5.0, P < 0.001). A lower median tacrolimus (TAC) level before vaccination and after the second dose of COVID-19 vaccine indicated a significantly higher antibody response (2.3 [1.6–3.2] vs. 7.0 [3.7–7.8], P = 0.006, 2.5 [1.6–3.3] vs. 5.7 [4.2–7.2], P = 0.003). Period between 2nd vaccination and serologic testing was significantly higher in the antibody-response group compared to the no-antibody-response group (30.2 ± 24.0 vs. 65.9 ± 35.0, P = 0.012). A multivariate analysis of antibody responses revealed TAC level before vaccination as a statistically significant factor. @*Conclusion@#A higher TAC level before vaccination resulted in less effective vaccination in LT patients. Booster vaccinations are required, especially for patients in the early stage after LT who have compromised immune function.

Clinical Utility of Sero-Immunological Responses Against SARS-CoV-2Nucleocapsid Protein During Subsequent Prevalence of Wild-Type, Delta Variant, and Omicron Variant

As nucleocapsid protein of severe acute respiratory syndrome coronavirus 2 is immunogenic but not targeted in vaccines, it could be useful in distinguishing natural infection from vaccination. We aimed to investigate the clinical utility of sero-immunological responses against the nucleocapsid protein. Nucleocapsid antibody immunoassay study with 302 coronavirus disease 2019 (COVID-19) patients showed lower titers in immunocompromised patients (P < 0.001), higher titers in higher severity (P = 0.031), and different seroconversion rates and titers according to variants of concern. Longitudinal evaluation of nucleocapsid antibodies using 513 samples from 291 COVID-19 patients revealed that it could persist up to 556 days from symptom onset. Interferon gamma release assay against the nucleocapsid protein showed poor response, precluding the deduction of a cut-off for the nucleocapsid protein. In conclusion, nucleocapsid antibody provides instructive clues about the immunogenicity of nucleocapsid proteins by different seroconversion rates and titers according to the severity of infection, host immune status, and different variants of concern.

Reducing Microbial Contamination in Hematopoietic Stem Cell Products and Quality Improvement Strategy: Retrospective Analysis of 1996-2021 Data

Background@#Sterility and safety assurance of hematopoietic stem cell (HSC) products is critical in transplantation. Microbial contamination can lead to product disposal and increases the risk of unsuccessful clinical outcomes. Therefore, it is important to implement and maintain good practice guidelines and regulations for the HSC collection and processing unit in each hospital. We aimed to share our experiences and suggest strategies to improve the quality assurance of HSC processing. @*Methods@#We retrospectively analyzed microbial culture results of 11,743 HSC products processed over a 25-year period (January 1996 to May 2021). Because of reorganization of the HSC management system in 2008, the 25-year period was divided into periods 1 (January 1996 to December 2007) and 2 (January 2008 to May 2021). We reviewed all culture results of the HSC products and stored aliquot samples and collected culture results for peripheral blood and catheter samples. @*Results@#Of the 11,743 products in total, 35 (0.3%) were contaminated by microorganisms, including 19 (0.5%) of 3,861 products during period 1 and 16 (0.2%) of 7,882 products during period 2. Penicillium was the most commonly identified microorganism (15.8%) during period 1 and coagulase-negative Staphylococcus was the most commonly identified (31.3%) during period 2. HSC product contamination occurred most often during HSC collection and processing. @*Conclusions@#The contamination rate decreased significantly during period 2, when the HSC management system was reorganized. Our results imply that handling HSC products by trained personnel and adopting established protocols, including quality assurance programs, aid in decreasing the contamination risk.

