Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 66
Filtrar
1.
Immunogenetics ; 76(2): 109-121, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38400869

RESUMO

In the past, identification of HLA alleles was limited to sequencing the region of the gene coding for the peptide binding groove, resulting in a lack of sequence information in the HLA database, challenging HLA allele assignment software programs. We investigated full-length sequences of 19 HLA class I and 7 HLA class II alleles, and we extended another 47 HLA class I alleles with sequences of 5' and 3' UTR regions that were all not yet available in the IPD-IMGT/HLA database. We resolved 8638 unknown nucleotides in the coding sequence of HLA class I and 2139 of HLA class II. Furthermore, with full-length sequencing of the 26 alleles, more than 90 kb of sequence information was added to the non-coding sequences, whereas extension of the 47 alleles resulted in the addition of 5.5 kb unknown nucleotides to the 5' UTR and > 31.7 kb to the 3' UTR region. With this information, some interesting features were observed, like possible recombination events and lineage evolutionary origins. The continuing increase in the availability of full-length sequences in the HLA database will enable the identification of the evolutionary origin and will help the community to improve the alignment and assignment accuracy of HLA alleles.


Assuntos
Evolução Biológica , Nucleotídeos , Alelos , Regiões 3' não Traduzidas/genética , Membrana Celular , Nucleotídeos/genética
2.
Blood ; 136(21): 2437-2441, 2020 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-32589698

RESUMO

A unique feature of Hodgkin lymphoma (HL) is the presence of CD4+ T cells that surround, protect, and promote survival of tumor cells. The adhesion molecules involved in this so-called T-cell rosetting are important components of the immunological synapse (IS). However, it is unknown whether this synapse is fully assembled and leads to T-cell activation by enabling interaction between the T-cell receptor (TCR) and human leukocyte antigen class II (HLA-II). We established a novel rosetting model by coculturing HLA-II-matched peripheral blood mononuclear cells with HL cell lines and showed IS formation with activation of rosetting T cells. HLA-II downregulation by class II transactivator knockout did not affect the extent of rosetting, but almost completely abrogated T-cell activation. Intriguingly, the level of CD58 expression correlated with the extent of rosette formation, and CD58 knockout or CD2 blockade reduced both rosette formation and T-cell activation. The extension of our findings to primary HL tissue by immunohistochemistry and proximity ligation assays showed interaction of CD2 with CD58 and of TCR-associated CD4 with HLA-II. In conclusion, T-cell rosetting in HL is established by formation of the IS, and activation of rosetting T cells critically depends on the interaction of both TCR-HLA-II and CD2-CD58.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Antígenos CD58/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Doença de Hodgkin/imunologia , Sinapses Imunológicas/imunologia , Ativação Linfocitária/imunologia , Receptores de Antígenos de Linfócitos T/imunologia , Formação de Roseta , Antígenos CD2/antagonistas & inibidores , Antígenos CD58/biossíntese , Antígenos CD58/genética , Sistemas CRISPR-Cas , Adesão Celular , Linhagem Celular Tumoral , Técnicas de Cocultura , Técnicas de Inativação de Genes , Humanos , Mapeamento de Interação de Proteínas
3.
Am J Physiol Renal Physiol ; 320(5): F947-F962, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33719571

RESUMO

Renal endothelial cells (ECs) play crucial roles in vasorelaxation, ultrafiltration, and selective transport of electrolytes and water, but also in leakage of the glomerular filtration barrier and inflammatory processes like complement activation and leukocyte recruitment. In addition, they are target cells for both cellular and antibody-mediated rejection in the transplanted kidney. To study the molecular and cellular processes underlying EC behavior in renal disease, well-characterized primary renal ECs are indispensible. In this report, we describe a straightforward procedure to isolate ECs from the perfusion fluid of human donor kidneys by a combination of negative selection of monocytes/macrophages, positive selection by CD31 Dynabeads, and propagation in endothelium-specific culture medium. Thus, we isolated and propagated renal ECs from 102 donor kidneys, representative of all blood groups and major human leukocyte antigen (HLA) class I and II antigens. The obtained ECs were positive for CD31 and von Willebrand factor, expressed other endothelial markers such as CD34, VEGF receptor-2, TIE2, and plasmalemmal vesicle associated protein-1 to a variable extent, and were negative for the monocyte marker CD14 and lymphatic endothelial marker podoplanin. HLA class II was either constitutively expressed or could be induced by interferon-γ. Furthermore, as a proof of principle, we showed the diagnostic value of this renal endothelial biobank in renal endothelium-specific cross-matching tests for HLA antibodies.NEW & NOTEWORTHY We describe a new and widely accessible approach to obtain human primary renal endothelial cells in a standardized fashion, by isolating from the perfusate of machine-perfused donor kidneys. Characterization of the cells showed a mixed population originating from different compartments of the kidney. As a proof of principle, we demonstrated a possible diagnostic application in an endothelium-specific cross-match. Next to transplantation, we foresee further applications in the field renal endothelial research.


