ABSTRACT
BACKGROUND/AIMS: Autoimmune hepatitis (AIH) is characterized by the presence of auto-antibodies and high blood immunoglobulin G (IgG) levels. In this study, the line immunoassay (LIA) was designed to assess various autoantibodies. METHODS: In total, 1371 patients who underwent autoimmune liver disease antibody testing between July 2019 and November 2022 were enrolled. Autoantibodies including antinuclear antibody (ANA) and anti-mitochondrial antibody (AMA) were tested, and clinical data were collected. Statistical analyses were performed by categorizing the data based on diagnosis and IgG quantification separately. A scoring system was applied to identify individuals with AIH. Patients were also classified into the AIH and non-AIH groups. RESULTS: The positivity rate for ANA was 80.2% in the AIH group. The IgG-high group had a high likelihood of the presence of detectable autoantibodies, with anti-Ro-52 being the most frequently detected antibody using LIA. The "Consider AIH" and "AMA" groups had 3-4 times more patients in the IgG-high group than in the "Not Considered" group. CONCLUSIONS: Among autoantibodies, the prevalence of ANA was the highest. As per LIA results, anti-Ro-52 was the most prevalent. AIH cannot be diagnosed based on IgG levels alone and must be distinguished via autoantibody testing. Therefore, extensive testing, including autoantibodies, IgG, ANA, and liver enzyme levels, will help accurately diagnose AIH.
Subject(s)
Antibodies, Antinuclear , Autoantibodies , Hepatitis, Autoimmune , Immunoglobulin G , Humans , Hepatitis, Autoimmune/immunology , Hepatitis, Autoimmune/blood , Hepatitis, Autoimmune/diagnosis , Male , Female , Middle Aged , Autoantibodies/blood , Autoantibodies/immunology , Immunoglobulin G/blood , Immunoglobulin G/immunology , Antibodies, Antinuclear/blood , Antibodies, Antinuclear/immunology , Adult , AgedABSTRACT
Peripheral blood stem cell transplantation (PBSCT) is an important therapeutic measure for both hematologic and non-hematologic diseases. For PBSCT to be successful, sufficient CD34+ cells need to be mobilized and harvested. Although risk factors associated with poor mobilization in patients with hematologic diseases have been reported, studies of patients with non-hematologic diseases and those receiving plerixafor are rare. To identify factors associated with poor mobilization, data from autologous PBSC harvest (PBSCH) in 491 patients were retrospectively collected and analyzed. A multivariate analysis revealed that in patients with a hematologic disease, an age older than 60 years (odds ratio [OR] 1.655, 95% confidence interval [CI] 1.049-2.611, p = 0.008), the use of myelotoxic agents (OR 4.384, 95% CI 2.681-7.168, p < 0.001), and a low platelet count (OR 2.106, 95% CI 1.205-3.682, p = 0.009) were associated with poor mobilization. In patients with non-hematologic diseases, a history of radiation on the pelvis/spine was the sole associated factor (OR 12.200, 95% CI 1.934-76.956, p = 0.008). Among the group of patients who received plerixafor, poor mobilization was observed in 19 patients (19/134, 14.2%) and a difference in the mobilization regimen was noted among the good mobilization group. These results show that the risk factors for poor mobilization in patients with non-hematologic diseases and those receiving plerixafor differ from those in patients with hematologic diseases; as such, non-hematologic patients require special consideration to enable successful PBSCH.
ABSTRACT
The Jra antigen, the only antigen within the JR blood group system, is a high-prevalence red blood cell (RBC) antigen found in over 99 % of the global population. An induced pluripotent stem cell line (YUCMi020-A) was generated from peripheral blood drawn from a Jr(a-) phenotype individual, who was homozygous for a null mutation of ABCG2*01N.01 (rs72552713, c.376C>T; p.Gln126*). The generated line exhibited pluripotent characteristics and no chromosomal aberrations. This cell line will serve as a cell source, enabling us to produce RBCs with the Jr(a-) phenotype in vitro, which can be used for transfusing individuals with anti-Jra antibodies.
Subject(s)
Induced Pluripotent Stem Cells , Leukocytes, Mononuclear , Humans , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Female , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/metabolism , Blood Group Antigens/metabolism , Cell Line , ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics , ATP Binding Cassette Transporter, Subfamily G, Member 2/metabolism , Cell DifferentiationABSTRACT
BACKGROUND: Understanding when and why endodontic treatments fail could help clinicians make prognoses and thus improve treatment outcomes. This study was aimed to assess potential predictors of early endodontic treatment failure. We explored factors contributing to the failure of initial root canal treatment were explored, with a specific emphasis on evaluating the influence of the time elapsed since the initial treatment. METHODS: This retrospective cohort study enrolled 1262 patients who sought endodontic treatment at our department and 175 patients were included for analysis. Potential causes of endodontic treatment failure were investigated, such as inadequate obturation quality, inadequate coronal status, the presence of additional untreated canals, anatomical complexity, instrument separation, iatrogenic perforation, cracks, and endodontic-periodontal lesions. The patients were divided into "short-term" and "long-term" groups depending on the time that had passed since the initial treatment (i.e., < 5 and > 10 years, respectively). The causes of failure in the short-term and long-term group were analyzed and compared using logistic regression analyses. Subgroup analysis was performed according to the number of years since the initial treatment in the short-term group to further investigate the association between the time and cause of failure (i.e., < 1, 2, 3, and 4 years, respectively). RESULTS: Untreated additional canals were present in 21.7% of all cases, and in 36.9 and 6.4% of cases in the short-term and long-term groups, respectively. Multivariable analysis showed that the presence of untreated additional canals was significantly associated with short-term compared to long-term failure. Untreated additional canals were also associated with endodontic failure within 1, 2, 3, and 4 years. CONCLUSIONS: The presence of untreated additional canals was a predictor of endodontic failure within 5 years following initial root canal treatment. To optimize long-term prognosis, it is important to detect and treat all root canals during the initial treatment.
Subject(s)
Dental Pulp Cavity , Root Canal Therapy , Humans , Retrospective Studies , Root Canal Therapy/adverse effects , Treatment Failure , Treatment OutcomeABSTRACT
ABSTRACT: ABO antigen weakness is rarely observed in ABO typing for transfusion. Hematologic diseases and associated gene mutations have been suggested as potential causes of this phenomenon, yet the precise etiology has not been elucidated. Through ABO typing and genetic analysis data conducted over 7 years, we have reconfirmed the association between ABO antigen weakness and hematologic diseases, especially acute myeloid leukemia (odds ratio [OR], 2.55; 95% confidence interval [CI], 1.12-5.83) and myelodysplastic syndrome (OR, 6.94; 95% CI, 2.86-16.83), and discovered previously unidentified candidate genes, CEBPA (OR, 43.70; 95% CI, 18.12-105.40), NRAS (OR, 3.37; 95% CI, 1.46-7.79), U2AF1 (OR, 8.12; 95% CI, 2.86-23.03), and PTPN11 (OR, 4.52; 95% CI, 1.51-13.50), seemingly associated with this phenomenon. Among these, CEBPA double mutations displayed a significant association, with ABO antigen weakness being observed in 20 of the 25 individuals (80.0%) possessing these mutations. From this study, new factors associated with ABO antigen weakness have been identified.
Subject(s)
Leukemia, Myeloid, Acute , Myelodysplastic Syndromes , Humans , Leukemia, Myeloid, Acute/genetics , Mutation , CCAAT-Enhancer-Binding Proteins/geneticsABSTRACT
Background: The Jra antigen is a high-prevalence red blood cell (RBC) antigen. Reports on cases of fatal hemolytic disease of the fetus and newborn and acute hemolytic transfusion reactions suggest that antibodies against Jra (anti-Jra) have potential clinical significance. Identifying anti-Jra is challenging owing to a lack of commercially available antisera. We developed an alternative approach to rapidly predict the presence of anti-Jra using the TaqMan single-nucleotide polymorphism (SNP)-genotyping method. Methods: Residual peripheral blood samples from 10 patients suspected of having the anti-Jra were collected. Two samples with confirmed Jr(a-) RBCs and anti-Jra were used to validate the TaqMan genotyping assay by comparing the genotyping results with direct sequencing. The accuracy of the assay in predicting the presence of anti-Jra was verified through crossmatching with in-house Jr(a-) O+ RBCs. Results: The TaqMan-genotyping method was validated with two Jr(a-) RBC- and anti-Jra-confirmed samples that showed concordant Jra genotyping and direct sequencing results. Jra genotyping for the remaining samples and crossmatching the serum samples with inhouse Jr(a-) O+ RBCs showed consistent results. Conclusions: We validated a rapid, simple, accurate, and cost-effective method for predicting the presence of anti-Jra using a TaqMan-based SNP-genotyping assay. Implementing this method in routine practice in clinical laboratories will assist in solving difficult problems regarding alloantibodies to high-prevalence RBC antigens and ultimately aid in providing safe and timely transfusions and proper patient care.
Subject(s)
Blood Grouping and Crossmatching , Polymorphism, Single Nucleotide , Humans , Blood Grouping and Crossmatching/methods , Genotype , Genotyping Techniques/methods , Isoantibodies/blood , Erythrocytes/immunology , Blood Group Antigens/genetics , Blood Group Antigens/immunology , Sequence Analysis, DNAABSTRACT
BACKGROUND: Tuberculosis (TB) remains a significant global health concern. Accurate detection of latent TB infection is crucial for effective control and prevention. We aimed to assess the performance of an interferon-gamma release assay blood test (QuantiFERON-TB Gold Plus [QFT-Plus]) in various clinical contexts and identify conditions that affect its results. METHODS: We conducted a retrospective analysis of 31 000 QFT-Plus samples collected from 26 000 subjects at a tertiary hospital in South Korea over a 4-year period and compared the rates of positivity and indeterminate results across diverse clinical situations. We also analysed the contribution of the QuantiFERON TB2 tube to the test's sensitivity and determined optimal cutoff values for 3 hematologic parameters to distinguish false-negative results. These cutoff values were validated in a separate cohort of subjects with microbiologically confirmed subclinical TB. RESULTS: Rates of QFT-Plus positivity and indeterminate results were disparate across diagnoses. The TB2 tube increased QFT-Plus sensitivity by 4.1% (95% CI, 1.1%-7.0%) in patients with subclinical TB. Absolute lymphocyte count ≤1.19 × 109/L, absolute neutrophil count ≥5.88 × 109/L, and neutrophil-to-lymphocyte ratio ≥4.33 were effective criteria to discriminate false-negative QFT-Plus results. Application of the hematologic criteria, individually or combined with mitogen response <10â IU/mL, substantially improved performance in the main study cohort and the validation cohort. CONCLUSIONS: These findings highlight the influence of clinical context and patient hematologic profiles on QFT-Plus results. To minimise neglected latent TB infections due to false-negative QFT-Plus results, serial retesting is advisable in patients with severe lymphopenia or neutrophilia, particularly when the mitogen response is <10â IU/mL.
Subject(s)
Latent Tuberculosis , Tuberculosis , Humans , Latent Tuberculosis/diagnosis , Interferon-gamma Release Tests , Retrospective Studies , Mitogens , Tuberculosis/diagnosis , Hematologic TestsABSTRACT
An important part of regenerative endodontic procedures involving immature permanent teeth is the regeneration of the pulp-dentin complex with continuous root development. Hydraulic calcium silicate cements (HCSCs) are introduced for the pulpal treatment of immature permanent teeth. The stem-cell-derived secretome recently has been applied for the treatment of various damaged tissues. Here, we evaluated the biocompatibility and osteogenic differentiation of HCSCs combined with secretome on human dental pulp stem cells. In the Cell Counting Kit-8 test and wound healing assays, significantly higher cell viability was observed with secretome application. In alkaline phosphatase analysis, the activity was significantly higher with secretome application in all groups, except for RetroMTA on day 2 and Endocem MTA Premixed on day 4. In an Alizarin Red S staining analysis, all groups with secretome application had significantly higher staining values. Quantitative real-time polymerase chain reaction results showed that the day 7 expression of OSX significantly increased with secretome application in all groups. SMAD1 and DSPP expression also increased significantly with secretome addition in all groups except for Biodentine. In conclusion, HCSCs showed favorable biocompatibility and osteogenic ability and are predicted to demonstrate greater synergy with the addition of secretome during regenerative endodontic procedures involving immature permanent teeth.
ABSTRACT
OBJECTIVES: This study aimed to evaluate the analytical performance of the cobas 6800 System (Roche Diagnostics) and assess the feasibility of using whole-blood specimens instead of plasma. METHODS: The analytical performance of the cobas EBV test (Roche Diagnostics) was evaluated. Thereafter, 120 clinical samples were collected to compare the cobas EBV test and the artus EBV RG PCR Kit (Qiagen). The results of the cobas EBV test conducted using paired plasma as well as 5× and 10× diluted whole-blood specimens were compared with those of the artus EBV RG PCR Kit performed using whole blood. RESULTS: The precision of the cobas EBV test was acceptable, and its linearity was confirmed to be within the range of 2.85 to 6.89 log IU/mL. Cross-reactivity was not observed. The best qualitative agreement (Cohen κ = 0.733) was observed using 5× diluted whole blood; the best quantitative correlation (Spearman correlation coefficient = 0.6865) was observed using 10× diluted whole blood. CONCLUSIONS: A significant discrepancy was observed in the results obtained from the 2 assays because of the different specimens used. We observed, however, that diluting whole blood before conducting the cobas EBV test effectively resolved polymerase chain reaction inhibition and viscosity issues, leading to an acceptable correlation with the results from the artus EBV RG PCR Kit conducted using whole blood.
Subject(s)
Herpesvirus 4, Human , Plasma , Humans , Herpesvirus 4, Human/genetics , Viral Load , Cross ReactionsABSTRACT
PURPOSE: BVAC-B is an autologous B cell- and monocyte-based immunotherapeutic vaccine that contains cells transfected with a recombinant human epidermal growth factor receptor 2 (HER2) gene and loaded with the natural killer T cell ligand alpha-galactosylceramide. Here, we report the first BVAC-B study in patients with HER2-positive advanced gastric cancer. MATERIALS AND METHODS: Patients with advanced gastric cancer refractory to standard treatment with HER2+ immunohistochemistry ≥ 1 were eligible for treatment. Patients were administered low (2.5×107 cells/dose), medium (5.0×107 cells/dose), or high dose (1.0×108 cells/dose) of BVAC-B intravenously four times every 4 weeks. Primary endpoints included safety and maximum tolerated BVAC-B dose. Secondary endpoints included preliminary clinical efficacy and BVAC-B-induced immune responses. RESULTS: Eight patients were treated with BVAC-B at low (n=1), medium (n=1), and high doses (n=6). No dose-limiting toxicity was observed, while treatment-related adverse events (TRAEs) were observed in patients treated with medium and high doses. The most common TRAEs were grade 1 (n=2) and grade 2 (n=2) fever. Out of the six patients treated with high-dose BVAC-B, three had stable disease with no response. Interferon gamma, tumor necrosis factor-α, and interleukin-6 increased after BVAC-B treatment in all patients with medium and high dose, and HER2-specific antibody was detected in some patients. CONCLUSION: BVAC-B monotherapy had a safe toxicity profile with limited clinical activity; however, it activated immune cells in heavily pretreated patients with HER2-positive gastric cancer. Earlier treatment with BVAC-B and combination therapy is warranted for evaluation of clinical efficacy.
Subject(s)
Stomach Neoplasms , Vaccines , Humans , Trastuzumab/therapeutic use , Stomach Neoplasms/drug therapy , Antibodies, Monoclonal, Humanized , Monocytes/pathology , Vaccines/therapeutic use , ImmunotherapyABSTRACT
Human cytomegalovirus (CMV) transmitted through breast milk poses fatal risks to preterm infants. However, current molecular assay systems often do not accommodate breast milk samples. In this study, we evaluated the analytical and clinical performance of the measurement procedure of CMV load in breast milk utilizing the Cobas CMV test on the Cobas 6,800 system. This was enabled by incorporating a simple independent sample preparation procedure before the application of samples on the automated assay system. Clinical data from electronic medical records were retrospectively analyzed. Breast milk samples from mothers of preterm infants born before 33 weeks of gestation were screened for CMV using the automated assay system. CMV positivity rates in breast milk and neonatal samples and the CMV transmission rate were calculated. Furthermore, to validate the analytical accuracy of the overall measurement procedure with newly obtained residual breast milk samples, the linearity of the measurement procedure was assessed, and a simplified sample preparation method was validated against a conventional method. The CMV positivity rates in maternal breast milk and neonatal samples were 57.8 and 5.2%, respectively. The CMV transmission rate through breast milk was 7.7%. No significant differences in gestational age or birth weight were found between the CMV-negative and CMV-positive neonates. The linearity of the procedure was observed within a range of 1.87-4.73 log IU/mL. The simplified sample preparation method had an equivalent or even improved CMV detection sensitivity than the conventional method. Incorporating a simple independent sample preparation procedure effectively resolved any potential issues regarding the application of breast milk on the automated assay system. Our approach contributed to reduced vertical transmission of CMV by providing a convenient and reliable method for the monitoring of breast milk CMV positivity for clinicians.
ABSTRACT
We evaluated the overall performance of the Cobas 6800 BKV test in detecting BK virus (BKV). We examined the imprecision of the Cobas 6800 BKV test and compared the qualitative and quantitative results obtained from the Cobas 6800 BKV test and the Real-Q BKV quantification assay. We assessed 88 plasma and 26 urine samples collected between September and November 2022 from patients with BKV infection using the Real-Q BKV quantitative assay. The lognormal coefficient of variation indicated that the inter-assay precision of the Cobas 6800 BKV test ranged from 13.86 to 33.83%. A strong correlation was observed between the quantitative results obtained using the Cobas 6800 BKV test and the Real-Q BKV quantification assay for plasma samples. The Spearman's rank correlation coefficients (ρ) for plasma, polymerase chain reaction (PCR) media-stabilized urine, and raw urine samples were 0.939, 0.874, and 0.888, respectively. Our analyses suggest that the Cobas 6800 BKV test is suitable for clinical applications owing to the strong correlation between the results obtained using this test and the Real-Q BKV quantification assay in plasma and urine samples. Furthermore, utilizing fresh raw urine samples can be a viable approach for the Cobas 6800 BKV test as it is less labor- and time-intensive.
ABSTRACT
Blood group antigens, which are prominently expressed in red blood cells, are important in transfusion medicine. The advent of high-throughput genome sequencing technology has facilitated the prediction of blood group antigen phenotypes based on genomic data. In this study, we analyzed data from a large Korean population to provide an updated prevalence of blood group antigen phenotypes, including rare ones. A robust dataset comprising 72,291 single nucleotide polymorphism arrays, 5318 whole-exome sequences, and 4793 whole-genome sequences was extracted from the Korean Genome and Epidemiology Study, Genome Aggregation Database, and Korean Variant Archive and then analyzed. The phenotype prevalence of clinically significant blood group antigens, including MNSs, RHCE, Kidd, Duffy, and Diego, was predicted through genotype analysis and corroborated the existing literature. We identified individuals with rare phenotypes, including 369 (0.51%) with Fy(a-b+), 188 (0.26%) with Di(a+b-), and 16 (0.02%) with Jr(a-). Furthermore, we calculated the frequencies of individuals with extremely rare phenotypes, such as p (0.000004%), Kell-null (0.000310%), and Jk(a-b-) (0.000438%), based on allele frequency predictions. These findings offer valuable insights into the distribution of blood group antigens in the Korean population and have significant implications for enhancing the safety and efficiency of blood transfusion.
Subject(s)
Blood Group Antigens , Humans , Prevalence , Genotype , Blood Group Antigens/genetics , Genomics , Republic of Korea/epidemiologyABSTRACT
BACKGROUND: A protocol for using human endometrium derived induced pluripotent stem cells (iPSCs) to derive hematopoietic and erythroid lineages will be elaborated, through a two-phase culture system. METHODS: Discarded endometrial tissues were obtained from women receiving hysterectomy in their 4th to 5th decade due to benign uterine conditions. pCE-Sox2, Oct4, Klf4, L-Myc and Lin28 episomal vectors were used to electrotransfect the endometrial stromal cells. The first 8 days involves commitment to hematopoietic stem cells through embryoid body with robust expansion on murine bone marrow stromal cells. The second phase involves feeder free conditions with hydrocortisone, stem cell factor, interleukin-3, and recombinant EPO. After 22 days of feeder free culture, the expression profiles of CD235a+, CD34+, CD43+ and CD 71+ were analyzed by flow cytometry and Wright-Giemsa staining for differential counting. The oxygen carrying capacity of cultured RBCs was measured using a hemoxanalyser. RESULTS: As a result of inducing these cells via co-culture with murine stromal fibroblasts, all endometrium derived iPSCs were differentiated into erythroblasts with a stable yield of approximately 80% for polychromatic and orthochromatic normoblasts. The protocol for complete induction of erythroid lineage cells starting from human endometrial tissue via iPS cells has been optimized. CONCLUSION: Successful directed erythroid differentiation has occurred from human endometrium-derived iPS cells. A comprehensive process of actually deriving iPS cells using discarded surgical hysterectomy specimens to the erythroid fate has significance in that the scope of using human iPSC cell lines for tissue regeneration could be expanded in the future.
Subject(s)
Induced Pluripotent Stem Cells , Humans , Female , Mice , Animals , Cell Differentiation , Hematopoietic Stem Cells , Antigens, CD34/metabolism , Endometrium/metabolismABSTRACT
The ideal treatment option for immature necrotic permanent teeth is regeneration of the pulp-dentin complex. Mineral trioxide aggregate (MTA), the conventional cement used for regenerative endodontic procedures, induces hard tissue repair. Various hydraulic calcium silicate cements (HCSCs) and enamel matrix derivative (EMD) also promote osteoblast proliferation. The purpose of the present study was to determine the osteogenic and dentinogenic potential of commercially distributed MTA and HCSCs when applied in combination with Emdogain gel on human dental pulp stem cells (hDPSCs). The presence of Emdogain resulted in greater cell viability, and higher alkaline phosphatase activity was detected in the Emdogain-supplemented groups in the early days of cell culture. On qRT-PCR, the groups treated, respectively, with Biodentine and Endocem MTA Premixed in the presence of Emdogain showed an increased expression of the dentin formation marker DSPP, and the group treated with Endocem MTA Premixed in the presence of Emdogain showed an upregulated expression of the bone formation markers OSX and RUNX2. In an Alizarin Red-S staining assay, all of the experimental groups exhibited a greater formation of calcium nodules when treated in combination with Emdogain. Overall, the cytotoxicity and osteogenic/odontogenic potential of HCSCs were similar to that of ProRoot MTA. The addition of the EMD increased the osteogenic and dentinogenic differentiation markers.
ABSTRACT
BACKGROUND AND IMPORTANCE: Appropriate decision-making is critical for transfusions to prevent unnecessary adverse outcomes; however, transfusion in the emergency department (ED) can only be decided based on sparse evidence in a limited time window. OBJECTIVES: This study aimed to identify factors associated with appropriate red blood cell (RBC) transfusion in the ED by analyzing retrospective data of patients who received transfusions at a single center. OUTCOME MEASURES AND ANALYSIS: This study analyzed associations between transfusion appropriateness and sex, age, initial vital signs, an ED triage score [the Korean Triage and Acuity Scale (KTAS)], the length of stay, and the hemoglobin (Hb) concentration. MAIN RESULTS: Of 10â 490 transfusions, 10â 109 were deemed appropriate, and 381 were considered inappropriate. A younger age ( P â <â 0.001) and a KTAS level of 3-5 ( P â =â 0.028) were associated with inappropriate transfusions, after adjusting for O 2 saturation and the Hb level. CONCLUSIONS: In this single-center retrospective study, younger age and higher ED triage scores were associated with the appropriateness of RBC transfusions.
Subject(s)
Emergency Service, Hospital , Erythrocyte Transfusion , Humans , Retrospective Studies , TriageABSTRACT
Atypical hemolytic uremic syndrome (aHUS) is a form of thrombotic microangiopathy (TMA) that can result in end-stage renal disease. Patients with aHUS often have predisposing dysfunction in the complement pathway, and continuous activation of complement proteins can be triggered after transplantation. Here, we report the first successful case of aHUS treatment in a kidney transplant recipient with early use of a C5 inhibitor, eculizumab, in South Korea. The patient was a 32-year-old man, and the donor was his 60-year-old mother. The graft showed immediate good function. On postoperative day (POD) 3, the clinical diagnosis of TMA was made. Persistent renal dysfunction despite 10 plasma exchange (PE) sessions prompted eculizumab treatment on POD 18 under suspicion of aHUS. Next-generation sequencing reported gene mutations classified as variants of unknown significance in coagulation-associated genes. The patient was discharged after three doses of eculizumab with serum creatinine of 1.82 mg/dL. In total, 16 doses of eculizumab were administered. At the last follow-up, 21 months after eculizumab discontinuation, the graft was well functioning. De novo TMA after kidney transplantation can be caused by sustained activation of the complement pathway, and early eculizumab treatment appears important in the successful treatment of aHUS refractory to PE.
ABSTRACT
BACKGROUND: Blood transfusion is an essential part of medicine. However, many countries have been facing a national blood crisis. To address this ongoing blood shortage issue, there have been efforts to generate red blood cells (RBCs) in vitro, especially from human-induced pluripotent stem cells (hiPSCs). However, the best source of hiPSCs for this purpose is yet to be determined. METHODS: In this study, hiPSCs were established from three different hematopoietic stem cell sources-peripheral blood (PB), cord blood (CB) and bone marrow (BM) aspirates (n = 3 for each source)-using episomal reprogramming vectors and differentiated into functional RBCs. Various time-course studies including immunofluorescence assay, quantitative real-time PCR, flow cytometry, karyotyping, morphological analysis, oxygen binding capacity analysis, and RNA sequencing were performed to examine and compare the characteristics of hiPSCs and hiPSC-differentiated erythroid cells. RESULTS: hiPSC lines were established from each of the three sources and were found to be pluripotent and have comparable characteristics. All hiPSCs differentiated into erythroid cells, but there were discrepancies in differentiation and maturation efficiencies: CB-derived hiPSCs matured into erythroid cells the fastest while PB-derived hiPSCs required a longer time for maturation but showed the highest degree of reproducibility. BM-derived hiPSCs gave rise to diverse types of cells and exhibited poor differentiation efficiency. Nonetheless, erythroid cells differentiated from all hiPSC lines mainly expressed fetal and/or embryonic hemoglobin, indicating that primitive erythropoiesis occurred. Their oxygen equilibrium curves were all left-shifted. CONCLUSIONS: Collectively, both PB- and CB-derived hiPSCs were favorably reliable sources for the clinical production of RBCs in vitro, despite several challenges that need to be overcome. However, owing to the limited availability and the large amount of CB required to produce hiPSCs, and the results of this study, the advantages of using PB-derived hiPSCs for RBC production in vitro may outweigh those of using CB-derived hiPSCs. We believe that our findings will facilitate the selection of optimal hiPSC lines for RBC production in vitro in the near future.