Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
Urologe A ; 60(12): 1546-1554, 2021 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-34738151

RESUMO

BACKGROUND: Long-term remission can be achieved by surgery in patients with metastatic renal cell carcinoma (mRCC), without chronic toxicity due to systemic treatment. Data on metastasectomy are mostly based on observations of metachronous metastasis. However, it is unclear whether patients with synchronous oligometastasis may also benefit from surgery alone as an alternative to highly effective systemic treatment combined with resection of the primary tumor. MATERIALS AND METHODS: The authors performed an unstructured literature search in PubMed including systematic reviews and meta-analyses. Results are discussed in regard of the current data and clinical practice. RESULTS AND DISCUSSION: Although there is no uniform definition for oligometastasis in mRCC, cytoreductive nephrectomy in selected patients seems to be mandatory before metastasectomy is performed in primary oligometastatic RCC. In particular, in those patients with oligometastasis of the lung, bone, central nervous system, liver, adrenal gland, and thyroid, metastasectomy appears to be an important therapeutic option. Ultimately, among the therapeutic options, surgery is also an important therapeutic approach in primary oligometastatic mRCC. A balanced consideration between surgery, other local therapies, and modern systemic treatment demands interdisciplinary decision-making that takes into account the patients' preference.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Metastasectomia , Carcinoma de Células Renais/cirurgia , Humanos , Neoplasias Renais/cirurgia , Nefrectomia , Resultado do Tratamento
3.
Unfallchirurg ; 124(9): 731-737, 2021 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-34255103

RESUMO

BACKGROUND: Pathological fractures are not only incisive events for tumor patients often with the need of surgical treatment but also often represent a relevant challenge in the overall concept of oncological treatment. OBJECTIVE: The aim of this article is to illustrate the necessity of a pre-interventional interdisciplinary consideration of disease-specific and patient-specific characteristics. MATERIAL AND METHODS: A literature search and evaluation of existing guidelines were carried out including the keywords "bone metastases" and "pathological fractures" with respect to the oncological and radiotherapeutic treatment. RESULTS: An essential classification of the surgical and other needs for treatment is carried out by the identification of the underlying disease and dissemination situation. For tumor-related pathological fractures a palliative treatment situation is present in most cases. Nevertheless, a possible oligometastasis and an increasing number of effective systemic treatment methods must be taken into consideration when planning the surgical treatment. In addition to the therapeutic emergency indications in spinal compression or symptomatic hypercalcemia, both additive radiotherapy and supplementary pharmaceutical osteoprotection have to be addressed in this context. Radiotherapy in particular represents an effective alternative option for symptom and tumor control. CONCLUSION: The work-up of the multifaceted oncological treatment concept represents an interdisciplinary challenge, which ideally defines the further treatment procedure, including fracture treatment, in an interdisciplinary tumor board within an overall oncological concept.


Assuntos
Neoplasias Ósseas , Fraturas Ósseas , Fraturas Espontâneas , Neoplasias Ósseas/terapia , Fraturas Ósseas/terapia , Fraturas Espontâneas/cirurgia , Humanos , Cuidados Paliativos
4.
Clin Exp Metastasis ; 38(3): 257-261, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33759009

RESUMO

Cancer patients represent a vulnerable cohort during the Sars-CoV-2 pandemic. Oncological societies have generated a plethora of recommendations, but precise instructions about routine oncological procedures remain scarce. Here, we report on local COVID-19 protection measures established in an interdisciplinary approach at a tertiary care center during the first wave of the pandemia in Germany. Following these measures, no additional morbidity or mortality during oncological procedures was observed, and no nosocomial infections were registered. However, Validation of our measures is outstanding and regional SARS-CoV-2 prevalence was low. However, specific oncological measures might be important to ensure optimal oncological results, especially for advanced cancer stages during this and future pandemia. In the future, communication about these measures might be crucial to a cancer patient´s assigned network to reduce the danger of excess mortality within the second wave of the COVID-19 pandemic.


