RESUMO
PURPOSE: A clinical implementation of ion-beam radiography (iRad) is envisaged to provide a method for on-couch verification of ion-beam treatment plans. The aim of this work is to introduce and evaluate a method for quantitative water-equivalent thickness (WET) measurements for a specific helium-ion imaging system for WETs that are relevant for imaging thicker body parts in the future. METHODS: Helium-beam radiographs (αRads) are measured at the Heidelberg Ion-beam Therapy Center with an initial beam energy of 239.5 MeV/u. An imaging system based on three pairs of thin silicon pixel detectors is used for ion path reconstruction and measuring the energy deposition (dE) of each particle behind the object to be imaged. The dE behind homogeneous plastic blocks is related to their well-known WETs between 280.6 and 312.6 mm with a calibration curve that is created by a fit to measured data points. The quality of the quantitative WET measurements is determined by the uncertainty of the measured WET of a single ion (single-ion WET precision) and the deviation of a measured WET value to the well-known WET (WET accuracy). Subsequently, the fitted calibration curve is applied to an energy deposition radiograph of a phantom with a complex geometry. The spatial resolution (modulation transfer function at 10 % -MTF10% ) and WET accuracy (mean absolute percentage difference-MAPD) of the WET map are determined. RESULTS: In the optimal imaging WET-range from â¼280 to 300 mm, the fitted calibration curve reached a mean single-ion WET precision of 1.55 ± $\,{\pm}\,$ 0.00%. Applying the calibration to an ion radiograph (iRad) of a more complex WET distribution, the spatial resolution was determined to be MTF10% = 0.49 ± $\,{\pm}\,$ 0.03 lp/mm and the WET accuracy was assessed as MAPD to 0.21 %. CONCLUSIONS: Using a beam energy of 239.5 MeV/u and the proposed calibration procedure, quantitative αRads of WETs between â¼280 and 300 mm can be measured and show high potential for clinical use. The proposed approach with the resulting image qualities encourages further investigation toward the clinical application of helium-beam radiography.
Assuntos
Hélio , Água , Calibragem , Íons , Imagens de Fantasmas , RadiografiaRESUMO
Chronic knee dislocations are rare but represent a therapeutic challenge. A staged concept is necessary to correctly address the pathological components. This article uses a case study to provide an algorithm for the successful treatment of chronic knee dislocations.
Assuntos
Artroplastia do Joelho/instrumentação , Artroplastia do Joelho/métodos , Fixadores Externos , Luxação do Joelho/diagnóstico por imagem , Luxação do Joelho/cirurgia , Adulto , Doença Crônica , Feminino , Humanos , Guias de Prática Clínica como Assunto , Padrões de Prática Médica , Radiografia , Resultado do TratamentoRESUMO
Presented here is the case of a paraneoplastic cerebral degeneration (PCD) in a female patient with breast cancer and the indication of anti-Yo antibodies in the cerebrospinal fluid (CSF) and serum. The patient's primary indications were dizziness and a severe gait ataxia. The indication of anti-Yo antibodies led to the conclusion of the existence of a paraneoplastic cerebral degeneration. The antibodies in question are anti-Purkinje-cell autoantibodies acting against the antigens common to tumor and Purkinje cells which occur in association with a certain percentage of breast or ovarian cancers. The diagnosis of the primary tumor, that is clinically undetectable with conventional imaging processes, is performed with the aid of positron emission tomography (PET) to detect the presence of axillary lymph node metastases. The micro-invasive mammary carcinoma was able to be localized with the aid of MR mammography and, after MR mammography marking, was removed. The patient subsequently received adjuvant treatment with epirubicine and cyclophosphamide. This treatment failed to influence the paraneoplastic neurological symptoms.