Assuntos
Separação Celular/métodos , Células Endoteliais/fisiologia , Rim/irrigação sanguínea , Rim/citologia , Técnicas de Cultura de Órgãos/métodos , Células Cultivadas , Antígenos de Histocompatibilidade Classe I , Humanos , Doadores de Tecidos
4.
Am J Transplant ; 21(9): 3133-3147, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33445220

RESUMO

Thrombosis after liver transplantation substantially impairs graft- and patient survival. Inevitably, heritable disorders of coagulation originating in the donor liver are transmitted by transplantation. We hypothesized that genetic variants in donor thrombophilia genes are associated with increased risk of posttransplant thrombosis. We genotyped 775 donors for adult recipients and 310 donors for pediatric recipients transplanted between 1993 and 2018. We determined the association between known donor thrombophilia gene variants and recipient posttransplant thrombosis. In addition, we performed a genome-wide association study (GWAS) and meta-analyzed 1085 liver transplantations. In our donor cohort, known thrombosis risk loci were not associated with posttransplant thrombosis, suggesting that it is unnecessary to exclude liver donors based on thrombosis-susceptible polymorphisms. By performing a meta-GWAS from children and adults, we identified 280 variants in 55 loci at suggestive genetic significance threshold. Downstream prioritization strategies identified biologically plausible candidate genes, among which were AK4 (rs11208611-T, p = 4.22 × 10-05 ) which encodes a protein that regulates cellular ATP levels and concurrent activation of AMPK and mTOR, and RGS5 (rs10917696-C, p = 2.62 × 10-05 ) which is involved in vascular development. We provide evidence that common genetic variants in the donor, but not previously known thrombophilia-related variants, are associated with increased risk of thrombosis after liver transplantation.


Assuntos
Transplante de Fígado , Trombose , Adulto , Criança , Estudo de Associação Genômica Ampla , Sobrevivência de Enxerto , Humanos , Transplante de Fígado/efeitos adversos , Doadores Vivos , Estudos Retrospectivos , Fatores de Risco , Trombose/genética , Doadores de Tecidos
5.
Am J Transplant ; 19(10): 2926-2933, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31155833

RESUMO

Whereas regular allocation avoids unacceptable mismatches on the donor organ, allocation to highly sensitized patients within the Eurotransplant Acceptable Mismatch (AM) program is based on the patient's HLA phenotype plus acceptable antigens. These are HLA antigens to which the patient never made antibodies, as determined by extensive laboratory testing. AM patients have superior long-term graft survival compared with highly sensitized patients in regular allocation. Here, we questioned whether the AM program also results in lower rejection rates. From the PROCARE cohort, consisting of all Dutch kidney transplants in 1995-2005, we selected deceased donor single transplants with a minimum of 1 HLA mismatch and determined the cumulative 6-month rejection incidence for patients in AM or regular allocation. Additionally, we determined the effect of minimal matching criteria of 1 HLA-B plus 1 HLA-DR, or 2 HLA-DR antigens on rejection incidence. AM patients showed significantly lower rejection rates than highly immunized patients in regular allocation, comparable to nonsensitized patients, independent of other risk factors for rejection. In contrast to highly sensitized patients in regular allocation, minimal matching criteria did not affect rejection rates in AM patients. Allocation based on acceptable antigens leads to relatively low-risk transplants for highly sensitized patients with rejection rates similar to those of nonimmunized individuals.


