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1.
Am J Transplant ; 17(12): 3076-3086, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28613392

RESUMO

De novo donor-specific HLA antibodies (dnDSA) are recognized as a risk factor for premature allograft failure. Determinants of DSA specificity are generated via the indirect allorecognition pathway. Here, we present supportive data for the relevance of predicted indirectly recognizable HLA epitopes (PIRCHE) to predict dnDSA following kidney transplantation. A total of 2787 consecutive kidney transplants performed between 1995 and 2015 without preformed DSA have been analyzed. De novo DSA were detected by single antigen bead assay. HLA epitope mismatches were determined by the HLAMatchmaker and PIRCHE approach and correlated in uni- and multivariate analyses with 10-year allograft survival and incidence of dnDSA. The PIRCHE-II score moderately predicted allograft survival. However, the predictive value of elevated PIRCHE-II scores >9 for the incidence of dnDSA was statistically significant (p < 0.001). In a multivariate Cox regression analysis adjusted for antigen mismatch and HLAMatchmaker epitopes, the PIRCHE-II score could be identified as an independent risk factor for dnDSA. The PIRCHE-II score independently from the antigen mismatch and HLAMatchmaker epitopes could be revealed as being a strong predictor for dnDSA. PIRCHE may help to identify acceptable mismatches with decreased risk of dnDSA and thus improve long-term renal allograft survival.


Assuntos
Antígenos/imunologia , Epitopos/imunologia , Rejeição de Enxerto/epidemiologia , Sobrevivência de Enxerto/imunologia , Antígenos HLA/imunologia , Isoanticorpos/sangue , Transplante de Rim/métodos , Doadores de Tecidos , Feminino , Seguimentos , Alemanha/epidemiologia , Taxa de Filtração Glomerular , Rejeição de Enxerto/imunologia , Teste de Histocompatibilidade , Humanos , Incidência , Isoanticorpos/imunologia , Falência Renal Crônica/cirurgia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Transplante Homólogo
2.
Stem Cells ; 33(10): 3087-99, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26184374

RESUMO

Although the immunomodulatory potency of mesenchymal stromal cells (MSC) is well established, the mechanisms behind are still not clear. The crosstalk between myeloid dendritic cells (mDC) and natural killer (NK) cells and especially NK cell-derived interferon-gamma (IFN-γ) play a pivotal role in the development of type 1 helper (Th1) cell immune responses. While many studies explored the isolated impact of MSC on either in vitro generated DC, NK, or T cells, there are only few data available on the complex interplay between these cells. Here, we investigated the impact of MSC on the functionality of human mDC and the consequences for NK cell and Th1 priming in vitro and in vivo. In critical limb ischemia patients, who have been treated with allogeneic placenta-derived mesenchymal-like stromal cells (PLX-PAD), no in vivo priming of Th1 responses toward the major histocompatibility complex (MHC) mismatches could be detected. Further in vitro studies revealed that mDC reprogramming could play a central role for these effects. Following crosstalk with MSC, activated mDC acquired a tolerogenic phenotype characterized by reduced migration toward CCR7 ligand and impaired ability to stimulate NK cell-derived IFN-γ production. These effects, which were strongly related to an altered interleukin (IL)-12/IL-10 production by mDC, were accompanied by an effective prevention of Th1 priming in vivo. Our findings provide novel evidence for the regulation of Th1 priming by MSC via modulation of mDC and NK cell crosstalk and show that off-the-shelf produced MHC-mismatched PLX-PAD can be used in patients without any sign of immunogenicity.


Assuntos
Células Dendríticas/imunologia , Imunidade Celular , Células Matadoras Naturais/imunologia , Células-Tronco Mesenquimais/imunologia , Células Th1/imunologia , Comunicação Celular/imunologia , Diferenciação Celular/imunologia , Técnicas de Cocultura , Células Dendríticas/metabolismo , Feminino , Humanos , Imunomodulação , Interferon gama/imunologia , Interferon gama/metabolismo , Interleucina-10/imunologia , Interleucina-10/metabolismo , Células Matadoras Naturais/metabolismo , Linfonodos/imunologia , Linfonodos/metabolismo , Ativação Linfocitária/imunologia , Células-Tronco Mesenquimais/metabolismo , Células Mieloides/imunologia , Células Mieloides/metabolismo , Placenta/citologia , Placenta/metabolismo , Gravidez , Células Th1/metabolismo
3.
Nano Lett ; 15(11): 7421-30, 2015 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-26426671

RESUMO

Intercalation of C60 molecules at the graphene-substrate interface by annealing leads to amorphous and crystalline structures. A comparison of topography and electronic structure with wrinkles and moiré patterns confirms intercalation. The intercalated molecules imprint a local strain/deformation on the graphene layer whose magnitude is controlled by the intermolecular distance. The crystalline intercalated structure exhibits a superlattice peak in the local density of states. This work provides control of local strain in graphene.