Assuntos
COVID-19/prevenção & controle , Controle de Infecções/métodos , Oncologia/métodos , Neoplasias/imunologia , Pandemias/prevenção & controle , COVID-19/epidemiologia , COVID-19/transmissão , COVID-19/virologia , Alemanha/epidemiologia , Humanos , Controle de Infecções/organização & administração , Controle de Infecções/normas , Oncologia/organização & administração , Oncologia/normas , Neoplasias/complicações , Pandemias/estatística & dados numéricos , Prevalência , SARS-CoV-2/imunologia , SARS-CoV-2/patogenicidade , Centros de Atenção Terciária/organização & administração
5.
Aktuelle Urol ; 47(6): 475-479, 2016 12.
Artigo em Alemão | MEDLINE | ID: mdl-28006830

RESUMO

c-Met plays a significant role in multiple cellular processes. Being encoded by a proto-oncogene, tyrosine kinase supports aggressive tumour behaviour such as tumour invasiveness and formation of metastases. For some subtypes of renal cell carcinoma studies have shown a association between c-Met expression and clinical outcome or prognosis. Therefore, c-Met represents a prognostic marker in renal cell carcinoma.Furthermore, c-MET will play a decisive role as a possible target for targeted therapies in the era of personalised medicine. Especially for RCC, the dual inhibition of VEGF and c-MET tyrosine kinase in cases of metastatic, treatment-resistant tumours is gaining clinical relevance. The role of c-Met has not been fully elucidated for all subtypes of renal cell carcinomas. The relevance of c-Met for the remaining subtypes of renal tumours has yet to be clarified.


Assuntos
Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Proteínas Proto-Oncogênicas c-met/genética , Carcinoma Papilar/genética , Carcinoma Papilar/mortalidade , Carcinoma Papilar/patologia , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Análise Mutacional de DNA , Humanos , Rim/patologia , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Invasividade Neoplásica/genética , Prognóstico , Proto-Oncogene Mas , Taxa de Sobrevida
6.
Med Oncol ; 33(7): 80, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27317388

RESUMO

The immunological checkpoints of programmed death 1 and its ligand (PD-L1) are currently in focus as novel therapeutic targets in renal cell carcinoma (RCC). The aim of this study was to evaluate the prognostic association of PD-L1 expression in clear cell (cc) RCC with clinical parameters, tumor aggressiveness and overall survival (OS). Patients who underwent renal surgery due to RCC between 1994 and 2003 were retrospectively evaluated. Tumor specimens were analyzed for PD-L1 expression by immunohistochemistry. One hundred and seventy-seven ccRCC patients were eligible for analysis, in which 140 (79.1 %) were negative and 37 (20.9 %) were positive for PD-L1 expression. PD-L1 positivity was associated with female gender (p = 0.001), lymph node metastasis (p = 0.004), distant metastasis (p = 0.002), higher AJCC stage (p = 0.004), as well as advanced disease (pT3/4 and/or N+ and/or M1) (p < 0.001). Kaplan-Meier analysis revealed a significantly diminished 5- and 10-year overall survival of 46.7 and 28.3 % for PD-L1(+) compared to PD-L1(-) tumors with 66 and 53.4 % (p = 0.005), respectively. Univariate analysis showed a significant negative association of OS with PD-L1 positivity [p = 0.005; HR: 2 (95 % CI 1.2-3.3)], even though PD-L1 positivity only tends to predict independently the OS using multivariate analyses [p = 0.066; HR: 1.6 (95 % CI 0.98-2.7)]. PD-L1 expression in ccRCC is associated with parameters of aggressiveness, as well as with poor OS, even though PD-L1 status was not identified as a significant independent prognostic parameter. However, further studies in larger cohorts are warranted.


