Combined Analysis of HLA Class II Eplet Mismatch and Tacrolimus Levels for the Prediction of De Novo Donor Specific Antibody Development in Kidney Transplant Recipients.

We investigated whether HLA class II eplet mismatch was related to dnDSA development and analyzed its combined impact with tacrolimus levels for kidney transplantation outcomes. A total of 347 kidney transplants were included. HLA Matchmaker was used for the single molecular eplet, total eplet, antibody (Ab)-verified eplet mismatch analyses, and Ab-verified single molecular analysis to identify HLA-DR/DQ molecular thresholds for the risk of dnDSA development. A time-weighted tacrolimus trough level (TAC-C0) of 5 ng/mL and a TAC-C0 time-weighted coefficient variability (TWCV) of 20% were applied to find the combined effects on dnDSA development. A high level of mismatch for single molecular eplet (DQ ≥ 10), total eplet (DQ ≥ 12), Ab-verified eplet (DQ ≥ 4), and Ab-verified single molecular eplet (DQ ≥ 4) significantly correlated with HLA class II dnDSA development. Class II dnDSA developed mostly in patients with low TAC-C0 and high eplet mismatch. In the multivariable analyses, low TAC-C0 and high eplet mismatch showed the highest hazard ratio for the development of dnDSA. No significant combined effect was observed in dnDSA development according to TWCV. In conclusion, the determination of HLA class II eplet mismatch may improve the risk stratification for dnDSA development, especially in conjunction with tacrolimus trough levels.

Characteristics of RAS pathway mutations in juvenile myelomonocytic leukaemia: a single-institution study from Korea.

Juvenile myelomonocytic leukaemia (JMML), a rare clonal haematopoietic disorder of childhood, is characterised as a myelodysplastic/myeloproliferative neoplasm. Despite ground-breaking genetic discoveries, JMML remains difficult to diagnose given its diverse clinical features and disease course. A total of 24 patients with JMML were diagnosed and treated at a single institution, and their genetic profiles and association with clinical and laboratory characteristics were analysed. In all, 22 of the patients received allogeneic haematopoietic stem cell transplantation after myeloablative conditioning, mostly from a haploidentical family donor. RAS pathway mutations were identified in 88% of patients: PTPN11 [nine (38%)], NRAS [nine (38%)], KRAS [two (8%)], NF1 [five (21%)] and CBL [one (4%)]. Secondary mutations were found in 25% of patients: SETBP1, JAK3, ASXL1, GATA2, KIT, KDM6A, and BCOR. Six patients showed cytogenetic abnormalities, including three with monosomy 7. The estimated 5-year event-free survival (EFS) and overall survival (± standard error) of the entire cohort were 58·9 (10·9)% and 73·5 (10·8)% respectively. NRAS (+) patients had a higher 5-year EFS than NRAS (-) patients [72·9 (16·5)% vs. 52·5 (13·1)%, P = 0·127]. NRAS (+) patients had a better 5-year EFS than PTPN11 (+) patients [41·7 (17·3)%, P = 0·071]. Our study revealed the genetic characteristics of Korean JMML patients with RAS pathway and secondary mutations.

Limited Contribution of Creatine Kinase-Myocardial Band Alongside High-Sensitivity Cardiac Troponin in Diagnosing Acute Myocardial Infarction in an Emergency Department.

Cardiac biomarkers, especially high-sensitivity cardiac troponin C or I (hs-cTnC or hs-cTnI, respectively), are vital for diagnosing acute myocardial infarction (AMI). Despite the specificity of hs-cTn as a biomarker, the creatine kinase-myocardial band (CK-MB) is commonly used alongside hs-cTn in emergency departments (EDs). We analyzed 23,771 simultaneous hs-cTn (hs-cTnT or hs-cTnI) and CK-MB requests for 17,185 patients in tertiary hospital ED in 2022. The objective of this study was to assess their practical value in diagnosing AMI in real-world settings. Among all 17,185 patients tested, 98.0% underwent hs-cTnT and CK-MB tests, and substantially fewer underwent hs-cTnI testing. We observed concordance between the initial hs-cTn and CK-MB results in 71.3% of patients. Of 131 AMI cases, 57 were positive for both biomarkers, 63 for hs-cTn only, and none for CK-MB alone. CK-MB positivity was often found in the absence of AMI. Discrepancies between the hs-cTnT and hs-cTnI results occurred in 30.0% of patients. Indiscriminate CK-MB testing for diagnosing AMI in EDs should be reconsidered. Efficient use of CK-MB is important for reducing costs and ensuring optimal patient care.

Evaluation of Long-Term Adaptive Immune Responses Specific to SARS-CoV-2: Effect of Various Vaccination and Omicron Exposure.

The immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) becomes increasingly complex as individuals receive different combinations of vaccine doses and encounter breakthrough infections. Our study focused on the immunogenicity observed over a two-year period in healthy individuals who completed a two-dose series and then experienced booster and/or Omicron infection. In June 2023, we recruited 78 healthcare workers who had previously participated in clinical research initiated in March 2021 at a single medical center in South Korea. At 1, 5, 11, and 25 months after a second dose, we assessed SARS-CoV-2-specific humoral and cellular immune responses. Longitudinal monitoring revealed a significant decline in humoral immunity levels after the second vaccine dose, followed by a substantial increase post-third vaccination or breakthrough infection. In contrast, stable cellular immune responses were consistently observed, with peak humoral and cellular immune measures reached at 25 months after the second dose. Among infection-naïve participants, three-dose vaccinated individuals had decreased neutralizing activity against wild-type (WT) and negative activities against Omicron subvariants BA.2 and BA.4/5, whereas those who received a fourth dose of bivalent BNT had significantly increased neutralizing activity (p < 0.05). All immune metrics tended to increase as the number of vaccine doses increased. Among participants with 4-exposure, homologous vaccination (mRNA × 4) led to higher humoral immunity, whereas heterologous vaccination (ChAd × 2/mRNA × 2) induced stronger cellular responses against multiple SARS-CoV-2 variants by enzyme-linked immunospot assays (p < 0.05). Immune responses from bivalent vaccines or Omicron infection did not show statistically significant differences among exposure number-matched participants (p > 0.05). Omicron exposure significantly increased cross-neutralizing activity, but magnitude of cellular immunity was not significantly altered by Omicron exposure. Our longitudinal study highlights the evolving complexity of SARS-CoV-2 immune responses, showing enhanced immunity with multiple vaccine doses and robust cellular responses from heterologous vaccination. These findings emphasize the need for ongoing surveillance to optimize vaccination strategies against emerging variants.

Humoral Response Kinetics and Cross-Immunity in Hospitalized Patients with SARS-CoV-2 WT, Delta, or Omicron Infections: A Comparison between Vaccinated and Unvaccinated Cohorts.

With the ongoing evolution of severe acute respiratory virus-2 (SARS-CoV-2), the number of confirmed COVID-19 cases continues to rise. This study aims to investigate the impact of vaccination status, SARS-CoV-2 variants, and disease severity on the humoral immune response, including cross-neutralizing activity, in hospitalized COVID-19 patients. This retrospective cohort study involved 122 symptomatic COVID-19 patients hospitalized in a single center. Patients were categorized based on the causative specific SARS-CoV-2 variants (33 wild-type (WT), 54 Delta and 35 Omicron) and their vaccination history. Sequential samples were collected to assess binding antibody responses (anti-S/RBD and anti-N) and surrogate virus neutralization tests (sVNTs) against WT, Omicron BA.1, and BA.4/5. The vaccinated breakthrough infection group (V) exhibited higher levels of anti-S/RBD compared to the variant-matched unvaccinated groups (UVs). The Delta infection resulted in a more rapid production of anti-S/RBD levels compared to infections with WT or Omicron variants. Unvaccinated severe WT or Delta infections had higher anti-S/RBD levels compared to mild cases, but this was not the case with Omicron infection. In vaccinated patients, there was no difference in antibody levels between mild and severe infections. Both Delta (V) and Omicron (V) groups showed strong cross-neutralizing activity against WT and Omicron (BA.1 and BA.4/5), ranging from 79.3% to 97.0%. WT (UV) and Delta (UV) infections had reduced neutralizing activity against BA.1 (0.8% to 12.0%) and BA.4/5 (32.8% to 41.0%). Interestingly, patients who received vaccines based on the ancestral spike exhibited positive neutralizing activity against BA.4/5, even though none of the study participants had been exposed to BA.4/5 and it is antigenically more advanced. Our findings suggest that a previous vaccination enhanced the humoral immune response and broadened cross-neutralizing activity to SARS-CoV-2 variants in hospitalized COVID-19 patients.

Comparison of humoral and cellular immune responses between ChAd-BNT heterologous vaccination and BNT-BNT homologous vaccination following the third BNT dose: A prospective cohort study.

Introduction: The differential immune responses after two additional BNT162b2 (BNT) booster doses between ChAdOx1 nCoV-10 (ChAd)-primed and BNT-primed groups have not been elucidated. The aim of this study was to compare vaccine-induced humoral and cellular immune responses and evaluate breakthrough infection between the two vaccination strategies. Methods: In 221 healthy subjects (111 in the ChAd group), longitudinal immune responses were monitored at 3, 4, and 6 months after the 2nd dose and 1, 3, and 6 months after the 3rd dose. Humoral immunity was measured by two fully automated chemiluminescent immunoassays (Elecsys and Abbott) and a surrogate virus neutralization test (sVNT). Cellular immunity was assessed by two interferon-γ (IFN-γ) release assays (QuantiFERON SARS-CoV-2 and Covi-FERON). Results: After the 2nd dose of BNT vaccination, total antibody levels were higher in the ChAd group, but IgG antibody and sVNT results were higher in the BNT group. Following the 3rd dose vaccination, binding antibody titers were significantly elevated in both groups (ChAD-BNT; 15.4 to 17.8-fold, BNT-BNT; 22.2 to 24.6-fold), and the neutralizing capacity was increased by 1.3-fold in both cohorts. The ChAd-BNT group had lower omicron neutralization positivity than the BNT-BNT group (P = 0.001) at 6 months after the 3rd dose. Cellular responses to the spike antigen also showed 1.7 to 3.0-fold increases after the 3rd dose, which gradually declined to the levels equivalent to before the 3rd vaccination. The ChAd cohort tended to have higher IFN-γ level than the BNT cohort for 3-6 months after the 2nd and 3rd doses. The frequency of breakthrough infection was higher in the ChAd group (44.8%) than in the BNT group (28.1%) (P = 0.0219). Breakthrough infection induced increased humoral responses in both groups, and increase of cellular response was significant in the ChAd group. Discussion: Our study showed differential humoral and cellular immune responses between ChAd-BNT-BNT heterologous and BNT-BNT-BNT homologous vaccination cohorts. The occurrence of low antibody levels in the ChAd-primed cohort in the humoral immune response may be associated with an increased incidence of breakthrough infections. Further studies are needed on the benefits of enhanced cellular immunity in ChAd-primed cohorts.

The influence of HLA A, B, C, DR alleles and HLA haplotypes on cytomegalovirus-specific cell mediated immunity in seropositive Korean kidney transplant candidates.

We evaluated the effect of specific HLA alleles and haplotypes on cytomegalovirus (CMV)-specific cell mediated immunity (CMI) in kidney transplant (KT) candidates. CMV-specific ELISPOT against pp65 and IE-1 antigens (hereafter referred to as pp65 and IE-1, respectively) was performed in 229 seropositive KT candidates. We analyzed the results related to 44 selected HLA alleles (9 HLA-A, 15 HLA-B, 9 HLA-C, and 11 HLA-DR) and 13 HLA haplotypes commonly found in study participants. The pp65 and IE-1 results in 229 seropositive candidates were 227.5 (114.5-471.5) and 41.0 (8.8-185.8) (median [interquartile range]) spots/2 × 105 PBMCs, respectively. The pp65 and IE-1 results showed significant differences between candidates with different HLA alleles (A*02 vs. A*26 [p = 0.016], A*24 vs. A*30 [p = 0.031], B*07 vs. B*46 [p = 0.005], B*54 vs. B*35 [p = 0.041], B*54 vs. B*44 [p = 0.018], B*54 vs. B*51 [p = 0.025], and C*06 vs. C*14 [p = 0.034]). HLA-A*02 and B*54 were associated with increased pp65 and IE-1 results, respectively (p = 0.005 and p < 0.001, respectively). In contrast, the HLA-A*26 and B*46 alleles were associated with a decreased pp65 response, whereas the A*30 allele was associated with a decreased IE-1 response (p < 0.05). The pp65 results correlated with the HLA-A allele frequencies (R = 0.7546, p = 0.019) and the IE-1 results correlated with the HLA-C allele frequencies of the study participants (R = 0.7882, p = 0.012). Among 13 haplotypes, HLA-A*30 ~ B*13 ~ C*06 ~ DRB1*07 showed decreased CMV-CMIs compared to the other HLA haplotypes, probably due to a combination of HLA alleles associated with lower CMV-CMIs. Our results demonstrated that CMV-specific CMIs may be influenced by the HLA allele as well as the HLA haplotype. To better predict CMV reactivation, it is important to estimate risk in the context of HLA allele and haplotype information.

Longitudinal Analysis of SARS-CoV-2-Specific Cellular and Humoral Immune Responses and Breakthrough Infection following BNT162b2/BNT162b2/BNT162b2 and ChAdOx1/ChAdOx1/BNT162b2 Vaccination: A Prospective Cohort in Naive Healthcare Workers.

Assessing immune responses post-SARS-CoV-2 vaccination is crucial for optimizing vaccine strategies. This prospective study aims to evaluate immune responses and breakthrough infection in 235 infection-naïve healthcare workers up to 13-15 months after initial vaccination in two vaccine groups (108 BNT/BNT/BNT and 127 ChAd/ChAd/BNT). Immune responses were assessed using the interferon-gamma enzyme-linked immunospot (ELISPOT) assay, total immunoglobulin, and neutralizing activity through surrogate virus neutralization test at nine different time points. Both groups exhibited peak responses one to two months after the second or third dose, followed by gradual declines over six months. Notably, the ChAd group exhibited a gradual increase in ELISPOT results, but their antibody levels declined more rapidly after reaching peak response compared to the BNT group. Six months after the third dose, both groups had substantial cellular responses, with superior humoral responses in the BNT group (p < 0.05). As many as 55 breakthrough infection participants displayed higher neutralization activities against Omicron variants, but similar cellular responses compared to 127 infection-naïve individuals, suggesting cross-immunity. Distinct neutralization classifications (<30%, >80% inhibition) correlated with different ELISPOT results. Our study reveals diverse immune response patterns based on vaccine strategies and breakthrough infections, emphasizing the importance of understanding these dynamics for optimized vaccination decisions.

Causes of Positive Pretransplant Crossmatches in the Absence of Donor-Specific Anti-Human Leukocyte Antigen Antibodies: A Single-Center Experience.

Pretransplant crossmatch (XM) testing is widely used for detecting preformed donor-specific antibodies (DSAs) against human leukocyte antigen (HLA). However, in some cases, there is a positive XM result in the absence of HLA-DSAs, the cause of which was rarely identified. We reviewed the causes of sequential positive XM results at a single center and analyzed the presence of non-HLA antibodies in patients with an unexplained positive pretransplant XM result. Among 251 patients with T-cell/B-cell complement-dependent cytotoxicity (CDC) or flow cytometric crossmatch (FCXM) positivity, HLA-DSAs were confirmed in 88 (35.1%) by a single antigen bead (SAB) assay, 150 (59.8%) used rituximab (anti-CD20), and 13 (5.2%) had neither HLA-DSAs nor a desensitization history. Anti-angiotensin II type 1 receptor IgG and 33 non-HLA antibodies were tested in the 13 patients with an unexplained positive pretransplant XM result, and more than one non-HLA antibody were revealed in all these patients; 11 patients had non-HLA antibodies reported to be associated with graft rejection, and two patients experienced rejection episode after kidney transplantation. Our study suggests considering non-HLA antibodies testing when a CDC or FCXM test is positive without a definite cause. Assessing non-HLA antibodies might be useful for interpreting XM results and evaluating immunologic risk in transplant recipients.

Assessment of Rapid Optimized 96-well Tray Flow Cytometric Crossmatch (Halifax-FCXM) with Luminex Single Antigen Test.

INTRODUCTION: Flow cytometric crossmatch assay (FCXM) is a sensitive cell-based method for evaluating the presence of donor-specific antibodies (DSA) before transplantation. Recently, 96-well tray FCXM protocol (Halifax FCXM) with improved test efficiency has been introduced. The objective of the present study was to assess the performance of Halifax FCXM by correlating with DSA results based on single antigen bead (SAB) assays (virtual crossmatch, VXM). METHODS: A total of 341 FCXMs were evaluated for the detection of HLA-DSA. A positive VXM was defined as having at least one HLA - DSA (HLA-A, B, Cw, DR, DQB1) with ≥ 1000 MFI (mean fluorescence intensity) identified by SAB assay. RESULTS: Of a total 341 cases, 113 showed class I VXM (+) with class I DSA MFI ≥ 1000 exclusively against one or more donor HLA class I antigens (HLA-A, B, Cw), 72 had class I-/II + DSA, and 156 had VXM(-). Halifax T-FCXM showed a sensitivity of 87.6% (99/113) and a specificity of 98.2% (224/228) for detecting class I VXM (+). The concordance between T-FCXM and class I VXM was 94.7% (323/341). Halifax B-FCXM showed a sensitivity of 58.3% (42/72) and a specificity of 98.7% (154/156) for detecting class I-/II + DSAs. The concordance between B-FCXM and class I-/II + VXM was 86.0% (196/228). When we separately analyzed data, B-FCXM detected HLA-DR (+) (68.8%) and HLA-DQ (+) DSAs (71.0%) similarly (P > 0.05). T-FCXM detected 87.6%, 97.2%, and 98.2% of class I DSA-positive cases with MFI values (sumDSA) ≥ 1000, ≥ 3000, and ≥ 5000, respectively. B-FCXM detected 58.3% of class I-II + DSA -positive (≥1000) cases, but detected 76.7% (33/43) and 89.2% (33/37) of class I-II + DSAs if MFI values of sumDSA and immunodominant DSA (iDSA) were above 5000, respectively. Halifax FCXM had sensitivities of 91.5% and 96.2% for detecting VXM (+) having MFI values above 5000 for class I or class II sumDSA and iDSA, respectively. CONCLUSION: Halifax FCXM showed a good correlation, especially with SAB assay-based high MFI DSA or sumDSA. Concurrent application of FCXM with VXM can improve pre-transplant risk assessment and progress organ allocation efficiency.

Association of citalopram with congenital anomalies: A meta-analysis.

OBJECTIVE: The antenatal use of citalopram, a widely prescribed selective serotonin reuptake inhibitor, has been suspected to be associated with congenital, particularly cardiac, anomalies. This study aimed to prove the association between citalopram use and congenital anomalies. METHODS: We searched the English literature from July 1998 to July 2015, by using the search terms ' citalopram', ' pregnancy', ' birth defects', ' congenital anomalies', and ' malformations' in PubMed, Embase, Web of Science, and the Cochrane Library. RESULTS: Eight eligible articles were analyzed including a total of 1,507,896 participants. The odds ratio (OR) of major malformations associated with citalopram use during pregnancy was 1.07 (95% confidence interval [CI], 0.98 to 1.17). Concerning cardiac malformations, the OR for all included studies was 1.31 (95% CI, 0.88 to 1.93). The analysis of cardiac malformations was repeated to reduce heterogeneity after excluding one outlier study (OR, 1.03; 95% CI, 0.84 to 1.26). CONCLUSION: From our data, it can be concluded that citalopram use is not associated with major birth defects. However, physicians should carefully weigh the benefits against the potential risks of citalopram use, and counsel patients accordingly.