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1.
Cell Rep Med ; 3(11): 100818, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36384101

RESUMO

Antibody-mediated rejection (AMR) is the leading cause of graft failure. While donor-specific antibodies (DSAs) are associated with a higher risk of AMR, not all patients with DSAs develop rejection, suggesting that the characteristics of alloantibodies determining their pathogenicity remain undefined. Using human leukocyte antigen (HLA)-A2-specific antibodies as a model, we apply systems serology tools to investigate qualitative features of immunoglobulin G (IgG) alloantibodies including Fc-glycosylation patterns and FcγR-binding properties. Levels of afucosylated anti-A2 antibodies are elevated in seropositive patients, especially those with AMR, suggesting potential cytotoxicity via FcγRIII-mediated mechanisms. Afucosylation of both glycoengineered monoclonal and naturally glycovariant polyclonal serum IgG specific to HLA-A2 drives potentiated binding to, slower dissociation from, and enhanced signaling through FcγRIII, a receptor widely expressed on innate effector cells, and greater cytotoxicity against HLA-A2+ cells mediated by natural killer (NK) cells. Collectively, these results suggest that afucosylated DSA may be a biomarker of AMR and contribute to pathogenesis.


Assuntos
Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Isoanticorpos , Rejeição de Enxerto , Imunoglobulina G , Antígenos HLA , Antígeno HLA-A2 , Virulência
2.
Acta Neurol Belg ; 117(1): 61-65, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27797002

RESUMO

This is one of the first studies to compare the frequencies of different human leucocyte antigen (HLA) class I and II alleles and haplotype HLA-DRB1*15-DQB1*06 in a cohort of 119 patients with multiple sclerosis (MS) and a cohort of 124 healthy controls in Belgium. An association with MS was found for the HLA-DRB1*15 (odds ratio [OR] 2.60 [95% confidence interval (CI) 1.51-4.50]) and HLA-DQB1*06 (OR 1.97 [95% CI 1.18-3.29]) alleles, and for haplotype DRB1*15-DQB1*06 (OR 2.63 [95% CI 1.52-4.56]). The HLA-B*07 allele also tended to be more frequent in MS patients (OR 1.46 [95% CI 0.80-2.65]) and more frequent among MS patients with than in those without the HLA-DRB1*15 allele (26/54 [48.1%] versus 6/65 [9.2%]; p value <0.0001). Other alleles were underrepresented in MS patients, such as the HLA-DRB1*07 (OR 0.39 [95% CI 0.21-0.73]) and HLA-A*02 (OR 0.56 [95% CI 0.34-0.94]), showing a protective role against the disease. The HLA-B*44 (OR 0.58 [95% CI 0.31-1.09]) and HLA-DRB1*04 (OR 0.75 [95% CI 0.42-1.34]) alleles tended to be less frequent in MS patients. Altogether, the significant results observed in this population are in line with those from other countries and confirm that propensity to MS can be due to a complex presence of various HLA class I and class II alleles.


Assuntos
Predisposição Genética para Doença/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe I/genética , Esclerose Múltipla/genética , Adulto , Bélgica , Feminino , Frequência do Gene , Haplótipos , Humanos , Masculino , Pessoa de Meia-Idade
3.
Cell Tissue Bank ; 13(1): 191-202, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21695483

RESUMO

The European Association of Tissue Banks (EATB) Donor Case Workshop and Quality System Case workshop are forums held within the program of the EATB Annual Congress. These workshops offer an opportunity to discuss and evaluate approaches taken to challenging situations, regarding donor selection and quality issues, and strengthen the professional tissue banking and regulatory networks across Europe. This report reflects some of the discussion at the congress workshops and also subsequent correspondence between the various individuals who submitted cases for discussion. The cases presented to the workshops demonstrate that the findings, their interpretation, deducted actions and preventive measures in tissue banks are not predictable. The varied responses and lack of consensus corroborate this and clearly indicate that operating procedures cannot comprehensively cover or prepare for all eventualities. For many of the issues raised there is a lack of information in the published literature. The workshops actively engage participants, representing a wide array of international expertise, in an informal, secure and enjoyable setting, which facilitates learning from peers and provides potential solutions to those submitting cases. By publishing a summary of the discussions, we hope to reach a wider audience and to stimulate individuals to undertake full literature reviews or research on some of the discussed subjects.


Assuntos
Congressos como Assunto , Sociedades Médicas , Bancos de Tecidos/normas , Doadores de Tecidos , Idoso , Condrócitos/microbiologia , Síndrome de Down , Europa (Continente) , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Controle de Qualidade , Fatores de Tempo
4.
Cell Tissue Bank ; 13(2): 297-304, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21512894

