HLA-B Matching Prolongs Allograft Survival in Islet Cell Transplantation.

Islet cell transplantation (ITx) is an effective therapeutic approach for selected patients with type 1 diabetes with hypoglycemia unawareness and severe hypoglycemia events. In organ transplantation, human leukocyte antigen (HLA) mismatching between donor and recipient negatively impacts transplant outcomes. We aimed to determine whether HLA matching has an impact on islet allograft survival. Forty-eight patients were followed up after islet transplantation at our institution from 2000 to 2020 in a retrospective cohort. Patients underwent intrahepatic ITx or laparoscopic omental approach. Immunosuppression was dependent upon the protocol. We analyzed HLA data restricted to A, B, and DR loci on allograft survival using survival and subsequent multivariable analyses. Patients were aged 42.8 ± 8.4 years, and 64.3% were female. Diabetes duration was 28.6 ± 11.6 years. Patients matching all three HLA loci presented longer graft survival (P = 0.030). Patients with ≥1 HLA-B matching had longer graft survival compared with zero matching (P = 0.025). The number of HLA-B matching was positively associated with time of graft survival (Spearman's rho = 0.590; P = 0.034). Analyses adjusted for confounders showed that ≥1 matching for HLA-B decreased the risk of allograft failure (P = 0.009). Our data suggest that HLA-B matching between recipients and donors improved islet allograft survival. Matching all three HLA loci (A, B, and DR) was also associated with prolonged islet allograft survival. Prospective studies and a larger sample size are warranted to validate our findings.

Distribution of tumor-infiltrating-T-lymphocytes and possible tumor-escape mechanisms avoiding immune cell attack in locally advanced adenocarcinomas of the esophagus.

INTRODUCTION: The inflammatory microenvironment has emerged as one of the focuses of cancer research. Little is known about the immune environment in esophageal adenocarcinoma (EAC) and possible tumor-escape mechanisms to avoid immune cell attack. PATIENTS AND METHODS: We measured T cell inflammation (CD3, CD8) in the microenvironment using a standardized software-based evaluation algorithm considering different predefined tumor areas as well as expression of MHC class 1 and PD-L1 on 75 analyzable primarily resected and locally advanced (≥ pT2) EACs. We correlated these findings statistically with clinical data. RESULTS: Patients with high amounts of T cell infiltration in their tumor center showed a significant survival benefit of 41.4 months compared to 16.3 months in T cell poor tumors (p = 0.025), although CD3 fails to serve as an independent prognostic marker in multivariate analysis. For the invasion zone, a correlation between number of T-cells and overall survival was not detectable. Loss of MHC1 protein expression on tumor cells was seen in 32% and PD-L1 expression using the combined positive score (CPS) in 21.2%. Most likely due to small numbers of cases, both markers are not prognostically relevant, even though PD-L1 expression correlates with advanced tumor stages. DISCUSSION: Our analyses reveal an outstanding, though not statistically independent, prognostic relevance of T-cell-rich inflammation in our group of EACs, in particular driven by the tumor center. For the first time, we describe that the inner part of the invasion zone in EACs shows significantly fewer T-cells than other tumor segments and is prognostically irrelevant. We also demonstrate that the loss of antigen presenting ability via MHC1 downregulation by the carcinoma cells is a common escape mechanism in EACs. Future work will need to show whether tumors with MHC class 1 loss respond less well to immunotherapy.

HLA-B*35:01 and Green Tea-Induced Liver Injury.