4.
Am J Transplant ; 15(8): 2159-69, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25808077

RESUMO

Quantification of BKV-load and BKV-specific immunity have been evaluated to monitor BKV-replication and outcomes in kidney transplant recipients (KTRs) with BKV-infection. However, it remains crucial to better understand how immune markers can predict the risk for later infection. We studied all KTRs between 2008 and 2011. Twenty-four KTRs were diagnosed with BKV-replication and a control group of 127 KTRs was used for comparison. Samples were collected before at +1, +2, and +3 months posttransplantation. BKV-specific and alloreactive T cells were measured using an interferon-γ Elispot assay. The extent of immunosuppression was quantified by lymphocyte subpopulations and interferon-gamma levels. KTRs with a loss of BKV-specific T cells directed to Large T-antigen from pretransplantation to posttransplantation were at increased risk of BKV-replication (p < 0.001). In contrast, KTRs with stable/rising BKV-specific T cells were more likely not to develop BKV-replication (p < 0.05). KTRs developing BKV-replication showed significantly lower CD3+, CD4+, CD8+ T cells and interferon-γ levels posttransplantation, but significantly higher alloreactive T cells (p < 0.05). Monitoring pretransplant and posttransplant BKV-specific T cells is suggested a sensitive marker to identify KTRs at increased risk of BKV-replication. Increased susceptibility to immunosuppression predisposes KTRs to a loss of protective BKV-specific immunity that results in impaired virus control and BKV-replication.


Assuntos
Transplante de Rim , Viroses/complicações , Replicação Viral , Adulto , Idoso , Feminino , Humanos , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Viroses/imunologia
5.
Am J Transplant ; 15(12): 3157-65, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26137874

RESUMO

Host protection upon vaccination usually results from the complex interplay of humoral and cellular components of the immune system. Exploring hepatitis B surface antigen (HBsAg)-specific T cell responses and their correlation with humoral responses under immunosuppression, we analyzed 51 renal transplant recipients, differing in HBV vaccine-specific antibody titers (non [NRs]-, low [LRs]-, and high responders [HRs]) and in 22 healthy controls (HCs) in a cross-sectional study. HBsAg-specific T cells were analyzed by flow cytometry according to expression of activation markers CD40L and/or CD69, and the cytokines IFNγ, IL-2, TNFα, and IL-17. No significant differences in responder rate and magnitude of HBsAg-specific T cell responses were found between HCs and HRs. Interestingly, HBsAg-specific Th-cells were also observed in 50% of humoral NRs. Frequencies of HBsAg-specific CD40L+ Th-cells were significantly higher in HRs compared to LRs (p = 0.009) and in LRs in comparison to NRs (p = 0.043). All but NRs showed a predominance of multi-potent HBsAg-specific TNFα+IL-2+ Th-cells. As expected, HBsAg-specific CD8(+) T cells were rarely found. In conclusion, mounting of hepatitis B vaccine-specific T cell responses is possible in kidney transplant recipients despite immunosuppression. Detection of HBV-specific Th-cells in a significant proportion of humoral NRs contributes to the current discussion on conferring immune protection by cellular memory in such patients.


Assuntos
Vacinas contra Hepatite B/uso terapêutico , Vírus da Hepatite B/imunologia , Hepatite B/imunologia , Imunidade Celular/imunologia , Imunidade Humoral/imunologia , Falência Renal Crônica/imunologia , Transplante de Rim , Linfócitos B/imunologia , Estudos de Casos e Controles , Feminino , Citometria de Fluxo , Seguimentos , Taxa de Filtração Glomerular , Sobrevivência de Enxerto , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Falência Renal Crônica/cirurgia , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Linfócitos T Reguladores/imunologia , Células Th1/imunologia
6.
Am J Transplant ; 15(10): 2625-35, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25988290

