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Background: Pronase pretreatment can reduce rituximab (RTX) interference by degrading CD20 in B-cell flow cytometry crossmatch (FCXM) testing. However, it may also reduce the assay sensitivity by degrading HLA molecules. We investigated the effects of various pronase concentrations on RTX interference and the analytical sensitivity of B-cell FCXM testing. Methods: Using 59 patient serum samples and 38 donor lymphocyte samples, we designed 97 recipient-donor pairs and divided them into three groups according to RTX use and the presence of weak-to-moderate donor HLA-specific antibody (DSA) reactions: RTX+/DSA-, RTX+/DSA+, and RTX-/DSA+. FCXM was performed after pretreating lymphocytes with six different pronase concentrations (0, 0.5, 1, 2, 3, and 4 mg/mL). Results: With B-FCXM testing, false-positive results due to RTX in the RTX+/DSA- group markedly decreased with increasing pronase concentrations. The median channel shift values in the RTX+/DSA+ and RTX-/DSA+ groups did not significantly decrease when the pronase concentration was increased from 1 mg/mL to 2 or 3 mg/mL. All eight RTX+/DSA+ cases that were positive at 1 mg/mL pronase but negative at 2 or 3 mg/mL had mean fluorescence intensity (MFI) DSA values of less than 3,000 except for DQ5 (MFI: 5,226). With T-cell FCXM, false-positive results were observed in 2.9% of 315 FCXM tests with pronase pretreatment. Conclusions: Higher concentrations (2 or 3 mg/mL) of pronase effectively eliminated RTX interference but still carried a risk for false negativity for weak DSA reactions in B-cell FCXM. Higher pronase concentrations can be used as an auxiliary method to detect moderate-to-strong DSA reactions in RTX-treated patients.
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Introduction: Kidney transplant recipients often experience significant alterations in their immune system, which can lead to increased susceptibility to infections. This study aimed to analyze time-dependent changes in serum immunoglobulin and complement levels and determine the risk factors associated with infection. Methods: A retrospective analysis of serum samples from 192 kidney transplant recipients who received transplantations between August 2016 and December 2019 was conducted. The serum samples were obtained at preoperative baseline (T0), postoperative 2 weeks (T1), 3 months (T2), and 1 year (T3). The levels of serum C3, C4, IgG, IgA, and IgM were measured to evaluate immune status over time. Results: The analysis revealed significant decreases in IgG and IgA levels at T1. This period was associated with the highest occurrence of hypogammaglobulinemia (HGG) and hypocomplementemia (HCC), as well as an increased incidence of severe infection requiring hospitalization and graft-related viral infections. Using a time-dependent Cox proportional hazards model adjusted for time-varying confounders, HGG was significantly associated with an increased risk of infection requiring hospitalization (HR, 1.895; 95% CI: 1.871-1.920, P-value<0.001) and graft-related viral infection (HR, 1.152; 95% CI: 1.144-1.160, P-value<0.001). Discussion: The findings suggest that monitoring serum immunoglobulin levels post-transplant provides valuable insights into the degree of immunosuppression. Hypogammaglobulinemia during the early post-transplant period emerges as a critical risk factor for infection, indicating that serum immunoglobulins could serve as feasible biomarkers for assessing infection risk in kidney transplant recipients.
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Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Masculino , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto , Fatores de Tempo , Imunoglobulinas/sangue , Fatores de Risco , Agamaglobulinemia/sangue , Agamaglobulinemia/imunologia , Agamaglobulinemia/etiologia , Biomarcadores/sangue , Infecções/etiologia , Infecções/imunologia , Infecções/sangue , Infecções/epidemiologiaRESUMO
Circulating tumor DNA (ctDNA) has emerged as a promising tool for various clinical applications, including early diagnosis, therapeutic target identification, treatment response monitoring, prognosis evaluation, and minimal residual disease detection. Consequently, ctDNA assays have been incorporated into clinical practice. In this review, we offer an in-depth exploration of the clinical implementation of ctDNA assays. Notably, we examined existing evidence related to pre-analytical procedures, analytical components in current technologies, and result interpretation and reporting processes. The primary objective of this guidelines is to provide recommendations for the clinical utilization of ctDNA assays.