Daratumumab-Induced Interference in Flow-Cytometry Crossmatch and Resolving It by DTT Treatment / 대한수혈학회지

Background@#Daratumumab is a human monoclonal antibody targeting CD38 used widely in various related conditions. Caution is advised when interpreting the pretransfusion tests in daratumumab-treated patients because they may show nonspecific reactions with red blood cells. This paper provides experimental evidence for the false-positive interference phenomena induced by daratumumab in in-vitro and ex-vivo experiments and experimental support for resolving it using dithiothreitol (DTT). @*Methods@#Fifteen crossmatching pairs, four cardiac amyloidosis (CA) patients treated with daratumumab, and three healthy individuals were included. The flow cytometry crossmatch (FCMXM) was conducted with negatively selected T and B cells. After spiking the sera with 500 μg/mL daratumumab, the T and B cells were treated with DTT. The prospective FCMXM was conducted with the sera of CA patients treated with daratumumab. The CD38 expression levels in T, B, and NK cells were measured without and with a DTT or pronase treatment. @*Results@#Five hundred μg/mL of daratumumab spiking was sufficient to elicit a false positive effect in T cell FCMXM. In particular, the administration of 0.1 M DTT efficiently resolved the induced false positivity in flow cytometry. Moreover, DTT caused a decrease in the CD38 expression levels in T, B, and NK cells. @*Conclusion@#A typical therapeutic dose of daratumumab causes false-positive FCMXM, which was effectively addressed by a DTT treatment. Therefore, information about the patient’s medical condition and the use of immunotherapeutics, such as daratumumab, is needed, given its impact on diverse CD38-expressing cells.

Severity-Adjusted Dexamethasone Dosing and Tocilizumab Combination for Severe COVID-19

Purpose@#Real-world experience with tocilizumab in combination with dexamethasone in patients with severe coronavirus disease (COVID-19) needs to be investigated. @*Materials and Methods@#A retrospective cohort study was conducted to evaluate the effect of severity-adjusted dosing of dexamethasone in combination with tocilizumab for severe COVID-19 from August 2020 to August 2021. The primary endpoint was 30-day clinical recovery, which was defined as no oxygen requirement or referral after recovery. @*Results@#A total of 66 patients were evaluated, including 33 patients in the dexamethasone (Dexa) group and 33 patients in the dexamethasone plus tocilizumab (DexaToci) group. The DexaToci group showed a statistically significant benefit in 30-day clinical recovery, compared to the Dexa group (p=0.024). In multivariable analyses, peak FiO2 within 3 days and tocilizumab combination were consistently significant for 30-day recovery (all p<0.05). The DexaToci group showed a significantly steeper decrease in FiO2 (-4.2±2.6) than the Dexa group (−2.7±2.6; p=0.021) by hospital day 15. The duration of oxygen requirement was significantly shorter in the DexaToci group than the Dexa group (median, 10.0 days vs. 17.0 days; p=0.006). Infectious complications and cellular and humoral immune responses against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the convalescence stage were not different between the two groups. @*Conclusion@#A combination of severity-adjusted dexamethasone and tocilizumab for the treatment of severe COVID-19 improved clinical recovery without increasing infectious complications or hindering the immune response against SARS-CoV-2.

Anti-Saccharomyces cerevisiae Antibody in Pediatric Crohn’s Disease Patients without Mucosal Healing Is a Useful Marker of Mucosal Damage

Background/Aims@#We evaluated whether anti-Saccharomyces cerevisiae antibody (ASCA) titers are associated with diagnostic findings, disease activity, Paris classification phenotypes, and persistence after infliximab (IFX) treatment in children with Crohn’s disease (CD). We also investigated the role of ASCA as a predictor of mucosal healing (MH) and clinical remission (CR). @*Methods@#This study included 61 CD patients aged 19 years or younger who were diagnosed and treated between September 2010 and January 2019 and followed for at least 1 year. ASCA was regularly measured at the diagnosis of CD and at least 1 year after IFX therapy. @*Results@#The average follow-up period was 3.8±3.4 years (range, 1.0 to 7.2 years). Regression analysis showed that the ASCA titer was the only factor associated with Simple Endoscopic Score for Crohn's Disease (SES-CD) or CR among all the parameters. In patients who had achieved MH (SES-CD=0), ASCA immunoglobulin G (IgG) was not associated with MH, but in patients without MH, ASCA IgG was associated with SES-CD (p=0.005) and CR (p<0.001). The cutoff value of ASCA IgG in patients with CR was 21.8 units. However, there was no difference in the relapse rate between the ASCA IgG-positive and -negative groups during the follow-up period. @*Conclusions@#In patients who have not achieved MH, ASCA IgG is closely related to mucosal damage and CR. Unlike Western studies, ASCA IgG may be more helpful in predicting prognosis than immunoglobulin A in Korean patients, but it is not an appropriate indicator to predict the relapse of CD.

Anti-Saccharomyces cerevisiae Antibody in Pediatric Crohn’s Disease Patients without Mucosal Healing Is a Useful Marker of Mucosal Damage

Background/Aims@#We evaluated whether anti-Saccharomyces cerevisiae antibody (ASCA) titers are associated with diagnostic findings, disease activity, Paris classification phenotypes, and persistence after infliximab (IFX) treatment in children with Crohn’s disease (CD). We also investigated the role of ASCA as a predictor of mucosal healing (MH) and clinical remission (CR). @*Methods@#This study included 61 CD patients aged 19 years or younger who were diagnosed and treated between September 2010 and January 2019 and followed for at least 1 year. ASCA was regularly measured at the diagnosis of CD and at least 1 year after IFX therapy. @*Results@#The average follow-up period was 3.8±3.4 years (range, 1.0 to 7.2 years). Regression analysis showed that the ASCA titer was the only factor associated with Simple Endoscopic Score for Crohn's Disease (SES-CD) or CR among all the parameters. In patients who had achieved MH (SES-CD=0), ASCA immunoglobulin G (IgG) was not associated with MH, but in patients without MH, ASCA IgG was associated with SES-CD (p=0.005) and CR (p<0.001). The cutoff value of ASCA IgG in patients with CR was 21.8 units. However, there was no difference in the relapse rate between the ASCA IgG-positive and -negative groups during the follow-up period. @*Conclusions@#In patients who have not achieved MH, ASCA IgG is closely related to mucosal damage and CR. Unlike Western studies, ASCA IgG may be more helpful in predicting prognosis than immunoglobulin A in Korean patients, but it is not an appropriate indicator to predict the relapse of CD.

Relationship of Circulating Cytomegalovirus Levels Obtained Through Antigenemia Testing and Quantitative PCR Differs Between Children and Adults

No abstract available.

Pre-Transplant Angiotensin II Type 1 Receptor Antibodies and Anti-Endothelial Cell Antibodies Predict Graft Function and Allograft Rejection in a Low-Risk Kidney Transplantation Setting

Background@#Non-HLA antibodies, anti-angiotensin II type 1 receptor antibodies (anti-AT1R) and anti-endothelial cell antibodies (AECA), are known to play a role in allograft rejection. We evaluated the role of both antibodies in predicting post-transplant outcomes in low-risk living donor kidney transplantation (LDKT) recipients. @*Methods@#In 94 consecutive LDKT recipients who were ABO compatible and negative for pre-transplant HLA donor-specific antibodies, we determined the levels of anti-AT1Rs using an enzyme-linked immunosorbent assay and the presence of AECAs using a flow cytometric endothelial cell crossmatch (ECXM) assay with pre-transplant sera. Hazard ratio (HR) was calculated to predict post-transplant outcomes. @*Results@#Pre-transplant anti-AT1Rs (≥11.5 U/mL) and AECAs were observed in 36 (38.3%) and 22 recipients (23.4%), respectively; 11 recipients had both. Pre-transplant anti-AT1Rs were a significant risk factor for the development of acute rejection (AR) (HR 2.09; P=0.018), while a positive AECA status was associated with AR or microvascular inflammation only (HR 2.47; P=0.004) throughout the follow-up period. In particular, AECA (+) recipients with ≥11.5 U/mL anti-AT1Rs exhibited a significant effect on creatinine and estimated glomerular filtration rate (P<0.001; P=0.028), although the risk of AR was not significant. @*Conclusions@#Pre-transplant anti-AT1Rs and AECAs have independent negative effects on post-transplant outcomes in low-risk LDKT recipients. Assessment of both antibodies would be helpful in stratifying the pre-transplant immunological risk, even in low-risk LDKT recipients.

Flow Cytometry for the Diagnosis of Primary Immunodeficiency Diseases: A Single Center Experience

PURPOSE: While there is an urgent need for diagnosis and therapeutic intervention in patients with primary immunodeficiency diseases (PIDs), current genetic tests have drawbacks. We retrospectively reviewed the usefulness of flow cytometry (FCM) as a quick tool for immunophenotyping and functional assays in patients suspected to have PIDs at a single tertiary care institute.METHODS: Between January 2001 and June 2018, patients suspected of having PIDs were subjected to FCM tests, including lymphocyte subset analysis, detection of surface- or intracellular-target proteins, and functional analysis of immune cells, at Samsung Medical Center, Seoul, Korea. The genetic diagnosis was performed using Sanger or diagnostic exome sequencing.RESULTS: Of 60 patients diagnosed with definite or probable PID according to the European Society of Immune Deficiencies criteria, 24 patients were provided with useful information about immunological dysfunction after initial FCM testing. In 10 patients, the PID diagnosis was based on abnormal findings in FCM testing without genetic tests. The FCM findings provided strong evidence for the diagnosis of severe combined immunodeficiency (n = 6), X-linked chronic granulomatous diseases (CGD) (n = 6), leukocyte adhesion deficiency type 1 (n = 3), X-linked agammaglobulinemia (n = 11), autoimmune lymphoproliferative syndrome-FASLG (n = 1), and familial hemophagocytic lymphohistiocytosis type 2 (n = 1), and probable evidence for autosomal recessive-CGD (n = 2), autosomal dominant-hyper-immunoglobulin E (IgE)-syndrome (n = 1), and STAT1 gain-of-function mutation (n = 1). In PIDs derived from PIK3CD (n = 2), LRBA (n = 2), and CTLA4 mutations (n = 3), the FCM test provided useful evidence of immune abnormalities and a tool for treatment monitoring.CONCLUSIONS: The initial application of FCM, particularly with known protein targets on immune cells, would facilitate the timely diagnosis of PIDs and thus would support clinical decisions and improve the clinical outcome.

Performance Evaluation and Clinical Usefulness of α-fetoprotein Test Measured on Sysmex HISCL-5000

Successful Sirolimus Treatment for Korean Patients with Activated Phosphoinositide 3-kinase δ Syndrome 1: the First Case Series in Korea

Activated phosphoinositide 3-kinase δ syndrome (APDS)1 is caused by gain-of-function mutations in PIK3CD, which encodes the catalytic p110δ subunit of phosphoinositide 3 kinase. We describe three patients with APDS1, the first thereof in Korea. Therein, we investigated clinical manifestations of APDS1 and collected data on the efficacy and safety profile of sirolimus, a mammalian target of rapamycin inhibitor and pathway-specific targeted medicine. The same heterozygous PIK3CD mutation was detected in all three patients (E1021K). After genetic diagnosis, all patients received sirolimus and experienced an excellent response, including amelioration of lymphoproliferation and improvement of nodular mucosal lymphoid hyperplasia in the gastrointestinal tract. The median trough level of sirolimus was 5.5 ng/mL (range, 2.8–7.5) at a dose of 2.6–3.6 mg/m2. Two patients who needed highdose, short-interval, immunoglobulin-replacement treatment (IGRT) had a reduced requirement for IGRT after initiating sirolimus, and the dosing interval was extended from 2 and 3 weeks to 4 weeks. The IgG trough level after sirolimus treatment (median, 594 mg/dL; range, 332–799 mg/dL) was significantly higher than that before sirolimus treatment (median, 290 mg/dL; range, 163–346 mg/dL) (p<0.001). One episode of elevated serum creatinine with a surge of sirolimus (Patient 2) and episodes of neutropenia and oral stomatitis (Patient 1) were observed. We diagnosed the first three patients with APDS1 in Korea. Low-dose sirolimus may alleviate clinical manifestations thereof, including hypogammaglobulinemia.

Hematopoietic Stem Cell Registry Report: 2018 / 대한수혈학회지

Background@#Hematopoietic stem cell (HSC) transplantation is an important therapeutic option for many malignant and non-malignant diseases. The whole transplant process involves multiple areas and complex steps. The laboratory procedures include the collection, processing, and storage of HSC. The HSC registry aims to identify the current situation and draw improvement points by voluntarily registering the information of an HSC graft collected by each institute sharing the analyzed data. This study analyzed and shared the data for 2018. @*Methods@#Data for 2018 registered at the HSC registry website (www.ksfa-registry.org) was downloaded and analyzed. The data were to enter the information of each collection and include the demography of the donors, transplant type, instrument, vascular access, mobilization modality, and the number of CD34＋ cells. @*Results@#Two thousand eight hundred eighty-eight collection datasets from 1,373 donors were registered from 19 institutes, which was slightly higher than that reported in 2017. The number of collections in one patient was in the range of 1∼17 times, and the average was two times. In allogeneic HSCT, the number of related donors was higher than that of unrelated donors. The frequency of collecting more than four times per donor was 25.2% for autologous donors, compared to 95.4% for allogeneic donors less than twice. @*Conclusion@#The HSC registry is not limited to identifying the current situation and sharing the analyzed data, but is expected to contribute to the development of guidelines, education of human resources, and the standardization of laboratory procedures involved in hematopoietic stem cell transplantation.

Analysis of the Change in Seropositive Rate of the Epstein-Barr Virus in Koreans: A Single-Center Study

Purpose@#Epstein-Barr virus (EBV) infection is related to infectious mononucleosis or nasopharyngeal cancer, and its epidemiology may change according to the socioeconomic development of communities. This study aimed to evaluate the recent epidemiology of EBV seropositive rate in Korea. @*Methods@#We retrospectively reviewed EBV serology test results obtained from a part of clinical care at Samsung Medical Center, Seoul, South Korea, from January 2000 to December 2017. @*Results@#The EBV seropositive rate in 26,527 subjects during the study period was 81.0% (21,485/26,527): 44.4% (2,716/6,122) in subjects aged 0–9 years, 75.8% (2,077/2,739) in those aged 10–19 years, and 94.5% (16,692/17,666) in those aged ≥20 years. The EBV seropositive rate decreased from 89.4% (8,592/9,616) in 2000–2008 to 76.2% (12,893/16,911) in 2009– 2017 (P<0.001). Especially, the EBV seropositive rate in subjects aged 0–19 years significantly decreased from 2000–2008 to 2009–2017 (0–9 years, 62.8% [1,172/1,866] in 2000–2008 and 36.3% [1,544/4,256] in 2009–2017; 10–19 years, 83.8% [745/858] in 2000–2008 and 70.8% (1,332/1,881) in 2009–2017) (P<0.001). @*Conclusions@#The EBV seropositive rate in children has decreased in the last 20 years. As the age of patients with primary EBV infection increased, there is a need for interest in clinical manifestation, such as infectious mononucleosis, in adolescents and young adults.

The Usefulness of Flow Cytometry for Measuring Phosphorylated Signal Transducer and Activator of Transcription 1 to Diagnose and Manage Chronic Mucocutaneous Candidiasis: A Case Report

Autosomal dominant chronic mucocutaneous candidiasis (AD-CMC) is a subtype of CMC caused by gain-of-function (GOF) mutation of the signal transducer and the activator of transcription 1 (STAT1) protein. GOF mutation of STAT1 disrupts Th17 cell differentiation and causes susceptibility to candida infection in mucous membranes. Although genetic testing is crucial to diagnose AD-CMC, a simple and fast diagnostic tool is required for the management and reduction of complications associated with infection. Flow cytometry (FCM) is suggested for the measurement of intracellular phosphorylated STAT1 (pSTAT1) in a stimulated status. Here, we report the application of FCM to show the activation status of STAT signaling in a 24-year-old female patient diagnosed with AD-CMC. Compared to the controls, the patient’s T cells showed increased levels of pSTAT1 after stimulation by interferon-γ and lesser extent of inhibition caused by an inhibitor. To the best of our knowledge, this is the first evaluation of the usefulness of FCM as an alternative diagnostic and monitoring tool of GOF STAT1 in Korea.

The Usefulness of Flow Cytometry for Measuring Phosphorylated Signal Transducer and Activator of Transcription 1 to Diagnose and Manage Chronic Mucocutaneous Candidiasis: A Case Report

Autosomal dominant chronic mucocutaneous candidiasis (AD-CMC) is a subtype of CMC caused by gain-of-function (GOF) mutation of the signal transducer and the activator of transcription 1 (STAT1) protein. GOF mutation of STAT1 disrupts Th17 cell differentiation and causes susceptibility to candida infection in mucous membranes. Although genetic testing is crucial to diagnose AD-CMC, a simple and fast diagnostic tool is required for the management and reduction of complications associated with infection. Flow cytometry (FCM) is suggested for the measurement of intracellular phosphorylated STAT1 (pSTAT1) in a stimulated status. Here, we report the application of FCM to show the activation status of STAT signaling in a 24-year-old female patient diagnosed with AD-CMC. Compared to the controls, the patient’s T cells showed increased levels of pSTAT1 after stimulation by interferon-γ and lesser extent of inhibition caused by an inhibitor. To the best of our knowledge, this is the first evaluation of the usefulness of FCM as an alternative diagnostic and monitoring tool of GOF STAT1 in Korea.

Comparison of Mac-2 Binding Protein Glycosylation Isomer, Fibroscan, and Other Fibrosis Markers for Assessing Liver Cirrhosis in Patients with Chronic Hepatitis B Virus-mediated Hepatocellular Carcinoma

Background@#Liver cirrhosis is advanced stage of hepatic brosis caused by viral hepatitis. Mac-2 binding protein glycosylation isomer (M2BPGi) is a serum marker to diagnose and evaluate hepatic brosis progression. In this study, we evaluated the efficacy of serum M2BPGi to predict chronic hepatitis B (HBV)-mediated cirrhosis by liver biopsy. @*Methods@#M2BPGi cut-off index (COI) was evaluated from 312 patients with chronic HBV-mediated hepatocellular carcinoma and 105 healthy controls. Comparative analysis was performed with conventional hepatic brosis markers such as brosis index based on four factors (FIB-4), aspartate aminotransferase-to-platelet ratio index (APRI), and Fibroscan. @*Results@#Korean Study Group for Pathology of Digestive Diseases classified 165 (52%) patients with histological stage F4 liver cirrhosis. Comparison of cases with stage F4 cirrhosis and stage F3 septal brosis revealed significant difference between M2BPGi, platelet count, APRI, FIB-4, and Fibroscan prediction. M2BPGi 2+ (COI ≥3) was found to be 8% in patients with F4 cirrhosis and 1% in patients with F3 brosis. In multi-regression analysis, M2BPGi showed higher odds ratio than that of other serum markers while M2BPGi 2+ showed comparable odds ratio to Fibroscan F3 and F4 assessment. @*Conclusions@#In patients with chronic HBV-mediated hepatocellular carcinoma, M2BPGi was neither comprehensive nor as effective as Fibroscan in assessing liver cirrhosis and brosis progression.

Annual Report of Korean Association of External Quality Assessment Service on Histocompatibility Testing (2018)

Here, we report the results of the first histocompatibility proficiency testing (PT) performed by the Korean Association of External Quality Assessment Service in 2018. The directly prepared PT specimens of whole blood, sera, and mononuclear cell suspensions were distributed to participants biannually. The number of participants was comparable to that in the previous external PT program, and the response rate was 88%–100%. The accuracy rates for human leukocyte antigen (HLA) A, B, C, DR, and DQ low and high resolution typing were 100%/100%, 100%/98%, 100%/99%, and 99%/98%, respectively; HLA-B27 typing, 99.1%; T cell and B cell crossmatching, 3.1% and 6.0%, respectively; and HLA antibody screening and identification, 100% and 100%, respectively. The results of HLA crossmatching were not reported from four participants due to poor cell viability. Further improvements of the specimen delivery process, grading criteria for crossmatching, and format of participant summary are warranted.