Assuntos
Neoplasias da Mama/complicações , Degeneração Paraneoplásica Cerebelar/complicações , Antibióticos Antineoplásicos/uso terapêutico , Antineoplásicos Alquilantes/uso terapêutico , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/patologia , Ciclofosfamida/uso terapêutico , Epirubicina/uso terapêutico , Humanos , Linfonodos/patologia , Pessoa de Meia-Idade , Degeneração Paraneoplásica Cerebelar/tratamento farmacológico , Degeneração Paraneoplásica Cerebelar/patologia , Tomografia Computadorizada de EmissãoRESUMO
The study was designed to investigate the role of ovarian volume, as assessed by three-dimensional (3D) sonography, in predicting conception in an in-vitro fertilization-embryo transfer (IVF-ET) programme. Transvaginal 3D sonography was performed in 152 cycles before initiation of ovarian stimulation (day 1) and on the day of oocyte retrieval. Ovarian volume showed no significant correlation with IVF outcome. On the contrary, all ovarian measurements were lower, albeit nonsignificantly, in the conception group. Fifteen patients (15/152, 9.9%) had a minimum unilateral ovarian volume of < or =3 mL (1 SD below the mean) on day 1 of the stimulation cycle. In this subgroup, the likelihood of conception was 6.7% (1/15) versus 21.9% (30/137) in patients with an initial minimum ovarian volume of >3 mL. This difference did not reach statistical significance. In both groups, cancellation rates due to poor ovarian response or lack of fertilization were similar. In conclusion, ovarian volumetry as assessed by three-dimensional ultrasound failed to predict conception in women undergoing IVF treatment.
Assuntos
Fertilização in vitro , Ovário/diagnóstico por imagem , Adulto , Transferência Embrionária , Feminino , Humanos , Infertilidade/terapia , Ovário/anatomia & histologia , Resultado do Tratamento , UltrassonografiaRESUMO
OBJECTIVE: To investigate the role of sonographic parameters in assessing endometrial receptivity in an in vitro fertilization (IVF) program. DESIGN: Prospective clinical study. SETTING: University setting. PATIENT(S): One hundred thirty-five patients in our IVF program, selected prospectively on the day of oocyte retrieval. INTERVENTION(S): Transvaginal ultrasound examination was performed before oocyte collection. MAIN OUTCOME MEASURE(S): Association between implantation rate and spiral artery blood flow (primary outcome measure) and between implantation rate and endometrial measurements as well as uterine artery blood flow (secondary outcome measures). RESULT(S): Overall implantation rate was 23.7% per cycle. Subendometrial blood flow was detected in 113 (83.7%) cases, with pregnancy occurring in 21.2%. Mean spiral artery pulsatility index values were 1.12 +/- 0.28 and 1.21 +/- 0.27 for nonconception and conception cycles, respectively. Nondetectable spiral artery blood flow was not associated with a lower implantation rate. Neither endometrial thickness nor endometrial volume was correlated with the likelihood of successful implantation. Minimum endometrial thickness and volume associated with pregnancy were 6.9 mm and 1.59 mL, respectively. CONCLUSION(S): Neither Doppler sonography of the spiral or uterine arteries nor measurement of the endometrial thickness or volume allowed a reliable prediction of subsequent IVF outcome.
Assuntos
Endométrio/diagnóstico por imagem , Endométrio/fisiologia , Fertilização in vitro , Útero/irrigação sanguínea , Artérias/fisiologia , Velocidade do Fluxo Sanguíneo , Implantação do Embrião , Transferência Embrionária , Feminino , Humanos , Estudos Prospectivos , Fluxo Pulsátil , UltrassonografiaRESUMO
In 1986, a programme was initiated by the senior author to develop a reliable, mechanically activated, intramedullary lengthening device with a non-invasive means of measuring the progress of lengthening without X-ray. We report results of design, biomechanical testing, in vivo animal testing and clinical implantation of the first 20 intramedullary skeletal kinetic distractors (ISKDs) in adult patients with limb-length discrepancies. Twenty ISKD devices were implanted in 18 patients (14 males and four females). Lengthening was required due to infection (ten), trauma (six), polio (one) and burn (one). Six femurs and 14 tibias were lengthened. Mean patient age was 40 years (range, 18-65 years). No implant related infections, non-unions, malunions or joint contractures were observed. A design change was made following two initial hardware failures, after which there were no further breakages. Average lengthening was 49 mm (range, 29-110 mm). The average lengthening rate was 0.82 mm/day (range, 1.7-0.4 mm/day). Ability to work, walk and drive before, during and after treatment with the ISKD compared favourably with that of similar patients undergoing lengthening using the 'monorail' method in our practice. The ISKD appears to be a safe and cost-effective alternative to external fixators that reduces lifestyle disruption and complications during adult limb-lengthening procedures.