Assuntos
Antígeno B7-H1/biossíntese , Biomarcadores Tumorais/análise , Carcinoma de Células Renais/patologia , Neoplasias Renais/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígeno B7-H1/análise , Carcinoma de Células Renais/mortalidade , Feminino , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Neoplasias Renais/mortalidade , Masculino , Pessoa de Meia-Idade , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Análise Serial de Tecidos
7.
World J Urol ; 34(7): 909-15, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-26586475

RESUMO

PURPOSE: To evaluate the impact of bone metastasis (BM) onset toward prognosis in metastatic renal cell carcinoma (mRCC) patients treated with sunitinib. METHODS: mRCC patients with BM and sunitinib as first targeted therapy between May 2005 and December 2012 were retrospectively analyzed. Patients with synchronous (s) BM or metachronous (m) BM were compared with regard to treatment and outcome [time to clinical progression (TTcP), overall survival (OS), skeletal-related events (SRE)]. Descriptive statistics, Kaplan-Meier estimation of TTcP and OS, Cox regression analyses, and a landmark analysis were administered. RESULTS: BM was identified in 127 mRCC patients; thereof, 82 sunitinib-treated patients were analyzed [sBM n = 57 (69.5 %), mBM n = 25 (30.5 %)]. Higher tumor grading (p = 0.029), male predominance (p = 0.02), and less second-line therapy (p = 0.001) were detected in sBM compared to mBM. SRE remained similar between subgroups (p = 0.462). TTcP during sunitinib was similar [median sBM 8.1 (95 % CI 3.9-12.3) vs. mBM 8.7 (95 % CI 2.7-14.8) months, p = 0.903]. OS remained significantly inferior in sBM patients compared to mBM [median sBM 21.1 (95 % CI 16-26.2) months vs. mBM 38.5 (95 % CI 15-62) months, p = 0.001], which was confirmed by landmark analyses at 1.5, 3, 6, 9, and 12 months. However, OS after occurrence of BM was similar in both groups [median sBM 24.2 (95 % CI 17.3-31.1) months vs. mBM 17.2 (95 % CI 8.4-26) months, p = 0.519]. CONCLUSIONS: mBM is associated with an improved OS compared to sBM in mRCC with sunitinib treatment, despite similar efficacy of sunitinib treatment in both groups of patients.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias Ósseas/mortalidade , Neoplasias Ósseas/secundário , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/mortalidade , Indóis/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Pirróis/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Renais/secundário , Feminino , Humanos , Neoplasias Renais/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Sunitinibe , Taxa de Sobrevida
8.
Aktuelle Urol ; 46(6): 467-72, 2015 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-26556569

RESUMO

A variety of therapeutic agents are currently available for the systemic treatment of metastatic renal cell carcinoma (mRCC). It was only when targeted treatment was developed in the past decade that a significant improvement was achieved in tumour therapy. This also led to the development of sequential treatment for mRCC.7 molecular targeted agents are available today (axitinib, bevacizumab/ IFNα, everolimus, pazopanib, sorafenib, sunitinib, and temsirolimus). Due to the individualisation of treatment it remains a challenge to choose the most appropriate drug in a given setting, with the choice being based on the knowledge of the relevant clinical data as well as individual patient parameters.During the recent past, efforts have been made to test different inhibitors or combinations without a major breakthrough. Instead, the development of novel specific immunotherapeutic approaches now heralds the next level of treatment in mRCC. The first significant trial results will be expected this year, and further trials for optimisation of treatment are warranted.


Assuntos
Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/secundário , Imunoterapia/métodos , Neoplasias Renais/tratamento farmacológico , Terapia de Alvo Molecular/métodos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Axitinibe , Bevacizumab/uso terapêutico , Carcinoma de Células Renais/mortalidade , Carcinoma de Células Renais/patologia , Progressão da Doença , Everolimo/uso terapêutico , Humanos , Imidazóis/uso terapêutico , Indazóis/uso terapêutico , Indóis/uso terapêutico , Interferon-alfa/uso terapêutico , Neoplasias Renais/mortalidade , Neoplasias Renais/patologia , Niacinamida/análogos & derivados , Niacinamida/uso terapêutico , Compostos de Fenilureia/uso terapêutico , Prognóstico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Sirolimo/análogos & derivados , Sirolimo/uso terapêutico , Sorafenibe , Sulfonamidas/uso terapêutico , Sunitinibe , Análise de Sobrevida
9.
Ann Oncol ; 26(3): 561-7, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25527417

RESUMO

BACKGROUND: Squamous cell carcinoma of the head and neck (SCCHN) is a common disease, which has a poor prognosis after failure of therapy. Activation of the PI3K-AKT-mTOR axis is commonly detected in recurrent or metastatic SCCHN, and provided the rationale for the clinical phase II trial in pretreated SCCHN. PATIENTS AND METHODS: The primary end point was the progression-free survival rate (PFR) at 12 weeks. Forty eligible patients have been recruited after failure of platinum chemotherapy and cetuximab. A preplanned futility analysis was successfully passed after ≥1 success was detected in 20 patients. Secondary objectives consisted of progression-free survival (PFS), disease control rate (DCR), overall survival (OS), safety and tolerability, and predictive biomarkers for KRAS, BRAF, PIK3CA mutations, and HPV status. Archived tumor tissue was analyzed for DNA sequence. RESULTS: A total of 40 patients were eligible. The PFR at 12 weeks was 40% (95% CI 25.0-54.6). The median PFS and OS were 56 days (95% CI 36-113 days) and 152 days (76-256 days), respectively. In 33 assessable patients, disease stabilization occurred in 57.6%, with tumor shrinkage in 13 patients (39.4%). Overall, the treatment was well tolerated. Fatigue (47.5%), anemia (25.0%), nausea (20.0%), and pneumonia (20.0%) were the most common adverse events. Neither PIK3CA mutations, nor HPV status were predictive for success with temsirolimus treatment. No mutations were found for KRAS or BRAF. CONCLUSION: Tumor shrinkage and efficacy parameter indicate that inhibition of the PI3K-AKT-mTOR axis was a putative novel treatment paradigm for SCCHN. We could not identify parameters predictive for treatment success of temsirolimus, which underscores the need for refinement of the molecular analysis in future studies. CLINICAL TRIALS NUMBER: NCT01172769.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Cetuximab/administração & dosagem , Cisplatino/administração & dosagem , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Sirolimo/análogos & derivados , Adulto , Idoso , Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/epidemiologia , Intervalo Livre de Doença , Feminino , Alemanha/epidemiologia , Neoplasias de Cabeça e Pescoço/diagnóstico , Neoplasias de Cabeça e Pescoço/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/diagnóstico , Sirolimo/administração & dosagem , Carcinoma de Células Escamosas de Cabeça e Pescoço , Resultado do Tratamento
10.
Am J Transplant ; 13(4): 911-918, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23406373

RESUMO

Chronic lung allograft dysfunction (CLAD) remains the leading cause of mortality in lung transplant recipients after the first year. Treatment remains limited and unpredictable. Existing data suggests extracorporeal photopheresis (ECP) may be beneficial. This study aimed to identify factors predicting treatment response and the prognostic implications. A single center retrospective analysis of all patients commencing ECP for CLAD between November 1, 2007 and September 1, 2011 was performed. In total 65 patients were included, 64 of whom had deteriorated under azithromycin. Median follow-up after commencing ECP was 503 days. Upon commencing ECP, all patients were classified using proposed criteria for emerging clinical phenotypes, including "restrictive allograft syndrome (RAS)", "neutrophilic CLAD (nCLAD)" and "rapid decliners". At follow-up, 8 patients demonstrated ≥10% improvement in FEV1 , 27 patients had stabilized and 30 patients exhibited ≥10% decline in FEV1 . Patients fulfilling criteria for "rapid decliners" (n=21, p=0.005), RAS (n=22, p=0.002) and those not exhibiting neutrophilia in bronchoalveolar lavage (n=44, p=0.01) exhibited poorer outcomes. ECP appears an effective second line treatment in CLAD patients progressing under azithromycin. ECP responders demonstrated improved progression-free survival (median 401 vs. 133 days). Proposed CLAD phenotypes require refinement, but appear to predict the likelihood of ECP response.