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DNA Tumoral Circulante , Humanos , DNA Tumoral Circulante/genética , Biomarcadores Tumorais/genética , Prognóstico , Neoplasia Residual/genética , Mutação , Sequenciamento de Nucleotídeos em Larga EscalaRESUMO
A novel null HLA-A*24 allele, HLA-A*24:608N, was identified in five Korean subjects including three from a family and two separate individuals. This study was performed to discern its immunological function in transplantation settings. Because this null variant had deletions of approximately 12 k base pairs from intron 3 to 3' end of the HLA-A gene, low resolution HLA typing and amplicon-based next generation sequencing (NGS) typing methods had failed to assign it. Hybrid capture-based NGS method confirmed that this novel variant had a large deletion. T-lymphocyte crossmatching by complement-dependent lymphocytotoxicity and flow cytometry with a serum consisting anti-HLA-A24 antibody revealed negative results, implying that an individual with this allele would not carry a functioning A24 antigen. These findings highlight the importance of identifying a null HLA allele by employing appropriate molecular method and providing expected crossmatching outcomes in a real-world transplantation setting.
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Antígenos HLA-A , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Alelos , Teste de Histocompatibilidade/métodos , Íntrons , Antígenos HLA-A/genética , República da Coreia , Sequenciamento de Nucleotídeos em Larga Escala/métodosRESUMO
BACKGROUND: Several types of transfusion-related registries have been developed to improve patient outcomes and blood banks. In Korea, a transfusion program functioning as a blood group antibody database and a reference laboratory has been in operation since July 2013. This study was conducted to determine the current status of blood group antigens and antibodies in Korea and propose a model for registries in the field of transfusion medicine. MATERIALS AND METHODS: Cases with unexpected red cell antibodies were registered online in the voluntary transfusion registry. Specific antigen-negative frequencies were calculated based on the recorded data. To determine the frequencies of RhCE antigens, data added via the Blood Information Sharing System were also analyzed. Data added to the registries between July 2013 and June 2022 were included in the analysis. RESULTS: Among 9,048 antibody cases registered from 29 hospitals, anti-E alone was identified most commonly, followed by anti-E and c, anti-C and e, anti-Lea, and anti-M (2,202, 1,792, 757, 618, and 383 cases, respectively). The frequencies of E-, E-c-, C-e-, Le(a-), and M- were 49.1%, 41.6%, 9.1%, 69.4%, and 21.8%, respectively. DISCUSSION: The distributions of antibodies and antigen frequencies were estimated through the transfusion registry. Antigen frequencies were calculated based on the results of antigen typing of red blood cell components performed at the time of issuing. The online transfusion registry serving as a blood group antibody database is useful for determining the frequencies of blood group antigens and antibodies.
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Background: Several T-cell response assays for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are available; however, their comparability and correlations with antibody responses remain unclear. We compared four SARS-CoV-2 T-cell response assays and two anti-SARS-CoV-2 spike antibody assays. Methods: We enrolled 89 participants who had received a booster dose of the BNT162b2 vaccine after two doses of the ChAdOx1 or BNT162b2 vaccine. Fifty-six participants without breakthrough infection (BI) (ChAdOx1/BNT162b2 group: N=27; BNT162b2 group: N=29) and 33 with BI were included. We evaluated two whole-blood interferon-gamma release assays (IGRAs) (QuantiFERON and Euroimmun), T-SPOT.COVID, an in-house enzyme-linked immunospot (ELISPOT) assay (targeting the spike and nucleocapsid peptides of wild-type and Omicron SARS-CoV-2), Abbott IgG II Quant, and Elecsys Anti-S, using Mann-Whitney U, Wilcoxon signed-rank, and Spearman's correlation tests. Results: The correlations between the IGRAs and between the ELISPOT assays (ρ=0.60-0.70) were stronger than those between the IGRAs and ELISPOT assays (ρ=0.33-0.57). T-SPOT.COVID showed a strong correlation with Omicron ELISPOT (ρ=0.70). The anti-spike antibody assays showed moderate correlations with T-SPOT.COVID, Euroimmun IGRA, and ELISPOT (ρ=0.43-0.62). Correlations tended to be higher in the BI than in the noninfected group, indicating that infection induces a stronger immune response. Conclusions: T-cell response assays show moderate to strong correlations, particularly when using the same platform. T-SPOT.COVID exhibits potential for estimating immune responses to the Omicron variant. To accurately define SARS-CoV-2 immune status, both T-cell and B-cell response measurements are necessary.
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Vacina BNT162 , COVID-19 , Humanos , Infecções Irruptivas , SARS-CoV-2 , Linfócitos T , Anticorpos AntiviraisRESUMO
Data on HLA genotype distribution, including DQA1 and DPA1, in the Korean population are limited. We aimed to investigate the allele and haplotype frequencies of 11 HLA loci in 339 Korean subjects using next-generation sequencing (NGS)-based HLA typing. A total of 339 samples from unrelated healthy subjects were genotyped for HLA-A, -B, -C, -DRB1, -DRB3, -DRB4, -DRB5, -DQB1, -DQA1, -DPB1, and -DPA1 using two different NGS-based HLA typing kits (166 tested using the NGSgo-MX11-3 kit [GenDx, Netherlands] and 173 by the AllType NGS 11 Loci Amplification kit [One Lambda, USA]). PyPop software was used to estimate allele and haplotype frequencies and linkage disequilibrium between the loci. Additionally, a principal component analysis was performed to compare the allele distribution of Koreans with that of other populations. A total of 214 HLA alleles (97 class I and 117 class II alleles) were assigned. The most frequent alleles for each locus were A*24:02:01 (24.78%), B*15:01:01 (10.18%), C*01:02:01 (18.44%), DRB1*04:05:01 (9.59%), DRB3*02:02:01 (13.72%), DRB4*01:03:01 (25.81%), DRB5*01:01:01 (9.0%), DQA1*01:02:01 (16.96%), DQB1*03:01:01 (14.31%), DPA1*01:03:01 (44.4%), and DPB1*05:01:01 (35.1%), respectively. The most frequent haplotypes were A*33:03:01-C*03:02:02-B*58:01:01 for HLA class I (5.01%) and DRB1*04:05:01-DQA1*03:03:01-DQB1*04:01:01-DPA1*02:02:02-DPB1*05:01:01 for HLA class II (6.23%). The total allelic ambiguities by NGS were estimated to be minimal and considerably decreased compared with those by Sanger sequencing. The Japanese population had the most similar allele distribution to Koreans, followed by the Chinese population. Frequency data of 11 HLA loci in Koreans can provide essential data for population genetics and disease association studies.
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População do Leste Asiático , Antígenos de Histocompatibilidade Classe II , Humanos , Haplótipos , Antígenos de Histocompatibilidade Classe II/genética , Alelos , Frequência do Gene , Sequenciamento de Nucleotídeos em Larga Escala , Cadeias HLA-DRB1/genéticaRESUMO
It is important to determine the clinical significance of non-human leukocyte antigen (HLA) antibodies and their association with antibody-mediated rejection (ABMR) of kidney allografts. We collected post-transplant sera from 68 ABMR patients, 67 T-cell mediated rejection (TCMR) patients, and 83 control subjects without rejection, and determined the titers of 39 non-HLA antibodies including antibodies for angiotensin II receptor type I and MICA. We compared all these non-HLA antibody titers among the study groups. Then, we investigated their association with the risk of death-censored graft failure in ABMR cases. Among the antibodies evaluated, anti-collagen type I (p = 0.001) and type III (p < 0.001) antibody titers were significantly higher in ABMR cases than in both TCMR cases and no-rejection controls. Both anti-collagen type I [per 1 standard deviation (SD), adjusted odds ratio (OR), 11.72 (2.73-76.30)] and type III [per 1 SD, adjusted OR, 6.22 (1.91-31.75)] antibodies were significantly associated with the presence of ABMR. Among ABMR cases, a higher level of anti-collagen type I [per 1 SD, adjusted hazard ratio (HR), 1.90 (1.32-2.75)] or type III per 1 SD, [adjusted HR, 1.57 (1.15-2.16)] antibody was associated with a higher risk of death-censored graft failure. In conclusion, post-transplant anti-collagen type I and type III antibodies may be novel non-HLA antibodies related to ABMR of kidney allografts.
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Rejeição de Enxerto , Transplante de Rim , Anticorpos , Colágeno Tipo I , Humanos , RimRESUMO
ABSTRACT: Medical care should be equally provided to the public regardless of their financial capability. In the real world, expenditures directly out from the patient sector decide the medical journey, even in a country with national health insurance. The aim of this study was to investigate whether there are differences in the diagnostic and treatment processes in hematologic malignancies based on patient characteristics, such as health insurance status.Through the review of 5614 "CBCs with differential count" results with abnormal cells from 358 patients from January 2010 to June 2017, 238 patients without past medical histories of hematologic malignancies were enrolled. Excluding reactive cases, 206 patients with hematologic malignancy were classified into 8 disease categories: acute leukemia, myelodysplastic syndrome, myeloproliferative neoplasm (MPN), myelodysplastic syndrome/MPN, lymphoid neoplasm, plasma cell neoplasm, r/o hematologic malignancy, and cancer.The patients' age, sex, disease categories and follow-up durations showed associations with the clinical course. The "refusal of treatment" group was the oldest and had a relatively higher percentage of females, whereas those who decided to transfer to a tertiary hospital were younger. The age, clinical course, and follow-up durations were different across health insurance statuses. The medical aid group was the oldest, and the group whose status changed from a medical insurance subscriber to a medical aid beneficiary during treatment was the youngest. The majority of patients who refused treatment or wished to be transferred to a tertiary hospital were medical insurance subscribers. The percentage of patients who were treated in this secondary municipal hospital was higher in the medical-aid beneficiaries group than in the medical insurance group. Follow-up durations were longest in the status change group and shortest in the medical insurance group.Almost all medical aid beneficiaries with hematologic malignancies opted to continue treatment at this secondary/municipal hospitals, indicating that this category of medical institutions provides adequate levels and qualified healthcare services to those patients. The secondary municipal hospital provides qualified healthcare services for medical aid beneficiaries with hematologic malignancies.
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Acessibilidade aos Serviços de Saúde , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/terapia , Cobertura do Seguro/estatística & dados numéricos , Seguro Saúde/economia , Seguro Saúde/estatística & dados numéricos , Programas Nacionais de Saúde , Fatores Etários , Feminino , Gastos em Saúde , Acessibilidade aos Serviços de Saúde/economia , Acessibilidade aos Serviços de Saúde/estatística & dados numéricos , Neoplasias Hematológicas/economia , Humanos , Fatores SexuaisRESUMO
BACKGROUND: Several type B adverse drug reactions (ADRs), especially severe cutaneous adverse reactions (SCARs), are associated with particular human leukocyte antigen (HLA) genotypes. However, pre-stored HLA information obtained from other clinical workups has not been used to prevent ADRs. We aimed to simulate the preemptive use of pre-stored HLA information in electronic medical records to evaluate whether this information can prevent ADRs. METHODS: We analyzed the incidence and the risk of ADRs for selected HLA alleles (HLA-B*57:01, HLA-B*58:01, HLA-A*31:01, HLA-B*15:02, HLA-B*15:11, HLA-B*13:01, HLA-B*59:01, and HLA-A*32:01) and seven drugs (abacavir, allopurinol, carbamazepine, oxcarbazepine, dapsone, methazolamide, and vancomycin) using pre-stored HLA information of transplant patients based on the Pharmacogenomics Knowledge Base guidelines and experts' consensus. RESULTS: Among 11,988 HLA-tested transplant patients, 4092 (34.1%) had high-risk HLA alleles, 4583 (38.2%) were prescribed risk drugs, and 580 (4.8%) experienced type B ADRs. Patients with HLA-B*58:01 had a significantly higher incidence of type B ADR and SCARs associated with allopurinol use than that of patients without HLA-B*58:01 (17.2% vs. 11.9%, odds ratio [OR] 1.53 [95% confidence interval {CI} 1.09-2.13], p = 0.001, 2.3% versus 0.3%, OR 7.13 [95% CI 2.19-22.69], p < 0.001). Higher risks of type B ADR and SCARs were observed in patients taking carbamazepine or oxcarbazepine if they had one of HLA-A*31:01, HLA-B*15:02, or HLA-B*15:11 alleles. Vancomycin and dapsone use in HLA-A*32:01 and HLA-B*13:01 carriers, respectively, showed trends toward increased risk of type B ADRs. CONCLUSION: Utilization of pre-stored HLA data can prevent type B ADRs including SCARs by screening high-risk patients.
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BACKGROUND: We aimed to define the maternal lipid profiles that are associated with fetal growth and cord blood (CB) hematopoietic cells in healthy Korean full-term newborns. METHODS: A total of 608 fetal-maternal pairs were enrolled; mothers voluntarily donated CB with informed consent. We analyzed birth weight (BW) as a marker of fetal growth, and we examined total nucleated cells (TNCs) and CD34+ cell concentrations of CB as markers of hematopoietic progenitor cell (HPC) contents. We also analyzed maternal lipid levels and investigated their associations with BW, TNCs and CD34+ cells. RESULTS: Maternal triglycerides (TG) showed a significant positive association with BW and CD34+ cells, and low-density lipoprotein (LDL) showed a negative association with BW and CD34+ cells. Though not statistically significant, higher maternal TG showed a tendency toward higher levels of TNCs. Maternal TG was independently and positively correlated with BW, and maternal LDL was independently and negatively correlated with CD34+ cells, although the impacts were not as strong, as indicated by small beta coefficients (0.157 and -0.226, respectively). CONCLUSIONS: We were able to investigate the association of maternal lipid profiles with BW and CB HPCs in healthy Korean newborn-mother pairs in this study. Both BW and the HPC contents showed independent associations with maternal TG and LDL, although the effect of maternal lipid levels on fetal growth and HPCs was not strong in the normal healthy population. Because maternal lipid levels were assessed once in the healthy fetal-maternal pairs, we could not investigate those associations across pregnancy.
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Sangue Fetal , Desenvolvimento Fetal , Antígenos CD34 , Feminino , Humanos , Recém-Nascido , Gravidez , República da Coreia , TriglicerídeosRESUMO
BACKGROUND: Associations between IgA nephropathy (IgAN) and HLA-DRB1 and -DQB1 alleles have been reported in several ethnic groups. We investigated the association of HLA-DRB1 and -DQB1 alleles with the predisposition for IgAN and disease progression to end-stage kidney disease (ESKD) in Korean patients. METHODS: We analyzed HLA-DRB1 and -DQB1 genotypes in 399 IgAN patients between January 2000 and January 2019 using a LIFECODES sequence-specific oligonucleotide (SSO) typing kit (Immucor, Stamford, CT, USA) or a LABType SSO Typing Test (One Lambda, Canoga Park, CA, USA). Alleles with a significant difference in two-digit resolution were further analyzed using in-house sequence-based typing and sequence-specific primer PCR. As controls, 613 healthy hematopoietic stem cell donors were included. Kidney survival was analyzed in 281 IgAN patients with available clinical and laboratory data using Cox regression analysis. Where needed, P-values were adjusted using Bonferroni correction. RESULTS: The allele frequencies of HLA-DRB1*04:05 (corrected P [Pc]<0.001), -DQB1 *04:01 (Pc=0.048), and -DQB1*03:02 (Pc=0.021) were significantly higher in IgAN patients than in controls, whereas those of HLA-DRB1*07:01, -DRB1*15:01, -DQB1*02:02, and -DQB1*06:02 (Pc<0.001 for all) were significantly lower in IgAN patients than in controls. The allele frequency of HLA-DQB1*05:03 (Pc=0.016) was significantly lower in the ESKD group than in the non-ESKD group; however, there was no significant difference for ESKD progression between these groups. CONCLUSIONS: We report novel associations of HLA-DRB1*15:01, DQB1*02:02, -DQB1*03:02, and -DQB1*04:01 with IgAN. Further studies of HLA alleles associated with IgAN progression in a larger cohort and in various ethnic groups are needed.
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Glomerulonefrite por IGA , Alelos , Predisposição Genética para Doença , Glomerulonefrite por IGA/diagnóstico , Glomerulonefrite por IGA/genética , Cadeias HLA-DRB1/genética , Teste de Histocompatibilidade , Humanos , República da CoreiaRESUMO
BACKGROUND: SARS-CoV-2 pandemic is currently ongoing, meanwhile vaccinations are rapidly underway in some countries. The quantitative immunoassays detecting antibodies against spike antigen of SARS-CoV-2 have been developed based on the findings that they have a better correlation with the neutralizing antibody. METHODS: The performances of the Abbott Architect SARS-CoV-2 IgG II Quant, DiaSorin LIAISON SARS-CoV-2 TrimericS IgG, and Roche Elecsys anti-SARS-CoV-2 S were evaluated on 173 sera from 126 SARS-CoV-2 patients and 151 pre-pandemic sera. Their correlations with GenScript cPass SARS-CoV-2 Neutralization Antibody Detection Kit were also analyzed on 173 sera from 126 SARS-CoV-2 patients. RESULTS: Architect SARS-CoV-2 IgG II Quant and Elecsys anti-SARS-CoV-2 S showed the highest overall sensitivity (96.0%), followed by LIAISON SARS-CoV-2 TrimericS IgG (93.6%). The specificities of Elecsys anti-SARS-CoV-2 S and LIAISON SARS-CoV-2 TrimericS IgG were 100.0%, followed by Architect SARS-CoV-2 IgG II Quant (99.3%). Regarding the correlation with cPass neutralization antibody assay, LIAISON SARS-CoV-2 TrimericS IgG showed the best correlation (Spearman rho = 0.88), followed by Architect SARS-CoV-2 IgG II Quant and Elecsys anti-SARS-CoV-2 S (all rho = 0.87). CONCLUSIONS: The three automated quantitative immunoassays showed good diagnostic performance and strong correlations with neutralization antibodies. These assays will be useful in diagnostic assistance, evaluating the response to vaccination, and the assessment of herd immunity in the future.
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Anticorpos Antivirais/sangue , Teste Sorológico para COVID-19/métodos , COVID-19/virologia , Imunoensaio/métodos , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Neutralizantes/sangue , Teste Sorológico para COVID-19/instrumentação , Humanos , Imunoglobulina G/sangue , Testes de Neutralização , Curva ROC , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Testes SorológicosRESUMO
The interleukin-33 (IL-33)/suppression of tumorigenicity 2 (ST2) pathway modulates immune response and inflammation, associated with allograft dysfunction and rejection. We hypothesized that IL-33/ST2 is a marker of renal allograft rejection and IL-33/ST2 expression may differ according to rejection type. IL-33/ST2 expression was measured in sera and kidney tissues from recipients with acute antibody-mediated rejection (AAMR), acute cell-mediated rejection (ACMR), chronic antibody-mediated rejection (CAMR), and healthy controls. The soluble ST2 and IL-33/ST2 expression levels were higher in participants with all three rejection types than in controls. Although the expression levels in recipients with AAMR and ACMR were significantly higher than those with CAMR, there was no significant difference between the expression levels in AAMR and ACMR. Although IL-33, IL-8, and fibronectin expression were significantly increased after the addition of the recipients' serum in primary cultured human renal proximal tubular epithelial cells, the levels decreased after treatment with an anti-ST2 antibody. Furthermore, the anti-ST2 antibody specifically suppressed the upregulation of the mixed lymphocyte reaction. Boyden chamber assays demonstrated that anti-ST2 antibody abrogated chemotaxis induced by recombinant IL-33. Thus, IL-33 and ST2 are potent mediators of rejection. Treatment with an anti-ST2 antibody ameliorates rejection and could be a potential therapeutic strategy for renal allograft rejection.
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Aloenxertos/imunologia , Rejeição de Enxerto/imunologia , Interleucina-33/metabolismo , Transplante de Rim , Adulto , Anticorpos/farmacologia , Biomarcadores/análise , Feminino , Humanos , Rim/imunologia , Transplante de Rim/métodos , Masculino , Pessoa de Meia-Idade , Transplante Homólogo/métodosRESUMO
Serological weak D is a reaction of 2+ or less to anti-D reagent and includes weak D and partial D phenotypes. Although identifying the RhD subtype is important for transfusion safety, serological tests are insufficient for defining the RhD subtype, and molecular tests are needed. To analyze the molecular characteristics of D variants in Koreans to facilitate the formulation of individualized transfusion strategies, molecular tests such as RhD genotyping using real-time polymerase chain reaction (PCR) and partial-D and/or weak-D sequence-specific amplification (SSP) were performed on 105 Korean Rare Blood Program (KRBP) patients exhibiting serological weak D. In total, 58 out of 68 serologically determined weak D KRBP patients were typed as having weak D or partial D phenotypes via RhD genotyping. In detail, eight (13.8%) were typed as partial DVa or DBS, nine (15.5%) as weak D type 15, and four others (6.8%) as partial DVI, partial DVII, weak D type 2, or weak D type 41 or 45, whereas the rest (n = 37, 63.8%) was typed as having either weak D or partial D. This suggests that serological weak D Koreans who require transfusion should be treated as D-negative.
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BACKGROUND: For HLA genotyping, PCR sequence-specific oligonucleotide (SSO) methods using the Luminex platform are widely used. We evaluated the performance of LabType-SSO (One Lambda, USA) in Koreans. METHODS: LabType-SSO were performed on 50 residual DNA samples analyzed by sequence-based typing (SBT) for all HLA-A, -B, -C, -DRB1, and -DQB1 alleles with gene frequency > 0.1% in Koreans. RESULTS: The LabType-SSO results were in complete agreement with SBT at the 2-digit level. For 4-digit level, 9 HLA-A alleles, 1 HLA-B allele, 3 HLA-C alleles, neither HLA-DRB1 nor -DQB1 allele showed ambiguous results for assignment of most probable types considering HLA gene frequency in Koreans. In addition, two cases of DQB1*04:01 allele were incorrectly assigned to DQB1*04:02. CONCLUSIONS: LabType-SSO tests showed accurate assignment of 2-digit level and LabType-SSO HLA-DRB1 test showed correct 4-digit most probable HLA type. The tests can be useful as intermediate resolution typing for solid organ transplantation.
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Antígenos HLA-A , Oligonucleotídeos , Alelos , Frequência do Gene , Antígenos HLA-A/genética , Cadeias HLA-DRB1/genética , Haplótipos , Teste de Histocompatibilidade , HumanosRESUMO
Recently, a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (B.1.1.529) Omicron variant originated from South Africa in the middle of November 2021. SARS-CoV-2 is also called coronavirus disease 2019 (COVID-19) since SARS-CoV-2 is the causative agent of COVID-19. Several studies already suggested that the SARS-CoV-2 Omicron variant would be the fastest transmissible variant compared to the previous 10 SARS-CoV-2 variants of concern, interest, and alert. Few clinical studies reported the high transmissibility of the Omicron variant but there is insufficient time to perform actual experiments to prove it, since the spread is so fast. We analyzed the SARS-CoV-2 Omicron variant, which revealed a very high rate of mutation at amino acid residues that interact with angiostatin-converting enzyme 2. The mutation rate of COVID-19 is faster than what we prepared vaccine program, antibody therapy, lockdown, and quarantine against COVID-19 so far. Thus, it is necessary to find better strategies to overcome the current crisis of COVID-19 pandemic.
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BACKGROUND: Although a diagnosis of infectious diseases is essential for timely treatment, the performance of diagnostic tests has been hardly evaluated due to variable results that are influenced by multiple factors in different conditions. In the present study, the performance of the Alinity i system, which is a newly developed immunoassay to diagnose infectious diseases, was evaluated. METHODS: We evaluated the precision, linearity, correlation, and carryover of 16 analytes (HAV Ab IgG, HBsAg, HBeAg, anti-HBc, anti-HBe, anti-HBs, anti-HCV, HIV Ag/Ab, EBV VCA IgM, EBV VCA IgG, EBV EBNA IgG, CMV IgM, CMV IgG, Toxoplasma IgG, Rubella IgG, and Syphilis TP) of Alinity i by comparison with ARCHITECT i2000SR system following the rationale of the Clinical and Laboratory Standards Institute (CLSI). RESULTS: For quantitative tests, the coefficients of variation (CV) % of repeatability and intermediate precision were between 0% and 4.18%. The coefficients of the linearity (r2 ) over a widely tested analytical range were ≥ 0.990 and the correlation between Alinity i and the ARCHITECT i2000SR system was strong (r ≥ 0.994). For qualitative tests, the agreement between Alinity i and the ARCHITECT i2000SR system was excellent (kappa coefficient 1) with 100% sensitivity and specificity. Carryover rates for all analytes were less than 1.0% (-0.11% ~ 0.21%). CONCLUSION: The Alinity i system showed good analytical performance and favorable comparability with the ARCHITECT i2000SR. It could be suitable as a routine immunoassay analyzer for screening and diagnosis of infectious disease.
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Imunoensaio/instrumentação , Imunoensaio/métodos , Infecções/diagnóstico , Citomegalovirus/imunologia , Antígenos de Superfície da Hepatite B/sangue , Humanos , Imunoglobulina G/sangue , Infecções/sangue , Reprodutibilidade dos Testes , Rubéola (Sarampo Alemão)/imunologia , Testes Sorológicos/instrumentação , Testes Sorológicos/métodos , Sífilis/imunologia , Toxoplasma/imunologiaRESUMO
The use of induced pluripotent stem cells (iPSCs) is an emerging therapeutic option for precision medicine. Cord blood (CB) cells with lower immunogenicity, fewer genomic changes, and persistent epigenetic memory might be ideal candidates for iPSC production. Based on the human leukocyte antigen (HLA) distribution of cord blood units (CBUs) in the public CB bank, we estimated the coverage of the Korean population with HLA-homozygous iPSCs to repurpose cryopreserved CBUs. We analyzed a total of 27,904 Korean CBUs donated to the public CB bank. Low-to-intermediate resolution typing was performed for HLA-A, -B, and -DRB1 alleles, and individuals possessing homozygous HLA haplotypes were identified by direct counting. Moreover, the matching probabilities for zero-mismatch transplantation were calculated for 27,904 CBUs and 50,000,000 potential Korean patients. Among the preserved CBUs, 15 HLA-A, 40 HLA-B, and 13 HLA-DRB1 alleles as well as 48 homozygous HLA-A-B-DRB1 haplotypes were identified at serological equivalents (2 digits). The 48 identified homozygous haplotypes cumulatively matched 78.18% of the 27,904 Korean CB donors as zero HLA-mismatch iPSC sources. Among the combinations of 1,699 haplotypes with frequencies greater than 0.001%, assuming a population of 50 million, those 48 haplotypes can provide a match for 78.37% of potential Korean recipients. A practicable number of HLA-A, -B, and -DRB1 homozygous iPSC lines derived from CBUs may be an efficient option in allogeneic iPSC therapy because this type of haplobanking may provide cell lines with optimal HLA matching for up to three-quarters of the Korean population.