Assuntos
Fêmur/cirurgia , Desigualdade de Membros Inferiores/cirurgia , Osteogênese por Distração/instrumentação , Tíbia/cirurgia , Adolescente , Adulto , Idoso , Animais , Fenômenos Biomecânicos , Pinos Ortopédicos , Desenho de Equipamento , Falha de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteogênese por Distração/métodos , Osteogênese por Distração/reabilitação , Ovinos , Estresse MecânicoRESUMO
BACKGROUND: This study was designed to detect the expression of CD44v splicing variants in primary ovarian carcinomas and their lymph node metastases, in order to evaluate the possible role in intraperitoneal and lymphogenic metastasization. MATERIAL AND METHODS: Paraffin-embedded tissue of 50 patients with ovarian cancer was available from both the primary tumors and from the lymph node metastases. The expression of the CD44 standard from (CD44s) and of the variant isoforms CD44v5, CD44v6, CD44v7 and 8, and CD44v10 was investigated in the tumor cell regions by immunohistochemistry. RESULTS: 45/50 (90%) primary ovarian carcinomas were found to be immunohistochemically positive for the CD44v5 splicing variant; 10 (20%) tumors expressed both CD44v5 and CD44v6. Apart from an additional v7 stain, all of the ovarian carcinomas studied were negative for the splicing variants v7, v7-8 and v10. No differences were revealed in the pattern of CD44 variants expression investigated in primary tumors and in the lymph node metastases. CONCLUSIONS: In ovarian cancer the expression of CD44v5 as a possible first step, as well as CD44v6, probably plays an important role in intraperitoneal implantation. In view of the comparatively heterogeneous expression patterns of CD44v in individual organs, it may be assumed that there are organ-specific differences in this respect, and that the invasion potential is influenced by both the expression pattern and the extent of expression.
Assuntos
Processamento Alternativo , Carcinoma/genética , Receptores de Hialuronatos/biossíntese , Receptores de Hialuronatos/genética , Metástase Linfática/genética , Neoplasias Ovarianas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma/patologia , Feminino , Glicoproteínas/biossíntese , Glicoproteínas/genética , Humanos , Imuno-Histoquímica , Metástase Linfática/patologia , Pessoa de Meia-Idade , Neoplasias Ovarianas/mortalidade , Neoplasias Ovarianas/patologia , Membrana Serosa/patologia , Fatores de TempoAssuntos
Transplante de Medula Óssea , Imunodeficiência Combinada Severa/cirurgia , Linfócitos B/imunologia , Transplante de Medula Óssea/efeitos adversos , Transplante de Medula Óssea/imunologia , Transplante de Medula Óssea/patologia , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro/etiologia , Antígenos HLA , Humanos , Lactente , Depleção Linfocítica , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , Linfócitos T/imunologiaRESUMO
In order to elucidate the role of HLA class II molecules in generation of self-nonself discrimination of human T cells, we have analyzed T cell functions in an HLA class II-negative severe combined immunodeficiency patient. Patient PBL expressed no HLA-DR, -DQ, and -DP antigens as judged by immunofluorescence using mAb, and failed to elicit MLR responses from unrelated controls. Patient PBL contained mature T cells (CD3+ TCR alpha beta+) of the CD4 and CD8 subset, showing an apparently normal TCR diversity, as judged by use of anti-V beta 5, -V beta 6, -V beta 8, -V beta 12, and -V alpha 2 mAb. Patient PBL proliferated in response to anti-TCR/CD3 mAb and PHA, but not against recall Ag, despite immunization, and mounted proliferative, but not cytotoxic, responses against allogeneic cells. To find out whether the MLR responses were a consequence of self-nonself discrimination, the patient HLA-DR and -DQ genotype was determined using sequence specific oligonucleotide probes, revealing DRB1*0401 DQB1*0301 alleles, and MLR were set up against a panel of HLA-DR4 DQw3 stimulators matched or mismatched for DRB1*0401 DQB1*0301. Results showed no MLR against DRB1*0401 DQB1*0301 stimulators, but significant responses against stimulators expressing DRB1*0408 and/or DQB1*0302 alleles. Moreover, the DRB1*0401 DQB1*0301 APC reconstituted proliferation of patient PBL against PPD; this response was completely blocked by an anti-IL-2R (p55) mAb and partially also by anti-HLA-DR and -DQ mAb, indicating recognition of these molecules as restriction element presenting Ag--i.e., as self--by patient T cells. In conclusion, the novel demonstration of self-nonself discrimination by T cells from an HLA class II-negative SCID patient suggests that it may not be absolutely dependent on regular HLA class II expression within the differentiation environment in humans.
Assuntos
Antígenos de Histocompatibilidade Classe II/análise , Imunodeficiência Combinada Severa/imunologia , Linfócitos T/imunologia , Antígenos de Diferenciação de Linfócitos T/análise , Sequência de Bases , Complexo CD3 , Antígenos CD4/análise , Pré-Escolar , Feminino , Genótipo , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Humanos , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Fenótipo , Reação em Cadeia da Polimerase , Receptores de Antígenos de Linfócitos T/análise , Receptores de Antígenos de Linfócitos T alfa-beta/análise , Imunodeficiência Combinada Severa/genética , Linfócitos T/ultraestruturaRESUMO
Following magnetic transcranial stimulation (TCS) a post-excitatory pause can be observed in surface electromyographic (EMG) recordings from pre-innervated muscles. We studied the duration of this silent period (SP) in the abductor pollicis brevis muscle while varying the stimulus intensity (SI) and the amount of the voluntary tonic contraction in 23 normal adults aged 20-78 years. A multivariate linear regression analysis revealed a positive correlation of SP with SI and a slight negative correlation with age. In 11 hemiparetic patients a relative increase of the SP was found on the affected side despite normal central motor conduction time. A marked shortening of the SP in relation to controls was observed in 6 parkinsonian patients.
Assuntos
Eletromiografia , Estimulação Magnética Transcraniana , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Feminino , Hemiplegia/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Muscular/fisiologia , Doença de Parkinson/fisiopatologia , Valores de ReferênciaRESUMO
BACKGROUND: We report on 9 infants with severe combined immunodeficiency (SCID), who additionally showed signs of Omenn syndrome with an exfoliative dermatopathy, alopecia, enlarged lymph nodes, a hepatomegalia and a striking blood eosinophilia. The immunological evaluation revealed the characteristic abnormalities of SCID with cellular and humoral immunodeficiency. All patients however had the unusual finding of mature T cells in the peripheral blood. By HLA typing these cells were noted to be of maternal origin in 5 patients. In the other 4 patients the T cells were of host origin. We asked for additional differences between both patient groups. METHOD: Both patient groups were analyzed and compared with regard to case histories, clinical, laboratory and histopathological parameters. RESULTS: No clinical or laboratory differences could be detected. The histomorphologic analysis of patients with or without maternal T cells was identical. The skin biopsies showed dense cell infiltrations of lymphocytes, histiocytes and eosinophils, in the enlarged lymph nodes the latter two cell types predominated. Therefore the only difference between the 2 patient groups was the presence or absence of maternal T cells. CONCLUSION: Since the Omenn syndrome is found in association with maternal as well as patient derived T cells, we postulate that the peculiar symptoms of this syndrome are the result of a T cell induced inflammatory reaction, similar but not identical to a graft versus host reaction, occurring on the basis of an inborn SCID.
Assuntos
Dermatite Esfoliativa/genética , Eosinofilia/genética , Transfusão Feto-Materna/genética , Linfadenopatia Imunoblástica/genética , Imunodeficiência Combinada Severa/genética , Linfócitos T/imunologia , Medula Óssea/patologia , Transplante de Medula Óssea/patologia , Dermatite Esfoliativa/imunologia , Dermatite Esfoliativa/patologia , Eosinofilia/imunologia , Eosinofilia/patologia , Feminino , Transfusão Feto-Materna/imunologia , Transfusão Feto-Materna/patologia , Antígenos HLA/genética , Haplótipos , Humanos , Linfadenopatia Imunoblástica/imunologia , Linfadenopatia Imunoblástica/patologia , Imunoglobulinas/análise , Lactente , Recém-Nascido , Linfonodos/patologia , Masculino , Gravidez , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/patologia , SíndromeRESUMO
The diagnosis of severe combined immunodeficiency complicated by chronic graft-vs-host disease affecting liver and skin in association with engraftment of maternal T cells was established in a 5-mo-old boy. Detailed immunologic and molecular genetic studies were performed because a unique T cell phenotype was identified on initial evaluation. A major proportion of the patient's peripheral T cells expressed a CD8+ and TCR-gamma/delta+ phenotype while CD4+ T cells were virtually absent. Southern blot analysis of cell subpopulations isolated by fluorescence activated cell sorting indicated that approximately 50% of CD8+/TCR-gamma/delta+ cells were clonally related. Immunophenotyping and -genotyping also identified a clonal TCR-gamma/delta+ cell population in the child's mother. Clonal identity of these T cell populations in mother and child was demonstrated by studies using a clonspecific TCR-delta probe generated by polymerase chain reaction as well DNA sequence analysis. HLA typing and DNA fingerprinting confirmed that the child had acquired this clone diaplacentally from the mother. According to immunohistology and DNA analysis the clone was found to be virtually absent in the liver tissue suggesting that this clonal T cell population plays a minor role, if any, in the pathogenesis of the liver abnormalities in the patient. In the mother the CD8+/TCR-gamma/delta+ clone spontaneously declined to a level around 1% of PBMC several months later and has remained at this level since. We conclude that 1) a clonal expansion of TCR-gamma/delta T cells, triggered by yet unknown stimuli, may occur in otherwise healthy individuals, 2) respective T cells are able to cross the placental barrier, and 3) in an microenvironment precluding rejection, i.e., in severely immunocompromised patients, these cells may persist and even represent a significant proportion of circulating T cells.
Assuntos
Receptores de Antígenos de Linfócitos T gama-delta/genética , Imunodeficiência Combinada Severa/imunologia , Subpopulações de Linfócitos T/imunologia , Alelos , Antígenos de Diferenciação de Linfócitos T/análise , Sequência de Bases , Southern Blotting , Complexo CD3 , Antígenos CD8/análise , Células Clonais , Impressões Digitais de DNA , Citometria de Fluxo , Rearranjo Gênico da Cadeia delta dos Receptores de Antígenos dos Linfócitos T , Dados de Sequência Molecular , Oligonucleotídeos/química , Reação em Cadeia da Polimerase , Receptores de Antígenos de Linfócitos T/análise , Receptores de Antígenos de Linfócitos T gama-delta/análiseRESUMO
Human severe combined immunodeficiency (SCID) patients were analyzed by a polymerase chain reaction assay for their recombination capability at the DHQ52-JH region of the immunoglobulin heavy chain locus. Five patients with B cells (B+ SCID) exhibited a recombination pattern also observed in healthy persons. In contrast, six patients lacking B cells (B- SCID) showed a grossly altered rearrangement pattern characterized by the (partial) absence of regular DHQ52-JH recombinations and the presence of abnormal rearrangements. These events were caused by deletions surpassing the boundaries of immunoglobulin coding elements and thus resemble the pattern of deletional recombinations previously described in SCID mice.
Assuntos
Linfócitos B/fisiologia , Mapeamento Cromossômico , Genes de Imunoglobulinas , Cadeias Pesadas de Imunoglobulinas/genética , Região de Junção de Imunoglobulinas/genética , Recombinação Genética , Imunodeficiência Combinada Severa/genética , Sequência de Bases , Pré-Escolar , Feminino , Rearranjo Gênico , Humanos , Região Variável de Imunoglobulina/genética , Lactente , Masculino , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Imunodeficiência Combinada Severa/imunologiaRESUMO
We have analyzed activation of resting human T cells by anti-T cell receptor (TCR) monoclonal antibody (mAb) BMA031, a murine mAb of the G2b isotype. Human peripheral blood lymphocytes (PBL) respond to anti-TCR mAb by short-term proliferation in vitro and by acquisition of responsiveness to interleukin 2 (rIL-2) in the absence of detectable IL-2 production. Cell depletion and limiting dilution experiments indicate that anti-TCR mAb +/- rIL-2 stimulation covers a substantial portion of human T cells, including CD4+ and CD8+ cells. Enhancement by rIL-2 of anti-TCR mAb-induced proliferation is blocked by anti-IL-2 receptor (IL-2R, p55) mAb, while anti-TCR mAb-induced proliferation is not. In contrast, anti-TCR mAb-induced proliferation is blocked by anti-lymphocyte function antigen 1 (LFA-1, CD11a) mAb and is not demonstrable in PBL from two patients with severe congenital LFA-1 deficiency, not even in the presence of irradiated LFA-1+ PBL. We conclude that stimulation of resting human T cells by anti-TCR mAb BMA031 enables dissociation of distinct steps in T cell activation that specifically require participation of IL-2R (p55) and LFA-1 cell surface molecules in a mutually exclusive way.
Assuntos
Anticorpos Monoclonais/imunologia , Ativação Linfocitária , Antígeno-1 Associado à Função Linfocitária/fisiologia , Receptores de Antígenos de Linfócitos T/imunologia , Receptores de Interleucina-2/fisiologia , Linfócitos T/imunologia , Humanos , Interleucina-2/farmacologia , Proteínas Recombinantes/farmacologiaRESUMO
We have studied T cell receptor (TCR) diversity in a group of six patients with severe combined immunodeficiency (SCID) previously treated by HLA-haploidentical bone marrow transplantation (BMT). At the time of study, all patients had developed stable T cell chimerism and full reconstitution of T cell functions in the absence of acute or chronic graft-versus-host disease. Peripheral blood lymphocytes (PBL) were analysed by immunofluorescence using a panel of monoclonal antibodies (MoAb) against TCR variable (V) region epitopes including V beta 5, V beta 6, V beta 8, V beta 12, and V alpha 2. Our results showed that in each patient studied a low but significant portion of PBL reacted with each anti-TCR V region epitope MoAb used, in a manner that was, on statistical grounds, indistinguishable from results obtained with PBL from healthy controls. We conclude that within the experimental resolution of a limited number of anti-TCR V region epitope MoAb, T cell reconstitution following BMT for SCID, even when performed across a full HLA-haplotype barrier, leads to an apparently normal TCR diversity. These novel findings may be relevant in the evaluation of functional capacities of T cells that have differentiated from transplanted precursor cells in an HLA-haplodifferent environment.
Assuntos
Transplante de Medula Óssea/imunologia , Receptores de Antígenos de Linfócitos T/metabolismo , Imunodeficiência Combinada Severa/imunologia , Imunodeficiência Combinada Severa/cirurgia , Quimera , Feminino , Variação Genética , Antígenos HLA , Humanos , Lactente , Depleção Linfocítica , Masculino , Receptores de Antígenos de Linfócitos T/genética , Imunodeficiência Combinada Severa/genética , Linfócitos T/imunologiaRESUMO
We have analyzed allorecognition, HLA restriction and T cell receptor (TcR) diversity in an HLA-heterozygous (HLA-DRw6,7) severe combined immunodeficiency (SCID) patient whose T cell system had been repopulated by HLA-homozygous (HLA-DRw6) paternal T cells following T cell-depleted bone marrow transplantation (BMT). Donor origin of T cells and host origin of antigen-presenting cells (APC) in peripheral blood and BM is shown by HLA typing of separated cell populations and two-color immunofluorescence using an anti-HLA monoclonal antibody (mAb). Peripheral blood lymphocytes (PBL) from the chimeric patient proliferate normally against PHA, anti-TcR/CD3 mAb, pooled allogeneic PBL, and also against the recall antigen (Ag) tetanus toxoid and purified protein derivative of tuberculin (PPD) following immunization, suggesting recognition by donor (DRw6) T cells of Ag presented by host (DRw6,7) APC. PPD-specific cytotoxic T lymphocytes generated in vitro from patient PBL post-BMT display specific cytotoxicity against targets expressing DRw6 and DR7, but not against DR-mismatched targets, suggesting that HLA restriction of Ag recognition may occur through determinants expressed by the host and not by the donor. Donor T cells differentiated in the HLA-semiallogeneic host show specific proliferative and cytotoxic responses against HLA-mismatched stimulators, but not against stimulators taken from the host, expressing the host-specific HLA-haplotype, or expressing the host-specific HLA-DR7 antigens. Compared to T cells directly taken from the donor, differentiation of donor T cells in the host is associated with a significant decrease of T cells expressing TcR V beta 5 and V alpha 2 determinants, while no differences in the abundance of of TcR V beta 6, V beta 8 and V beta 12 subsets were noticed. We conclude that allorecognition, major histocompatibility complex (MHC) restriction and TcR diversity generation of human T cells can be modulated through differentiation in an MHC-different environment, as had been previously shown to be the case in murine model systems.
Assuntos
Transplante de Medula Óssea/imunologia , Antígenos HLA/imunologia , Imunodeficiência Combinada Severa/imunologia , Linfócitos T/imunologia , Células Apresentadoras de Antígenos/imunologia , Autoantígenos/imunologia , Diferenciação Celular , Citotoxicidade Imunológica , Haplótipos , Humanos , Imunidade Celular , Depleção Linfocítica , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Imunodeficiência Combinada Severa/cirurgia , Linfócitos T/citologia , Linfócitos T Citotóxicos/imunologiaRESUMO
We report the outcome of a non-T-cell-depleted bone marrow transplant from an HLA partially incompatible, MLR-positive, parental donor in a patient with an unusual form of immunodeficiency characterized by a lack of CD8 T cells and a failure of the CD4 cells to display functional activity in vitro. Without conditioning, and following a mild and transient GVHD, donor T cells persist in trace amounts in the host, where they coexist with the nonfunctional host T cells and cooperate with host APC in antigen recognition, thereby leading to a reconstitution of T cell functions in vitro and in vivo and development of a stable, so far unprecedented, human T-T split chimera across MHC barriers.
Assuntos
Transplante de Medula Óssea , Antígenos CD4/análise , Antígenos HLA-A/imunologia , Síndromes de Imunodeficiência/imunologia , Linfócitos T/fisiologia , Antígenos de Diferenciação de Linfócitos T/análise , Linfócitos B/fisiologia , Antígenos CD8 , Feminino , Humanos , Lactente , Interleucina-2/farmacologia , Teste de Cultura Mista de LinfócitosRESUMO
Circulating maternal T lymphocytes were noted in the peripheral blood of six patients with severe combined immunodeficiency. Phenotypical analyses revealed the presence of both CD4 and CD8 subsets in some but not all cases. The maternal T cells could be stimulated by anti-TCR/CD3 mAb +/- rIL-2, but were virtually silent in the MLR and against the recall Ag purified protein derivative of tuberculin and tetanus toxoid, even in immunized patients engrafted with T cells from a responding mother. Using a panel of mAb against TCR V region gene encoded epitopes including V beta 5, V beta 6, V beta 8, V beta 12, and V alpha 2, we show that maternal T cells displayed a profoundly reduced TCR diversity, characterized by a lack of one or even several TCR V subsets in all six cases and a dramatic (5- to 25-fold) expansion of other TCR V subsets in three cases. In one patient analyzed, limited TCR diversity was also seen in T cells cultured from bone marrow and skin; restimulation experiments of these cells against cells expressing host MHC Ag were unsuccessful, as were attempts to exclusively allocate anti-host proliferative responses of maternal control T cells to the TCR V subsets that had undergone expansion in vivo. We conclude that a severely reduced TCR diversity is a common feature of maternal T cells engrafted in severe combined immunodeficiency patients. These novel findings provide a structural basis to understand the failure of these cells to protect the host from infections and may also help to understand their relative inefficiency to induce lethal, multi-organ, graft vs host disease. Moreover, as an experiment of nature, the reported phenomenon clearly illustrates the functional consequences in vivo of an insufficient TCR diversity.
Assuntos
Imunidade Materno-Adquirida , Síndromes de Imunodeficiência/imunologia , Receptores de Antígenos de Linfócitos T/análise , Linfócitos T/imunologia , Anticorpos Monoclonais/imunologia , Antígenos CD/fisiologia , Medula Óssea/imunologia , Epitopos/análise , Feminino , Doença Enxerto-Hospedeiro/imunologia , Humanos , Lactente , Ativação Linfocitária , Gravidez , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/fisiologia , Pele/imunologiaRESUMO
We have analyzed the immunocompetence of blood donor-derived, allogeneic T cells that had engrafted in a patient with severe combined immunodeficiency following transfusion with unirradiated blood. The blood donor T cells multiply and persist in the patients' bone marrow and peripheral blood over several months without leading to a graft-versus-host disease. The allogeneic T cells can be expanded in vitro and restimulated by cells expressing host HLA-DR antigens. The presence of blood donor-derived T cells prevented engraftment of a bone marrow graft from an HLA-identical sibling; in contrast, engraftment and immunological reconstitution by bone marrow donor-derived cells was seen following elimination of the allogeneic T cells in vivo. We conclude that the allogeneic T cells sensitized against host histocompatibility antigens were responsible for bone marrow graft failure, even though this sensitization did not lead to a graft-versus-host disease.