RESUMO

To evaluate the efficiency of decontamination practice in European Homograft Bank (EHB), the data of the cardiovascular tissues received during recent 2 years were retrospectively analysed in this study. After initial assessment, the tissues were incubated in a 3-antibiotics' cocktail at 4°C for 20-48 h. The states of contamination were evaluated before and after incubation with the focus on the differences in donor type, tissue type, germ type and incubation time. Amongst 1,055 eligible tissues, 77.2% were hearts and 22.8% were arteries. 82.2% of the tissues were retrieved from the multi-organ donors (MOD), 15.4% from the recipients of heart transplantation (RHT) and 2.4% from the non-heart beating donors (NHBD). The initial contamination rate was 27.4% with a significantly higher incidence in arteries. The RHT tissues had the lowest contamination rate comparing to that of MOD and NHBD. Staphylococcus species was the major source of contamination. After antibiotic incubation, 76.8% of the contaminated tissues were disinfected, which was significantly higher for the hearts than the arteries. The RHT tissues had the highest decontamination rate than that of MOD and NHBD tissues. Propionibacterium acnes was detected in 48.1% of the remaining contaminated cases. The average incubation time of the Propionibacterium-positive tissues was significantly shorter than that of decontaminated tissues. In conclusion, the current decontamination protocol of EHB is sufficient for most of the initially contaminated bacteria, whereas it is inadequate for Propionibacterium acnes. This may be related to the slow-growing nature of this bacterium and thereby the relative shorter antibiotic incubation time.


Assuntos
Artérias/microbiologia , Descontaminação/métodos , Valvas Cardíacas/microbiologia , Bancos de Tecidos , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Europa (Continente) , Transplante de Coração , Humanos , Testes de Sensibilidade Microbiana , Estudos Retrospectivos , Fatores de Tempo , Doadores de Tecidos , Transplante Homólogo
5.
Acta Biol Hung ; 58(1): 61-74, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17385544

RESUMO

In this study pesticides with different chemical structures (dichlofluanid, endosulfan, simazine, tolylfluanid and triallate) were examined for their potential cytotoxic effect on proliferative activity of cell cultures of mammalian origin. Cell lines Madin-Darby Bovine Kidney (MDBK), Rabbit Kidney (RK13), Porcine Kidney (PK15), and semicontinual line of Bovine Embryonic Pulmonary Cells (BEPC) were used in the study. From these cell cultures cell proliferative activity was suppressed most intensively in PK15 culture by endosulfan (10(-1) - 10(-6) M). The least effect on cell proliferation in all cell cultures tested, with the exception PK 15 (10(-1) - 10(-2) M), was recorded after simazine exposure. On the basis of IC50 values the cytotoxic effect was: dichlofluanid (IC50 = 10(-3.94) M) > tolylfluanid (IC50 = 10(-3.69) M) > endosulfan (IC50 = 10(-3.24) M) > triallate (IC50 = 10(-3.12) M) > simazine (IC50 = 10(-1.78) M). The comparison of average IC50 values of cell cultures revealed that the most sensitive cell lines were PK15 (IC50 = 10(-3.27) M) and RK13 (IC50 = 10(-3.21) M), whereas MDBK (IC50 = 10(-2.55) M) and BEPC (IC50 = 10(-2.52) M) were less sensitive to pesticide exposure.


Assuntos
Divisão Celular/efeitos dos fármacos , Praguicidas/farmacologia , Animais , Bovinos , Células Cultivadas , Cães , Rim , Cinética , Coelhos , Suínos
6.
Toxicology ; 188(1): 73-81, 2003 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-12748042

RESUMO

The effect of eight pesticides with different chemical structure (atrazine, bentazone, chloridazone, dichlofluanid, endosulfan, MCPA, simazine, triallate) on sheep peripheral blood phagocytes and lymphocytes was examined under in vitro conditions by iodo-nitro-tetrazolium reductase test and leukocyte migration-inhibition assay. The pesticides, dissolved in DMSO, were tested at the concentrations of 10(-1)-10(-6) M. The significant suppression of metabolic activity of phagocytic cells was registered after exposure to dichlofluanid (10(-1)-10(-3) M), endosulfan, simazine and triallate (10(-1) M). The significant cytotoxic effect (the decrease of spontaneous migration of leukocytes) was registered for bentazone, dichlofluanid, endosulfan and MCPA (10(-1) M); chloridazone (10(-1) M-10(-2) M) and triallate (10(-1)-10(-5) M). The significant immunotoxic effect (the decrease of lymphocyte activation with PHA) was observed for atrazine (10(-1)-10(-2) M); bentazone (10(-2)-10(-4) M); dichlofluanid, endosulfan (10(-2)-10(-3) M); MCPA (10(-2)-10(-6) M) and simazine (10(-1)-10(-4) M). Three of the pesticides tested suppressed both, the metabolic activity of phagocytes and mitogenic activation of lymphocytes (dichlofluanid, endosulfan and simazine). Triallate suppressed the metabolic activity of phagocytes and showed a strong cytotoxic effect. Pesticides atrazine, bentazone and MCPA influenced the mitogenic activation of lymphocytes and chloridazone showed a significant cytotoxic effect. The different chemical structure of pesticides influenced the metabolic activity of phagocytic cells as well as mitogenic activation of lymphocytes to various intensity.


Assuntos
Linfócitos/efeitos dos fármacos , Praguicidas/toxicidade , Fagócitos/efeitos dos fármacos , Animais , Inibição de Migração Celular , Linfócitos/imunologia , Linfócitos/metabolismo , Praguicidas/imunologia , Fagócitos/imunologia , Fagócitos/metabolismo , Ovinos , Relação Estrutura-Atividade , Testes de Toxicidade/métodos
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