BACKGROUND AND AIMS: Herbal supplements, and particularly multi-ingredient products, have become increasingly common causes of acute liver injury. Green tea is a frequent component in implicated products, but its role in liver injury is controversial. The aim of this study was to better characterize the clinical features, outcomes, and pathogenesis of green tea-associated liver injury. APPROACH AND RESULTS: Among 1,414 patients enrolled in the U.S. Drug-Induced Liver Injury Network who underwent formal causality assessment, 40 cases (3%) were attributed to green tea, 202 to dietary supplements without green tea, and 1,142 to conventional drugs. The clinical features of green tea cases and representation of human leukocyte antigen (HLA) class I and II alleles in cases and control were analyzed in detail. Patients with green tea-associated liver injury ranged in age from 17 to 69 years (median = 40) and developed symptoms 15-448 days (median = 72) after starting the implicated agent. The liver injury was typically hepatocellular (95%) with marked serum aminotransferase elevations and only modest increases in alkaline phosphatase. Most patients were jaundiced (83%) and symptomatic (88%). The course was judged as severe in 14 patients (35%), necessitating liver transplantation in 3 (8%), but rarely resulting in chronic injury (3%). In three instances, injury recurred upon re-exposure to green tea with similar clinical features, but shorter time to onset. HLA typing revealed a high prevalence of HLA-B*35:01, found in 72% (95% confidence interval [CI], 58-87) of green tea cases, but only 15% (95% CI, 10-20) caused by other supplements and 12% (95% CI, 10-14) attributed to drugs, the latter rate being similar to population controls (11%; 95% CI, 10.5-11.5). CONCLUSIONS: Green tea-related liver injury has distinctive clinical features and close association with HLA-B*35:01, suggesting that it is idiosyncratic and immune mediated.

IgA Nephropathy Recurrence after Kidney Transplantation: Role of Recipient Age and Human Leukocyte Antigen-B Mismatch.

BACKGROUND: Recurrence of immunoglobulin (Ig)A nephropathy (rIgAN) is a growing cause of kidney allograft dysfunction. This study was aimed at investigating factors associated with rIgAN and the subsequent progression to end-stage renal disease (ESRD). METHODS: Retrospective study including consecutive patients with IgA nephropathy (IgAN) who received a kidney transplant in our center between 1992 and 2016 and had a renal biopsy by clinical indication. The date of detection of chronic kidney disease (CKD) 5 was used as renal outcome. RESULTS: Eighty-six kidney transplants were performed in patients with IgAN, 38 (44%) were from living donors (related n = 26). rIgAN was diagnosed in 23 allografts (27%). Renal function and proteinuria at the end of the follow-up period were worst in the rIgAN patients compared to those without rIgAN (2.2 vs. 1.4 mg/dL, p = 0.014, and 1.16 vs. 0.49 g/day, p = 0.005, respectively). Risk of rIgAN and progression to CKD 5 decreased with patient's age (hazard ratio [HR] 0.95, 95% CI 0.92-0.98, p = 0.002, and HR 0.97, 95% CI 0.83-0.97, p = 0.008 per year, respectively). Patients with rIgAN had a higher risk of progression to CKD 5 (HR 6.7, 95% CI 1.3-35.7, p = 0.025). Full donor-recipient mismatch in the human leukocyte antigen (HLA)-B loci decreased the risk of rIgAN (HR 0.22, 95% CI 0.06-0.76, p = 0.017). CONCLUSIONS: rIgAN was an independent risk factor for ESRD after renal allograft. Younger age increased the risk of rIgAN and CKD 5. Conversely, HLA-B mismatching was a potential protective factor for rIgAN of this glomerular disease.

Rapid Detection of HLA-B*57:01-Expressing Cells Using a Label-Free Interdigitated Electrode Biosensor Platform for Prevention of Abacavir Hypersensitivity in HIV Treatment.

Pre-treatment screening of individuals for human leukocyte antigens (HLA) HLA-B*57:01 is recommended for the prevention of life-threatening hypersensitivity reactions to abacavir, a drug widely prescribed for HIV treatment. However, the implementation of screening in clinical practice is hindered by the slow turnaround time and high cost of conventional HLA genotyping methods. We have developed a biosensor platform using interdigitated electrode (IDE) functionalized with a monoclonal antibody to detect cells expressing HLA-B*57:01. This platform was evaluated using cell lines and peripheral blood mononuclear cells expressing different HLA-B alleles. The functionalized IDE sensor was able to specifically capture HLA-B*57:01 cells, resulting in a significant change in the impedance magnitude in 20 min. This IDE platform has the potential to be further developed to enable point-of-care HLA-B*57:01 screening.

Corneal transplant follow-up study II (CTFS II): a prospective clinical trial to determine the influence of HLA class II matching on corneal transplant rejection: baseline donor and recipient characteristics.

PURPOSE: To describe a study to determine the influence of HLA class II matching on allograft rejection of high-risk, full-thickness corneal transplants. METHODS: A prospective, longitudinal, clinical trial (ISRCTN25094892) with a primary outcome measure of time to first clinically determined rejection episode. Tissue typing used DNA-based techniques. Corneas were allocated to patients with ≤2 human leucocyte antigen (HLA) class I antigen mismatches by cohort minimisation to achieve 0, 1 or 2 HLA class II (HLA-DR) antigen mismatches. Transplants were to be followed up at 6 months and then annually on the anniversary of surgery for 5 years. Power calculations estimated a sample size of 856 transplants to detect a 0.1 difference in probability of rejection at 1 year between HLA class II matched and mismatched transplants at the 5% level of significance with 80% power. RESULTS: To allow for loss to follow-up, 1133 transplants in 980 patients were accrued to the study between 3 September 1998 and 2 June 2011. 17% of transplants had 0 HLA-DR mismatches. The most frequent indication was bullous keratopathy, accounting for 27% of transplants and 54% of the transplants were regrafts. Median waiting time for a matched graft was 3 months. Donor and recipient characteristics were distributed evenly across the study groups. CONCLUSION: Recruitment to the CFS II has closed with 1077/1133 transplants meeting all the study criteria. Follow-up has been completed and final analysis of the data has started. TRIAL REGISTRATION NUMBER: ISRCTN25094892 andUKCRNID9871, Pre-results.

Rapid, Reliable, and Inexpensive HLA-B*58:01 Detection Method Using DNA Binding Dye-based Duplex Allele-specific Melting Curve Analysis.

BACKGROUND: Allopurinol is the most commonly used drug for the treatment of gout and also one of the most common causes of severe cutaneous adverse reactions (SCARs). Human leukocyte antigen-B*58:01 (HLA-B*58:01) is strongly associated with allopurinol-induced SCARs. The aim of the present study was to develop and validate a rapid and economic screening method for HLA-B*58:01. METHODS: The accuracy of duplex allele-specific melting curve analysis using DNA-binding dye for HLA-B*58:01 was evaluated in 150 blood samples with sequence-based typing (SBT) as the reference method. RESULTS: Fifty HLA-B*58:01-positive and 100 negative results obtained by duplex allele-specific melting curve analysis were completely in agreement with the SBT results. CONCLUSION: Duplex allele-specific melting curve analysis is a rapid, reliable and inexpensive assay that is appropriate for screening for the HLA-B*58:01 allele.

Cost effectiveness analysis of HLA-B*58:01 genotyping prior to initiation of allopurinol for gout.

Objective: To determine whether prospective testing for HLA-B*58:01, as a strategy to prevent serious adverse reactions to allopurinol in patients with gout, is cost-effective from the perspective of the National Health Service in the UK. Methods: A systematic review and meta-analysis for the association of HLA-B*58:01 with cutaneous and hypersensitivity adverse drug reactions informed a decision analytic and Markov model to estimate lifetime costs and outcomes associated with testing vs standard care (with febuxostat prescribed for patients who test positive). Scenario analyses assessed alternative treatment assumptions and patient populations. Results: The number of patients needed to test to prevent one case of adverse drug reaction was 11 286 (95% central range (CR): 2573, 53 594). Cost and quality-adjusted life-year (QALY) gains were small, £103 (95% CR: £98, £106) and 0.0023 (95% CR: -0.0006, 0.0055), respectively, resulting in an incremental cost-effectiveness ratio (ICER) of £44 954 per QALY gained. The probability of testing being cost-effective at a threshold of £30 000 per QALY was 0.25. Reduced costs of testing or febuxostat resulted in an ICER below £30 000 per QALY gained. The ICER for patients with chronic renal insufficiency was £38 478 per QALY gained. Conclusion: Routine testing for HLA-B*58:01 in order to reduce the incidence of adverse drug reactions in patients being prescribed allopurinol for gout is unlikely to be cost-effective in the UK; however testing is expected to become cost-effective with reductions in the cost of genotyping, and with the future availability of cheaper, generic febuxostat.

Successful kidney transplantation across a positive complement-dependent cytotoxicity crossmatch by using C1q assay-directed, bortezomib-assisted desensitization: A case report.

RATIONALE: Human leukocyte antigen (HLA) is the major immunologic barrier in kidney transplantation (KT). Various desensitization protocols to overcome the HLA barrier have increased the opportunity for transplantation in sensitized patients. In addition, technological advances in solid-phase assays have permitted more comprehensive assessment of donor-specific antibodies. Although various desensitization therapies and immunologic techniques have been developed, the final transplantation decision is still based on the classic complement-dependent cytotoxicity (CDC) crossmatch (XM) technique. Some patients who fail to achieve negative XM have lost their transplant opportunities, even after receiving sufficient desensitization therapies. PATIENT CONCERNS: A 57-year-old male with end-stage renal disease secondary to chronic glomerulonephritis was scheduled to have a second transplant from his son, but CDC XM was positive. DIAGNOSES: Initial CDC XM (Initial T-AHG 1:32) and flow-cytometry XM were positive. Anti-HLA-B59 donor specific antibody was detected by Luminex single antigen assay. INTERVENTIONS: Herein, we report a successful case of KT across a positive CDC XM (T-AHG 1:8 at the time of transplantation) by using C1q assay-directed, bortezomib-assisted desensitization. After confirming a negative conversion in the C1q donor-specific antibody, we decided to perform KT accepting a positive AHG-CDC XM of 1:8 at the time of transplantation. OUTCOMES: The posttransplant course was uneventful and a protocol biopsy at 3 months showed no evidence of rejection. The patient had excellent graft function at 12 months posttransplant. LESSONS: The results of XM test and solid-phase assay should be interpreted in the context of the individual patient.

Estudio de la prevalencia de marcadores genéticos asociados a la lenta progresión del virus de la inmunodeficiencia humana tipo 1 en la población gallega / Prevalence study of the genetic markers associated with slow progression of human inmunodefiency virus type 1 in the Galician population (Northwest of Spain)

INTRODUCCIÓN: La deleción en el gen CCR5 (CCR5Δ32), el haplotipo HLA-B*27:05 y los polimorfismos rs2395029 y rs9264942 han sido relacionados con la lenta progresión de la infección por VIH-1. MÉTODOS: Analizamos a 408 pacientes en seguimiento. El análisis de la carga viral, linfocitosT CD4+ y demás variables clínicas fueron recogidas desde el diagnóstico. RESULTADOS: La prevalencia de los marcadores genéticos rs9264942, CCR5wt/Δ32, rs2395029 y alelo HLA-B*27:05 fue del 17,9, del 11,5, del 7,6 y del 6,4%, respectivamente. Del total de los pacientes, 354 fueron clasificados como progresores y 46 como no progresores a largo plazo (LTNP). Exceptuando el alelo HLA-B*27:05, los demás marcadores genéticos se relacionaron con la lenta progresión: CCR5wt/Δ32 (p = 0,011) y los SNP rs2395029 y rs9264942 (p < 0,0001), así como su asociación (p < 0,0001). CONCLUSIÓN: La frecuencia hallada del alelo HLA-B*57:01 fue mayor a lo publicado a nivel nacional. Con respecto al alelo HLA-B*27:05, no hemos podido relacionar su presencia con la lenta progresión

INTRODUCTION: The deletion in the CCR5 gene (CCR5Δ32), the HLA-B*27:05, and polymorphisms rs2395029 and rs9264942 have been associated with slower progression of HIV-1. METHODS: An analysis was performed on 408 patients on follow-up. The analysis of viral load, CD4+ Tlymphocytes and other clinical variables since the diagnosis of the infection were collected. RESULTS: The prevalence of the genetic markers rs9264942, CCR5wt/Δ32, rs2395029, HLA-B*27:05 was 17.9%, 11.5%, 7.6%, and 6.4%, respectively. Of all the patients, 354 were classified as progressors and 46 as long-term non-progressors (LTNPs). Except for the HLA-B*27:05 allele, other genetic markers were associated with slower progression: CCR5wt/Δ32 (P=.011) and SNPs rs2395029 and rs9264942 (P<.0001), as well as their association (P<.0001). CONCLUSION: The prevalence of the HLA-B*57:01 allele was higher than described nationally. No association could be found between the HLA-B*27:05 allele and the presence of slower disease progression

The effect of inter-unit HLA matching in double umbilical cord blood transplantation for acute leukemia.

The effects of inter-unit HLA-match on early outcomes with regards to double cord blood transplantation have not been established. Therefore, we studied the effect of inter-unit HLA-mismatching on the outcomes of 449 patients with acute leukemia after double cord blood transplantation. Patients were divided into two groups: one group that included transplantations with inter-unit mismatch at 2 or less HLA-loci (n=381) and the other group with inter-unit mismatch at 3 or 4 HLA-loci (n=68). HLA-match considered low resolution matching at HLA-A and -B loci and allele-level at HLA-DRB1, the accepted standard for selecting units for double cord blood transplants. Patients', disease, and transplant characteristics were similar in the two groups. We observed no effect of the degree of inter-unit HLA-mismatch on neutrophil (Hazard Ratio 1.27, P=0.11) or platelet (Hazard Ratio 0.1.13, P=0.42) recovery, acute graft-versus-host disease (Hazard Ratio 1.17, P=0.36), treatment-related mortality (Hazard Ratio 0.92, P=0.75), relapse (Hazard Ratio 1.18, P=0.49), treatment failure (Hazard Ratio 0.99, P=0.98), or overall survival (Hazard Ratio 0.98, P=0.91). There were no differences in the proportion of transplants with engraftment of both units by three months (5% after transplantation of units with inter-unit mismatch at ≤2 HLA-loci and 4% after transplantation of units with inter-unit mismatch at 3 or 4 HLA-loci). Our observations support the elimination of inter-unit HLA-mismatch criterion when selecting cord blood units in favor of optimizing selection based on individual unit characteristics.

Fulminant type I diabetes mellitus associated with nivolumab in a patient with relapsed classical Hodgkin lymphoma.

We report the case of a patient with relapsed classical Hodgkin lymphoma who developed fulminant type I diabetes mellitus as a severe adverse event of treatment with the anti-programmed cell death-1 (PD-1) antibody, nivolumab. On the first day of the sixth cycle, the blood glucose level was markedly elevated (375 mg/dL). Although neither ketoacidosis nor ketonuria was detected, the markedly acute onset of the hyperglycemia was consistent with the typical clinical course of fulminant type I diabetes mellitus, and this diagnosis was supported by clinical data. All autoantibodies associated with type I diabetes mellitus were negative. The endogenous insulin secretion ceased completely within 2 weeks. After the blood glucose level was brought under control, nivolumab was resumed and continued without other major adverse events. Human leukocyte antigen (HLA) analysis revealed that the patient carried the HLA-B*4002 haplotype, a susceptibility allele for this type of diabetes mellitus. This case suggests that fulminant type I diabetes mellitus may be triggered by nivolumab in patients with a genetic background associated with the condition, warranting careful future consideration of this particular adverse event.

Survival and HLA-B*57 in HIV/HCV Co-Infected Patients on Highly Active Antiretroviral Therapy (HAART).

BACKGROUND AND AIMS: HLA class I alleles, in particular HLA-B*57, constitute the most consistent host factor determining outcomes in untreated HCV- and HIV-infection. In this prospective cohort study, we analysed the impact of HLA class I alleles on all-cause mortality in patients with HIV-, HCV- and HIV/HCV- co-infection receiving HAART. METHODS: In 2003 HLA-A and B alleles were determined and patients were prospectively followed in 3-month intervals until 2013 or death. HLA-A and B alleles were determined by strand-specific oligonucleotide hybridisation and PCR in 468 Caucasian patients with HCV- (n=120), HIV- (n=186) and HIV/HCV-infection (n=162). All patients with HIV-infection were on HAART. In each patient group, HLA class I-associated survival was analysed by Kaplan-Meier method and Cox regression analysis. RESULTS: At recruitment the proportion of patients carrying a HLA-B*57 allele differed between HIV- (12.9%) and HCV-infection (4.2%). Kaplan Meier analysis revealed significantly increased mortality in HLA-B*57-positive patients with HIV-infection (p=0.032) and HIV/HCV-co-infection (p=0.004), which was apparently linked to non-viral infections. Cox logistic regression analysis confirmed HLA-B*57 (p=0.001), serum gamma-glutamyltranspeptidase (p=0.003), serum bilirubin (p=0.022) and CD4 counts (p=0.041) as independent predictors of death in HIV-infected patients. CONCLUSION: Differences in the prevalence of HLA-B*57 at study entry between HIV- and HCV- infected patients may reflect immune selection in the absence of antiviral therapy. When patients were treated with HAART, however, HLA-B*57 was associated with increased mortality and risk to die from bacterial infections and sepsis, suggesting an ambiguous role of HLA-B*57 for survival in HIV/HCV infection depending on the circumstances.

