Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 61
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Am J Hum Genet ; 109(5): 928-943, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-35397207

RESUMO

Organ fibrosis is a shared endpoint of many diseases, yet underlying mechanisms are not well understood. Several pathways governed by the primary cilium, a sensory antenna present on most vertebrate cells, have been linked with fibrosis. Ciliopathies usually start early in life and represent a considerable disease burden. We performed massively parallel sequencing by using cohorts of genetically unsolved individuals with unexplained liver and kidney failure and correlated this with clinical, imaging, and histopathological analyses. Mechanistic studies were conducted with a vertebrate model and primary cells. We detected bi-allelic deleterious variants in TULP3, encoding a critical adaptor protein for ciliary trafficking, in a total of 15 mostly adult individuals, originating from eight unrelated families, with progressive degenerative liver fibrosis, fibrocystic kidney disease, and hypertrophic cardiomyopathy with atypical fibrotic patterns on histopathology. We recapitulated the human phenotype in adult zebrafish and confirmed disruption of critical ciliary cargo composition in several primary cell lines derived from affected individuals. Further, we show interaction between TULP3 and the nuclear deacetylase SIRT1, with roles in DNA damage repair and fibrosis, and report increased DNA damage ex vivo. Transcriptomic studies demonstrated upregulation of profibrotic pathways with gene clusters for hypertrophic cardiomyopathy and WNT and TGF-ß signaling. These findings identify variants in TULP3 as a monogenic cause for progressive degenerative disease of major organs in which affected individuals benefit from early detection and improved clinical management. Elucidation of mechanisms crucial for DNA damage repair and tissue maintenance will guide novel therapeutic avenues for this and similar genetic and non-genomic diseases.


Assuntos
Cardiomiopatia Hipertrófica , Cílios , Adulto , Animais , Cardiomiopatia Hipertrófica/metabolismo , Criança , Cílios/genética , Cílios/metabolismo , Fibrose , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Rim , Fígado , Mutação/genética , Peixe-Zebra/genética
2.
J Pediatr Gastroenterol Nutr ; 76(5): 627-633, 2023 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-36705669

RESUMO

OBJECTIVES: Protocol liver biopsies (PLBs) are part of the follow-up program at many pediatric liver transplant centers, but the impact on clinical decision-making and allograft histology following adjustments of immunosuppression (IS) after PLB has not been thoroughly analyzed. METHODS: Following our previous single-center cohort study, we have now evaluated histological findings of 178 PLBs of 118 pediatric patients transplanted at our center between 1998 and 2017. In particular, we focused on the changes in allograft histology in the follow-up biopsy of a subgroup of 22 patients, in which the histologic findings led to an adjustment of immunosuppressive therapy. All biopsies of this sub-study group were reevaluated by an experienced pathologist. RESULTS: The overall frequency and severity of fibrosis increased over time after orthotopic liver transplantation. Patients with donor-specific antibodies (DSAs) had a higher prevalence of fibrosis than DSA-negative patients. Graft inflammation decreased significantly after intensifying IS, but renal function needs to be monitored. A significant increase in fibrosis was detected in children with reduced IS. CONCLUSION: The adjustment of IS following PLBs has a significant impact on allograft histology. Since chronic inflammatory changes may lead to graft failure, adjustment of IS seems to be of major importance for the long-term outcome.


Assuntos
Transplante de Fígado , Criança , Humanos , Transplante de Fígado/métodos , Estudos de Coortes , Rejeição de Enxerto/prevenção & controle , Fígado/patologia , Fibrose , Terapia de Imunossupressão , Biópsia
3.
Clin Transplant ; 35(7): e14336, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33949011

RESUMO

Here the impact of donor specific human leukocyte antigen (HLA) class 2 antibodies (DSA cl 2) on long term outcome after liver transplantation (LT) was investigated. Altogether 156 (44 pediatric and 112 adult) LT recipients were included in the study. Graft fibrosis was assessed by liver elastography and biopsy. DSA cl 2 were determined by Luminex technology. 46% of LT recipients were positive for DSA cl 2 after a median follow-up of 15 years. In the multivariate analysis DSA cl 2 were significantly associated with immunosuppressive monotherapy (OR 5.42; 95% CI: 1.02-28.90; p = .048). Compared to DSA cl 2 negative patients, positive recipients had significantly more graft fibrosis based on the liver stiffness (mean 9.4 ± 9.0 kPa vs. 6.5 ± 6.3 kPa; p < .002) and fibrosis stages determined by liver elastography (p = .016) and the performed liver biopsies (p = .002). Also, a significantly higher incidence of chronic rejections (11% vs. 2%; p = .045) and graft losses (6% vs. 0%; p = .043) were found. In the multivariate regression analysis DSA cl 2 were significantly associated with graft fibrosis (OR 4.57; 95% CI 1.59-13.10; p = .005). So, these data suggest that development of DSA cl 2 occurs more often with immunosuppressive monotherapy and may ultimately result in chronic rejection and graft fibrosis.


Assuntos
Transplante de Fígado , Adulto , Criança , Fibrose , Rejeição de Enxerto/etiologia , Sobrevivência de Enxerto , Antígenos HLA , Teste de Histocompatibilidade , Humanos , Isoanticorpos , Transplante de Fígado/efeitos adversos , Estudos Retrospectivos
4.
Pediatr Transplant ; 25(8): e14121, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34428322

RESUMO

BACKGROUND: Young adults who underwent liver transplantation in childhood (YALTs) are highly vulnerable to non-adherent behavior and psychosocial problems. During the COVID-19 pandemic, special efforts may be necessary to maintain contact with these patients and offer support. This can be achieved through the use of telemedicine. The study's objective was to assess adherence and the psychosocial situation of YALTs during the COVID-19 pandemic in Germany and to evaluate the utilization of video consultations. METHODS: In May 2020, a questionnaire was sent to YALTs treated at the Hamburg University Transplant Center, accompanied by the offer of video appointments with the attending physician. The questionnaire included the Generalized Anxiety Disorder Scale 7, the Patient Health Questionnaire 2, and questions compiled by the authors. RESULTS: Of 98 YALTs, 12% used the video consultation, while 65% had an in-person appointment. The 56 patients who completed the questionnaire did not report reduced medication adherence during the pandemic, but 40% missed follow-up visits with their primary care physician or check-up laboratory tests. About 70% of YALTs were afraid to visit their physician and the transplant center, and 34% were afraid of a SARS-CoV-2 infection. Mental health and well-being were unimpaired. CONCLUSIONS: During the COVID-19 pandemic, YALTs in our study did not show an increased need for psychosocial support, but a majority were afraid to attend medical appointments, and 40% reported lower appointment adherence. Acceptance of video consultations was lower than expected. The reasons for this need to be further investigated in order to optimize care.


Assuntos
COVID-19/epidemiologia , Transplante de Fígado/psicologia , Cooperação do Paciente , Telemedicina , Adolescente , Adulto , Alemanha , Humanos , Masculino , Adesão à Medicação , Pandemias , SARS-CoV-2 , Inquéritos e Questionários , Adulto Jovem
5.
J Pediatr Gastroenterol Nutr ; 68(2): 169-174, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30664572

RESUMO

OBJECTIVES: Bile salt export pump (BSEP) deficiency is an important reason for chronic cholestasis leading to liver transplantation (LT) in early childhood. The underlying pathology is a dysfunction of BSEP due to various mutations in the ABCB11 gene. Cases of clinical recurrence after LT due to alloantibodies directed against BSEP (antibody-induced BSEP deficiency [AIBD]) have been reported. Most of these patients could be controlled by intensified immunosuppression. METHODS: We here report on 3 children with BSEP-deficiency and end-stage liver disease, which developed AIBD after LT refractory to extensive immunosuppressive and immunomodulatory treatments; retransplantation was necessary in all 3 patients. In 1 patient, a stem cell transplantation was performed successfully. RESULTS: AIBD seems to be induced by triggering factors such as initial impaired graft function or infections after LT. CONCLUSIONS: The underlying mutation may play a role in this process. Intensifying immunosuppression may be able to control AIBD, but some cases seem to be refractory to treatment and require retransplantation. Stem cell transplantation may provide a new therapeutic option for cases refractory to conservative treatment.


Assuntos
Anticorpos/imunologia , Colestase Intra-Hepática/cirurgia , Doença Hepática Terminal/cirurgia , Transplante de Fígado/efeitos adversos , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/deficiência , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/imunologia , Pré-Escolar , Colestase Intra-Hepática/genética , Colestase Intra-Hepática/imunologia , Doença Hepática Terminal/genética , Doença Hepática Terminal/imunologia , Feminino , Humanos , Lactente , Masculino , Período Pós-Operatório , Recidiva , Transplante de Células-Tronco
6.
Biopharm Drug Dispos ; 40(7): 217-224, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31242332

RESUMO

PURPOSE: Topical nonsteroidal anti-inflammatory drug formulations are used commonly to treat musculoskeletal pain and inflammation. Drug properties and formulation composition are the primary determinants of the transdermal drug delivery rate. The ex vivo transdermal flux through human skin of three topical diclofenac formulations was compared. METHODS: The formulations tested were hydrogel 1% diclofenac sodium and two emulsion gels (1.16%/2.32% diclofenac diethylamine, equivalent to 1%/2% diclofenac sodium). Human abdominal skin obtained during unrelated surgical procedures was stored at -20 °C until use. Skin specimens were thawed, prepared and placed in Franz diffusion cells (stratum corneum facing donor cell). The test formulation (~200 mg) was applied to the donor cell skin surface, and the receptor compartment was periodically sampled over 48 hours. The drug concentration in the receptor medium was determined by a validated HPLC method. Raman spectral imaging was performed to visualize the location and distribution of diclofenac. RESULTS: After 5 hours, the cumulative amount of hydrogel diclofenac transiting the skin was about 10 times that of the emulsion gel 1.16% (P=0.0004) and about twice that of the emulsion gel 2.32% (P=0.022). Similar results were seen after 9 hours. Raman spectroscopy showed that the hydrogel formulation was a homogeneous mixture of its various components, including diclofenac. The emulsion gels were non-homogeneous, with diclofenac in close proximity to the lipophilic (paraffin) phase. CONCLUSIONS: The transdermal transit of diclofenac from the hydrogel demonstrated a faster onset and a greater absorption rate than either emulsion gel formulation, suggesting that the hydrogel formulation may have a faster onset of action in underlying tissues vs. the emulsion gel products.


Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Diclofenaco/administração & dosagem , Hidrogéis/administração & dosagem , Absorção Cutânea/efeitos dos fármacos , Pele/efeitos dos fármacos , Feminino , Humanos , Técnicas In Vitro , Permeabilidade/efeitos dos fármacos , Pele/metabolismo
7.
J Hepatol ; 69(4): 961-965, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29935200

RESUMO

Progressive familial intrahepatic cholestasis 2 is an autosomal-recessive disorder caused by mutations in the ABCB11 gene, which encodes the bile salt export pump (BSEP). Recurrence of BSEP deficiency after liver transplantation is caused by the development of anti-BSEP antibodies. Antibody-induced BSEP deficiency is typically treated by increasing immunosuppressive therapy. We report, in a child, the first case of allogeneic haematopoietic stem cell transplantation for antibody-induced BSEP deficiency that was refractory to intensive pharmacological immunosuppression and immunoadsorption. After haematopoietic stem cell transplantation, anti-BSEP antibodies were cleared from the patient's serum and later from the canalicular space of the liver graft.


Assuntos
Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/deficiência , Autoanticorpos/sangue , Transplante de Células-Tronco Hematopoéticas , Transplante de Fígado/efeitos adversos , Membro 11 da Subfamília B de Transportadores de Cassetes de Ligação de ATP/imunologia , Humanos , Terapia de Imunossupressão , Lactente , Masculino , Transplante Homólogo
8.
Analyst ; 143(17): 4027-4039, 2018 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-29956693

RESUMO

Latent fingermarks are an important form of crime-scene trace evidence and their usefulness may be increased by a greater understanding of the effect of chemical distribution within fingermarks on the sensitivity and robustness of fingermark detection methods. Specifically, the relative abundance and micro-distribution of sebaceous (lipophilic) and eccrine (hydrophilic) material in fingermarks have long been debated in the field, yet direct visualisation of relative abundance and micro-distribution was rarely achieved. Such a visualisation is nonetheless essential to provide explanations for the variation in reproducibility or robustness of latent fingermark detection with existing methods, and to identify new strategies to increase detection capabilities. In this investigation, we have used SR-ATR-FTIR and confocal Raman microscopy to probe the spatial micro-distribution of the sebaceous and eccrine chemical components within latent fingermarks, deposited on non-porous surfaces. It was determined that fingermarks exhibit a complex spatial distribution, influenced by the ratio of lipophilic to aqueous components, and to a first approximation resemble a water-in-oil or oil-in-water emulsion. Detection of a substantial lipid component in "eccrine enriched fingermarks" (wherein hands are washed to remove lipids) is noteworthy, as it provides a potential explanation for several scenarios of unexpected fingermark detection using methods previously thought unsuitable for "eccrine deposits". Furthermore, the pronounced distribution of lipids observed in natural fingermark deposits was intriguing and agrees with recent discussion in this research field that natural fingermarks contain a much higher lipid content than previously thought.

9.
Cytotherapy ; 17(10): 1396-405, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26188965

RESUMO

BACKGROUND AIMS: Evidence of the criticality of the adaptive immune response for controlling invasive aspergillosis has been provided. This observation is supported by the fact that invasive aspergillosis, a grave complication of allogeneic stem cell transplantation, occurs long after myeloid reconstitution in patients with low T-cell engraftment and/or on immunosuppressants. Adoptive T-cell transfer might be beneficial, but idiosyncrasies of Aspergillus fumigatus and the anti-Aspergillus immune response render established selection technologies ineffective. METHODS: We developed a Good Manufacturing Practice (GMP)-compliant protocol for preparation of A. fumigatus-specific CD4+ cells by sequentially depleting regulatory and cytotoxic T cells, activating A. fumigatus-specific T-helper cells with GMP-grade A. fumigatus lysate, and immuno-magnetically isolating them via the transiently up-regulated activation marker, CD137. RESULTS: In 13 full-scale runs, we demonstrate robustness and feasibility of the approach. From 2 × 10(9) peripheral blood mononuclear cells, we isolated 27 × 10(3)-318 × 10(3)Aspergillus-specific T-helper cells. Frequency among total T cells was increased, on average, by 200-fold. Specific studies indicate specificity and functionality: After non-specific in vitro expansion and re-stimulation with different antigens, we observed strong cytokine responses to A. fumigatus and some other fungi including Candida albicans, but none to unrelated antigens. DISCUSSION: Our technology isolates naturally occurring Aspergillus-specific T-helper cells within 2 days of identifying the clinical indication. Rapid adoptive transfer of Aspergillus-specific T cells may be quite feasible; the clinical benefit remains to be demonstrated. A manufacturing license as an advanced-therapy medicinal product was received and a clinical trial in post-transplantation invasive aspergillosis patients approved. The product is dosed at 5 × 10E3/kg T cells (single intravenous injection), of which at least 10% must be A. fumigatus-specific.


Assuntos
Aspergilose/terapia , Aspergillus fumigatus/imunologia , Separação Celular/métodos , Imunoterapia Adotiva/métodos , Ativação Linfocitária/imunologia , Linfócitos T Auxiliares-Indutores/transplante , Antígenos de Fungos/imunologia , Aspergilose/imunologia , Candida albicans/imunologia , Citocinas/imunologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Leucócitos Mononucleares/imunologia , Depleção Linfocítica/métodos , Linfócitos T Auxiliares-Indutores/imunologia , Membro 9 da Superfamília de Receptores de Fatores de Necrose Tumoral/metabolismo
10.
Proc Natl Acad Sci U S A ; 109(5): 1661-6, 2012 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-22307627

RESUMO

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a childhood-onset neurological disease resulting from mutations in the SACS gene encoding sacsin, a 4,579-aa protein of unknown function. Originally identified as a founder disease in Québec, ARSACS is now recognized worldwide. Prominent features include pyramidal spasticity and cerebellar ataxia, but the underlying pathology and pathophysiological mechanisms are unknown. We have generated an animal model for ARSACS, sacsin knockout mice, that display age-dependent neurodegeneration of cerebellar Purkinje cells. To explore the pathophysiological basis for this observation, we examined the cell biological properties of sacsin. We show that sacsin localizes to mitochondria in non-neuronal cells and primary neurons and that it interacts with dynamin-related protein 1, which participates in mitochondrial fission. Fibroblasts from ARSACS patients show a hyperfused mitochondrial network, consistent with defects in mitochondrial fission. Sacsin knockdown leads to an overly interconnected and functionally impaired mitochondrial network, and mitochondria accumulate in the soma and proximal dendrites of sacsin knockdown neurons. Disruption of mitochondrial transport into dendrites has been shown to lead to abnormal dendritic morphology, and we observe striking alterations in the organization of dendritic fields in the cerebellum of knockout mice that precedes Purkinje cell death. Our data identifies mitochondrial dysfunction/mislocalization as the likely cellular basis for ARSACS and indicates a role for sacsin in regulation of mitochondrial dynamics.


Assuntos
Genes Recessivos , Mitocôndrias/patologia , Espasticidade Muscular/patologia , Células de Purkinje/patologia , Ataxias Espinocerebelares/congênito , Animais , Células Cultivadas , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/fisiologia , Humanos , Camundongos , Camundongos Knockout , Espasticidade Muscular/genética , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/patologia
11.
PLoS Genet ; 8(9): e1002903, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22969434

RESUMO

Left-sided congenital heart disease (CHD) encompasses a spectrum of malformations that range from bicuspid aortic valve to hypoplastic left heart syndrome. It contributes significantly to infant mortality and has serious implications in adult cardiology. Although left-sided CHD is known to be highly heritable, the underlying genetic determinants are largely unidentified. In this study, we sought to determine the impact of structural genomic variation on left-sided CHD and compared multiplex families (464 individuals with 174 affecteds (37.5%) in 59 multiplex families and 8 trios) to 1,582 well-phenotyped controls. 73 unique inherited or de novo CNVs in 54 individuals were identified in the left-sided CHD cohort. After stringent filtering, our gene inventory reveals 25 new candidates for LS-CHD pathogenesis, such as SMC1A, MFAP4, and CTHRC1, and overlaps with several known syndromic loci. Conservative estimation examining the overlap of the prioritized gene content with CNVs present only in affected individuals in our cohort implies a strong effect for unique CNVs in at least 10% of left-sided CHD cases. Enrichment testing of gene content in all identified CNVs showed a significant association with angiogenesis. In this first family-based CNV study of left-sided CHD, we found that both co-segregating and de novo events associate with disease in a complex fashion at structural genomic level. Often viewed as an anatomically circumscript disease, a subset of left-sided CHD may in fact reflect more general genetic perturbations of angiogenesis and/or vascular biology.


Assuntos
Variações do Número de Cópias de DNA , Cardiopatias Congênitas/genética , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Criança , Pré-Escolar , Família , Feminino , Coração/embriologia , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Miocárdio/metabolismo , Neovascularização Fisiológica , Adulto Jovem
12.
Liver Transpl ; 20(4): 464-72, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24478274

RESUMO

Deoxyguanosine kinase (DGUOK) deficiency is a well-known cause of hepatocerebral mitochondrial DNA depletion syndromes, which include a broad spectrum of clinical presentations. Affected patients often develop life-threatening liver failure, but the benefits of liver transplantation (LT) are controversial because of the frequently severe neurological involvement due to the underlying mitochondrial disease. We describe the long-term clinical course of 2 patients from our institution and provide an update on their outcomes after LT with this condition. Another 12 pediatric patients were identified through a systematic search of the literature. All 14 reported patients underwent transplantation in infancy despite mild to moderate neurological impairment in some cases. The 2 DGUOK-deficient patients from our center displayed liver failure and mild to moderate neurological involvement. At the time of this writing, they had been followed for 5 and 8 years after LT, both patients were alive, and they had only mild neurological symptoms. Three of the 12 patients identified through the literature review survived for a long time (17, 12, and 23 years); 8 died during early follow-up; and for 1 patient, no follow-up information was available. The 1-year survival rate was 64%; 36% survived for more than 5 years. The long-term survivors had good quality of life. In conclusion, although survival after LT for DGUOK deficiency is lower than survival after LT for other indications, a significant proportion of patients benefit from LT with long-term survival and a stable neurological situation despite initial neurological abnormalities. Nevertheless, a decision to carry out LT for patients with DGUOK deficiency remains difficult because neurological symptoms may occur and worsen after LT despite their absence before transplantation.


Assuntos
Transplante de Fígado , Feminino , Seguimentos , Humanos , Lactente , Hepatopatias/etiologia , Hepatopatias/cirurgia , Masculino , Doenças Mitocondriais/mortalidade , Doenças Mitocondriais/fisiopatologia , Doenças Mitocondriais/cirurgia , Fatores de Tempo , Resultado do Tratamento
13.
Clin Transplant ; 28(9): 1061-8, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25040668

RESUMO

Liver allocation in the Eurotransplant (ET) region has changed from a waiting time to an urgency-based system using the model of end-stage liver disease (MELD) score in 2006. To allow timely transplantation, pediatric recipients are allocated by an assigned pediatric MELD independent of severity of illness. Consequences for children listed at our center were evaluated by retrospective analysis of all primary pediatric liver transplantation (LTX) from deceased donors between 2002 and 2010 (110 LTX before/50 LTX after new allocation). Of 50 children transplanted in the MELD era, 17 (34%) underwent LTX with a high-urgent status that was real in five patients (median lab MELD 22, waiting time five d) and assigned in 12 patients (lab MELD 7, waiting time 35 d). Thirty-three children received a liver by their assigned pediatric MELD (lab MELD 15, waiting time 255 d). Waiting time in the two periods was similar, whereas the wait-list mortality decreased (from about four children/yr to about one child/yr). One- and three-yr patient survival showed no significant difference (94.5/97.7%; p = 0.385) as did one- and three-yr graft survival (80.7/75.2%; and 86.5/82%; p = 0.436 before/after). Introduction of a MELD-based allocation system in ET with assignment of a granted score for pediatric recipients has led to a clear priorization of children resulting in a low wait-list mortality and good clinical outcome.


Assuntos
Implementação de Plano de Saúde , Hepatopatias/cirurgia , Transplante de Fígado , Seleção de Pacientes , Alocação de Recursos/métodos , Adolescente , Criança , Pré-Escolar , Europa (Continente) , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Estudos Prospectivos , Estudos Retrospectivos , Índice de Gravidade de Doença , Taxa de Sobrevida , Obtenção de Tecidos e Órgãos , Listas de Espera
14.
Pediatr Transplant ; 18(4): 377-84, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24802344

RESUMO

In case of graft failure, re-LTX is the only life-saving option but it has been associated with inferior results. This study analyzes the outcome following pediatric re-LTX with a main focus on the timely relation between initial transplant and re-LTX. All pediatric LTX at our institution between 2000 and 2010 divided into patients with primary LTX and patients undergoing re-LTX early (≤30 days) or late (>30 days) after previous LTX were analyzed. Two hundred and ninety-eight primary LTX(79%), 33 early (9%), and 46 late (12%) re-LTX were performed. Patient/graft survival was significantly worse for children undergoing early re-LTX compared to primary LTX and late re-LTX (p = 0.024/0.001 and p = 0.015/0.03). One-/five-yr graft survival rates were 66%/49% for early re-LTX compared to 86%/76% for late re-LTX and 90%/74% for primary LTX. The inferior results in children undergoing early re-LTX were due to events occurring in the first six months with similar survival thereafter. No difference in outcome was evident after adjustment of the groups for high-urgency status. Outcome was excellent for primary LTX and late re-LTX, supporting late re-LTX in children. Early re-LTX takes an elevated risk of early graft loss and patient death; however, beyond the early postoperative period, the outcome was comparable.


Assuntos
Sobrevivência de Enxerto , Transplante de Fígado/mortalidade , Adolescente , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Estimativa de Kaplan-Meier , Transplante de Fígado/métodos , Masculino , Avaliação de Resultados da Assistência ao Paciente , Reoperação/métodos , Reoperação/mortalidade , Estudos Retrospectivos , Taxa de Sobrevida , Fatores de Tempo
15.
Pediatr Transplant ; 17(2): 185-90, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23331338

RESUMO

Outcomes of pediatric liver transplantation have constantly improved in the last decade. Living-related liver transplantation does not seem to improve long-term outcomes following liver transplantation, but few studies have evaluated immunological parameters of the alloimmune response after living vs. deceased donor organ transplantation. We analyzed numbers of regulatory T cells, lymphocyte subsets, and serum cytokine concentrations in 12 pediatric recipients of living-related liver transplants and in 28 pediatric recipients of deceased donor organs during their annual follow-ups. Transplant recipients who underwent living donor organ transplantation had significantly higher numbers of regulatory T cells and IL-4 serum concentrations than recipients of deceased donor organs; both of these factors are associated with beneficial outcomes and transplantation tolerance. Living-related liver transplantation may have potentially beneficial immunological aspects, although long-term outcomes do not seem to be better in recipients of living donor organs than in recipients of deceased donor organs. Further studies are needed to compare immunological aspects of the two transplant procedures.


Assuntos
Citocinas/sangue , Hepatopatias/cirurgia , Transplante de Fígado/imunologia , Doadores Vivos , Linfócitos T Reguladores/metabolismo , Adolescente , Adulto , Biomarcadores/sangue , Contagem de Linfócito CD4 , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Seguimentos , Humanos , Interleucina-4/sangue , Masculino , Resultado do Tratamento , Adulto Jovem
16.
Pediatr Transplant ; 17(6): 543-9, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23834615

RESUMO

Liver transplantation offers excellent results for children with end-stage liver disease, and efforts should be directed toward maintaining long-term graft health. We evaluate graft pathology in healthy pediatric transplant recipients with low-maintenance immunosuppressive medications to assess whether protocol biopsies are helpful for adapting immunosuppression and protecting long-term graft function. Liver biopsies were performed on 60 healthy pediatric liver transplant recipients, and histological findings were correlated with laboratory, serological, and radiological results. Fourteen patients (23%) were diagnosed with acute or early chronic rejection, and immunosuppressive medications were increased in these children. Liver function tests did not correlate with histological findings. The incidence of fibrosis was 36% in transplant recipients five or more years after liver transplantation. We observed an unexpectedly high prevalence of rejection and fibrosis in children with no laboratory abnormalities, which led to changes in their immunosuppressive medications. Scheduled biopsies appear to be useful in pediatric transplant recipients with low immunosuppressive medications for early detection of morphological changes in liver transplants. Further studies are needed to evaluate whether adaption of immunosuppression helps to reduce tissue damage and the incidence of allograft dysfunction in the long term.


Assuntos
Falência Hepática/terapia , Transplante de Fígado/métodos , Adolescente , Autoanticorpos/química , Biópsia , Criança , Pré-Escolar , Rejeição de Enxerto/diagnóstico , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão/métodos , Imunossupressores/química , Lactente , Isquemia/patologia , Fígado/patologia , Fígado/fisiopatologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/patologia , Testes de Função Hepática
17.
Pediatr Transplant ; 17(8): 757-64, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24164827

RESUMO

Individualization of immunosuppressive medications is an important objective in transplantation medicine. Reliable biomarkers to distinguish between patients dependent from intensive immunosuppressive therapy and those where therapy can be minimized among pediatric transplant recipients receiving immunosuppressive medications are still not established. We evaluated the potential of cross-sectional quantification of regulatory T cells, lymphocyte subsets, and cytokine concentrations as biomarkers in 60 pediatric liver transplant recipients with AR, CR, or normal graft function and in 11 non-transplanted patients. Transplant recipients presenting with AR had significantly higher CD8+ T-cell counts, significantly higher concentrations of IL-2, and increased levels of IFN-γ compared with asymptomatic patients or controls. Regulatory T-cell numbers did not differ between children with rejection and children with good graft function. A tendency toward increased concentrations of IL-4 and TGF-ß was detected in transplant recipients with good graft function. Cross-sectional parameters of peripheral regulatory T cells in pediatric liver transplant recipients do not seem to be valuable biomarkers for individualizing immunosuppressive therapy prior to the weaning process. Lymphocyte subsets, IL-2, IFN-γ, IL-4, and TGF-ß serum concentrations may be helpful to identify children in whom immunosuppression can be reduced or discontinued.


Assuntos
Biomarcadores/sangue , Transplante de Fígado , Linfócitos T Reguladores/citologia , Adolescente , Linfócitos T CD8-Positivos/citologia , Separação Celular , Criança , Pré-Escolar , Estudos Transversais , Feminino , Citometria de Fluxo , Rejeição de Enxerto , Sobrevivência de Enxerto , Humanos , Terapia de Imunossupressão , Imunossupressores/uso terapêutico , Lactente , Interferon gama/sangue , Interleucina-2/sangue , Interleucina-4/sangue , Transplante de Rim , Masculino , Tacrolimo/uso terapêutico , Fator de Crescimento Transformador beta/sangue
18.
Mol Cell Neurosci ; 50(3-4): 250-9, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22659578

RESUMO

Collybistin (Cb) is a brain specific guanine nucleotide exchange factor that interacts with the inhibitory postsynaptic scaffold protein gephyrin. Cb is essential for the postsynaptic clustering of gephyrin and major GABA(A) receptor subtypes during the formation and maintenance of GABAergic synapses in the hippocampus and other areas of the forebrain. In the rat, four distinct splice variants (Cb1, Cb2(SH3-), Cb2(SH3+) and Cb3), have been described, which differ in their C-termini (Cb1-3) and in respect of the SH3-domain that is absent in Cb2(SH3-). In the human brain, only a single isoform (hPEM2) corresponding to Cb3, was found to be expressed. This has been implicated in neurological defects such as hyperekplexia, epilepsy, anxiety, aggression and mental retardation. In this study, we address the functional significance of the differentially spliced Cb isoforms by generating a shRNA-mediated knock-down of endogenous Cb in hippocampal cultured neurons that is subsequently rescued by the expression of distinct Cb isoforms. We found that the Cb knock-down induced impairment in GABAergic neurotransmission could be rescued by the expression of any of the Cb isoforms, independent of their C-termini or the presence of the SH3-domain in the N-terminal region. Thus, the different Cb isoforms all confer basic functionality.


Assuntos
Neurônios GABAérgicos/metabolismo , Fatores de Troca do Nucleotídeo Guanina/metabolismo , Receptores de GABA-A/metabolismo , Sinapses/metabolismo , Animais , Fatores de Troca do Nucleotídeo Guanina/antagonistas & inibidores , Hipocampo/metabolismo , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , RNA Interferente Pequeno , Ratos , Fatores de Troca de Nucleotídeo Guanina Rho , Potenciais Sinápticos
19.
Cardiol Young ; 23(1): 89-98, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22475273

RESUMO

Genetic disturbances in folate metabolism may increase risk for congenital heart defects. We examined the association of heart defects with four polymorphisms in folate-related genes (methylenetetrahydrofolate reductase (MTHFR) c.677C.T, MTHFR c.1298A.C, methionine synthase reductase (MTRR) c.66A.G, and reduced folate carrier (SLC19A1) c.80A.G) in a case-control study of children (156 patients, 69 controls) and mothers of children with heart defects (181 patients, 65 controls), born before folic acid fortification. MTRR c.66A.G in children modified odds ratios for overall heart defects, specifically ventricular septal defect and aortic valve stenosis (p-value below 0.05). The 66GG and AG genotypes were associated with decreased odds ratios for heart defects (0.42, 95% confidence interval (0.18-0.97) and 0.39 (0.18-0.84), respectively). This overall association was driven by decreased risk for ventricular septal defect for 66GG and AG (odds ratio 0.32 (0.11-0.91) and 0.25 (0.09-0.65)) and decreased odds ratio for aortic valve stenosis for 66AG (0.27 (0.09-0.79)). The association of ventricular septal defect and 66AG remained significant after correction for multiple testing (p = 0.0044, multiple testing threshold p = 0.0125). Maternal MTHFR 1298AC genotype was associated with increased odds ratio for aortic valve stenosis (2.90 (1.22-6.86), p = 0.0157), but this association did not meet the higher multiple testing threshold. No association between MTHFR c.677C.T or SLC19A1 c.80A.G and heart defect risk was found. The influence of folate-related polymorphisms may be specific to certain types of heart defects; larger cohorts of mothers and children with distinct sub-classes are required to adequately address risk.


Assuntos
Ferredoxina-NADP Redutase/genética , Ácido Fólico/metabolismo , Cardiopatias Congênitas/genética , Metilenotetra-Hidrofolato Redutase (NADPH2)/genética , Proteína Carregadora de Folato Reduzido/genética , Estenose da Valva Aórtica/congênito , Estenose da Valva Aórtica/genética , Estudos de Casos e Controles , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Comunicação Interventricular/genética , Humanos , Masculino , Razão de Chances , Fenótipo , Polimorfismo de Nucleotídeo Único
20.
Children (Basel) ; 10(2)2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36832496

RESUMO

INTRODUCTION: Immunosuppression after pediatric liver transplantation remains a major challenge. MTOR inhibitors provide a promising therapeutic approach in combination with reduced CNI after transplantation. However, there are still few data regarding their use in children. PATIENTS: We analyzed 37 patients with a median age of 10 years, who received Everolimus for one or more of the following indications: I = chronic graft dysfunction (n = 22); II = progressive renal impairment (n = 5); III = non-tolerable side effects with previous immunosuppressive medication (n = 6); and IV = malignancies (n = 10). The median follow-up time was 36 months. RESULTS: Patient survival was 97%, and graft survival 84%, respectively. Stabilization of graft function was observed in 59% in subgroup 1, with 18.2% ultimately requiring retransplantation. No patient in subgroup IV developed recurrence of his primary tumor or PTLD by the endpoint of the study. Side effects were observed in 67.5% of the study patients, with infections being the most frequent (n = 20; 54.1%). There were no relevant effects on growth and development. CONCLUSION: Everolimus seems to be a treatment option in selected pediatric liver graft recipients for whom other regimens are not suitable. Overall, the efficacy was good and the side effect profile appeared to be acceptable.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA