RESUMO
Long QT syndrome (LQTS) is a human inherited heart condition that can cause life-threatening arrhythmia including sudden cardiac death. Mutations in the ubiquitous Ca2+-sensing protein calmodulin (CaM) are associated with LQTS, but the molecular mechanism by which these mutations lead to irregular heartbeats is not fully understood. Here, we use a multidisciplinary approach including protein biophysics, structural biology, confocal imaging, and patch-clamp electrophysiology to determine the effect of the disease-associated CaM mutation E140G on CaM structure and function. We present novel data showing that mutant-regulated CaMKIIδ kinase activity is impaired with a significant reduction in enzyme autophosphorylation rate. We report the first high-resolution crystal structure of a LQTS-associated CaM variant in complex with the CaMKIIδ peptide, which shows significant structural differences, compared to the WT complex. Furthermore, we demonstrate that the E140G mutation significantly disrupted Cav1.2 Ca2+/CaM-dependent inactivation, while cardiac ryanodine receptor (RyR2) activity remained unaffected. In addition, we show that the LQTS-associated mutation alters CaM's Ca2+-binding characteristics, secondary structure content, and interaction with key partners involved in excitation-contraction coupling (CaMKIIδ, Cav1.2, RyR2). In conclusion, LQTS-associated CaM mutation E140G severely impacts the structure-function relationship of CaM and its regulation of CaMKIIδ and Cav1.2. This provides a crucial insight into the molecular factors contributing to CaM-mediated arrhythmias with a central role for CaMKIIδ.
Assuntos
Canais de Cálcio Tipo L , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina , Calmodulina , Síndrome do QT Longo , Humanos , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatologia , Cálcio/metabolismo , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , Síndrome do QT Longo/genética , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Mutação , Estrutura Secundária de Proteína/genética , Ligação Proteica/genética , CristalografiaRESUMO
Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited condition that can cause fatal cardiac arrhythmia. Human mutations in the Ca2+ sensor calmodulin (CaM) have been associated with CPVT susceptibility, suggesting that CaM dysfunction is a key driver of the disease. However, the detailed molecular mechanism remains unclear. Focusing on the interaction with the cardiac ryanodine receptor (RyR2), we determined the effect of CPVT-associated variants N53I and A102V on the structural characteristics of CaM and on Ca2+ fluxes in live cells. We provide novel data showing that interaction of both Ca2+/CaM-N53I and Ca2+/CaM-A102V with the RyR2 binding domain is decreased. Ca2+/CaM-RyR23583-3603 high-resolution crystal structures highlight subtle conformational changes for the N53I variant, with A102V being similar to wild type (WT). We show that co-expression of CaM-N53I or CaM-A102V with RyR2 in HEK293 cells significantly increased the duration of Ca2+ events; CaM-A102V exhibited a lower frequency of Ca2+ oscillations. In addition, we show that CaMKIIδ (also known as CAMK2D) phosphorylation activity is increased for A102V, compared to CaM-WT. This paper provides novel insight into the molecular mechanisms of CPVT-associated CaM variants and will facilitate the development of strategies for future therapies.
Assuntos
Calmodulina , Taquicardia Ventricular , Cálcio/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , Células HEK293 , HumanosRESUMO
Citrus is an economically important fruit crop, belongs to family Rutaceae, cultivated commercially in over 130 countries, which holds a leading profitable position in the international market. The most important citrus varieties are mandarins, oranges, lemons, sweet limes, grapefruits and pomelos. Citrus yellow vein clearing virus (CYVCV) is an important graft transmissible plant pathogen known to reduce productivity of citrus fruits due to its predominant association and widespread occurrence. Requirement of fast, reliable, efficient & economical CYVCV indexing assay is a prerequisite for production of healthy planting material. Currently, nucleic acid isolation and thermal cycler-based assay available for CYVCV indexing is a cumbersome lab intensive method. The present study was undertaken to develop and validate reverse transcription-recombinase polymerase amplification (RT-RPA) assay requiring no tedious RNA isolation, separate cDNA synthesis and costlier instrument like thermo-cycler. Optimized RT-RPA assay was able to amplify CYVCV up to 10-7 dilution (equivalent to 0.1 pg/µl) with the prepared templates of both RNA and crude saps and showed higher sensitivity in detection of CYVCV infection in field samples as compared to the conventional RT-PCR. Developed RT-RPA assay showed high specificity without any cross-reaction with other citrus pathogens (Indian citrus ringspot virus, citrus yellow mosaic virus, citrus tristeza virus, citrus exocortis viroid and huanglongbing). RT-RPA using crude leaf sap as template is quite simple, robust, highly sensitive, time and cost effective; therefore, it can be used in resource constrained laboratories as screening tool, for field surveys and on-site testing programs in farms, nurseries and biosecurity. Present study, first time reports the development, optimization and validation of crude sap-based RT-RPA assay for the detection of CYVCV infection in citrus plants namely; Kinnow mandarin, Mosambi and Grape fruit.