Assuntos
Rejeição de Enxerto/diagnóstico , Antígenos HLA/imunologia , Histocompatibilidade/imunologia , Imunização/métodos , Falência Renal Crônica/imunologia , Transplante de Rim/efeitos adversos , Seleção de Pacientes , Doadores de Tecidos/provisão & distribuição , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/química , Teste de Histocompatibilidade , Humanos , Isoanticorpos/efeitos adversos , Falência Renal Crônica/cirurgia , Transplante de Rim/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Obtenção de Tecidos e Órgãos/métodos , Imunologia de Transplantes
6.
Am J Transplant ; 19(12): 3335-3344, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31194283

RESUMO

The clinical significance of non-HLA antibodies on renal allograft survival is a matter of debate, due to differences in reported results and lack of large-scale studies incorporating analysis of multiple non-HLA antibodies simultaneously. We developed a multiplex non-HLA antibody assay against 14 proteins highly expressed in the kidney. In this study, the presence of pretransplant non-HLA antibodies was correlated to renal allograft survival in a nationwide cohort of 4770 recipients transplanted between 1995 and 2006. Autoantibodies against Rho GDP-dissociation inhibitor 2 (ARHGDIB) were significantly associated with graft loss in recipients transplanted with a deceased-donor kidney (N = 3276) but not in recipients of a living-donor kidney (N = 1496). At 10 years after deceased-donor transplantation, recipients with anti-ARHGDIB antibodies (94/3276 = 2.9%) had a 13% lower death-censored covariate-adjusted graft survival compared to the anti-ARHGDIB-negative (3182/3276 = 97.1%) population (hazard ratio 1.82; 95% confidence interval, 1.32-2.53; P = .0003). These antibodies occur independently from donor-specific anti-HLA antibodies (DSA) or other non-HLA antibodies investigated. No significant relations with graft loss were found for the other 13 non-HLA antibodies. We suggest that pretransplant risk assessment can be improved by measuring anti-ARHGDIB antibodies in all patients awaiting deceased-donor transplantation.


Assuntos
Autoanticorpos/imunologia , Rejeição de Enxerto/mortalidade , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/efeitos adversos , Complicações Pós-Operatórias/mortalidade , Inibidor beta de Dissociação do Nucleotídeo Guanina rho/imunologia , Adulto , Feminino , Seguimentos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Humanos , Isoanticorpos/imunologia , Falência Renal Crônica/imunologia , Falência Renal Crônica/mortalidade , Falência Renal Crônica/cirurgia , Doadores Vivos/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Prognóstico , Estudos Retrospectivos , Fatores de Risco
7.
Nephrol Dial Transplant ; 34(8): 1417-1422, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-30561730

RESUMO

BACKGROUND: Few studies have evaluated the effect of different immunosuppressive strategies on long-term kidney transplant outcomes. Moreover, as they were usually based on historical data, it was not possible to account for the presence of pretransplant donor-specific human-leukocyte antigen antibodies (DSA), a currently recognized risk marker for impaired graft survival. The aim of this study was to evaluate to what extent frequently used initial immunosuppressive therapies increase graft survival in immunological low-risk patients. METHODS: We performed an analysis on the PROCARE cohort, a Dutch multicentre study including all transplantations performed in the Netherlands between 1995 and 2005 with available pretransplant serum (n = 4724). All sera were assessed for the presence of DSA by a luminex single-antigen bead assay. Patients with a previous kidney transplantation, pretransplant DSA or receiving induction therapy were excluded from the analysis. RESULTS: Three regimes were used in over 200 patients: cyclosporine (CsA)/prednisolone (Pred) (n = 542), CsA/mycophenolate mofetil (MMF)/Pred (n = 857) and tacrolimus (TAC)/MMF/Pred (n = 811). Covariate-adjusted analysis revealed no significant differences in 10-year death-censored graft survival between patients on TAC/MMF/Pred therapy (79%) compared with patients on CsA/MMF/Pred (82%, P = 0.88) or CsA/Pred (79%, P = 0.21). However, 1-year rejection-free survival censored for death and failure unrelated to rejection was significantly higher for TAC/MMF/Pred (81%) when compared with CsA/MMF/Pred (67%, P < 0.0001) and CsA/Pred (64%, P < 0.0001). CONCLUSION: These results suggest that in immunological low-risk patients excellent long-term kidney graft survival can be achieved irrespective of the type of initial immunosuppressive therapy (CsA or TAC; with or without MMF), despite differences in 1-year rejection-free survival.


Assuntos
Ciclosporina/uso terapêutico , Rejeição de Enxerto , Terapia de Imunossupressão/métodos , Transplante de Rim , Ácido Micofenólico/uso terapêutico , Tacrolimo/uso terapêutico , Adulto , Estudos de Coortes , Intervalo Livre de Doença , Feminino , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Humanos , Terapia de Imunossupressão/efeitos adversos , Imunossupressores/uso terapêutico , Rim/imunologia , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Prednisolona
8.
Nephrol Dial Transplant ; 34(6): 1056-1063, 2019 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-30365008

RESUMO

BACKGROUND: Pre-transplant donor-specific anti-human leucocyte antigen (HLA) antibodies (DSAs) are associated with impaired kidney graft survival while the clinical relevance of non-donor-specific anti-HLA antibodies (nDSAs) is more controversial. The aim of the present paired kidney graft study was to compare the clinical relevance of DSAs and nDSAs. METHODS: To eliminate donor and era-dependent factors, a post hoc paired kidney graft analysis was performed as part of a Dutch multicentre study evaluating all transplantations between 1995 and 2005 with available pre-transplant serum samples. Anti-HLA antibodies were detected with a Luminex single-antigen bead assay. RESULTS: Among 3237 deceased donor transplantations, we identified 115 recipient pairs receiving a kidney from the same donor with one recipient being DSA positive and the other without anti-HLA antibodies. Patients with pre-transplant DSAs had a significantly lower 10-year death-censored graft survival (55% versus 82%, P=0.0001). We identified 192 pairs with one recipient as nDSA positive (against Class I and/or II) and the other without anti-HLA antibodies. For the patients with nDSAs against either Class I or II, graft survival did not significantly differ compared with patients without anti-HLA antibodies (74% versus 77%, P = 0.79). Only in patients with both nDSAs Class I and II was there a trend towards a lower graft survival (58%, P = 0.06). Lastly, in a small group of 42 recipient pairs, 10-year graft survival in recipients with DSAs was 49% compared with 68% in recipients with nDSAs (P=0.11). CONCLUSION: This paired kidney analysis confirms that the presence of pre-transplant DSAs in deceased donor transplantations is a risk marker for graft loss, whereas nDSAs in general are not associated with a lower graft survival. Subgroup analysis indicated that only in broadly sensitized patients with nDSAs against Class I and II, nDSAs may be a risk marker for graft loss in the long term.


Assuntos
Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Isoanticorpos/sangue , Adulto , Feminino , Antígenos de Histocompatibilidade Classe I , Humanos , Transplante de Rim/mortalidade , Masculino , Pessoa de Meia-Idade , Países Baixos , Risco , Doadores de Tecidos , Adulto Jovem
9.
J Am Soc Nephrol ; 29(9): 2279-2285, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30049681

RESUMO

Background Complement-fixing antibodies against donor HLA are considered a contraindication for kidney transplant. A modification of the IgG single-antigen bead (SAB) assay allows detection of anti-HLA antibodies that bind C3d. Because early humoral graft rejection is considered to be complement mediated, this SAB-based technique may provide a valuable tool in the pretransplant risk stratification of kidney transplant recipients.Methods Previously, we established that pretransplant donor-specific anti-HLA antibodies (DSAs) are associated with increased risk for long-term graft failure in complement-dependent cytotoxicity crossmatch-negative transplants. In this study, we further characterized the DSA-positive serum samples using the C3d SAB assay.Results Among 567 pretransplant DSA-positive serum samples, 97 (17%) contained at least one C3d-fixing DSA, whereas 470 (83%) had non-C3d-fixing DSA. At 10 years after transplant, patients with C3d-fixing antibodies had a death-censored, covariate-adjusted graft survival of 60%, whereas patients with non-C3d-fixing DSA had a graft survival of 64% (hazard ratio, 1.02; 95% confidence interval, 0.70 to 1.48 for C3d-fixing DSA compared with non-C3d-fixing DSA; P=0.93). Patients without DSA had a 10-year graft survival of 78%.Conclusions The C3d-fixing ability of pretransplant DSA is not associated with increased risk for graft failure.


Assuntos
Anticorpos Anti-Idiotípicos/imunologia , Complemento C3d/imunologia , Rejeição de Enxerto/imunologia , Antígenos HLA/imunologia , Transplante de Rim/efeitos adversos , Sistema de Registros , Adulto , Distribuição por Idade , Soro Antilinfocitário/imunologia , Estudos de Coortes , Feminino , Seguimentos , Rejeição de Enxerto/epidemiologia , Humanos , Incidência , Transplante de Rim/métodos , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios/métodos , Estudos Retrospectivos , Medição de Risco , Distribuição por Sexo , Doadores de Tecidos , Transplantados/estatística & dados numéricos , Imunologia de Transplantes
10.
Haematologica ; 102(1): 176-183, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27561721

RESUMO

Between 2001 and 2012, the number of unrelated donors registered worldwide increased from 7 to 21 million, and the number of public cord blood units increased to over 500,000. We addressed the question of whether this expansion resulted in higher percentages of patients reaching transplantation. Unrelated donor searches were evaluated for 3,124 eligible patients in the Netherlands in two cohorts (2001-2006, n=995; 2007-2012, n=2129), comparing results for patients of Northwestern European and non-Northwestern European origin. Endpoints were 'donor found' and 'transplantation reached'. The substantial growth of the donor inventory over the period studied did not increase the median number of potential unrelated donors (n=7) for non-Northwestern European patients, but almost doubled the number for Northwestern European patients from 42 to 71. Before and after 2007, an unrelated donor or cord blood was identified for 91% and 95%, respectively, of Northwestern European patients and for 65% and 82% of non-Northwestern European patients (P<0.0001). Non-Northwestern European patients more often needed a cord blood transplant. The degree of HLA matching was significantly lower for non-Northwestern European patients (P<0.0006). The time needed to identify a donor decreased for both populations. The percentage of Northwestern European patients reaching transplantation increased from 77% to 83% and for non-Northwestern European patients from 57% to 72% (P=0.0003). The increase of the global inventory resulted in more transplants for patients lacking a family donor, although the quality and quantity of (potential) haematopoietic cell grafts for patients of a non-Northwestern European descent remained inferior, indicating the need for adaptation of recruitment.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Sistema de Registros , Doadores de Tecidos , Adolescente , Adulto , Criança , Feminino , Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Teste de Histocompatibilidade , Humanos , Masculino , Neoplasias/diagnóstico , Neoplasias/epidemiologia , Neoplasias/terapia , Países Baixos , Grupos Populacionais , Adulto Jovem
11.
Pediatr Transplant ; 21(7)2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28627016

RESUMO

In the majority of long-term survivors after PLTx, graft fibrosis has been identified. Recently, subtypes of graft fibrosis have been described based on their predominant acinar localization. We aimed to evaluate whether the development of portal, perisinusoidal, and centrilobular distribution of graft fibrosis is related to patient or transplantation-related parameters. We reviewed the histological features in protocol liver biopsies taken at 1 and 5 years after PLTx of 47 children on a tacrolimus-based immunosuppressive regimen. Fibrosis was assessed according to the LAFSc. The prevalence of portal fibrosis increased from 31% to 62%, sinusoidal from 68% to 79%, and centrilobular from 76% to 85%. The presence of portal fibrosis was associated with total bilirubin and γGT levels (each P<.02) and tended to be associated with biliary complications (P=.06). Sinusoidal fibrosis was associated with prior rejection episodes (P<.02) and centrilobular fibrosis with the presence of HLA mismatches (P=.02). In conclusion, using the LAFSc, we found a high incidence of progressive fibrosis in the 1-year and 5-year protocol biopsies after PLTx. Progression of fibrosis was observed in all acinar compartments, and each of the three locations is associated with different clinical conditions.


Assuntos
Cirrose Hepática/etiologia , Transplante de Fígado , Complicações Pós-Operatórias/etiologia , Adolescente , Biópsia , Criança , Pré-Escolar , Progressão da Doença , Feminino , Seguimentos , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/patologia , Rejeição de Enxerto/prevenção & controle , Humanos , Imunossupressores/uso terapêutico , Incidência , Lactente , Recém-Nascido , Fígado/patologia , Cirrose Hepática/diagnóstico , Cirrose Hepática/epidemiologia , Cirrose Hepática/patologia , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/patologia , Prevalência , Estudos Retrospectivos , Fatores de Risco , Tacrolimo/uso terapêutico
12.
J Bodyw Mov Ther ; 37: 344-349, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38432827

RESUMO

BACKGROUND: Soccer is one of the most popular sports with millions of active professional and non-professional players worldwide. Traumatic hip dislocations are rare in soccer but can lead to major sequelae both physically and psychologically. The aim of this review was to obtain insight into the outcomes after surgerically repaired hip fracture-dislocation in soccer players as well as rehabilitation and prevention. METHODS: Two cases of a posterior hip fracture-dislocation that occurred during an amateur soccer match are presented and mechanism of injury, complications and rehabilitation were analysed. Follow-up of both patients was at least one year after surgery. Questionnaires and physical examinations were obtained to quantify and qualify outcome. RESULTS: In both cases the hip-dislocations were reduced within 3 h after injury. Semi-elective open reduction and internal fixation was performed within seven days. In one case, there was a concomitant Pipkin fracture and sciatic nerve neuropathy. There were no postoperative complications. Follow-up showed full of range of motion and normal hip functionality in both cases. However, both patients indicated a reduced quality of life and anxiety related to the accident. CONCLUSION: Traumatic hip fracture-dislocations during soccer practice are extremely rare. Despite uncomplicated fracture healing after surgery and return of hip function, both patients still suffer from psychological problems resulting in a decreased quality of life. Further research is required to enhance psychological outcomes, as well as to facilitate return to pre-injury levels of participation and engagement in sports following traumatic hip fracture-dislocations related to soccer.


Assuntos
Luxação do Quadril , Fraturas do Quadril , Futebol , Esportes , Humanos , Luxação do Quadril/etiologia , Luxação do Quadril/cirurgia , Fraturas do Quadril/cirurgia , Qualidade de Vida
14.
Front Immunol ; 15: 1360627, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38646525

RESUMO

Background: Repeated exposure to sensitizing events can activate HLA-specific memory B cells, leading to the production of donor-specific memory B cell antibodies (DSAm) that pose a risk for antibody-mediated rejection (ABMR) in kidney transplant recipients (KTRs). This single-center retrospective study aimed to identify DSAm and assess their association with outcomes in a cohort of KTRs with pretransplant serum donor-specific antibodies (DSA). Methods: We polyclonally activated pretransplant peripheral blood mononuclear cells (PBMCs) from 60 KTRs in vitro, isolated and quantified IgG from the culture supernatant using ELISA, and analyzed the HLA antibodies of eluates with single antigen bead (SAB) assays, comparing them to the donor HLA typing for potential DSAm. Biopsies from 41 KTRs were evaluated for rejection based on BANFF 2019 criteria. Results: At transplantation, a total of 37 DSAm were detected in 26 of 60 patients (43%), of which 13 (35%) were found to be undetectable in serum. No significant association was found between pretransplant DSAm and ABMR (P=0.53). Similar results were observed in a Kaplan-Meier analysis for ABMR within the first year posttransplant (P=0.29). Additionally, MFI levels of DSAm showed no significant association with ABMR (P=0.28). Conclusion: This study suggests no significant association between DSAm and biopsy-proven clinical ABMR. Further prospective research is needed to determine whether assessing DSAm could enhance existing immunological risk assessment methods for monitoring KTRs, particularly in non-sensitized KTRs.


Assuntos
Rejeição de Enxerto , Antígenos HLA , Isoanticorpos , Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Estudos Retrospectivos , Masculino , Feminino , Pessoa de Meia-Idade , Rejeição de Enxerto/imunologia , Isoanticorpos/imunologia , Isoanticorpos/sangue , Adulto , Antígenos HLA/imunologia , Células B de Memória/imunologia , Doadores de Tecidos , Idoso , Transplantados , Sobrevivência de Enxerto/imunologia
15.
HLA ; 103(1): e15297, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38226401

RESUMO

In kidney transplantation, donor HLA antibodies are a risk factor for graft loss. Accessibility of donor eplets for HLA antibodies is predicted by the ElliPro score. The clinical usefulness of those scores in relation to transplant outcome is unknown. In a large Dutch kidney transplant cohort, Ellipro scores of pretransplant donor antibodies that can be assigned to known eplets (donor epitope specific HLA antibodies [DESAs]) were compared between early graft failure and long surviving deceased donor transplants. We did not observe a significant Ellipro score difference between the two cohorts, nor significant differences in graft survival between transplants with DESAs having high versus low total Ellipro scores. We conclude that Ellipro scores cannot be used to identify DESAs associated with early versus late kidney graft loss in deceased donor transplants.


Assuntos
Nefropatias , Transplante de Rim , Humanos , Sobrevivência de Enxerto , Alelos , Anticorpos , Rim , Epitopos , Rejeição de Enxerto , Antígenos HLA , Doadores de Tecidos
16.
HLA ; 103(1): e15346, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38239046

RESUMO

In kidney transplantation, survival rates are still partly impaired due to the deleterious effects of donor specific HLA antibodies (DSA). However, not all luminex-defined DSA appear to be clinically relevant. Further analysis of DSA recognizing polymorphic amino acid configurations, called eplets or functional epitopes, might improve the discrimination between clinically relevant vs. irrelevant HLA antibodies. To evaluate which donor epitope-specific HLA antibodies (DESAs) are clinically important in kidney graft survival, relevant and irrelevant DESAs were discerned in a Dutch cohort of 4690 patients using Kaplan-Meier analysis and tested in a cox proportional hazard (CPH) model including nonimmunological variables. Pre-transplant DESAs were detected in 439 patients (9.4%). The presence of certain clinically relevant DESAs was significantly associated with increased risk on graft loss in deceased donor transplantations (p < 0.0001). The antibodies recognized six epitopes of HLA Class I, 3 of HLA-DR, and 1 of HLA-DQ, and most antibodies were directed to HLA-B (47%). Fifty-three patients (69.7%) had DESA against one donor epitope (range 1-5). Long-term graft survival rate in patients with clinically relevant DESA was 32%, rendering DESA a superior parameter to classical DSA (60%). In the CPH model, the hazard ratio (95% CI) of clinically relevant DESAs was 2.45 (1.84-3.25) in deceased donation, and 2.22 (1.25-3.95) in living donation. In conclusion, the developed model shows the deleterious effect of clinically relevant DESAs on graft outcome which outperformed traditional DSA-based risk analysis on antigen level.


Assuntos
Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Epitopos , Antígenos HLA/genética , Relevância Clínica , Isoanticorpos , Alelos , Doadores de Tecidos , Rejeição de Enxerto
17.
Physiol Genomics ; 45(6): 201-9, 2013 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-23341218

RESUMO

Genome-wide association studies reported SLC22A2 variants to be associated with serum creatinine. As SLC22A2 encodes the organic cation transporter 2 (OCT2), the association might be due to an effect on tubular creatinine handling. To test this hypothesis we studied the association of SLC22A2 polymorphisms with phenotypes of net tubular creatinine secretion: fractional creatinine excretion (FEcreat) and bias of estimated glomerular filtration rate (eGFR). We also studied the association with end-stage renal disease (ESRD) and graft failure (GF) in renal transplant recipients. SLC22A2 single nucleotide polymorphisms (SNPs), rs3127573 and rs316009, were genotyped in 1,142 ESRD patients receiving renal transplantation and 1,186 kidney donors as controls. GFR was measured with (125)I-iothalamate clearance. Creatinine clearance was also assessed. FEcreat was calculated from the simultaneous clearances of creatinine and (125)I-iothalamate. Donor rs316009 was associated with FEcreat (beta -0.053, P = 0.024) and with estimated [modification of diet in renal disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI)] but not measured GFR. In line with this, donor rs316009 was associated with bias of the MDRD and CKD-EPI but not the Cockroft-Gault equation. Both SNPs were associated with ESRD: odds ratios [95% CI] 1.39 [1.16-1.67], P = 0.00065, and 1.23 [1.02-1.48], P = 0.042, for rs3127573 and rs316009, respectively. Neither SNP was associated with GF. Thus, SLC22A2 is associated with phenotypes of net tubular creatinine secretion and ESRD.


Assuntos
Creatinina/metabolismo , Taxa de Filtração Glomerular , Transplante de Rim , Túbulos Renais/metabolismo , Proteínas de Transporte de Cátions Orgânicos/genética , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Transportador 2 de Cátion Orgânico
19.
Blood ; 118(19): 5211-7, 2011 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-21921049

RESUMO

The pathogenesis of classical Hodgkin lymphoma (cHL) involves environmental and genetic factors. To explore the role of the human leukocyte antigen (HLA) genes, we performed a case-control genotyping study in 338 Dutch cHL patients and more than 5000 controls using a PCR-based sequence-specific oligonucleotide probe hybridization approach. HLA-A68 and HLA-DR11 (5) were significantly increased in the cHL patient population compared with the controls. Three class II associations were observed in the EBV(-) cHL population with an increase of HLA-DR15 (2) and a decrease of HLA-DR4 and HLA-DR7. Allele frequencies of HLA-A1, HLA-B37, and HLA-DR10 were significantly increased in the EBV(+) cHL population; these alleles are in strong linkage disequilibrium and form a common haplotype in whites. The allele frequency of HLA-A2 was significantly decreased in the EBV(+) cHL population. Sequence-specific oligonucleotide probe analysis revealed significant differences between EBV(+) and EBV(-) cHL patients for 19 probes that discriminate between HLA-A*01 and HLA-A*02. In conclusion, the HLA-A1 and HLA-A2 antigens and not specific single nucleotide variants shared by multiple alleles are responsible for the association with EBV(+) cHL. Furthermore, several new protective and predisposing HLA class I and II associations for the EBV(+), the EBV(-), and the entire cHL population were identified.


Assuntos
Genes MHC da Classe II , Genes MHC Classe I , Doença de Hodgkin/genética , Doença de Hodgkin/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Infecções por Vírus Epstein-Barr/genética , Infecções por Vírus Epstein-Barr/imunologia , Feminino , Frequência do Gene , Estudos de Associação Genética , Predisposição Genética para Doença , Herpesvirus Humano 4/isolamento & purificação , Herpesvirus Humano 4/patogenicidade , Doença de Hodgkin/classificação , Doença de Hodgkin/virologia , Humanos , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Países Baixos , Adulto Jovem
20.
BMC Med Genet ; 13: 78, 2012 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-22947327

RESUMO

BACKGROUND: In recent genetic association studies, common variants including rs12917707 in the UMOD locus have shown strong evidence of association with eGFR, prevalent and incident chronic kidney disease and uromodulin urinary concentration in general population cohorts. The association of rs12917707 with end-stage renal disease (ESRD) in a recent case-control study was only nominally significant. METHODS: To investigate whether rs12917707 associates with ESRD, graft failure (GF) and urinary uromodulin levels in an independent cohort, we genotyped 1142 ESRD patients receiving a renal transplantation and 1184 kidney donors as controls. After transplantation, 1066 renal transplant recipients were followed up for GF. Urinary uromodulin concentration was measured at median [IQR] 4.2 [2.2-6.1] yrs after kidney transplantation. RESULTS: The rs12917707 minor allele showed association with lower risk of ESRD (OR 0.89 [0.76-1.03], p = 0.04) consistent in effect size and direction with the previous report (Böger et al, PLoS Genet 2011). Meta-analysis of these findings showed significant association of rs12917707 with ESRD (OR 0.91 [0.85-98], p = 0.008). In contrast, rs12917707 was not associated with incidence of GF. Urinary uromodulin concentration was lower in recipients-carriers of the donor rs12917707 minor allele as compared to non-carriers, again consistent with previous observations in general population cohorts. CONCLUSIONS: Our study thus corroborates earlier evidence and independently confirms the association between UMOD and ESRD.


Assuntos
Falência Renal Crônica/genética , Uromodulina/genética , Adulto , Alelos , Estudos de Casos e Controles , Estudos de Coortes , Suscetibilidade a Doenças , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Polimorfismo de Nucleotídeo Único , Fatores de Risco , Doadores de Tecidos , Uromodulina/urina
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA