Validation of a Simple, Rapid, and Cost-Effective Method for Acute Rejection Monitoring in Lung Transplant Recipients.

Despite advances in immunosuppression therapy, acute rejection remains the leading cause of graft dysfunction in lung transplant recipients. Donor-derived cell-free DNA is increasingly being considered as a valuable biomarker of acute rejection in several solid organ transplants. We present a technically improved molecular method based on digital PCR that targets the mismatch between the recipient and donor at the HLA-DRB1 locus. Blood samples collected sequentially post-transplantation from a cohort of lung recipients were used to obtain proof-of-principle for the validity of the assay, correlating results with transbronchial biopsies and lung capacity tests. The results revealed an increase in dd-cfDNA during the first 2 weeks after transplantation related to ischemia-reperfusion injury (6.36 ± 5.36%, p < 0.0001). In the absence of complications, donor DNA levels stabilized, while increasing again during acute rejection episodes (7.81 ± 12.7%, p < 0.0001). Respiratory tract infections were also involved in the release of dd-cfDNA (9.14 ± 15.59%, p = 0.0004), with a positive correlation with C-reactive protein levels. Overall, the dd-cfDNA percentages were inversely correlated with the lung function values measured by spirometry. These results confirm the value of dd-cfDNA determination during post-transplant follow-up to monitor acute rejection in lung recipients, achieved using a rapid and inexpensive approach based on the HLA mismatch between donor and recipient.

Impact of viral eradication with sofosbuvir-based therapy on the outcome of post-transplant hepatitis C with severe fibrosis.

BACKGROUND & AIMS: Several studies have shown that new direct-acting antivirals maintain their efficacy in liver transplant (LT) recipients with severe hepatitis C virus (HCV) recurrence. We determined the clinical impact of sofosbuvir/ribavirin in LT through the changes in liver function and fibrosis state at 24 and 48 weeks after treatment. METHODS: Between June 2014 and July 2015, 126 patients (30 F3, 96 F4 Metavir stage) were enrolled to receive sofosbuvir + ribavirin (24 weeks, 118 patients) or sofosbuvir + simeprevir + ribavirin (12 weeks, 8 patients); treatment was initiated at a median time of 4.3 years from LT. Median follow-up after therapy completion was 461 days. RESULTS: All 30 F3 patients achieved a sustained virological response at week 24 after treatment (SVR24) and showed a distinct amelioration of the AST-to-platelet ratio index (APRI), FIB-4 and liver stiffness at elastography by week 24 post-therapy, which were maintained at week 48. Of the 96 F4 cirrhotic patients, 72 (75%) achieved SVR24 accompanied by significant improvement of liver function, which was maintained at week 48 (Child B-C 22% baseline, 11% week 24, 7% week 48); APRI, FIB-4 and liver stiffness further improved significantly between weeks 24 and 48 of follow-up. Among the 77 responders (27 F3, 50 F4) who underwent elastography at baseline and at the end of follow-up, 39 (50.6%; 18 F3, 21 F4) exhibited a regression in fibrosis stage. CONCLUSION: At about 1 year from the completion of successful sofosbuvir-based therapy, patients with post-LT HCV and severe fibrosis experienced a long-term liver function improvement accompanied by a regression of fibrosis stage in half of them.

Early reduced liver graft survival in hepatitis C recipients identified by two combined genetic markers.

HLA and IL-28B genes were independently associated with severity of HCV-related liver disease. We investigated the effects of these combined genetic factors on post-transplant survival in HCV-infected recipients, aiming to provide new data to define the optimal timing of novel antiviral therapies in the transplant setting. HLA-A/B/DRB1 alleles and IL-28B rs12979860 (C > T) polymorphism frequencies were determined in 449 HCV viremic recipients and in their donors. Median follow-up was 10 years; study outcome was graft survival. HLA-DRB1*11 phenotype and IL-28B C/C genotype were significantly less frequent in recipients than donors (27.8% vs. 45.9% and 27.4% vs. 44.9%, respectively, P < 0.00001). Ten-year graft survival was better in patients with HLA-DRB1*11 (P = 0.0183) or IL-28B C/C (P = 0.0436). Conversely, concomitant absence of HLA-DRB1*11 and IL-28B C/C in 228 (50.8%) predicted worse survival (P = 0.0006), which was already evident at the first post-transplant year (P = 0.0370). In multivariable Cox analysis, absence of both markers ranked second as risk factor for survival (HR = 1.74), following donor age ≥ 70 years (HR = 1.77). In the current era of direct-acting antiviral agents, the negative effects of this common immunogenetic profile in HCV-infected recipients could be most effectively neutralized by peri-transplant treatment. This should be particularly relevant in countries where elderly donors represent an unavoidable resource.