Assuntos
Citrus , Recombinases , Recombinases/genética , Bioensaio , Fazendas , RNARESUMO
Calmodulin (CaM) is a highly conserved mediator of calcium (Ca2+ )-dependent signalling and modulates various cardiac ion channels. Genotyping has revealed several CaM mutations associated with long QT syndrome (LQTS). LQTS patients display prolonged ventricular recovery times (QT interval), increasing their risk of incurring life-threatening arrhythmic events. Loss-of-function mutations to Kv7.1 (which drives the slow delayed rectifier potassium current, IKs, a key ventricular repolarising current) are the largest contributor to congenital LQTS (>50% of cases). CaM modulates Kv7.1 to produce a Ca2+ -sensitive IKs, but little is known about the consequences of LQTS-associated CaM mutations on Kv7.1 function. Here, we present novel data characterising the biophysical and modulatory properties of three LQTS-associated CaM variants (D95V, N97I and D131H). We showed that mutations induced structural alterations in CaM and reduced affinity for Kv7.1, when compared with wild-type (WT). Using HEK293T cells expressing Kv7.1 channel subunits (KCNQ1/KCNE1) and patch-clamp electrophysiology, we demonstrated that LQTS-associated CaM variants reduced current density at systolic Ca2+ concentrations (1 µm), revealing a direct QT-prolonging modulatory effect. Our data highlight for the first time that LQTS-associated perturbations to CaM's structure impede complex formation with Kv7.1 and subsequently result in reduced IKs. This provides a novel mechanistic insight into how the perturbed structure-function relationship of CaM variants contributes to the LQTS phenotype. KEY POINTS: Calmodulin (CaM) is a ubiquitous, highly conserved calcium (Ca2+ ) sensor playing a key role in cardiac muscle contraction. Genotyping has revealed several CaM mutations associated with long QT syndrome (LQTS), a life-threatening cardiac arrhythmia syndrome. LQTS-associated CaM variants (D95V, N97I and D131H) induced structural alterations, altered binding to Kv7.1 and reduced IKs. Our data provide a novel mechanistic insight into how the perturbed structure-function relationship of CaM variants contributes to the LQTS phenotype.
Assuntos
Calmodulina , Síndrome do QT Longo , Humanos , Calmodulina/genética , Calmodulina/metabolismo , Cálcio/metabolismo , Células HEK293 , Síndrome do QT Longo/genética , Mutação , Canal de Potássio KCNQ1/genéticaRESUMO
BACKGROUND: Patient-reported outcome measures (PROMs) are not routinely used in clinical care by pediatric liver transplant (LT) teams. The Starzl Network for Excellence in Pediatric Transplantation (SNEPT) assessed feasibility of using a disease-specific Quality of Life (QoL) questionnaire in the ambulatory setting at 10 SNEPT sites. METHODS: A mixed methods feasibility project assessing administration processes, barriers, and user experiences with the Pediatric Liver Transplant Quality of Life (PeLTQL) tool. Iterative processes sought stakeholder feedback across four phases (Pilot, Extended Pilot, Development of a Mobile App PeLTQL version, and Pilot App use). RESULTS: A total of 149 patient-parent dyads completed the PeLTQL during LT clinic follow-up. Clinicians, parents, and patients evaluated and reported on feasibility of operationalization. Only two of 10 SNEPT sites continued PeLTQL administration after the initial two pilot phases. Reasons include limited clinical time and available personnel aggravated by the COVID-19 pandemic. In response, a mobile application version of the PeLTQL was initiated. Providing PeLTQL responses electronically was "very easy" or "easy" as reported by 96% (22/23) parents. CONCLUSIONS: Administration of a PROM into post-pediatric LT clinical care was feasible, but ongoing utilization stalled. Use of a mobile app towards facilitating completion of the PeLTQL outside of clinic hours may address the time and work-flow barriers identified.
