Search

The authors reflect on the study conducted by X. Wang and colleagues on the relationship of c-Abl in the DNA damage response (DDR). The study reveals that ataxia telangiectasia mutated (ATM) and ataxia telangiectasia and rad3-related protein (ATR) strongly depend on c-Abl. It also mentions the refractoriness of the foci levels of ATR and ATM to the presence of c-Abl. The authors assert that the study may serve in facilitating new researches for better understanding of the c-Abl function.

Background & Aim: Patatin-like phospholipase domain-containing 3 gene (PNPLA3) polymorphism has been implicated in susceptibility to non-alcoholic fatty liver disease (NAFLD), with evidence for potential interaction with nutrition. However, the combination of meat consumption with genetic polymorphism has not been tested. Therefore, this study aims to test the association between the joint presence of PNPLA3 rs738409 G-allele with high meat consumption and NAFLD in populations with diverse meat consumption., Methods: A cross-sectional study among Israeli screening and Brazilian primary healthcare populations. Food consumption was assessed by a food-frequency questionnaire. PNPLA3 polymorphism was defined as homozygous (GG) or heterozygous (GC). Inconclusive/probable NAFLD was defined as a fatty liver index (FLI) ≥ 30 and probable NAFLD as FLI ≥ 60., Results: The sample included 511 subjects from the screening and primary healthcare populations (n = 213 and n = 298, respectively). Genetic polymorphism (homozygous GG or heterozygous GC) combined with high consumption of total meat, red and/or processed meat, unprocessed red meat, and processed meat was associated with the highest odds for inconclusive/probable NAFLD (OR = 2.75, 95%CI 1.27-5.97, p = 0.011; OR = 3.24, 1.43-7.34, p = 0.005; OR = 2.92, 1.32-6.47, p = 0.008; OR = 3.16, 1.46-6.83, p = 0.003, respectively), adjusting for age, gender, BMI, alcohol consumption, carbohydrate, and saturated fat intake. In addition, genetic polymorphism combined with high processed meat consumption was associated with the highest odds for probable NAFLD (OR = 2.40, 95%CI 1.04-5.56, p = 0.040)., Conclusions: High red meat intake may confer a greater risk for NAFLD among PNPLA3 polymorphism carriers. Prospective studies are needed to confirm these findings and consider minimizing red and processed meat consumption among PNPLA3 polymorphism carriers., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Introduction: Pancreatic ductal adenocarcinoma (PDAC) has a poor 5-year survival rate. PDAC surveillance is recommended in high-risk individuals (HRIs) with strong PDAC family history or a pathogenic germline variant (PGV) in a PDAC susceptibility gene. We aimed to explore a potential correlation between genetic status, extent of family history, pancreatic findings, and surveillance implications in heterogeneous PDAC HRIs., Methods: A total of 239 HRIs from 202 families were tested genetically and underwent prospective pancreatic surveillance for 6 years., Results: The cohort was divided into 3 groups: familial pancreatic cancer (FPC; 70 individuals, 54 families), familial non-FPC (81 individuals, 73 families), and hereditary pancreatic cancer (PC) (88 individuals, 75 families). PGVs were detected in 37.6% of all families, including 11.1% of FPC families and 9.6% of familial non-FPC families. The hereditary PC group had earlier onset of PDAC compared with the other 2 groups. BRCA2 PGV carriers showed earlier onset of PDAC and pancreatic cysts. Of the 239 HRIs, PDAC was detected in 11 individuals (4.6%), with 73% diagnosed at an early stage; 4 (1.67%) had pancreatic neuroendocrine tumor; 6 (2.5%) had main-duct intraductal papillary neoplasm (IPMN); and 41 (17.15%) had side-branch IPMN. Seventeen individuals were referred to surgery, and 12 were alive at the end of the study., Discussion: The percentage of PDAC was similar in the 3 groups studied. The hereditary PC group, and particularly BRCA2 PGV carriers, had an earlier age of PDAC onset. PGVs were detected in a significant percentage of HRIs with PC. Surveillance seems effective for detection of early-stage PDAC and precursor lesions., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Background: Surveillance of high-risk individuals for pancreatic ductal adenocarcinoma (PDAC) is recommended. This study aimed to determine the prevalence and outcomes of PDAC and its precursor lesions in BRCA1/2 pathogenic variants (PVs) carriers undergoing pancreatic surveillance., Methods: A retrospective multicenter cohort study of pancreatic surveillance outcomes in Israeli BRCA1/2 carriers preferably with a family history of PDAC., Results: A total of 180 asymptomatic carriers participated in the screening programs, including 57 (31.7%) with BRCA1 PVs, 121 (67.2%) with BRCA2 PVs, and 12 (6.6%) with PVs in BRCA1/2 and other genes, for a median follow-up period of 4 years. Ninety-one individuals (50.5%) fulfilled the International Cancer of the Pancreas Screening (CAPS) criteria for surveillance whereas 116 (64.4%) fulfilled the American College of Gastroenterology (ACG) criteria. There were four cases of adenocarcinoma and four cases of grade 1-neuroendocrine tumor (G1-NET). All were BRCA2 carriers, and two had no family history of PDAC. Three cancer patients were at resectable stages (IA, IIA, IIB) whereas one had a stage IIIB tumor. Of the G1-NET cases, one had surgery and the others were only followed. Success rate for detection of confined pancreatic carcinoma was thus 1.6% (three of 180) in the whole cohort, 1.6% (two of 116) among individuals who fulfilled ACG criteria and 2.2% (two of 91) in those fulfilling CAPS criteria for surveillance., Conclusions: Despite the low detection rate of PDAC and its' high-risk neoplastic precursor lesions among BRCA1/2 carriers undergoing pancreatic surveillance, 75% of cancer cases were detected at a resectable stage., (© 2023 American Cancer Society.)

Background: Most solid organ transplant recipients did not develop an appreciable serologic response after 2 doses of the mRNA SARS-CoV-2 vaccine., Methods: We analyzed the humoral response after a third dose of the BNT162b2 vaccine in 130 kidney transplant recipients, compared to 48 health care workers, and associated factors, including prevaccine cellular immune response, by evaluating intracellular cytokine production after stimulation of donor's peripheral blood mononuclear cells., Results: After 2 doses, most of the controls (47 out of 48, 98%) and only 40% of kidney recipients (52 of 130) kidney recipients were seropositive (P < .001). Most seronegative recipients developed a serologic response after the booster (47 out 78, 60%), thus bringing the total number of seropositive recipients to 99 out of 130 (76%). After the third dose, there was a significant increase in antibodies titers in both groups. Decreased humoral response was significantly associated with an older age, lower lymphocyte count, and a lower level of antibodies before booster administration. CD4 + TNFα + and CD4 + INFγ + were correlated with mean increase in antibody titers., Conclusions: A third dose of the BNT162b2 mRNA vaccine in kidney recipients is safe and effectively results in increased IgG anti-S levels, including in individuals who were seronegative after 2 doses. Long-term studies of the length of the immune response and protection are required., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Objectives: The recent surge in coronavirus disease 2019 cases led to the consideration of a booster vaccine in previously vaccinated immunosuppressed individuals. However, the immunogenic effect of a third-dose severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in immunosuppressed patients is still unknown., Methods: This was an observational cohort study of 279 previously vaccinated immunosuppressed patients followed at a single tertiary hospital in Israel. Patients were administered a third dose of the Pfizer-BioNTech mRNA vaccine (BNT162b2) between July 14 and July 21, 2021. Levels of IgG antibodies against the spike receptor-binding domain of SARS-CoV-2 were measured 3 to 4 weeks after vaccination., Results: Of the cohort of 279 patients, 124 (44.4%) had haematologic malignancies, 57 (20.4%) had rheumatologic diseases, and 98 (35.1%) were solid organ-transplant recipients. Anti-SARS-CoV-2 antibody levels increased in 74.9% of cases. Across the entire cohort, the median absolute antibody levels (expressed in AU/mL) increased from 7 (interquartile range (IQR), 0.1-69) to 243 (IQR, 2-4749) after the booster dose. The response significantly varied across subgroups: The transplant cohort showed the greatest increase in absolute antibody levels (from 52 (IQR, 7.25-184.5) to 1824 (IQR, 161-9686)), followed by the rheumatology (from 22 (IQR, 1-106) to 1291 (IQR, 6-6231)) and haemato-oncology (from 1 (IQR, 0.1-7) to 7.5 (IQR, 0.1-407.5)) cohorts. The χ 2 test was 8.30 for difference in fold change (p = 0.016). Of the 193 patients who were seronegative at baseline, 76 became seropositive after vaccination, corresponding to a 39.4% (95% CI, 32.8%-46.4%) seroconversion rate. Transplant patients had the highest seroconversion rate (58.3% (95% CI, 44.3%-71.2%)), followed by rheumatology (44.1% (95% CI, 28.9%-60.5%)) and haemato-oncology (29.7% (95% CI, 22%-38.8%); χ 2  = 11.87; p = 0.003) patients., Discussion: A third dose of BNT162b2 is immunogenic in most immunosuppressed individuals, although antibody response may differ based on the type of disease and immunosuppression. The antibody level that correlates with protection is still unknown; thus, future studies are needed to evaluate clinical outcomes., (Copyright © 2022 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Majority of transplant recipients did not develop an appreciable humoral response following SARS-CoV-2 vaccine, in contrast to dialysis patients and healthy individuals. We analyzed the serologic response to BNT162b2 (Pfizer-BioNTech) vaccine in a cohort of 19 kidney transplant recipients, vaccinated prior to transplantation, compare to 109 recipients vaccinated after transplantation, and to 39 healthcare workers, by determining the level of anti-spike antibodies after transplantation. All controls and 17 of 19 (90%) of recipients vaccinated before transplant were seropositive, while only 49 of 109 (45%) recipients vaccinated post-transplant had positive serology (P < .001). Median anti-spike IgG in the group of kidney transplant recipients vaccinated after transplantation (10.7 AU/ml, [IQR 0-62.5]) was lower than the patients vaccinated before transplantation (66.2 AU/ml [21.6-138]), which was significantly lower than in the controls (156 AU/ml [99.7-215.5]). Negative humoral response was associated with vaccination post transplantation (odds ratio 22.4), older age (OR = 1.04), and longer time on dialysis (OR = 1.02), while higher lymphocyte count at time of vaccination was protective (OR = .52). Our findings of sustained superior humoral response to SARS-CoV-2 vaccine in kidney transplant recipients vaccinated prior to transplantation strongly support the recommendations of SARS-CoV-2 vaccination of transplant candidates, especially those younger than 60 years., (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background & Aims: Two SARS-CoV-2 mRNA vaccines were approved to prevent COVID-19 infection, with reported vaccine efficacy of 95%. Liver transplant (LT) recipients are at risk of lower vaccine immunogenicity and were not included in the registration trials. We assessed vaccine immunogenicity and safety in this special population., Methods: LT recipients followed at the Tel-Aviv Sourasky Medical Center and healthy volunteers were tested for SARS-CoV-2 IgG antibodies directed against the Spike-protein (S) and Nucleocapsid-protein (N) 10-20 days after receiving the second Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine dose. Information regarding vaccine side effects and clinical data was collected from patients and medical records., Results: Eighty LT recipients were enrolled. Mean age was 60 years and 30% were female. Twenty-five healthy volunteer controls were younger (mean age 52.7 years, p = 0.013) and mostly female (68%, p = 0.002). All participants were negative for IgG N-protein serology, indicating immunity did not result from prior COVID-19 infection. All controls were positive for IgG S-protein serology. Immunogenicity among LT recipients was significantly lower with positive serology in only 47.5% (p <0.001). Antibody titer was also significantly lower in this group (mean 95.41 AU/ml vs. 200.5 AU/ml in controls, p <0.001). Predictors for negative response among LT recipients were older age, lower estimated glomerular filtration rate, and treatment with high dose steroids and mycophenolate mofetil. No serious adverse events were reported in either group., Conclusion: LT recipients developed substantially lower immunological response to the Pfizer-BioNTech SARS-CoV-2 mRNA-based vaccine. Factors influencing serological antibody responses include age, renal function and immunosuppressive medications. The findings require re-evaluation of vaccine regimens in this population., Lay Summary: The Pfizer-BioNTech BNT162b2 SARS-CoV-2 vaccine elicited substantially inferior immunity in liver transplant recipients. Less than half of the patients developed sufficient levels of antibodies against the virus, and in those who were positive, average antibody levels were 2x less compared to healthy controls. Factors predicting non-response were older age, renal function and immunosuppressive medications., Competing Interests: Conflict of interest The authors declare no conflicts of interest that pertain to this work. Please refer to the accompanying ICMJE disclosure forms for further details., (Copyright © 2021 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

COVID-19 is associated with increased morbidity and mortality in transplant recipients. There are no efficacy data available regarding these patients with any of the available SARS-CoV-2 vaccines. We analyzed the humoral response following full vaccination with the BNT162b2 (Pfizer-BioNTech) in 136 kidney transplant recipients, and compared it to 25 controls. In order to exclude prior exposure to the virus, only participants with negative serology to SARS-CoV-2 nucleocapsid protein were included. All controls developed a positive response to spike protein, while only 51 of 136 transplant recipients (37.5%) had positive serology (p < .001). Mean IgG anti-spike level was higher in the controls (31.05 [41.8] vs. 200.5 [65.1] AU/mL, study vs. control, respectively, p < .001). Variables associated with null humoral response were older age (odds ratio 1.66 [95% confidence interval 1.17-2.69]), high-dose corticosteroids in the last 12 months (1.3 [1.09-1.86]), maintenance with triple immunosuppression (1.43 [1.06-2.15]), and regimen that includes mycophenolate (1.47 [1.26-2.27]). There was a similar rate of side effects between controls and recipients, and no correlation was found between the presence of symptoms and seroconversion. Our findings suggest that most kidney transplant recipients remain at high risk for COVID-19 despite vaccination. Further studies regarding possible measures to increase recipient's response to vaccination are required., (© 2021 The American Society of Transplantation and the American Society of Transplant Surgeons.)

Background: Germline mutations in the DNA polymerase genes POLD1 and POLE confer high risk for multiple colorectal adenomas and colorectal cancer. However, prevalence and the clinical phenotype of mutation carriers are still not fully characterized., Objective: The purpose of this study was to assess the prevalence of germline mutations and to describe the genotype-phenotype correlation in POLD1 and POLE genes in Jewish subjects with multiple colorectal adenomas and/or early-onset mismatch repair proficient colorectal cancers., Design: This study is a comparison of genetic and clinical data from affected and control groups., Settings: The study was conducted at a high-volume tertiary referral center., Patients: The study cohort included 132 subjects: 68 with multiple colorectal adenomas and 64 with early-onset mismatch repair proficient colorectal cancers. The control group included 5685 individuals having no colorectal cancer or colorectal adenomas., Main Outcome Measures: Study and control subjects were tested for POLD1 and POLE mutations and a clinical correlation was assessed., Results: Eleven of the 132 study subjects (8.3%) carried either a POLD1 or a POLE mutation: 7 of 68 (10.3%) subjects with multiple colorectal adenomas and 4 of 64 (6.2%) subjects with early-onset mismatch repair proficient colorectal cancer. Three mutations were detected, showing statistical significance in frequency between study and control groups (p < 0.001). Eight of the 11 mutation carriers were Ashkenazi Jews carrying the same POLD1 mutation (V759I), implicating it as a possible low-to-moderate risk founder mutation. Phenotype of mutation carriers was notable for age under 50 at diagnosis, a propensity toward left-sided colorectal cancer, and extracolonic tumors (64%, 100%, and 27% of cases)., Limitations: The study cohort was limited by its relatively small size., Conclusions: Germline mutations in POLD1 and POLE were found to be relatively frequent in our Jewish cohorts. Further studies are needed to clarify the importance of POLD1 and POLE mutations and to define the most suitable surveillance program for Jewish and other POLD1 and POLE mutation carriers. See Video Abstract at http://links.lww.com/DCR/A658.

Background: Antibiotic treatment of Clostridium difficile infection (CDI) has a high failure rate. Fecal microbiota transplantation (FMT) has proven very effective in treating these recurrences., Objectives: To determine which method of fecal microbiota transplantation (upper or lower gastrointestinal) and which type of donor (a relative or unrelated) is superior., Methods: This is a retrospective analysis of treatment protocols and outcomes in 22 patients with refractory or recurrent CDI who underwent FMT at two Israeli facilities. Each center used a different donor type, stool preparation and method of delivery. The Tel Aviv Sourasky Medical Center used unrelated fecal donors and frozen stool samples and delivered them primarily (92%) via the lower gastrointestinal (GI) tract. Shaare Zedek Medical Center used fresh donor stool of relatives and delivered them primarily (90%) via the upper GI tract., Results: FMT had an overall 2 month cure rate of 89%. Patients treated with FMT that was executed through the lower GI tract recovered faster from the infection (1.6 ± 1.08 vs. 2.4 ± 1 days for the upper tract, P = 0.03). The results also showed that patients who received lower GI tract FMTs were more likely to be cured of CDI (100% vs. 75% for upper tract FMTs, P = 0.16). Five patients (22%) died of CDI/FMT-unrelated causes and two (10%) died of CDI/FMT-related causes during the study period., Conclusions: Lower GI tract FMT is a safe and effective treatment for refractory and recurrent CDI, and yields quicker results than upper GI tract FMT.

Background: Infliximab (IFX) is effective therapy for ulcerative colitis and Crohn's disease, but it may be associated with side effects and loss of response. One loss of response mechanism is increased IFX clearance (IFX-CL), resulting in short half-life and decreased troughs., Methods: Patients were recruited, and relevant demographic, clinical, and laboratory data were recorded. IFX serum concentrations and antibodies against IFX (ATI) were measured for therapeutic drug monitoring and modeled using NONMEM., Results: There were 169 IFX concentrations (Crohn's disease = 73, ulcerative colitis = 92, and diagnosis undetermined = 4). Patient factors significantly associated with high IFX-CL were low albumin, high body weight, and the presence of ATI (P ≤ 0.001). Disease type did not affect IFX-CL. The typical IFX-CL was 0.381 L/d. ATI formation was associated with a 259% increase in IFX-CL. The estimated median IFX effective half-life was 5.6 ± 2.4 days. Patients with low weight are more likely to have low troughs because IFX CL is not linearly related to weight, but IFX dosing is weight-based (in mg/kg). Simulations investigating alternative dose strategies suggested that more reliably measurable concentrations over the dose interval were achieved when the dose interval was shortened than by increasing administered dose., Conclusions: IFX-CL is significantly influenced by patient factors, specifically, albumin, body weight, and ATI. There should be a decreasing IFX dose interval strategy, particularly for low albumin patients. Higher starting doses may benefit low body weight patients. Pharmacokinetic models and therapeutic drug monitoring may ensure that patients maintain measurable concentrations throughout dose intervals. Individualized dosing may improve outcomes for IFX-treated patients with Crohn's disease and ulcerative colitis.

DNA interstrand crosslinks (ICLs) are the most toxic lesions induced by chemotherapeutic agents such as mitomycin C and cisplatin. By covalently linking both DNA strands, ICLs prevent DNA melting, transcription, and replication. Studies on ICL signaling and repair have been limited, because these drugs generate additional DNA lesions that trigger checkpoint signaling. Here, we monitor sensing, signaling from, and repairing of a single site-specific ICL in cell-free extract derived from Xenopus eggs and in mammalian cells. Notably, we demonstrate that ICLs trigger a checkpoint response independently of origin-initiated DNA replication and uncoupling of DNA polymerase and DNA helicase. The Fanconi anemia pathway acts upstream of RPA-ATR-Chk1 to generate the ICL signal. The system also repairs ICLs in a reaction that involves extensive, error-free DNA synthesis. Repair occurs by both origin-dependent and origin-independent mechanisms. Our data suggest that cell sensitivity to crosslinking agents results from both checkpoint and DNA repair defects.

DNA replication is a highly conserved and controlled process. To maintain genome integrity, the DNA must be faithfully duplicated once before chromosomes are segregated to daughter cells. Experimental insults to cells during DNA replication trigger an array of responses to help cells cope with DNA damage and replication stress. This has been coined the DNA damage response. During an unperturbed S-phase, DNA lesions and aberrant DNA structures arise as a consequence of normal DNA replication. Recent data suggest that the same pathways regulating the response to acute DNA damage also operate during normal S-phase to maintain genome integrity in the face of low levels of damage. This review will focus on the role of key proteins and signaling pathways, originally identified by their requirement to maintain genome stability during DNA replication following experimental insults, in the regulation of progression through normal S-phase.

c-Abl has been implicated in many cellular processes including differentiation, division, adhesion, death, and stress response. c-Abl is a latent tyrosine kinase that becomes activated in response to numerous extra- and intra-cellular stimuli. Here we briefly review the current knowledge about c-Abl involvement in the DNA-damage stress response and its implication on cell physiology.

p73 is a structural and functional homologue of the p53 tumor-suppressor protein. Like p53, p73 is activated in response to DNA-damaging insults to induce cell cycle arrest or apoptosis. Under these conditions p73 is tyrosine-phosphorylated by c-Abl, a prerequisite modification for p73 to elicit cell death in fibroblasts. In this study we report that in response to ionizing radiation, p73 undergoes nuclear redistribution and becomes associated with the nuclear matrix. This association is c-Abl-dependent because it was not observed in cells that are defective in c-Abl kinase activation. Moreover, STI-571, a specific c-Abl kinase inhibitor, is sufficient to block significantly p73 alpha nuclear matrix association. The observed c-Abl dependence of nuclear matrix association was recapitulated in the heterologous baculovirus system. Under these conditions p73 alpha but not p53 is specifically tyrosine-phosphorylated by c-Abl. Moreover, the phosphorylated p73 alpha is predominantly found in association with the nuclear matrix. Thus, in response to ionizing radiation p73 is modified in a c-Abl-dependent manner and undergoes nuclear redistribution and translocates to associate with the nuclear matrix. Our data describe a novel mechanism of p73 regulation.

p73 is the first identified homolog of p53, but its function has not been established. Our study investigated the expression of p73 in liver tissue of patients with hepatitis C virus (HCV)-associated hepatocellular carcinoma (HCC). RT-PCR was performed on RNA extracted from tumorous and nontumorous liver tissue of HCV-associated HCC, and control tissue and the cDNA were sequenced. Anti-p73 polyclonal antibodies were used for protein analysis and immunohistochemistry, and patients' sera were analyzed for anti-p73 antibodies by radioimmunoassay. Analysis of the p53 gene was performed by SSCP and RFLP-PCR. The p73 mRNA and protein were highly expressed and accumulated in HCC tissues. Immunohistochemical studies revealed significant immunoreactivity in the nuclei of HCC cells. No mutations were detected in the p73 gene or in p53, and no loss of heterozygosity of the p53 gene was found. Anti-p73 antibodies were detected in sera of HCC patients, but were not significantly different from that occurring in non-HCV or non-HCC patients. In conclusion, p73 protein is overexpressed and accumulates in the nuclei of HCV-associated HCCs and may play a role in HCC development.