Assuntos
Transplante de Pulmão/métodos , Fotoferese , Disfunção Primária do Enxerto/prevenção & controle , Adulto , Algoritmos , Antibacterianos/farmacologia , Azitromicina/farmacologia , Bronquiolite Obliterante/fisiopatologia , Bronquiolite Obliterante/terapia , Lavagem Broncoalveolar , Intervalo Livre de Doença , Feminino , Volume Expiratório Forçado , Humanos , Luz , Pulmão/fisiopatologia , Masculino , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Fenótipo , Disfunção Primária do Enxerto/fisiopatologia , Estudos Retrospectivos , Transplante Homólogo , Resultado do Tratamento
11.
World J Urol ; 29(3): 355-60, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21258806

RESUMO

PURPOSE: The tyrosine kinase inhibitor (TKI) sunitinib induces partial remissions (PR) in a substantial proportion of patients with metastatic renal cell carcinoma (mRCC). Only little is known about the activity of sunitinib in renal lesions in patients with metastatic disease, as most patients with synchronous metastases receive palliative nephrectomy. METHODS: Fourteen patients with clear cell mRCC with renal lesions and sunitinib therapy (50 mg OD, 4/2 scheme) were retrieved retrospectively from clinic records. Tumor assessment consisted of CT scans at least every two cycles, analyzed according to RECIST. In 5 of 14 patients, renal tumors were considered as the primary tumor, while the remaining patients had kidney metastases. In total, 65 target lesions were evaluated. RESULTS: The median progression-free survival (PFS) of sunitinib was 8.7 months (range: 2.7-40.2). Median overall survival (OS) from initiation of TKI therapy was 26 months (range: 3-55). Best response according to RECIST consisted of partial remission (PR) in 4 patients, stable disease (SD) in 7 patients, a complete remission (CR) in 1 patient, and 2 patients with progressive disease (PD). Analyzing the response of renal lesions only, 1 patient had PD, 8 patients had SD, 4 patients had PR, and 1 had a CR. Palliative nephrectomy was performed after two courses of sunitinib in 2 patients. CONCLUSIONS: In our cohort, similar responses of renal tumors and peripheral metastases were achieved with sunitinib treatment. Our results support the use of sunitinib to control renal tumor lesions in metastatic patients.


Assuntos
Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Carcinoma de Células Renais/secundário , Indóis/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Neoplasias Renais/secundário , Pirróis/uso terapêutico , Adulto , Idoso , Carcinoma de Células Renais/cirurgia , Progressão da Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Rim/patologia , Rim/cirurgia , Neoplasias Renais/cirurgia , Masculino , Pessoa de Meia-Idade , Nefrectomia , Cuidados Paliativos , Proteínas Tirosina Quinases/antagonistas & inibidores , Estudos Retrospectivos , Sunitinibe , Resultado do Tratamento
12.
Transplantation ; 65(9): 1275-8, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9603182

RESUMO

BACKGROUND: Cryopreserved cord blood may be stored for decades before being used for allogeneic stem cell transplantation. Little is known about the effect of long-term cryopreservation in liquid nitrogen on the viability and function of cord blood cells. We examined the recovery, viability, clonogenic capacity, and T-cell reactivity to HLA alloantigens of cord blood samples cryopreserved up to 15 years. METHODS: Progenitor cell recoveries were studied by (colony-forming unit-granulocyte-macrophage) clonogenic assays from 18 cord blood samples short-term frozen for 2-8 weeks and from 8 samples cryopreserved for 15 years. Proliferative and cytotoxic responses against HLA antigens of thawed cord blood mononuclear cells after short-term or long-term cryopreservation were tested in standard mixed lymphocyte cultures and cell-mediated lympholysis assays. RESULTS: After thawing, the mononuclear cell recovery from long-term frozen cord blood low-density fractions averaged 80% (range, 64% to 92%). The presented data show that long-term frozen cord blood cells keep their clonogenic potential. No damaging effect was seen on the proliferative and cytotoxic capacities of long-term frozen cord blood T cells. CONCLUSIONS: The results support the possibility of long-term storage of progenitor cells from umbilical cord blood for future bone marrow reconstitution.