Abacavir (Ziagen(®)) use between 2003 and 2008 in France according to the electronic medical record NADIS(®).

OBJECTIVE: The authors had for objective to describe HIV-infected patients treated with ABC (Ziagen(®), ABC), and the immune, virological, and clinical treatment outcome between 2003 and 2008. PATIENTS AND METHODS: We performed a retrospective analysis of the Dat'AIDS database on patients who were treated with ABC for the first time between 2003 and 2008. RESULTS: Eight hundred and thirty-six patients were included. Before initiation of ABC, 26.3% has stopped the previous treatment because of immuno-virological failure, 30.5% because of adverse events, and 29.8% for other reasons. Thirteen percent were antiretroviral naive. One third of patients were ranked as CDC class C, and more than 2/3 had a viral load<5 log copies/mL or a CD4 count≥200mm(3). ABC was mainly included in a combination containing 2 NRTI and 1 PI (63%), or 1 non-NRTI (16%). Thirty-two percent of patients were still treated with ABC after 2years of treatment and the median of ABC treatment was 11months (IQ 84days-2years). The main causes for stopping ABC were therapeutic simplification (47.4% of patients), intolerance (19.0%), and immuno-virological failure (9.8%). Suspected hypersensitivity reactions were the main cause of discontinuation due to intolerance (27.6%); the rate was 3.8% when ABC had been introduced before the routine use of the screening test HLA-B*5701. The incidence of myocardial infarction was 3.8 per 1000 patient-years; 70.6% of patients received a fixed combination including ABC after discontinuation of ABC as a single agent (Ziagen(®)). CONCLUSION: This retrospective analysis confirmed the effectiveness and the good tolerance of ABC in the therapeutic strategy, between 2003 and 2008.

Flow cytometry analysis with a new FITC-conjugated monoclonal antibody-3E12 for HLA-B*57:01 rapid screening in prevention of abacavir hypersensitivity in HIV-1-infected patients.

BACKGROUND: Rapid screening for the detection of HLA-B*57:01 in the prevention of abacavir hypersensitivity in HIV-1-infected patients is a hallmark for clinical services. OBJECTIVE: The aim of this work was to analyze the utility of flow cytometry with a new FITC-conjugated B-17 monoclonal antibody (mAb3E12) for HLA-B*57:01 screening in a Spanish cohort of 577 HIV-1+ individuals. METHODS: Cryopreserved peripheral blood mononuclear cell samples from HIV-1+ individuals were analyzed by flow cytometry with the mAb 3E12 that recognizes both HLA-B*57 and HLA-B*58 alleles (members of the group specificity, HLA-B17). Patients' DNA samples had been previously typed for HLA-B*57:01 with PCR-SSO or PCR-SSP and additional DNA sequencing (EPI Study). The results obtained by flow cytometry were compared with the results obtained by the DNA-PCR techniques. RESULTS: By flow cytometry, 46 samples (7.97%) were positive for HLA-B17, 530 (91.86%) were negative, and 1 (0.17%) was undetermined. All samples found negative by flow cytometry were negative for HLA-B*57:01 by DNA-PCR. Of the HLA-B17 positive samples, 31 (67.4%) were positive for HLA-B*57:01, 2 (3.25%) were positive for HLA-B*57:03, 11 (26.1%) were positive for HLA-B*58, and 2 (3.25%) were negative for both HLA-B*57 and HLA-B*58 antigens. The undetermined sample was negative for HLA-B*57 and HLA-B*58 alleles by DNA-PCR. CONCLUSIONS: This study shows that flow cytometry with mAb3E12 is a highly sensitive method (no false negatives) to implement prior to DNA-PCR analysis for rapid screening of HLA-B*57:01. Additional confirmation by molecular HLA typing method would be required in less than 10% of the cohort of HIV-1-infected individuals.

Comprehensive evaluation of two HLA-B17 monoclonal antibodies for flow cytometry-based HLA-B57/B58 screening prior to abacavir prescription.