Dietary flavonoid intake and cardiovascular risk: a population-based cohort study.

BACKGROUND: The cardio-protective effects of flavonoids are still controversial; many studies referred to the benefits of specific foods, such as soy, cocoa, tea. A population-based cohort of middle-aged adults, coming from a semi-rural area where the consumption of those foods is almost negligible, was studied. AIMS: The primary objective was establishing if flavonoid intake was inversely associated with the cardiovascular (CV) risk evaluated after 12-year follow-up; the associations between flavonoid intake and CV incidence and mortality and all-cause mortality were also evaluated. METHODS: In 2001-2003, a cohort of 1,658 individuals completed a validated food-frequency questionnaire. Anthropometric, laboratory measurements, medical history and the vital status were collected at baseline and during 2014. The CV risk was estimated with the Framingham risk score. RESULTS: Individuals with the lowest tertile of flavonoid intake showed a worse metabolic pattern and less healthy lifestyle habits. The 2014 CV risk score and the increase in the risk score from baseline were significantly higher with the lowest intake of total and all subclasses of flavonoids, but isoflavones, in a multiple regression model. During follow-up, 125 CV events and 220 deaths (84 of which due to CV causes) occurred. CV non-fatal events were less frequent in individuals with higher flavonoid intake (HR = 0.64; 95%CI 0.42-1.00 and HR = 0.46; 95%CI 0.28-0.75 for the second and third tertiles, respectively) in Cox-regression models, after multiple adjustments. All subclasses of flavonoids, but flavones and isoflavones, were inversely correlated with incident CV events, with HRs ranging from 0.42 (flavan-3-ols) to 0.56 (anthocyanidins). Being in the third tertile of flavan-3-ols (HR = 0.68; 95% CI 0.48-0.96), anthocyanidins (HR = 0.66; 95% CI 0.46-0.95) and flavanones (HR = 0.59; 95% CI 0.40-0.85) was inversely associated with all-cause mortality. Total and subclasses of flavonoids were not significantly associated with the risk of CV mortality. CONCLUSIONS: Flavonoid intake was inversely associated with CV risk, CV non-fatal events and all-cause mortality in a cohort with a low consumption of soy, tea and cocoa, which are typically viewed as the foods responsible for flavonoid-related benefits.

HLA-DPB1*13:01 associates with enhanced, and KIR2DS4*001 with diminished protection from developing severe COVID-19.

Extreme polymorphism of HLA and killer-cell immunoglobulin-like receptors (KIR) differentiates immune responses across individuals. Additional to T cell receptor interactions, subsets of HLA class I act as ligands for inhibitory and activating KIR, allowing natural killer (NK) cells to detect and kill infected cells. We investigated the impact of HLA and KIR polymorphism on the severity of COVID-19. High resolution HLA class I and II and KIR genotypes were determined from 403 non-hospitalized and 1575 hospitalized SARS-CoV-2 infected patients from Italy collected in 2020. We observed that possession of the activating KIR2DS4*001 allotype is associated with severe disease, requiring hospitalization (OR = 1.48, 95% CI 1.20-1.85, pc = 0.017), and this effect is greater in individuals homozygous for KIR2DS4*001 (OR = 3.74, 95% CI 1.75-9.29, pc = 0.003). We also observed the HLA class II allotype, HLA-DPB1*13:01 protects SARS-CoV-2 infected patients from severe disease (OR = 0.49, 95% CI 0.33-0.74, pc = 0.019). These association analyses were replicated using logistic regression with sex and age as covariates. Autoantibodies against IFN-α associated with COVID-19 severity were detected in 26% of 156 hospitalized patients tested. HLA-C*08:02 was more frequent in patients with IFN-α autoantibodies than those without, and KIR3DL1*01502 was only present in patients lacking IFN-α antibodies. These findings suggest that KIR and HLA polymorphism is integral in determining the clinical outcome following SARS-CoV-2 infection, by influencing the course both of innate and adaptive immunity.

The humoral and cellular response to mRNA SARS-CoV-2 vaccine is influenced by HLA polymorphisms.

Host genetic variability contributes to susceptibility to SARS-CoV-2 infection and COVID-19 evolution and the role of HLA system has not clearly emerged, suggesting the involvement of other factors. Studying response to vaccination with Spyke protein mRNA represents an ideal model to highlight whether the humoral or cellular responses are influenced by HLA. Four hundred and sixteen workers, vaccinated with Comirnaty beginning 2021, were selected within the Azienda Ospedaliera Universitaria "Città della Salute e della Scienza di Torino." The humoral response was determined with the LIAISON® kit, while the analysis of the cellular response was performed with the Quantiferon SARS-CoV-2 assay, for the S1 (receptor-binding domain; Ag1) and S1 and S2 (Ag2) subunits of the Spyke protein. Six HLA loci were typed by next-generation sequencing. Associations between HLA and vaccine response were performed with univariate and multivariate analyses. An association was found between A*03:01, B*40:02 and DPB1*06:01 and high antibody concentration and between A*24:02, B*08:01 and C*07:01 and low humoral responses. The haplotype HLA-A*01:01 ~ B1*08:01 ~ C*07:01 ~ DRB1*03:01 ~ DQB1*02:01 conferred an increased risk of low humoral response. Considering cellular responses, 50% of the vaccinated subjects responded against Ag1 and 59% against Ag2. Carriers of DRB1*15:01 displayed a higher cellular response both to Ag1 and Ag2 compared to the rest of the cohort. Similarly, DRB1*13:02 predisposed to a robust cellular response to Ag1 and Ag2, while DRB1*11:04 showed an opposite trend. Cellular and humoral responses to Comirnaty are influenced by HLA. Humoral response is mainly associated to class I alleles, with A*03:01, previously associated to protection against severe COVID-19, and response to vaccination, standing out. Cellular response predominantly involves class II alleles, with DRB1*15:01 and DPB1*13:01 prevailing. Affinity analysis for Spyke peptides is generally in line with the association results.

HLA and AB0 Polymorphisms May Influence SARS-CoV-2 Infection and COVID-19 Severity.

BACKGROUND: SARS-CoV-2 infection is heterogeneous in clinical presentation and disease evolution. To investigate whether immune response to the virus can be influenced by genetic factors, we compared HLA and AB0 frequencies in organ transplant recipients and waitlisted patients according to presence or absence of SARS-CoV-2 infection. METHODS: A retrospective analysis was performed on an Italian cohort composed by transplanted and waitlisted patients in a January 2002 to March 2020 time frame. Data from this cohort were merged with the Italian registry of COVID+ subjects, evaluating infection status of transplanted and waitlisted patients. A total of 56 304 cases were studied with the aim of comparing HLA and AB0 frequencies according to the presence (n = 265, COVID+) or absence (n = 56 039, COVID-) of SARS-CoV-2 infection. RESULTS: The cumulative incidence rate of COVID-19 was 0.112% in the Italian population and 0.462% in waitlisted/transplanted patients (OR = 4.2; 95% CI, 3.7-4.7; P < 0.0001). HLA-DRB1*08 was more frequent in COVID+ (9.7% and 5.2%: OR = 1.9, 95% CI, 1.2-3.1; P = 0.003; Pc = 0.036). In COVID+ patients, HLA-DRB1*08 was correlated to mortality (6.9% in living versus 17.5% in deceased: OR = 2.9, 95% CI, 1.15-7.21; P = 0.023). Peptide binding prediction analyses showed that these DRB1*08 alleles were unable to bind any of the viral peptides with high affinity. Finally, blood group A was more frequent in COVID+ (45.5%) than COVID- patients (39.0%; OR = 1.3; 95% CI, 1.02-1.66; P = 0.03). CONCLUSIONS: Although preliminary, these results suggest that HLA antigens may influence SARS-CoV-2 infection and clinical evolution of COVID-19 and confirm that blood group A individuals are at greater risk of infection, providing clues on the spread of the disease and indications about infection prognosis and vaccination strategies.

HLA-DRB1 mismatch-based identification of donor-derived cell free DNA (dd-cfDNA) as a marker of rejection in heart transplant recipients: A single-institution pilot study.

BACKGROUND: Donor-derived cell-free DNA (dd-cfDNA) is considered a reliable marker of organ damage with potential applications in the follow-up of transplant recipients. METHODS: In this work we present an assay based on the donor-recipient HLA-mismatch (human leukocyte antigen) at the HLA-DRB1 locus to monitor rejection by quantifying the percentage of dd-cfDNA using a droplet digital PCR (polymerase chain reaction) technique. A panel of probes targeting the HLA-DRB1 locus and covering >85% genetic variability was validated and used to assess dd-cfDNA levels in a prospective cohort of 19 adult heart transplant recipients (mean age 50.9±14.8 years). The assay was carried out on a total of 232 liquid biopsies collected at the same time as endomyocardial biopsy (EMB) during routine post-transplant follow-up. RESULTS: Results show a significant increase of dd-cfDNA related to ischemia-reperfusion injury (2.22±2.09%) and to acute cellular rejection (1.71±3.10%) compared to stable conditions (0.43±1.04%, p < 0.0001). On the contrary, no increase was observed during infections or vascular complications, underlining the potential role of this biomarker for rejection monitoring. With a cut-off of 0.11%, the test showed 70.8% specificity (95% CI, 58.17% - 81.40%) and 64.2% sensitivity (95% CI, 49.80% - 76.86%) in discriminating acute rejection from no rejection. CONCLUSIONS: These data demonstrate that this HLA mismatch-based droplet digital PCR method is effective for monitoring rejection in heart transplant recipients. Compared to next generation sequencing approaches, it is far more flexible, less expensive and provides faster results.

The frequency of rare and monogenic diseases in pediatric organ transplant recipients in Italy.

BACKGROUND: Rare diseases are chronic and life-threatening disorders affecting < 1 person every 2,000. For most of them, clinical symptoms and signs can be observed at birth or childhood. Approximately 80% of all rare diseases have a genetic background and most of them are monogenic conditions. In addition, while the majority of these diseases is still incurable, early diagnosis and specific treatment can improve patients' quality of life. Transplantation is among the therapeutic options and represents the definitive treatment for end-stage organ failure, both in children and adults. The aim of this paper was to analyze, in a large cohort of Italian patients, the main rare genetic diseases that led to organ transplantation, specifically pointing the attention on the pediatric cohort. RESULTS: To the purpose of our analysis, we considered heart, lung, liver and kidney transplants included in the Transplant Registry (TR) of the Italian National Transplantation Center in the 2002-2019 timeframe. Overall, 49,404 recipients were enrolled in the cohort, 5.1% of whom in the pediatric age. For 40,909 (82.8%) transplant recipients, a disease diagnosis was available, of which 38,615 in the adult cohort, while 8,495 patients (17.2%) were undiagnosed. There were 128 disease categories, and of these, 117 were listed in the main rare disease databases. In the pediatric cohort, 2,294 (5.6%) patients had a disease diagnosis: of the 2,126 (92.7%) patients affected by a rare disease, 1,402 (61.1%) presented with a monogenic condition. As expected, the frequencies of pathologies leading to organ failure were different between the pediatric and the adult cohort. Moreover, the pediatric group was characterized, compared to the adult one, by an overall better survival of the graft at ten years after transplant, with the only exception of lung transplants. When comparing survival considering rare vs non-rare diseases or rare and monogenic vs rare non-monogenic conditions, no differences were highlighted for kidney and lung transplants, while rare diseases had a better survival in liver as opposed to heart transplants. CONCLUSIONS: This work represents the first national survey analyzing the main genetic causes and frequencies of rare and/or monogenic diseases leading to organ failure and requiring transplantation both in adults and children.

B cell positive cross-match not due to anti-HLA Class I antibodies and first kidney graft outcome.

The effect of B cell cross-match (XM) was investigated in 680 first deceased-donor kidney transplants in a single centre from 1990 to 1999: 74 transplants presented a B-positive XM (Group 1) 606 had a B-negative XM (Group 2). The absence in Group 1 of weak/low-titre anti-HLA Class I antibodies was assured blocking anti-Class I reactivity by treating B cells with non-cytotoxic anti-beta2 microglobulin (alphabeta2 M) serum before XM. Graft survivals up to 5 years were not significantly different; some differences were nevertheless observed: HLA-A,B,DR mismatches influenced graft outcome in Group 1: patients with 0-2 mismatches had better survival than patients with 3-4. When analysed according DR mismatch, patients with 1 mismatch had worse graft survival than well matched patients (p<0.05). No significant difference depending on HLA match was observed in Group 2. Early acute rejection rate was similar in the Groups except the rejection episodes after one year: Group 1 had significantly more. 61/74 patients of Group 1 were retrospectively analysed for anti-HLA-DR,DQ reactivity: only 11/61 had anti-HLA-DR or DQ antibodies (3/11 were donor specific); graft survival and rejections were not significantly different in the patients with and without anti-HLA Class II antibodies. Anti-donor B cell reactivity, at XM, once excluded the presence of weak/low-titre anti-HLA Class I antibodies, did not influence first kidney graft survival.

Efficacy and safety of long-term entecavir therapy in a European population.

BACKGROUND: Therapy in chronic hepatitis B (chronic hepatitis B) patients aims at improving their survival by preventing disease progression to cirrhosis and its complications. Entecavir (ETV) is currently a first line therapeutic agent recommended for the treatment of CHB. Our aim was to evaluate the long term outcome of a cohort of CHB patients treated with ETV. METHODS: Thirty-four patients treated with ETV for at least 6 months were included in this study. The virologic response was determined by the dosage of serum HBV-DNA, HBsAg, HBeAg, anti-HBs and anti-HBe antibodies. Death, acute pancreatitis, lactic acidosis and kidney function impairment were considered as major adverse events. RESULTS: The median period of treatment was 55 months (range 15-81). Thirty-three (97%) patients responded to the therapy after a mean time of 14.7 weeks (4-60); of these, 29 (85.3%) maintained the HBV-DNA negativity in serum, while 4 patients (11.8%) had a breakthrough. The remaining patient did not respond. Seroconversion to anti-HBs and anti-HBe was not observed, although 2 patients lost the e and the s antigen, respectively. Baseline alanine aminostransferase (ALT) levels in serum were altered in 18 patients (52.9%), and returned to normal levels during the follow-up, with a reduction of 87.7 IU/L (P<0.0001). A case (3.4%) of hepatocellular carcinoma was observed after 24 months. No major adverse events were recorded. CONCLUSIONS: ETV is effective in suppressing viral replication as well as in normalizing serum ALT levels, without anti-HBs seroconversion. Finally, ETV is a safe drug, substantially free of major side effects.

Italian blood donors with anti-HBc and occult hepatitis B virus infection.

BACKGROUND AND OBJECTIVES: Occult hepatitis B virus (HBV) infection might allow the release of viremic units into the blood supply network if blood is tested only for hepatitis B surface antigen (HBsAg). The aim of our study was to evaluate the actual prevalence, viral load and genotype of occult HBV infections among first-time blood donors in north-western Italy and to suggest a way to minimize risks of transmission of this infection. DESIGN AND METHODS: We assayed 6313 consecutive blood donors for antibodies to HBV core antigen (anti-HBc) in addition to mandatory screening. HBsAg-negative/anti-HBc-positive donors were assayed for antibodies to HBsAg (anti-HBs) and for HBV-DNA using COBAS Ampliscreen HBV (Roche) on individual donations. All HBV-DNA-positive samples underwent confirmatory testing with additional polymerase chain reaction-based assays. RESULTS: The prevalence of anti-HBc positive subjects was 4.85%. Fourteen out of 288 blood donors (4.86%) were confirmed to have circulating HBV-DNA at a low level (range 8-108 IU/mL). All viremic donors were also anti-HBs-positive. INTERPRETATION AND CONCLUSIONS: We estimate that in north-western Italy up to 2298 units per million donated units from first-time donors may contain HBV-DNA. The risk of an HBV-DNA positive unit from an occult carrier being released into the blood supply is more than 100 times higher than the estimated residual risk related to the window phase of HBV infection in our country. The potential infectivity of these units is debated, but their use cannot be considered safe at least in immunocompromised patients.

Long-Term Outcomes and Discard Rate of Kidneys by Decade of Extended Criteria Donor Age.

BACKGROUND AND OBJECTIVES: Extended criteria donors represent nowadays a main resource for kidney transplantation, and recovery criteria are becoming increasingly inclusive. However, the limits of this approach are not clear as well as the effects of extreme donor ages on long-term kidney transplantation outcomes. To address these issues, we performed a retrospective study on extended criteria donor kidney transplantation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In total, 647 consecutive extended criteria donor kidney transplantations performed over 11 years (2003-2013) were included. Donor, recipient, and procedural variables were classified according to donor age decades (group A, 50-59 years old [n=91]; group B, 60-69 years old [n=264]; group C, 70-79 years old [n=265]; and group D, ≥80 years old [n=27]). Organs were allocated in single- or dual-kidney transplantation after a multistep evaluation including clinical and histologic criteria. Long-term outcomes and main adverse events were analyzed among age groups and in either single- or dual-kidney transplantation. Kidney discard rate incidence and causes were evaluated. RESULTS: Median follow-up was 4.9 years (25th; 75th percentiles: 2.7; 7.6 years); patient and graft survival were comparable among age groups (5-year patient survival: group A, 87.8%; group B, 88.1%; group C, 88.0%; and group D, 90.1%; P=0.77; graft survival: group A, 74.0%; group B, 74.2%; group C, 75.2%; and group D, 65.9%; P=0.62) and between dual-kidney transplantation and single-kidney transplantation except for group D, with a better survival for dual-kidney transplantation (P=0.04). No difference was found analyzing complications incidence or graft function over time. Kidney discard rate was similar in groups A, B, and C (15.4%, 17.7%, and 20.1%, respectively) and increased in group D (48.2%; odds ratio, 5.1 with A as the reference group; 95% confidence interval, 2.96 to 8.79). CONCLUSIONS: Discard rate and long-term outcomes are similar among extended criteria donor kidney transplantation from donors ages 50-79 years old. Conversely, discard rate was strikingly higher among kidneys from octogenarian donors, but appropriate selection provides comparable long-term outcomes, with better graft survival for dual-kidney transplantation.

Prognostic values of soluble CD30 and CD30 gene polymorphisms in heart transplantation.

Pretransplant soluble CD30 (sCD30) is a predictor of kidney graft outcome. Its status as a predictor of heart transplant (HT) outcome has not been established. We have studied this question by assessing sCD30 levels and the number of (CCAT)n repeats of the microsatellite in the CD30 promoter region, which is able alone to repress gene transcription, in the sera of 83 HT patients and 77 of their donors. sCD30 was non-significantly increased in the patients, whereas there were no differences in the CD30 microsatellite allele frequencies. A negative correlation between the number of (CCAT)n and sCD30 levels was evident in the donors. Patients with pretransplant sCD30

Prognostic value of donor cytotoxic T-lymphocyte precursor frequencies for acute graft-versus-host disease in hematopoietic stem cell transplantation from HLA-matched siblings: a single center experience in a cohort of 92 patients.

We investigated the prognostic value of cytotoxic T-lymphocyte precursor frequencies (CTL-p-f) for the development of graft-versus-host disease (GvHD) in a cohort of 92 recipients of a hematopoietic stem cell transplantation from HLA-matched sibling donors. CTL-p-f and clinical variables were correlated with acute GvHD and chronic GvHD in univariate and multivariate analyses. CTL-p-f resulted an independent risk factor for severe acute GvHD. Moreover, a trend towards a correlation between CTL-p-f and chronic GvHD was observed. In summary CTL-p-f may be considered as a functional assay useful for identifying patients at high risk of severe GVHD.

Phosphorylated alpha-enolase induces autoantibodies in HLA-DR8 pancreatic cancer patients and triggers HLA-DR8 restricted T-cell activation.

Pancreatic ductal adenocarcinoma (PDAC) is the fourth cause of cancer-induced death in the Western World. In PDAC patients, alpha-enolase (ENOA), a glycolytic enzyme that also acts as plasminogen receptor, is up-regulated and elicits the production of autoantibodies. Our previous studies revealed that most PDAC patients specifically produce antibodies to Serine(419)phosphorylated ENOA (Ser(419)P-ENOA) isoforms (ENOA1,2), and that this humoral response correlates with a better clinical outcome. Since autoantibody production can be influenced by HLA polymorphisms, and the ENOA sequence presents multiple peptides predicted to preferentially bind HLA-DR molecules, including the peptide containing Ser(419), we hypothesized that the presence of autoantibodies against ENOA1,2 is associated with specific HLA-DRB1 alleles. Here, we demonstrate that the HLA-DRB1*08 allele is significantly more frequent in PDAC patients with autoantibodies to ENOA1,2 (ENOA1,2(+), 8%) compared to healthy controls (3%, p=0.0112). We observed that a Ser(419)P-ENOA peptide, bioinformatically predicted to bind with high affinity to the HLA-DR8 allele coded by HLA-DRB1*08:01 or *08:04 alleles, was able to activate specific CD4(+) T cell clones derived from a HLA-DRB1*08:01. Thus complexes of the Ser(419)P-ENOA peptide with the HLA that trigger T-cell signaling might be relevant for induction of anti-tumor immune response.