RESUMO

Adoptive immunotherapy with regulatory T cells (Treg) is a new option to promote immune tolerance following solid organ transplantation (SOT). However, Treg from elderly patients awaiting transplantation are dominated by the CD45RA(-) CD62L(+) central memory type Treg subset (TregCM), and the yield of well-characterized and stable naïve Treg (TregN) is low. It is, therefore, important to determine whether these TregCM are derived from the thymus and express high stability, suppressive capacity and a broad antigen repertoire like TregN. In this study, we showed that TregCM use a different T cell receptor (TCR) repertoire from conventional T cells (Tconv), using next-generation sequencing of all 24 Vß families, with an average depth of 534 677 sequences. This showed almost no contamination with induced Treg. Furthermore, TregCM showed enhanced suppressive activity on Tconv at early checkpoints of immune activation controlling activation markers expression and cytokine secretion, but comparable inhibition of proliferation. Following in vitro expansion under mTOR inhibition, TregCM expanded equally as well as TregN without losing their function. Despite relatively limited TCR repertoire, TregCM also showed specific alloresponse, although slightly reduced compared to TregN. These results support the therapeutic usefulness of manufacturing Treg products from CD45RA(-) CD62L(+) Treg-enriched starting material to be applied for adoptive Treg therapy.


Assuntos
Linfócitos T Reguladores/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/metabolismo , Citocinas/metabolismo , Citometria de Fluxo , Fatores de Transcrição Forkhead/metabolismo , Voluntários Saudáveis , Humanos , Transplante de Rim , Antígenos Comuns de Leucócito/metabolismo , Pessoa de Meia-Idade , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Reguladores/metabolismo , Timo/citologia , Timo/imunologia
7.
Am J Transplant ; 15(1): 119-28, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25521535

RESUMO

ZEUS study was an open-label, 12-month, multicenter study in which 300 de novo kidney transplant recipients were randomized to continue receiving cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant. Five-year follow-up data were available for 245/269 patients (91.1%) who completed the core 12-month study (123 everolimus, 109 CsA). At 5 years, adjusted estimated GFR was 66.2 mL/min/1.73 m(2) with everolimus versus 60.9 mL/min/1.73 m(2) with CsA; the mean difference was 5.3 mL/min/1.73 m(2) in favor of everolimus (95% CI 2.4, 8.3; p < 0.001 [intent-to-treat population]). In a post hoc analysis of patients remaining on study drug at 5 years (everolimus 77, CsA 86), mean difference was 8.2 mL/min/1.73 m(2) (95% CI 4.3, 12.1; p < 0.001) in favor of everolimus. The cumulative incidence of biopsy-proven acute rejection postrandomization was 13.6% with everolimus versus 7.5% with CsA (p = 0.095), largely accounted for by grade I rejection (16/21 patients and 7/11 patients, respectively). Postrandomization, graft loss, mortality, serious adverse events and neoplasms were similar in both arms. In conclusion, conversion of kidney transplant patients to everolimus at 4.5 months posttransplant is associated with a significant improvement in renal function that is maintained to at least 5 years. The increase in early mild acute rejection did not affect long-term graft function.


Assuntos
Ciclosporina/uso terapêutico , Rejeição de Enxerto/tratamento farmacológico , Sobrevivência de Enxerto/efeitos dos fármacos , Imunossupressores/uso terapêutico , Falência Renal Crônica/cirurgia , Transplante de Rim , Sirolimo/análogos & derivados , Adolescente , Adulto , Idoso , Everolimo , Feminino , Seguimentos , Taxa de Filtração Glomerular , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Falência Renal Crônica/complicações , Testes de Função Renal , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Prognóstico , Projetos de Pesquisa , Fatores de Risco , Sirolimo/uso terapêutico , Transplantados , Adulto Jovem
8.
Am J Transplant ; 15(4): 1091-100, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25736912

RESUMO

Tailoring treatment by patient strata based on the risk of disease progression and treatment toxicity might improve outcomes of patients with posttransplant lymphoproliferative disorder (PTLD). We analysed the cohort of 70 patients treated in the international, multicenter phase II PTLD-1 trial (NCT01458548) to identify such factors. Of the previously published scoring systems in PTLD, the international prognostic index (IPI), the PTLD prognostic index and the Ghobrial score were predictive for overall survival. None of the scoring systems had a considerable effect on the risk for disease progression. Age and ECOG performance status were the baseline variables with the highest prognostic impact in the different scoring systems. Baseline variables not included in the scoring systems that had an impact on overall survival and disease progression were the type of transplant and the response to rituximab at interim staging. Thoracic organ transplant recipients who did not respond to rituximab monotherapy were at particularly high risk for death from disease progression with subsequent CHOP-based chemotherapy. Patients in complete remission after four courses of rituximab and patients in partial remission with low-risk IPI had a low risk of disease progression. We speculate that chemotherapy might not be necessary in this patient cohort.


Assuntos
Antígenos CD20/imunologia , Linfócitos B/imunologia , Transtornos Linfoproliferativos/tratamento farmacológico , Rituximab/uso terapêutico , Humanos , Transtornos Linfoproliferativos/imunologia , Transtornos Linfoproliferativos/patologia , Pessoa de Meia-Idade , Prognóstico
9.
Am J Transplant ; 14(3): 594-606, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24467477

RESUMO

The adoptive transfer of natural regulatory T cells (nTreg) is a new option to reshape undesired immune reactivity in autoimmunity and transplantation toward "tolerance." The first clinical trials using adoptive transfer of polyclonal nTreg demonstrated safety and hints of efficacy. However, the low frequencies of antigen-specific cells among the pool of polyclonal nTreg and their broad antigen nonspecific suppression are limitations of this approach regarding efficacy and safety. Recently, the isolation and expansion of (allo)antigen-specific nTreg have successfully been achieved by using Treg-specific activation markers but the yield is relatively low. Here, we describe a novel good manufacturing practice (GMP)-compatible expansion protocol of alloantigen-specific nTreg based on the stimulation of nTreg by allogeneic activated B cells. Their functionality and specificity are superior compared to polyclonal nTreg both in vitro and in vivo. Employing an allogeneic B cell bank, designed to cover the majority of HLA types, allows fast GMP-compliant manufacturing for donor-specific nTreg for clinical application in organ and stem cell transplantation. TCR repertoire analyses by next generation sequencing revealed impressive expansion by several log-steps of even very low-abundance alloantigen-specific nTreg clones. This novel method offers a simple approach for expanding antigen-specific nTreg and is characterized by high replicability and easy transferability to full GMP standards.


Assuntos
Linfócitos B/imunologia , Protocolos Clínicos/normas , Rejeição de Enxerto/imunologia , Tolerância Imunológica/imunologia , Isoantígenos/imunologia , Transplante de Pele , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Linfócitos B/citologia , Células Cultivadas , Proteínas de Ligação a DNA/fisiologia , Teste de Histocompatibilidade , Humanos , Terapia de Imunossupressão , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Reguladores/citologia
10.
Med Microbiol Immunol ; 203(6): 395-408, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25052009

RESUMO

Reactivation of polyomavirus BK (BKV) infection represents a severe complication in kidney transplant (KTX) patients. We previously reported an association between a declining BK viral load and the reconstitution of CD4(+) T cell BKV-specific immunity in patients following kidney transplantation. However, the specific contribution of CD4(+) T cells in the regulation of BKV-replication is unknown. Nevertheless, in vitro enrichment of BKV-specific T cells and subsequent adoptive T cell transfer may improve the restoration of immune competence in KTX patients with BKV infection. To date, strategies to capture human BKV-specific T cells with the ensuing expansion to clinically useful numbers are lacking. Here, we demonstrated a comprehensive flow cytometric analysis of the BKV-specific T cell response that permits access to the majority of T cells specific for immunodominant BKV antigens. A full-spectrum evaluation of the BKV-specific T cell response was performed by stimulating peripheral blood mononuclear cells (PBMC) with a mixture of BKV immunodominant peptide pools at varying concentrations and measuring activation marker expression and cytokine secretion. We also examined the effects of co-stimulation and PBMC resting time prior to activation. We defined the narrow range of stimulation conditions that permit the capture and expansion of functional BKV-specific T cell lines. The generated BKV-specific T cell lines showed the highest specificity and functionality when the T cells were captured according to IFNγ-secretion. This study highlights the multifunctional and cytolytic BKV-specific CD4(+) T cells as a dominant population within the generated T cell product. This method offers a novel approach for the generation of BKV-specific T cell lines for adoptive immunotherapy and underscores the critical role of CD4(+) T cells in the clearance of BKV.


Assuntos
Vírus BK/imunologia , Linfócitos T CD4-Positivos/imunologia , Infecções por Polyomavirus/imunologia , Subpopulações de Linfócitos T/imunologia , Infecções Tumorais por Vírus/imunologia , Citotoxicidade Imunológica , Citometria de Fluxo , Humanos , Transplante de Rim , Infecções por Polyomavirus/virologia , Transplantados , Infecções Tumorais por Vírus/virologia
11.
Infection ; 42(6): 981-9, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25168263

RESUMO

BACKGROUND: Trimethoprim/sulfamethoxazole (TMP/SMX) is considered first-line therapy for pneumocystis jiroveci pneumonia (PCP) in renal transplant patients. Alternatives have not been formally studied. Clindamycin-primaquine (C-P) is effective in HIV-associated PCP, but data in renal transplant patients are lacking. PATIENTS AND METHODS: Retrospective cohort study of 57 consecutive renal transplant patients who developed PCP and were treated with C-P (n = 23) or TMP/SMX (n = 34). RESULTS: A non-significantly higher failure rate was observed in patients on C-P due to lack of efficacy (30.4 versus 20.6%, p = 0.545). The difference was more pronounced in severe PCP (60 versus 37.5%, p = 0.611) and a significantly lower efficacy of C-P was seen when used as salvage therapy. The two patients who had received C-P after not responding to TMP/SMX failed this regimen, but all seven patients who had failed initial treatment with C-P and had been switched to TMP/SMX were cured (p = 0.028). No treatment-limiting adverse reactions were reported for patients on C-P while six patients (17.6%) on TMP/SMX developed possibly related treatment-limiting toxicity (p = 0.071). However, in only two patients adverse events were definitely related to TMP/SMX (5.9%). CONCLUSIONS: Clindamycin-primaquine appears to be safe and well tolerated for treating PCP in renal transplant patients but is probably less effective than TMP/SMX, the standard regimen. However, our data indicates that C-P represents an acceptable alternative for patients with contraindications or treatment emergent toxicities during TMP/SMX use. Notably, TMP/SMX was also acceptably tolerated in most patients. TMP/SMX remains an effective salvage regimen in case of C-P failure.


Assuntos
Antifúngicos/uso terapêutico , Clindamicina/uso terapêutico , Transplante de Rim , Pneumocystis carinii/isolamento & purificação , Pneumonia por Pneumocystis/tratamento farmacológico , Primaquina/uso terapêutico , Adulto , Idoso , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Combinação Trimetoprima e Sulfametoxazol/uso terapêutico
12.
Transpl Infect Dis ; 16(4): 568-77, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24966022

RESUMO

INTRODUCTION: The clinical course of cytomegalovirus (CMV) infections in the current era is poorly described. We characterized the symptoms and outcome of all CMV infections in a large cohort of kidney transplant recipients. Among 1129 kidney transplant recipients transplanted between 2004 and 2011 in Charité Universitätsmedizin Berlin and Helsinki University Hospital, 297 patients with CMV infection were characterized. RESULTS: CMV disease occurred in 217/1129 patients (19.2%), and CMV infection in 297/1129 (26.3%). Gastrointestinal symptoms were recorded in 58% and fever in 47% patients with primary CMV disease, compared to 46% and 27% patients with symptomatic CMV reactivation, whereas leukopenia or thrombocytopenia were seen in only 17-28% patients, and malaise in 9-10%. Tissue-invasive CMV gastroenteritis was confirmed in 11% and CMV pneumonia in only 1% of patients with CMV disease. Only 1 patient died because of CMV infection (mortality 0.3%). Virus-related factors or the use of secondary prophylaxis did not predict the risk of recurrence, which occurred in 33% patients. CONCLUSION: In conclusion, CMV disease remains a common problem after kidney transplantation. Gastrointestinal symptoms were common, especially in patients with primary CMV infection, whereas bone marrow suppression, hepatopathy, or malaise were seen less frequently.


Assuntos
Infecções por Citomegalovirus/etiologia , Transplante de Rim/efeitos adversos , Adulto , Idoso , Antivirais/uso terapêutico , Proteínas de Bactérias , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/epidemiologia , Feminino , Finlândia/epidemiologia , Ganciclovir/análogos & derivados , Ganciclovir/uso terapêutico , Alemanha , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Chaperonas Moleculares , Estudos Retrospectivos , Valganciclovir
13.
Am J Transplant ; 13(11): 2842-54, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24020931

RESUMO

Clonotype analysis is essential for complete characterization of antigen-specific T cells. Moreover, knowledge on clonal identity allows tracking of antigen-specific T cells in whole blood and tissue infiltrates and can provide information on antigenic specificity. Here, we developed a next generation sequencing (NGS)-based platform for the highly quantitative clonotype characterization of T cells and determined requirements for the unbiased characterization of the input material (DNA, RNA, ex vivo derived or cell culture expanded T cells). Thereafter we performed T cell receptor (TCR) repertoire analysis of various specimens in clinical settings including cytomegalovirus (CMV), polyomavirus BK (BKV) reactivation and acute cellular allograft rejection. Our results revealed dynamic nature of virus-specific T cell clonotypes; CMV reactivation was linked to appearance of new highly abundant antigen-specific clonalities. Moreover, analysis of clonotype overlap between BKV-, alloantigen-specific T cell-, kidney allograft- and urine-derived lymphocytes provided hints for the differential diagnosis of allograft dysfunction and enabled appropriate therapy adjustment. We believe that the established approach will provide insights into the regulation of virus-specific/anti-tumor immunity and has high diagnostic potential in the clinical routine.


Assuntos
Infecções por Citomegalovirus/diagnóstico , Citomegalovirus/imunologia , Rejeição de Enxerto/genética , Sequenciamento de Nucleotídeos em Larga Escala , Infecções por Polyomavirus/diagnóstico , Receptores de Antígenos de Linfócitos T/genética , Linfócitos T/patologia , Infecções Tumorais por Vírus/diagnóstico , Vírus BK/genética , Citomegalovirus/patogenicidade , Infecções por Citomegalovirus/genética , Infecções por Citomegalovirus/virologia , Diagnóstico Diferencial , Humanos , Transplante de Rim/efeitos adversos , Infecções por Polyomavirus/genética , Infecções por Polyomavirus/virologia , Estudos Retrospectivos , Linfócitos T/imunologia , Linfócitos T/virologia , Infecções Tumorais por Vírus/genética , Infecções Tumorais por Vírus/virologia , Ativação Viral
14.
Am J Transplant ; 13(7): 1880-90, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23763435

RESUMO

Assessment of donor-specific alloreactive memory/effector T cell responses using an IFN-γ Elispot assay has been suggested to be a novel immune-monitoring tool for evaluating the cellular immune risk in renal transplantation. Here, we report the cross-validation data of the IFN-γ Elispot assay performed within different European laboratories taking part of the EU RISET consortium. For this purpose, development of a standard operating procedure (SOP), comparisons of lectures of IFN-γ plates assessing intra- and interlaboratory assay variability of allogeneic or peptide stimuli in both healthy and kidney transplant individuals have been the main objectives. We show that the use of a same SOP and count-settings of the Elispot bioreader allow low coefficient variation between laboratories. Frozen and shipped samples display slightly lower detectable IFN-γ frequencies than fresh samples. Importantly, a close correlation between different laboratories is obtained when measuring high frequencies of antigen-specific primed/memory T cell alloresponses. Interestingly, significant high donor-specific alloreactive T cell responses can be similarly detected among different laboratories in kidney transplant patients displaying histological patterns of acute T cell mediated rejection. In conclusion, assessment of circulating alloreactive memory/effector T cells using an INF-γ Elispot assay can be accurately achieved using the same SOP, Elispot bioreader and experienced technicians in kidney transplantation.


Assuntos
ELISPOT/métodos , Rejeição de Enxerto/imunologia , Imunidade Celular/imunologia , Memória Imunológica , Interferon gama/imunologia , Transplante de Rim/imunologia , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Linfócitos T/imunologia
15.
Am J Transplant ; 12(3): 669-81, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22081907

RESUMO

Cytomegalovirus (CMV) infections have a major impact on morbidity and mortality of transplant patients. Among the complex antiviral T-cell response, CMV-IE-1 antigen-specific CD8+ cells are crucial for preventing CMV disease but do not protect from recurring/lasting CMV reactivation. Recently, we confirmed that adoptive transfer of autologous IE-1/pp65-specific T-cell lines was able to combat severe CMV disease; however, the control of CMV infection was only temporary. We hypothesized that CMV-induced regulatory T cells (iTreg) might be related to recurring/lasting CMV infection. In fact, kidney transplant patients with recurring CMV infections expressed enhanced suppression on CMV response. Analysis of in vitro expanded CD4+ epitope-specific cells revealed that CMV-specific CD4+CD25(high) Treg cells functionally suppress CD25(low) effector T cells (Teff) upon epitope-specific reactivation. Their phenotype is similar to iTreg - CD39(high) /Helios-/IL-2(low) /IFNγ(high) /IL-10±/TGFß-LAP±/FOXP3+ and methylated foxp3 locus. Remarkably, in vitro expanded CD4+CD25(high) iTreg share the same dominant TCR-Vß-CDR3 clones with functionally distinct CD4+CD25(low) Teff. Moreover, the same clones were present in freshly isolated CD4+CD25(high) and CD4+CD25(low) T cells suggesting their in vivo generation. These findings directly demonstrate that Teff and iTreg can differentiate from one "mother" clone with specificity to the same viral epitope and indicate that peripheral iTreg generation is related to frequent antigen appearance.


Assuntos
Antígenos Virais/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T/imunologia , Proliferação de Células , Citocinas/metabolismo , Infecções por Citomegalovirus/microbiologia , Citometria de Fluxo , Humanos , Receptores de Antígenos de Linfócitos T/imunologia , Recidiva
16.
Am J Transplant ; 12(6): 1528-40, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22642473

RESUMO

The long-term effect of conversion from calcineurin inhibitor (CNI) therapy to an mTOR inhibitor requires clarification. Following completion of the 12-month, open-label, multicenter ZEUS study, in which 300 kidney transplant recipients were randomized to continue cyclosporine (CsA) or convert to everolimus at 4.5 months posttransplant, outcomes were assessed at month 36 (n = 284; 94.7%). CNI therapy was reintroduced in 28.4% of everolimus patients by month 36. The primary efficacy endpoint, estimated glomerular filtration rate (Nankivell, ANCOVA) was significantly higher with everolimus versus the CsA group at month 24 (7.6 mL/min/1.73 m(2) , 95%CI 4.3, 11.0 mL/min/1.73 m(2) ; p < 0.001) and month 36 (7.5 mL/min/1.73 m(2) , 95%CI 3.6, 11.4 mL/min/1.73 m(2) ; p < 0.001). The incidence of biopsy-proven acute rejection from randomization to month 36 was 13.0% in the everolimus arm and 4.8% in the CsA arm (p = 0.015). Patient and graft survival, as well as incidences of malignancy, severe infections and hospitalization, were similar between groups. Kidney transplant patients who are converted from CsA to everolimus at month 4.5 and who remain on everolimus thereafter may achieve a significant improvement in renal function that is maintained to 3 years. There was a significantly higher rate of rejection in the everolimus arm but this did not exert a deleterious effect by 3 years posttransplant.


Assuntos
Ciclosporina/administração & dosagem , Imunossupressores/administração & dosagem , Sirolimo/análogos & derivados , Adolescente , Adulto , Idoso , Análise de Variância , Everolimo , Humanos , Transplante de Rim , Pessoa de Meia-Idade , Sirolimo/administração & dosagem , Adulto Jovem
17.
Am J Transplant ; 12(9): 2384-94, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22702307

RESUMO

Recent data suggest that donor-specific memory T cells (T(mem)) are an independent risk factor for rejection and poor graft function in patients and a major challenge for immunosuppression minimizing strategies. Many tolerance induction protocols successfully proven in small animal models e.g. costimulatory blockade, T cell depletion failed in patients. Consequently, there is a need for more predictive transplant models to evaluate novel promising strategies, such as adoptive transfer of regulatory T cells (Treg). We established a clinically more relevant, life-supporting rat kidney transplant model using a high responder (DA to LEW) recipients that received donor-specific CD4(+)/ 8(+) GFP(+) T(mem) before transplantation to achieve similar pre-transplant frequencies of donor-specific T(mem) as seen in many patients. T cell depletion alone induced long-term graft survival in naïve recipients but could not prevent acute rejection in T(mem)(+) rats, like in patients. Only if T cell depletion was combined with permanent CNI-treatment, the intragraft inflammation, and acute/chronic allograft rejection could be controlled long-term. Remarkably, combining 10 days CNI treatment and adoptive transfer of Tregs (day 3) but not Treg alone also induced long-term graft survival and an intragraft tolerance profile (e.g. high TOAG-1) in T(mem)(+) rats. Our model allows evaluation of novel therapies under clinically relevant conditions.


Assuntos
Inibidores de Calcineurina , Rejeição de Enxerto , Imunossupressores/farmacologia , Transplante de Rim , Linfócitos T Reguladores/imunologia , Transferência Adotiva , Animais , Citometria de Fluxo , Memória Imunológica , Depleção Linfocítica , Ratos , Ratos Endogâmicos Lew , Reação em Cadeia da Polimerase Via Transcriptase Reversa
18.
Am J Transplant ; 11(11): 2443-52, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21831150

RESUMO

Impaired BKV-specific immunity is associated with development of BKV-associated nephropathy. Suitable immunological parameters to identify patients at risk, however, are still debated. We monitored 18 kidney-transplant recipients through the course of self-limited BKV-reactivation (n = 11) and BKV-associated nephropathy (n = 7). BKV-specific cellular immunity directed to nonstructural small and Large T-antigen, and structural VP1-3 was analyzed in an interferon-γ Elispot assay. BKV-specific IgM and IgG were measured using an enzyme-linked immunosorbent assay simultaneously. BKV-specific cellular immunity directed to five BKV-proteins increased significantly from diagnosis to resolution of BKV-reactivation (p < 0.001). Patients with self-limited BKV-reactivation developed BKV-specific T cells without therapeutic interventions, and cleared BKV-reactivation within a median period of 1 month. Patients with BKV-associated nephropathy, however, showed BKV-specific T cells after a median period of 5 months after therapeutic interventions only, and cleared BKV-reactivation after a median period of 8 months. Anti-structural T cells were detected earlier than anti-nonstructural T cells, which coincided with BKV-clearance. Patients with BKV-associated nephropathy showed the highest frequencies of BKV-specific T cells at recovery, the highest increase in BKV-specific IgG and persistence of increased IgM levels (p < 0.05). Our results suggest prognostic values of BKV-specific immune monitoring to identify those patients at risk of BKV-associated nephropathy and to aid in the management of therapeutic interventions.


Assuntos
Anticorpos Antivirais/imunologia , Vírus BK/imunologia , Nefropatias/virologia , Transplante de Rim/imunologia , Infecções por Polyomavirus/imunologia , Infecções Tumorais por Vírus/imunologia , Adulto , Idoso , Antígenos Virais de Tumores/imunologia , Vírus BK/fisiologia , Feminino , Humanos , Imunidade Celular/imunologia , Nefropatias/imunologia , Masculino , Pessoa de Meia-Idade , Linfócitos T/imunologia , Ativação Viral
19.
Nat Med ; 3(6): 678-81, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9176497

RESUMO

Neutralization of proinflammatory cytokines, such as tumor necrosis factor-alpha (TNF-alpha) or interleukin-1 (IL-1), decreases mortality in several animal models of sepsis. However, recent clinical trials did not show an unequivocal improvement in survival. In contrast to animals, which succumb to shock during the first 72 hours, we found that many patients die much later with signs of opportunistic infections accompanied by downregulation of their monocytic HLA-DR expression and reduced ability to produce lipopolysaccharide (LPS)-induced TNF-alpha in vitro. This phenomenon of monocyte deactivation in septic patients with fatal outcome shows similarities to experimental monocytic refractoriness induced by LPS desensitization or by pretreatment with its endogenous mediators IL-10 and transforming growth factor-beta (TGF-beta). In order to strengthen their antimicrobial defense, here we tested whether interferon-gamma (IFN-gamma) can improve monocytic functions in these patients and in experimental monocytic deactivation. The considerably lowered in vitro levels of LPS-induced TNF-alpha in these situations were significantly enhanced by IFN-gamma, but did not reach the extremely high levels of IFN-gamma primed naive cells from healthy donors. Moreover, IFN-gamma applied to septic patients with low monocytic HLA-DR expression restored the deficient HLA-DR expression and in vitro LPS-induced TNF-alpha secretion. Recovery of monocyte function resulted in clearance of sepsis in eight of nine patients. These data suggest that IFN-gamma treatment in carefully selected septic patients is a novel therapeutic strategy worth pursuing.


Assuntos
Interferon gama/uso terapêutico , Monócitos/imunologia , Sepse/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Relação Dose-Resposta a Droga , Antígenos HLA-DR/sangue , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/metabolismo , Lipopolissacarídeos/farmacologia , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Sepse/imunologia , Fator de Necrose Tumoral alfa/metabolismo
20.
Scand J Surg ; 110(1): 66-72, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31906794

RESUMO

BACKGROUND AND AIMS: There are only few data on the influence of cinacalcet on the outcome of parathyroidectomy in patients with renal hyperparathyroidism. Indication and timing of surgery have changed since its introduction, especially with regard to kidney transplantation. Therefore, we retrospectively analyzed patients undergoing parathyroidectomy for renal hyperparathyroidism in our institution. MATERIAL AND METHODS: Between 2008 and 2015, 196 consecutive operations in 191 patients were analyzed. About 80 operations (41%) were performed in patients receiving cinacalcet compared with 116 operations (59%) in patients without cinacalcet. Clinical data, preoperative medication, pre- and postoperative laboratory values, type and details of surgery including complications, as well as cardiovascular complications and kidney transplantation with graft function were recorded. RESULTS: Demographical data were similar in patients with or without cinacalcet treatment. A total of 54% of patients received a kidney graft before or after parathyroidectomy. Pre- and postoperative parathormone levels were similar in both groups (preoperatively 755 vs 742 ng/L, postoperatively 50 vs 46 ng/L, p > 0.10), whereas patients with cinacalcet showed significantly lower calcium levels preoperatively (2.28 vs 2.41 mmol/L, p = 0.0002). There was no difference in recurrence or persistence of hyperparathyroidism, duration of surgery, hospital stay, or complication rate. Creatinine levels in patients with tertiary hyperparathyroidism were similar after 1-year follow-up. CONCLUSION: Cinacalcet did not influence outcome of patients with parathyroidectomy for renal hyperparathyroidism and can be safely offered to patients not responding to medical treatment.


Assuntos
Calcimiméticos/uso terapêutico , Cinacalcete/uso terapêutico , Hiperparatireoidismo/tratamento farmacológico , Hiperparatireoidismo/cirurgia , Paratireoidectomia , Biomarcadores/sangue , Doenças Cardiovasculares/epidemiologia , Feminino , Humanos , Transplante de Rim , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Estudos Retrospectivos
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