Identification of 8-Digit HLA-A, -B, -C, and -DRB1Allele and Haplotype Frequencies in Koreans Using the One Lambda AllType Next-Generation Sequencing Kit

Background@#Recent studies have successfully implemented next-generation sequencing (NGS) in HLA typing. We performed HLA NGS in a Korean population to estimate HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies up to an 8-digit resolution, which might be useful for an extended application of HLA results. @*Methods@#A total of 128 samples collected from healthy unrelated Korean adults, previously subjected to Sanger sequencing for 6-digit HLA analysis, were used. NGS was performed for HLA-A, -B, -C, and -DRB1 using the AllType NGS kit (One Lambda, West Hills, CA, USA), Ion Torrent S5 platform (Thermo Fisher Scientific, Waltham, MA, USA), and Type Steam Visual NGS analysis software (One Lambda). @*Results@#Eight HLA alleles showed frequencies of ≥ 10% in the Korean population, namely, A*24:02:01:01 (19.5%), A*33:03:01 (15.6%), A*02:01:01:01 (14.5%), A*11:01:01:01 (13.3%), B*15:01:01:01 (10.2%), C*01:02:01 (19.9%), C*03:04:01:02 (11.3%), and DRB1*09:01:02 (10.2%). Nine previous 6-digit HLA alleles were further identified as two or more 8-digit HLA alleles. Of these, eight alleles (A*24:02:01, B*35:01:01, B*40:01:02, B*55:02:01, B*58:01:01, C*03:02:02, C*07:02:01, and DRB1*07:01:01) were identified as two 8-digit HLA alleles, and one allele (B*51:01:01) was identified as three 8-digit HLA alleles. The most frequent four-loci haplotype was HLA-A*33:03:01-B*44:03:01:01-C*14:03-DRB1*13:02:01. @*Conclusions@#We identified 8-digit HLA-A, -B, -C, and -DRB1 allele and haplotype frequencies in a healthy Korean population using NGS. These new data can be used as a representative Korean data for further disease-related HLA type analysis.

Prediction of HLA-DQ in Deceased Donors and its Clinical Significance in Kidney Transplantation

Background@#HLA-DQ typing in deceased donors is not mandatory in Korea. Therefore, when patients develop DQ antibodies after kidney transplantation (KT) from deceased donor, it is impossible to determine whether they are donor-specific antibodies (DSA). We developed DQ prediction programs for the HLA gene and evaluated their clinical utility. @*Methods@#Two HLA-DQ prediction programs were developed: one based on Lewontin’s linkage disequilibrium (LD) and haplotype frequency and the other on an artificial neural network (ANN). Low-resolution HLA-A, -B, -DR, and -DQ typing data of 5,603 Korean patients were analyzed in terms of haplotype frequency and used to develop an ANN DQ prediction program. Predicted DQ (pDQ) genotype accuracy was analyzed using the typed DQ data of 403 patients. pDQ DSA agreement, sensitivity, specificity, and false-negative rate was evaluated using 1,970 single-antigen bead assays performed on 885 KT recipients. The clinical significance of DQ and pDQ DSA was evaluated in 411 KT recipients. @*Results@#pDQ genotype accuracies were 75.4% (LD algorithm) and 75.7% (ANN). When the second most likely pDQ (LD algorithm) was also considered, the genotype accuracy increased to 92.6%. pDQ DSA (LD algorithm) agreement, sensitivity, specificity, and falsenegative rate were 97.5%, 97.3%, 98.6%, and 2.4%, respectively. The antibody-mediated rejection treatment frequency was significantly higher in DQ or pDQ DSA-positive patients than in DQ or pDQ DSA-negative patients (P < 0.001). @*Conclusions@#Our DQ prediction programs showed good accuracy and could aid DQ DSA detection in patients who had undergone deceased donor KT without donor HLA-DQ typing.

Annual Report of the Korean Association of External Quality Assessment Service on Transfusion Medicine (2019)

This report summarizes the 2019 survey results of the external quality assessment (EQA) scheme for the Transfusion Medicine Program (TMP) in Korea. Proficiency testing materials were prepared at the Asan Medical Center for the biannual distribution to participating laboratories. The average accuracy rates and number of participants (in parenthesis) for ten survey items were as follows: ABO typing, 99.4%–99.9% (N=875); RhD typing, 99.8%–100% (N=864); crossmatching, 90.8%–99.6% (N=760); ABO subtyping, 98.2% and 100% (N=58); Rh CcEe antigen testing, both 100% (N=55); weak D test, 97.9%–100% (N=232); antibody screening, 99.7%– 100% (N=316); direct antiglobulin test (DAT) using a polyspecific reagent, 99.6%–100% (N=273); DAT using an immunoglobulin-G monospecific reagent, both 100.0% (N=67); DAT using a C3d monospecific reagent, 95.6%–98.5% (N=67); antibody identification, 87.9%–99.2% (N=132); and ABO Ab titration, 85.7%–100% (N=134). The number of participants showed an average increase of 14% across the ten survey items, with the ABO antibody titration showing the highest increase at 83.6%. While results were generally excellent, antibody identification and ABO antibody titration results showed room for improvement. The 2019 EQA scheme for TMP has contributed to the improvement and maintenance of the participating laboratories to the program.

Elimination of Anti-CD47 Interference in Pretransfusion Testing by Multiple Platelet Alloadsorption: A Case Report

Hu5F9-G4, an immunoglobulin 4 (IgG4) monoclonal humanized antibody targeting CD47, is under active clinical trials as a novel immunotherapeutic for hematologic and solid malignancies and can cause pretransfusion testing interference. In this study, we demonstrate our first experience of Hu5F9-G4 interference with serologic testing and mitigate this interference through multiple platelet alloadsorption. A 69-year-old woman with a history of ureter cancer presented with anemia. On routine blood group typing, the patient showed strong agglutination (4+) with anti-A, A, and B cells. Unexpectedly, antibody screening and identification showed panreactivity to all panel cells, although the autocontrol result was negative. Medical records revealed that she was enrolled in an anti-CD47 clinical trial. To eliminate interference by the drug, we attempted alloadsorption using pooled platelets that were prepared from segments of random single donor platelets. After seven alloadsorption sessions using pooled allogeneic platelets, the ABO discrepancy and panreactivity was resolved. To our knowledge, this is the first demonstration of anti-CD47 interference elimination in Korea.

Elimination of Anti-CD47 Interference in Pretransfusion Testing by Multiple Platelet Alloadsorption: A Case Report

Hu5F9-G4, an immunoglobulin 4 (IgG4) monoclonal humanized antibody targeting CD47, is under active clinical trials as a novel immunotherapeutic for hematologic and solid malignancies and can cause pretransfusion testing interference. In this study, we demonstrate our first experience of Hu5F9-G4 interference with serologic testing and mitigate this interference through multiple platelet alloadsorption. A 69-year-old woman with a history of ureter cancer presented with anemia. On routine blood group typing, the patient showed strong agglutination (4+) with anti-A, A, and B cells. Unexpectedly, antibody screening and identification showed panreactivity to all panel cells, although the autocontrol result was negative. Medical records revealed that she was enrolled in an anti-CD47 clinical trial. To eliminate interference by the drug, we attempted alloadsorption using pooled platelets that were prepared from segments of random single donor platelets. After seven alloadsorption sessions using pooled allogeneic platelets, the ABO discrepancy and panreactivity was resolved. To our knowledge, this is the first demonstration of anti-CD47 interference elimination in Korea.

Disseminated Gonococcal Infection Presenting as Bacteremia and Liver Abscesses in a Healthy Adult

Herein, we describe a bacteremia caused by Neisseria gonorrhoeae that presented as liver abscesses. The patient had no risk factors for disseminated gonococcal infection. Periodic fever, skin rashes, and papules were present and the results of an abdominal computed tomography scan indicated the presence of small liver abscesses. The results of blood culture and 16S rRNA sequencing of the bacterial isolates confirmed the presence of N. gonorrhoeae. The patient improved with antibiotic therapy.

Possibility of Frequent Detection of Invasive Cyberlindera fabianii Infection Using Molecular Method / 대한임상미생물학회지

A case of fungemia caused by Cyberlindera fabianii was reported in the September issue of Annals of Clinical Microbiology. The C. fabianii that causes rare invasive infection can easily be misidentified as Candida utilis by Vitek-2 YST ID (bioMerieux, USA) and as Candida pelliculosa by API kit (bioMerieux, USA) with high probability. Recently, we also experienced a case of fungemia caused by C. fabianii that was misidentified as C. pelliculosa using API 20C Aux (bioMerieux, USA). As molecular identification is becoming more widespread, cases of C. fabianii infection are expected to be more frequently identified.

A Novel Case of Extreme Thrombocytosis in Acute Myeloid Leukemia Associated With Isochromosome 17q and Copy Neutral Loss of Heterozygosity

No abstract available.

Evaluation of a Chromogenic Culture Medium for the Detection of Clostridium difficile

PURPOSE: Clostridium difficile (C. difficile) is an important cause of nosocomial diarrhea. Diagnostic methods for detection of C. difficile infection (CDI) are shifting to molecular techniques, which are faster and more sensitive than conventional methods. Although recent advances in these methods have been made in terms of their cost-benefit, ease of use, and turnaround time, anaerobic culture remains an important method for detection of CDI. MATERIALS AND METHODS: In efforts to evaluate a novel chromogenic medium for the detection of C. difficile (chromID CD agar), 289 fecal specimens were analyzed using two other culture media of blood agar and cycloserine-cefoxitin-fructose-egg yolk agar while enzyme immunosorbent assay and polymerase chain reaction-based assay were used for toxin detection. RESULTS: ChromID showed the highest detection rate among the three culture media. Both positive rate and sensitivity were higher from chromID than other culture media. ChromID was better at detecting toxin producing C. difficile at 24 h and showed the highest detection rate at both 24 h and 48 h. CONCLUSION: Simultaneous use of toxin assay and anaerobic culture has been considered as the most accurate and sensitive diagnostic approach of CDI. Utilization of a more rapid and sensitive chromogenic medium will aid in the dianogsis of CDI.

16S Ribosomal RNA Identification of Prevotella nigrescens from a Case of Cellulitis

No abstract available.

Molecular methods for genomic analyses of variant PML-RARA or other RARA-related chromosomal translocations in acute promyelocytic leukemia / 대한혈액학회지

No abstract available.

Diagnostic Usefulness of Genomic Breakpoint Analysis of Various Gene Rearrangements in Acute Leukemias: A Perspective of Long Distance- or Long Distance Inverse-PCR-based Approaches

No abstract available.

Detection of RUNX1-MECOM Fusion Gene and t(3;21) in a Very Elderly Patient Having Acute Myeloid Leukemia with Myelodysplasia-Related Changes

An 87-yr-old woman was diagnosed with AML with myelodysplasia-related changes (AML-MRC). The initial complete blood count showed Hb level of 5.9 g/dL, platelet counts of 27x10(9)/L, and white blood cell counts of 85.33x10(9)/L with 55% blasts. Peripheral blood samples were used in all the tests, as bone marrow examination could not be performed because of the patient's extremely advanced age and poor general health condition. Flow cytometric analysis, chromosome analysis, FISH, and reverse transcriptase-PCR (RT-PCR) results indicated AML-MRC resulting from t(3;21) with the RUNX1-MECOM fusion gene. To our knowledge, this is the second most elderly de novo AML patient associated with t(3;21) to be reported.