Hypersensitivity reactions to the drug abacavir, used to treat HIV/AIDS patients, is associated with possession of HLA-B*57:01. We have carefully assessed two commercially available HLA-B57/B58 murine monoclonal antibodies [0196HA and BIH0243 (One Lambda Inc.)] in a simple flow cytometry-based assay. The evaluation involved tests on 228 reference and random samples covering 91% of all WHO recognized HLA-A, B and C specificities. These involved donors with six different HLA-B*57 alleles and included 19 examples of B*57:01. Both antibodies unambiguously detected B57, but there were small difference in their reactivity against B57-positive non-B*57:01 samples. Importantly, there was no reactivity against B57/B58-negative samples. The possible amino acid motifs involved in the reactivity of these antibodies with B57/B58 were delineated. Thus, HLA-B57/B58, normally present in <10% of patients, can be easily recognized using these two antibodies and further tested by a DNA-based typing method to identify B*57:01.

Individual composition of human leukocyte antigens and periodontopathogens in the background of periodontitis.

BACKGROUND: Human leukocyte antigens (HLAs) are a basic precondition to induce the immune response to pathogens. Therefore, this study evaluates associations among periodontitis, five key periodontopathic bacteria, and HLAs to test their impact together with additional risk factors in multivariate analyses. METHODS: Eighty-five patients with generalized aggressive periodontitis (GAgP) and 71 patients with generalized chronic periodontitis (CP) were compared to 88 periodontitis-free controls. HLA Class I and II typing was performed by polymerase chain reaction (PCR) with sequence-specific primers. Subgingival plaque specimens were detected by PCR with sequence-specific oligonucleotides. Risk-factor analyses were performed with respect to the cofactors age, sex, smoking, and plaque level by logistic regression. RESULTS: In the total patient group (GAgP + CP), the adjusted odds ratio (OR) of periodontitis was decreased in cases who were carriers of HLA-B*57 (OR = 0.259, 95% confidence interval [CI] = 0.086 to 0.782), HLA-DQB1*08 (OR = 0.404, 95% CI = 0.187 to 0.871), or the combination HLA-DRB1*04;DRB4*;DQB1*0302 (OR = 0.407, 95% CI = 0.185 to 0.895). Moreover, individuals who expressed HLA-DRB1*04 (OR = 0.36, 95% CI = 0.148 to 0.886) or HLA-DRB1*04;DRB4*;DQB1*0302 (OR = 0.29, 95% CI = 0.092 to 0.884) had a decreased colonization risk with Aggregatibacter actinomycetemcomitans. CONCLUSIONS: Certain HLA markers were negatively associated to the manifestation of a generalized periodontitis and/or the individual colonization of A. actinomycetemcomitans. The underlying mechanisms have to be investigated in future studies.

Loop-mediated isothermal amplification for detection of HLA-B*58:01 allele.

Strong association of human leukocyte antigen (HLA)-B*58:01 allele with allopurinol-induced hypersensitivity was found worldwide, especially in the Han Chinese populations. This study aims to develop and evaluate a loop-mediated isothermal amplification (LAMP) assay for rapid detection of HLA-B*58:01. Two sets of LAMP primers targeting exons 2 and 3 of HLA-B*58:01 allele were designed and their annealing temperatures were optimized accordingly. The heating devices for LAMP assay were tested. The analytical sensitivities of the two sets of LAMP primers were determined by 1:10 serial dilution of a positive control with homozygous HLA-B*58:01 allele from 100 ng down to 1 fg. The analytical specificities of the LAMP primers were evaluated by 30 selected University of California, Los Angeles (UCLA) DNA Exchange Program samples with known HLA-B loci typings previously typed by sequencing. Both sets of LAMP primers targeting exons 2 and 3 amplified optimally at 67°C. Thermal cycler is essential in achieving a more precise and specific LAMP result. The sensitivity of the exon 2 LAMP primer set was found to be 1 pg, whereas it was 10 ng for the exon 3 primer set in a 60-min amplification. The LAMP primers were highly specific because LAMP results were perfectly concordant to the sequencing results. The HLA-B*58:01 LAMP assay has compatible sensitivity and specificity to routine genotyping assays, and it is potentially an alternative screening test for the detection of HLA-B*58:01 and ultimately allopurinol-induced hypersensitivity.