Assuntos
COVID-19 , Transplante de Fígado , Criança , Humanos , Qualidade de Vida , Estudos de Viabilidade , Pandemias , Medidas de Resultados Relatados pelo PacienteRESUMO
Leek yellow stripe virus (LYSV) is one of the most important potyviruses, associated with garlic throughout the world, including India. LYSV causes stunting and yellow streaks in garlic and leek leaves and with other coinfecting viruses leading to severe symptom expression and yield reduction. In this study, we have made the first reported attempt to produce specific polyclonal antibodies to LYSV using expressed recombinant coat protein (CP), which would be useful for screening and routine indexing of the garlic germplasm. The CP gene was cloned, sequenced, and further subcloned in pET-28a(+) expression vector, which yielded â¼35 kDa fusion protein. The fusion protein was obtained in insoluble fraction after purification and its identity was confirmed by SDS-PAGE and western blotting. The purified protein was used as immunogen for production of polyclonal antisera in New Zealand white rabbit. Antisera raised, was able to recognize the corresponding recombinant proteins in western blotting, immunosorbent electron microscopy and dot immunobinding assay (DIBA). Developed antisera to LYSV (titer 1:2000) was used for screening of 21 garlic accessions in antigen coated plate enzyme-linked immunosorbent assay (ACP-ELISA) and 16 accessions were found positive for LYSV, indicating its widespread presence within the collection tested. To the best of our knowledge, this is the first report of a polyclonal antiserum against the in-vitro expressed CP of LYSV and its successful application in diagnosis of LYSV in garlic accessions in India.
Assuntos
Alho , Potyvirus , Animais , Coelhos , Cebolas , Escherichia coli/genética , Sequência de Bases , Proteínas Recombinantes/genética , Alho/genética , Potyvirus/genética , Soros Imunes/genéticaRESUMO
Management of unresectable pediatric hepatoblastoma (HB) and hepatocellular carcinoma (HCC) remains challenging. The Society of Pediatric Liver Transplantation (SPLIT) database was used to study survival predictors in pediatric liver transplantation (LT) for HB and HCC. Event-free survival (EFS), associated risk factors, and postoperative complications were studied in children requiring LT for HB/HCC at 16 SPLIT centers. Three-year EFS was 81% for HB (n = 157) and 62% for HCC (n = 18) transplants. Of HB transplants, 6.9% were PRETEXT II and 15.3% were POST-TEXT I/II. Tumor extent did not impact survival (p = NS). Salvage (n = 13) and primary HB transplants had similar 3-year EFS (62% versus 78%, p = NS). Among HCC transplants, 3-year EFS was poorer in older patients (38% in ≥8-year-olds vs 86% <8-year-olds) and those with larger tumors (48% for those beyond versus 83% within Milan criteria, p = NS). Risk of infection (HR 1.5, 95% CI 1.1-2.2, p = .02) and renal injury (HR 2.4, 95% CI 1.7-3.3, p < .001) were higher in malignant versus nonmalignant LT. Survival is favorable for pediatric HB and HCC LT, including outcomes after salvage transplant. Unexpected numbers of LTs occurred in PRE/POST-TEXT I/II tumors. Judicious patient selection is critical to distinguish tumors that are potentially resectable; simultaneously, we must advocate for patients with unresectable malignancies to receive organs.
Assuntos
Carcinoma Hepatocelular , Hepatoblastoma , Neoplasias Hepáticas , Transplante de Fígado , Idoso , Carcinoma Hepatocelular/patologia , Criança , Hepatoblastoma/patologia , Hepatoblastoma/cirurgia , Humanos , Neoplasias Hepáticas/cirurgia , Recidiva Local de Neoplasia , Estudos RetrospectivosRESUMO
The alternative (noncanonical) nuclear factor-κB (NF-κB) signaling pathway predominantly regulates the function of the p52/RelB heterodimer. Germline Nfkb2 deficiency in mice leads to loss of p100/p52 protein and offers protection against a variety of gastrointestinal conditions, including azoxymethane/dextran sulfate sodium (DSS)-induced colitis-associated cancer and lipopolysaccharide (LPS)-induced small intestinal epithelial apoptosis. However, the common underlying protective mechanisms have not yet been fully elucidated. We applied high-throughput RNA-Seq and proteomic analyses to characterize the transcriptional and protein signatures of the small intestinal mucosa of naïve adult Nfkb2-/- mice. Those data were validated by immunohistochemistry and quantitative ELISA using both small intestinal tissue lysates and serum. We identified a B-lymphocyte defect as a major transcriptional signature in the small intestinal mucosa and immunoglobulin A as the most downregulated protein by proteomic analysis in Nfkb2-/- mice. Small intestinal immunoglobulins were dramatically dysregulated, with undetectable levels of immunoglobulin A and greatly increased amounts of immunoglobulin M being detected. The numbers of IgA-producing, cluster of differentiation (CD)138-positive plasma cells were also reduced in the lamina propria of the small intestinal villi of Nfkb2-/- mice. This phenotype was even more striking in the small intestinal mucosa of RelB-/- mice, although these mice were equally sensitive to LPS-induced intestinal apoptosis as their RelB+/+ wild-type counterparts. NF-κB2/p52 deficiency confers resistance to LPS-induced small intestinal apoptosis and also appears to regulate the plasma cell population and immunoglobulin levels within the gut.NEW & NOTEWORTHY Novel transcriptomic analysis of murine proximal intestinal mucosa revealed an unexpected B cell signature in Nfkb2-/- mice. In-depth analysis revealed a defect in the CD38+ B cell population and a gut-specific dysregulation of immunoglobulin levels.
Assuntos
Subunidade p52 de NF-kappa B , Plasmócitos , Animais , Imunoglobulina A/metabolismo , Imunoglobulinas/metabolismo , Mucosa Intestinal/metabolismo , Lipopolissacarídeos/farmacologia , Camundongos , NF-kappa B/metabolismo , Subunidade p52 de NF-kappa B/genética , Subunidade p52 de NF-kappa B/metabolismo , Plasmócitos/metabolismo , ProteômicaRESUMO
Children who undergo liver transplantation are at risk for portal vein complications (PVCs) including thrombosis (PVT) and stenosis (PVS). Using multicenter data from the Society of Pediatric Liver Transplantation, we analyzed the prevalence, timing, and risk factors for PVC following a first liver transplantation, and assessed the potential impact of PVC on patient outcomes. Our cohort included 4278 patients, of whom 327 (7.6%) developed PVC. Multivariate analysis discovered several factors independently associated with PVC: younger recipient age, lower weight at time of transplantation, diagnosis of biliary atresia (BA), receiving a technical variant graft (TVG), warm ischemia time over 3 h, PVT in the recipient's pretransplantation native liver, and concurrent hepatic artery thrombosis (all p < 0.05). Subgroup analysis of those with BA found higher prevalence in patients transplanted at less than 2 years of age and those with TVGs. There was no difference in PVC prevalence among patients with BA with vs. without prior Kasai portoenterostomy. Most PVT (77.7%) presented within 90 days after transplantation. Patients with PVC had a higher risk of graft failure (23.9% vs. 8.3%; adjusted hazard ratio [HR], 3.08; p < 0.001) and a higher risk of death (16.4% vs. 8.9%; adjusted HR, 1.96; p = 0.01). Recurrence after retransplantation was similar to the overall prevalence in the cohort (8.2%). Our results recognize the common occurrence of PVC following pediatric liver transplantation, describe independently associated risk factors, and determine that patients with PVC have worse outcomes. Further studies are needed to improve PVC prevention, detection, and management strategies.
Assuntos
Atresia Biliar , Transplante de Fígado , Trombose , Criança , Humanos , Atresia Biliar/cirurgia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Veia Porta , Estudos Retrospectivos , Trombose/etiologia , Resultado do TratamentoRESUMO
With advances in surgical techniques, medical management, and more equitable allocation systems, children who receive a liver transplantation (LT) today can expect remarkable outcomes early after LT. However, beyond 1 year after transplant, attrition rates have not improved. We reviewed two separate eras (Era 1: January 1995-June 2004 vs. Era 2: July 2004-March 2018) of the Society of Pediatric Liver Transplantation registry to explore the evolution and associated factors contributing to late graft loss (LGL) and late mortality (LM). The fraction of long-term pediatric LT recipients surviving after 1 year with their first graft significantly improved (81.5% in Era 1 vs. 85.7% in Era 2; p < 0.0001). This improvement occurred despite significant changes in patient selection toward higher risk populations (p < 0.001) and without notable improvement in perioperative complications such as hepatic artery thrombosis (p = 0.24) and early posttransplant reoperation (p = 0.94) that have historically contributed to poor late-allograft outcomes. Improved outcomes were associated with changes in patient characteristics and perioperative practices, which subsequently impacted both early post-LT complications as well as other sequalae known to contribute to adverse events in long-term pediatric LT recipients. In conclusion, despite significant changes in patient selection toward higher risk populations, and without notable improvement in several perioperative complications known to contribute to poor late-allograft outcomes, significant improvements in LGL and a trend toward improvement in LM was seen in a more contemporary cohort of children receiving an LT.
Assuntos
Sobrevivência de Enxerto , Transplante de Fígado , Criança , Humanos , Transplante de Fígado/métodos , Reoperação , Fatores de Risco , Transplantados , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Biliary strictures affect 4%-12% of pediatric liver transplantations. Biliary strictures can contribute to graft loss if left untreated; however, there remains no consensus on the best course of treatment. Study objectives included analyses of outcomes associated with biliary stricture management strategies via percutaneous transhepatic cholangiography (PTC), endoscopic retrograde cholangiopancreatography (ERCP), or surgery. We identified pediatric liver transplantation recipients (2011-2016) with biliary strictures from the Society of Pediatric Liver Transplantation (SPLIT) registry and retrieved imaging, procedural, and operative reports from individual centers. Subanalyses were performed to specifically evaluate PTC and ERCP for "optimal biliary outcome" (OBO), defined as graft survival with stricture resolution and without recurrence or surgery. A total of 113 children with a median follow-up of 3.9 years had strictures diagnosed 100 days (interquartile range, 30-290) after liver transplantation; 81% were isolated anastomotic strictures. Stricture resolution was achieved in 92% within 101 days, more frequently with isolated anastomotic strictures (96%). 20% of strictures recurred, more commonly in association with hepatic artery thrombosis (32%). Patient and graft survival at 1 and 3 years were 99% and 98% and 94% and 92%, respectively. In a subgroup analysis of 79 patients with extrahepatic strictures managed by PTC/ERCP, 59% achieved OBO following a median of 4 PTC, and 75% following a median of 3 ERCP (P < 0.001). Among patients with OBO, those with ERCP had longer time intervals between successive procedures (41, 47, 54, 62, 71 days) than for PTC (27, 31, 36, 41, 48 days; P < 0.001). Allograft salvage was successful across all interventions. Stricture resolution was achieved in 92%, with 20% risk of recurrence. Resolution without recurrence was highest in patients with isolated anastomotic strictures and without hepatic artery thrombosis.
Assuntos
Colestase , Transplante de Fígado , Criança , Colangiopancreatografia Retrógrada Endoscópica/métodos , Colestase/etiologia , Colestase/cirurgia , Constrição Patológica/etiologia , Constrição Patológica/cirurgia , Humanos , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , América do Norte/epidemiologia , Sistema de Registros , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND AND AIMS: Recurrent primary sclerosing cholangitis (rPSC) following liver transplant (LT) has a negative impact on graft and patient survival; little is known about risk factors for rPSC or disease course in children. APPROACH AND RESULTS: We retrospectively evaluated risk factors for rPSC in 140 children from the Pediatric PSC Consortium, a multicenter international registry. Recipients underwent LT for PSC and had >90 days of follow-up. The primary outcome, rPSC, was defined using Graziadei criteria. Median follow-up after LT was 3 years (interquartile range 1.1-6.1). rPSC occurred in 36 children, representing 10% and 27% of the subjects at 2 years and 5 years following LT, respectively. Subjects with rPSC were younger at LT (12.9 vs. 16.2 years), had faster progression from PSC diagnosis to LT (2.5 vs. 4.1 years), and had higher alanine aminotransferase (112 vs. 66 IU/L) at LT (all P < 0.01). Inflammatory bowel disease was more prevalent in the rPSC group (86% vs. 66%; P = 0.025). After LT, rPSC subjects had more episodes of biopsy-proved acute rejection (mean 3 vs. 1; P < 0.001), and higher prevalence of steroid-refractory rejection (41% vs. 20%; P = 0.04). In those with rPSC, 43% developed complications of portal hypertension, were relisted for LT, or died within 2 years of the diagnosis. Mortality was higher in the rPSC group (11.1% vs. 2.9%; P = 0.05). CONCLUSIONS: The incidence of rPSC in this cohort was higher than previously reported, and was associated with increased morbidity and mortality. Patients with rPSC appeared to have a more aggressive, immune-reactive phenotype. These findings underscore the need to understand the immune mechanisms of rPSC, to lay the foundation for developing new therapies and improve outcomes in this challenging population.
Assuntos
Colangite Esclerosante/cirurgia , Rejeição de Enxerto/epidemiologia , Hipertensão Portal/epidemiologia , Transplante de Fígado , Adolescente , Fatores Etários , Alanina Transaminase/sangue , Aspartato Aminotransferases/sangue , Criança , Colangite Esclerosante/sangue , Colangite Esclerosante/epidemiologia , Progressão da Doença , Resistência a Medicamentos , Feminino , Glucocorticoides/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Humanos , Hipertensão Portal/fisiopatologia , Doenças Inflamatórias Intestinais/epidemiologia , Internacionalidade , Masculino , Recidiva , Sistema de Registros , Fatores de Risco , Fatores de Tempo , gama-Glutamiltransferase/sangueRESUMO
BACKGROUND AND AIMS: Many children with primary sclerosing cholangitis (PSC) receive oral vancomycin therapy (OVT) or ursodeoxycholic acid (UDCA). There is a paucity of data on whether these medications improve outcomes. APPROACH AND RESULTS: We analyzed retrospective data from the Pediatric PSC Consortium. Children treated with OVT were matched 1:1:1 to those treated with UDCA or managed with observation (no treatment) based on the closest propensity score, ensuring similar baseline characteristics. Two hundred sixty-four patients (88 each with OVT, UDCA, or observation) had matching propensity scores and were similar in demographics, phenotype, immunosuppression, baseline biochemistry, and hepatic fibrosis. After 1 year in an intention-to-treat analysis, all outcome metrics were similar regardless of treatment group. In OVT, UDCA, and untreated groups, respectively: Gamma-glutamyltransferase normalized in 53%, 49%, and 52% (P = not significant [NS]), liver fibrosis stage was improved in 20%, 13%, and 18% and worsened in 11%, 29%, and 18% (P = NS), and the 5-year probability of liver transplant listing was 21%, 10%, and 12% (P = NS). Favorable outcome was associated with having a mild phenotype of PSC and minimal hepatic fibrosis. CONCLUSIONS: We presented the largest-ever description of outcomes on OVT in PSC and compared them to carefully matched patients on UDCA or no therapy. Neither OVT nor UDCA showed improvement in outcomes compared to a strategy of observation. Patients progressed to end-stage liver disease at similar rates. Spontaneous normalization of biochemistry is common in children receiving no therapy, particularly in the majority of children with a mild phenotype and an early stage of disease. Placebo-controlled treatment trials are needed to identify effective treatments for pediatric PSC.
Assuntos
Colangite Esclerosante/tratamento farmacológico , Ácido Ursodesoxicólico/uso terapêutico , Vancomicina/uso terapêutico , Administração Oral , Adolescente , Bilirrubina/sangue , Criança , Feminino , Humanos , Masculino , Pontuação de Propensão , Estudos Retrospectivos , Albumina Sérica/análise , Resultado do Tratamento , Ácido Ursodesoxicólico/administração & dosagem , Vancomicina/administração & dosagemRESUMO
BACKGROUND AND AIMS: Tolerance is transplantation's holy grail, as it denotes allograft health without immunosuppression and its toxicities. Our aim was to determine, among stable long-term pediatric liver transplant recipients, the efficacy and safety of immunosuppression withdrawal to identify operational tolerance. APPROACH AND RESULTS: We conducted a multicenter, single-arm trial of immunosuppression withdrawal over 36-48 weeks. Liver tests were monitored biweekly (year 1), monthly (year 2), and bimonthly (years 3-4). For-cause biopsies were done at investigators' discretion but mandated when alanine aminotransferase or gamma glutamyltransferase exceeded 100 U/L. All subjects underwent final liver biopsy at trial end. The primary efficacy endpoint was operational tolerance, defined by strict biochemical and histological criteria 1 year after stopping immunosuppression. Among 88 subjects (median age 11 years; 39 boys; 57 deceased donor grafts), 33 (37.5%; 95% confidence interval [CI] 27.4%, 48.5%) were operationally tolerant, 16 were nontolerant by histology (met biochemical but failed histological criteria), and 39 were nontolerant by rejection. Rejection, predicted by subtle liver inflammation in trial entry biopsies, typically (n = 32) occurred at ≤32% of the trial-entry immunosuppression dose and was treated with corticosteroids (n = 32) and/or tacrolimus (n = 38) with resolution (liver tests within 1.5 times the baseline) for all but 1 subject. No death, graft loss, or chronic, severe, or refractory rejection occurred. Neither fibrosis stage nor the expression level of a rejection gene set increased over 4 years for either tolerant or nontolerant subjects. CONCLUSIONS: Immunosuppression withdrawal showed that 37.5% of selected pediatric liver-transplant recipients were operationally tolerant. Allograft histology did not deteriorate for either tolerant or nontolerant subjects. The timing and reversibility of failed withdrawal justifies future trials exploring the efficacy, safety, and potential benefits of immunosuppression minimization.
Assuntos
Imunossupressores/administração & dosagem , Transplante de Fígado , Medicina de Precisão/métodos , Criança , Pré-Escolar , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/etiologia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Lactente , Transplante de Fígado/efeitos adversos , Transplante de Fígado/métodos , Masculino , Estudos Prospectivos , Suspensão de TratamentoRESUMO
BACKGROUND AND AIMS: Disease progression in children with primary sclerosing cholangitis (PSC) is variable. Prognostic and risk-stratification tools exist for adult-onset PSC, but not for children. We aimed to create a tool that accounts for the biochemical and phenotypic features and early disease stage of pediatric PSC. APPROACH AND RESULTS: We used retrospective data from the Pediatric PSC Consortium. The training cohort contained 1,012 patients from 40 centers. We generated a multivariate risk index (Sclerosing Cholangitis Outcomes in Pediatrics [SCOPE] index) that contained total bilirubin, albumin, platelet count, gamma glutamyltransferase, and cholangiography to predict a primary outcome of liver transplantation or death (TD) and a broader secondary outcome that included portal hypertensive, biliary, and cancer complications termed hepatobiliary complications (HBCs). The model stratified patients as low, medium, or high risk based on progression to TD at rates of <1%, 3%, and 9% annually and to HBCs at rates of 2%, 6%, and 13% annually, respectively (P < 0.001). C-statistics to discriminate outcomes at 1 and 5 years were 0.95 and 0.82 for TD and 0.80 and 0.76 for HBCs, respectively. Baseline hepatic fibrosis stage was worse with increasing risk score, with extensive fibrosis in 8% of the lowest versus 100% with the highest risk index (P < 0.001). The model was validated in 240 children from 11 additional centers and performed well. CONCLUSIONS: The SCOPE index is a pediatric-specific prognostic tool for PSC. It uses routinely obtained, objective data to predict a complicated clinical course. It correlates strongly with biopsy-proven liver fibrosis. SCOPE can be used with families for shared decision making on clinical care based on a patient's individual risk, and to account for variable disease progression when designing future clinical trials.
Assuntos
Colangite Esclerosante/diagnóstico , Adolescente , Bilirrubina/sangue , Biópsia , Criança , Colangiografia , Colangite Esclerosante/mortalidade , Colangite Esclerosante/patologia , Colangite Esclerosante/cirurgia , Progressão da Doença , Feminino , Humanos , Transplante de Fígado , Masculino , Contagem de Plaquetas , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Albumina Sérica/análise , gama-Glutamiltransferase/sangueRESUMO
OBJECTIVES: To analyze demographic, psychosocial, and clinical factors in pediatric liver transplant recipients for their association with death or loss to follow up in adulthood. We aimed to better understand known health disparities in transplant outcomes and identify potentially modifiable risk factors prior to transfer. METHODS: A retrospective cohort study of children who underwent liver transplantation at a large tertiary transplant center and were transferred to adult care between 2000 and 2015. RESULTS: During the study period, 101 qualifying patients were transferred. Ninety-three individuals followed with an adult provider, while 8 were lost to follow up. In total 23 of 93 patients died after transfer (24.7%). Several childhood factors were associated with adult death: Black race [odds ratio (OR) 6.59, P < 0.001]; psychiatric illness or substance use (OR 2.81, P = 0.04); failure to graduate high school before transfer (OR 9.59, P < 0.001); posttransplant tacrolimus medication-level variability index >2.5 (OR 5.36, P = 0.04); provider documentation of medication nonadherence (OR 4.72, P = 0.02); acute cellular rejection (OR 4.44, P = 0.03); the presence of diabetes mellitus (OR 5.71, P = 0.001), and chronic kidney disease (OR 2.82, P = 0.04). Failure to graduate HS was associated with loss to follow up ( P < 0.001). On multivariate analysis, Black race, substance use, diabetes, and failure to graduate HS retained association with adult death (each P < 0.05). CONCLUSIONS: Complex, intertwined patient characteristics are associated with increased odds of death in pediatric liver transplant recipients transferred to adult care. Early recognition of high-risk patients and intervention for modifiable factors, such as improved HS graduation and substance use prevention, may improve long-term outcomes.
Assuntos
Diabetes Mellitus , Transplante de Fígado , Transtornos Relacionados ao Uso de Substâncias , Adulto , Humanos , Criança , Transplante de Fígado/efeitos adversos , Sobrevivência de Enxerto , Estudos Retrospectivos , Rejeição de Enxerto/epidemiologia , Fatores de Risco , Adesão à Medicação , Diabetes Mellitus/etiologia , Transtornos Relacionados ao Uso de Substâncias/etiologia , Transplantados/psicologiaRESUMO
A steatotic liver is increasingly vulnerable to ischemia reperfusion injury (IRI), and the underlying mechanisms are incompletely defined. Caspases are endo-proteases, which provide critical regulatory connections between cell death and inflammation. Caspase 1 is driven by inflammasomes which are key signaling platforms, that detect sterile stressors (DAMPs), releasing the highly pro-inflammatory cytokine interleukin IL-8 and IL-1ß. To delineate the involvement of Caspase 1 and 11 in hepatocellular injury in steatotic liver undergoing IRI. Male C57BL6/Wild Type and Caspase 1Null, Caspase 11-/- and Caspase 1-/-/11-/- mice were fed a high fat diet (HFD) for 12 weeks. These mice were subjected to 40 min of ischemia followed by 2-24 h of reperfusion. Hepatocellular injury was assessed by histopathologic injury scoring, serum ALT and propidium iodide (PI) uptake, mRNA levels of Caspase 1, IL-1ß by RT PCR, Caspase 1 activity assay and Caspase 1. Specific Caspase 1, inhibitor experiments were carried out. All groups gained similar body weight after a 12-week HFD. Cleaved Caspase 1 protein levels, Caspase 1 mRNA levels were significantly higher in steatotic liver undergoing IRI. Executor of pyroptosis cleaved GSDMD levels were higher in HFD fed mouse compared to lean. In addition, genetic deletion of Caspase 1, Casp1Null mouse expressing Caspase-11 and Caspase 1/11 double knock out demonstrated significant reduction in serum ALT (p < 0.01), Injury Score, (p < 0.0002) but not in Caspase 11 alone. Caspase 1 is the driver of hepatocellular injury in a steatotic liver undergoing IRI, inhibition of which leads to hepatoprotection, thus providing a therapeutic target for clinical use.
Assuntos
Caspase 1/metabolismo , Fígado Gorduroso/patologia , Piroptose/fisiologia , Traumatismo por Reperfusão/patologia , Animais , Caspase 1/genética , Caspases Iniciadoras/genética , Caspases Iniciadoras/metabolismo , Linhagem Celular , Dieta Hiperlipídica/efeitos adversos , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Hepatócitos/metabolismo , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas de Ligação a Fosfato/metabolismo , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/metabolismoRESUMO
Inflammatory bowel disease (IBD), especially when associated with primary sclerosing cholangitis (PSC), is a risk factor for developing colorectal cancer (CRC).1-3 We aimed to determine the incidence of CRC in a large cohort of pediatric-onset PSC-ulcerative colitis (UC) patients.
Assuntos
Colangite Esclerosante , Colite Ulcerativa , Neoplasias Colorretais , Doenças Inflamatórias Intestinais , Criança , Colangite Esclerosante/complicações , Colangite Esclerosante/epidemiologia , Colite Ulcerativa/complicações , Neoplasias Colorretais/epidemiologia , Humanos , Doenças Inflamatórias Intestinais/complicações , Fatores de RiscoRESUMO
OBJECTIVE: To analyze the long-term outcomes in pediatric liver transplant recipients after they have transferred to an adult provider and assess for racial disparities in health outcomes. STUDY DESIGN: This is a single-center, retrospective review of pediatric patients who underwent liver transplantation between July 1990 and August 2015 at a tertiary healthcare system with a large transplant center. Patient mortality and retransplantation were assessed after transfer to adult care. RESULTS: There were 120 patients who were transferred, of whom 19 did not meet the inclusion criteria. Of the remaining 101 patients, 64 (63%) transferred care to a nearby affiliated tertiary adult facility, 29 (29%) were followed by other healthcare systems, and 8 (8%) were lost to follow-up. Of the patients followed at our affiliated adult center, 18 of the 64 (28%) died. Of those 18 deaths, 4 (22%) occurred within the first 2 years after transfer, and 10 (55%) within 5 years of transfer. Four patients were retransplanted by an adult provider, of whom 2 eventually received a third transplant. African Americans had higher rates of death after transfer than patients of other races (44% mortality vs 16%, representing 67% of all cases of death; P = .032), with nearly 50% mortality at 20 years from time of transplantation. CONCLUSIONS: Death is common in pediatric liver transplant recipients after transfer to adult care, with African Americans having disproportionately higher mortality. This period of transition of care is a vulnerable time, and measures must be taken to ensure the safe transfer of young adults with chronic health care needs.
Assuntos
Negro ou Afro-Americano , Hepatopatias/mortalidade , Transplante de Fígado , Transição para Assistência do Adulto , Transplantados , Adolescente , Adulto , Criança , Estudos de Coortes , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/cirurgia , Humanos , Hepatopatias/cirurgia , Masculino , Reoperação/estatística & dados numéricos , Estudos Retrospectivos , Estados Unidos/epidemiologia , Adulto JovemRESUMO
Recurrent autoimmune hepatitis (rAIH) occurs in patients who undergo liver transplantation (LT) for AIH and de novo AIH (dAIH) is seen in patients who are transplanted for etiologies other than AIH. Whether these are distinct diseases with a similar phenotype remains understudied. The aim of this study was to identify clinical and immunologic factors affecting outcome in patients with dAIH and rAIH. A retrospective review of 387 LT patients from 1997 to 2014 was carried out, and they were followed until 2018. Patients with rAIH or dAIH were identified based on the pre-transplant diagnosis of AIH (or not) and characteristic histology. Liver biopsies were stained with H&E, B-cell marker CD20, and plasma cell marker CD138. Out of 387 patients, 31 were transplanted for AIH, and 8/31 developed rAIH. Of the remaining 356 patients, eight developed dAIH. Compared to the dAIH group, rAIH occurred in older patients, had an earlier onset in the allograft, and had higher IgG and serum ALT levels. It was most commonly seen in African American (AA) patients (87%). rAIH patients had significantly higher CD20 and CD138 positivity in liver biopsies. In addition, they had increased rejection episodes prior to the onset of recurrence, increased graft loss, and mortality. rAIH is a more aggressive disease, and has a preponderance of B cells and plasma cells in the liver tissue as compared to dAIH. The concurrent association with increased graft loss and patient mortality in rAIH warrants further investigations into B cell-targeted therapies.