Assuntos
Células Sanguíneas/imunologia , Criopreservação , Sangue Fetal/citologia , Sangue Fetal/fisiologia , Células-Tronco/fisiologia , Divisão Celular/fisiologia , Ensaio de Unidades Formadoras de Colônias , Sangue Fetal/imunologia , Granulócitos/fisiologia , Antígenos HLA/imunologia , Humanos , Teste de Cultura Mista de Linfócitos , Macrófagos/fisiologia , Monócitos/citologia , Monócitos/imunologia , Linfócitos T/citologia , Linfócitos T/fisiologia , Fatores de Tempo
13.
Hum Immunol ; 44(2): 97-102, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8847234

RESUMO

Functional studies of helper and cytotoxic T cells in families with recombinant HLA haplotypes have played a crucial role in the early studies of the HLA chromosomal region. It has been shown that for the generation of CTLs directed against HLA-A or -B antigen differences an additional difference in the HLA-D region between responder and stimulator cells was a prerequisite. We have re-examined in a sensitive limiting dilution assay the possibility of generating CTL against HLA class I antigens in responder-stimulator pairs with a negative MLC reaction of two recombinant families (differing in one or two HLA class I antigens but identical in class II antigens) and two pairs of unrelated individuals. In all cases we could detect low but definitely measurable CTL activity (8-15 CTL precursors in 10(6) PBMCs) directed against the mismatched class I HLA antigen(s). We conclude that mismatches in class I HLA antigens in MLC nonreactive responder-stimulator pairs can induce generation of allospecific CTLs. This has implications in allogeneic bone marrow transplantation with HLA-matched unrelated donors; i.e., in the case of an HLA-A,B,DR matched donor a low donor CTLpf against the recipient may be an indication of a serologically not-detected class I HLA "subtype" incompatibility which might cause graft-versus-host disease.


Assuntos
Antígenos de Histocompatibilidade Classe I/imunologia , Teste de Cultura Mista de Linfócitos , Células-Tronco/imunologia , Linfócitos T Citotóxicos/imunologia , Testes Imunológicos de Citotoxicidade , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-C/imunologia , Antígenos HLA-DR/imunologia , Humanos , Ativação Linfocitária/genética , Recombinação Genética
16.
Ann Rheum Dis ; 51(6): 783-9, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1616364

RESUMO

Some microorganisms which are pathogenic in humans share amino acid sequences with human proteins (molecular mimicry). It has been suggested that molecular mimicry might be a reason for autoimmunity as a result of immunological cross reactivity. A homologous sequence of six amino acids has been found in both Klebsiella pneumoniae nitrogenase and the HLA-B27.5 molecule. In addition, (auto)antibodies to a synthetic peptide that contained the HLA-B27.5/klebsiella mimicking epitope have been detected in serum samples from HLA-B27 positive patients with ankylosing spondylitis and Reiter's syndrome. Confirmation of these data is important, because ankylosing spondylitis and Reiter's syndrome have so far been assumed to be 'seronegative' rheumatic diseases. It was, however, not possible to confirm the presence of autoantibodies against the mimicking peptide in serum samples from patients with ankylosing spondylitis and Reiter's syndrome. Serum samples from 81 patients with ankylosing spondylitis, 38 patients with Reiter's syndrome, and 81 healthy blood donors were tested against the 'mimicking peptide' in an enzyme linked immunosorbent assay (ELISA). Some of the serum samples from patients showed high but non-specific binding to the mimicking peptide. A highly significant correlation between binding to plastic coated with the mimicking peptide, to plastic coated with an irrelevant peptide, and even to non-coated plastic was observed. The nature of the serum component(s) in these patient serum samples (and some control serum samples) responsible for the high non-specific binding to plastic remains unclear. It was also shown that antibodies to the HLA-B27 peptide (containing the mimicking epitope) induced in rabbits do not cross react with the klebsiella peptide and vice versa.


Assuntos
Artrite Reativa/imunologia , Autoanticorpos/análise , Antígeno HLA-B27/imunologia , Klebsiella pneumoniae/enzimologia , Nitrogenase/imunologia , Peptídeos/imunologia , Espondilite Anquilosante/imunologia , Adulto , Idoso , Animais , Reações Cruzadas , Feminino , Antígeno HLA-B27/química , Humanos , Masculino , Pessoa de Meia-Idade , Nitrogenase/química , Coelhos , Homologia de Sequência do Ácido Nucleico
17.
J Exp Med ; 174(1): 15-9, 1991 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-1905337

RESUMO

Recently, independent lines of evidence strongly suggested that peptides derived from one foreign major histocompatibility complex (MHC) molecule bound to another MHC molecule can give rise to multiple composite MHC complexes that are able to stimulate allo-(xeno)-reactive T cells. In this study, we describe that in vivo immunization of mice with cells mismatched with the recipient for a single class I antigen results in the induction of CD8+ cytotoxic T lymphocytes (CTL) specific for allogeneic class I locus products (Dd, Kd, Dq) in the context of other class I molecules (Ks, Kd, Kk) present on stimulator cells. Evidently, the target antigen for these class I-restricted alloreactive CTL is not the native class I molecule but peptides derived from endogenous processing of allogeneic class I products presented by class I molecules. Using a combination of limiting dilution and split-well analyses, we estimated for Kk-restricted Dq-specific alloreactive CTL a precursor frequency (CTLpf) that was approximately 10 times lower than the CTLpf for "classical" nonrestricted Dq-specific alloreactive CTL. These data suggest that H-2 class I peptides presented by intact H-2 class I molecules are allostimulatory, supporting the concept that the capacity for presentation of MHC peptides by MHC molecules constitutes a part of the allogeneic immune response.


Assuntos
Antígenos H-2/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Antígenos de Diferenciação de Linfócitos T/análise , Antígenos CD8 , Células Cultivadas , Citotoxicidade Imunológica , Antígenos de Histocompatibilidade Classe I/análise , Complexo Principal de Histocompatibilidade , Camundongos , Camundongos Endogâmicos , Especificidade da Espécie , Baço/imunologia
18.
Transplantation ; 51(5): 1096-103, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2031263

RESUMO

Frequencies of HLA class 1-specific cytotoxic T lymphocyte precursors (CTLp) from 33 responders were determined in 115 responder/stimulator combinations. In each combination there was a single HLA-A or HLA-B antigen mismatch. A wide range of CTLp frequency (CTLpf) values was found for most A and B locus antigens. Some A locus antigens appeared less immunogenic than other A locus antigens. The effect of additional C locus differences was negligible. The relationship between responder and stimulator HLA antigens is of minor importance because HLA-specific CTLpf against crossreactive (CREG) and subtype antigens were not significantly lower than CTLpf against non-CREG antigens. The CTLpf did not correlate with Bw4 or Bw6 mismatches. The existence of a broad range of values for HLA class I-specific CTLpf is of general interest. We have arbitrarily subdivided the CTLpf values into high, medium, low, and very low. In about 20% of the combinations the HLA-specific CTLpf were low or not even detectable in our assay. In contrast, HLA-specific CTLpf in combinations with multiple HLA antigen differences were regularly high. Our results confirm the high values of allospecific CTLpf in general but simultaneously point to unexpected variations. Frequency analysis of HLA-specific CTLp may be considered a new parameter in clinical transplantation for the selection of appropriate donor/recipient pairs.


Assuntos
Células-Tronco Hematopoéticas/imunologia , Antígenos de Histocompatibilidade Classe I/análise , Linfócitos T Citotóxicos/imunologia , Reações Cruzadas , Antígenos HLA-A/análise , Antígenos HLA-B/análise , Antígenos HLA-C/análise , Humanos
19.
J Immunol ; 144(12): 4513-9, 1990 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-2351823

RESUMO

Previous studies have shown that the lymphocytes of naive mice produce a strong primary CTL responses in vitro to human MHC class I Ag presented by HLA-transgenic mouse (TGM) cells. A limiting dilution (LD) assay was used to analyze this xenoreactive CTL repertoire in mice. Frequencies of HLA class I-specific CTL precursors (CTLp) were estimated in naive normal and HLA-B27.2-, -B27.5- and HLA-Cw3-double TGM (i.e., mice expressing HLA and human beta 2-microglobulin (hu beta 2m]. The xenoreactive CTLp frequencies were compared to frequencies of CTLp to H-2 alloantigens estimated in naive normal mice. The results showed that the frequencies of HLA class I-specific CTLp are comparable with those of alloreactive CTLp. This overlap in CTLp frequencies suggests that HLA class I xenoantigens are recognized by primary mouse CTL as allelic variants of H-2K and H-2D. This was confirmed in split well analysis by the observation that the xenoreactive response was not restricted by self-MHC of the responding mouse. Thus, primary HLA class I-specific mouse CTL clones recognized their target Ag regardless of whether they were expressed on H-2-mismatched mouse cells or on human cells. The frequencies of HLA class I-specific CTLp in HLA-TGM were comparable to those in normal mice. We propose that MHC allo- and xenoreactive CTL responses are not caused by the activation of CTLp specific for self-MHC plus peptide but to the activation of CTLp recognizing MHC allo- and xenoantigens directly or as peptides presented by their native MHC molecules.


Assuntos
Antígenos H-2/imunologia , Antígenos HLA/imunologia , Camundongos Transgênicos/imunologia , Linfócitos T Citotóxicos/imunologia , Animais , Citotoxicidade Imunológica , Antígeno HLA-B27/genética , Antígeno HLA-B27/imunologia , Antígenos HLA-C/genética , Antígenos HLA-C/imunologia , Imunidade Celular , Linfonodos/citologia , Complexo Principal de Histocompatibilidade , Camundongos
20.
Hum Immunol ; 27(1): 1-15, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1689283

RESUMO

Allospecific anti-HLA class I antigen cytotoxic T-lymphocyte precursor frequencies (CTLpf) have been estimated in peripheral blood of healthy blood donors with responder stimulator combinations mismatched for one HLA-A,B antigen. The CTLpf ranged from 1 in 400 to 1 in 10,000, with most frequent values of 1 in 600 to 4000. The following observations were made: (1) CTLpf against the same HLA antigen vary among different responders; (2) CTLpf of one responder against various HLA antigens may be different; (3) "narrow" responders produce cytotoxic T lymphocytes that recognize only the private (stimulator) alloantigen, while "broad" responders produce mainly broadly cross-reactive cytotoxic T lymphocytes with public specificity. Split-well analysis shows that very few cytotoxic T lymphocytes of "broad" responders recognize the private alloantigen only. These individual variations are not dependent on the HLA phenotype, because they also occurred in unrelated HLA-identical responders stimulated against the same mismatched stimulator cells.


Assuntos
Antígenos HLA , Linfócitos T Citotóxicos/imunologia , Testes Imunológicos de Citotoxicidade , Epitopos , Antígenos HLA-A , Antígenos HLA-B , Células-Tronco Hematopoéticas/imunologia , Humanos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA