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1.
Am J Transplant ; 15(12): 3134-42, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26372745

RESUMO

In 2002, the Organ Procurement and Transplantation Network (OPTN) Minority Affairs Committee (MAC) implemented a national, prospective, "variance of practice" to allow deceased donor, ABO blood group incompatible, A2 antigen, kidney transplantation into blood group B recipients; outcomes of this cohort were compared to ABO compatible recipients. The goal of the variance was to increase the number of transplants to B candidates without negatively impacting survival or compromising system equity. Only B recipients with low anti-A IgG titers (<1:8) were eligible to receive these kidneys. Across eight participating Donation Service Areas (DSA), there were 101 A2 /A2 B to B transplants through 12/31/11, of which the majority of the recipients (61%) were ethnic minorities. At 12, 24, and 36 months, Kaplan-Meier graft survival rates for the B recipients of A2 /A2 B kidneys were 95.0%, 90.6%, and 85.4%, respectively, comparable to outcomes for B recipients of B kidneys, 92.6%, 87.9%, and 82.5%, respectively (p-value = 0.48). Five DSAs increased the proportion of B transplants during 41 months postvariance, with a lesser proportional decrease in blood group A transplants. The data support the proposition that this allocation algorithm may provide a robust mechanism to increase access of blood group B minority candidates to kidney transplantation.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Incompatibilidade de Grupos Sanguíneos/imunologia , Isoanticorpos/imunologia , Transplante de Rim , Alocação de Recursos , Obtenção de Tecidos e Órgãos/organização & administração , Adolescente , Adulto , Idoso , Cadáver , Criança , Pré-Escolar , Etnicidade , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Grupos Minoritários , Prognóstico , Taxa de Sobrevida , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Adulto Jovem
2.
Am J Transplant ; 14(7): 1599-611, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24903438

RESUMO

We report here the long-term results of HLA-mismatched kidney transplantation without maintenance immunosuppression (IS) in 10 subjects following combined kidney and bone marrow transplantation. All subjects were treated with nonmyeloablative conditioning and an 8- to 14-month course of calcineurin inhibitor with or without rituximab. All 10 subjects developed transient chimerism, and in seven of these, IS was successfully discontinued for 4 or more years. Currently, four subjects remain IS free for periods of 4.5-11.4 years, while three required reinstitution of IS after 5-8 years due to recurrence of original disease or chronic antibody-mediated rejection. Of the 10 renal allografts, three failed due to thrombotic microangiopathy or rejection. When compared with 21 immunologically similar living donor kidney recipients treated with conventional IS, the long-term IS-free survivors developed significantly fewer posttransplant complications. Although most recipients treated with none or two doses of rituximab developed donor-specific antibody (DSA), no DSA was detected in recipients treated with four doses of rituximab. Although further revisions of the current conditioning regimen are planned in order to improve consistency of the results, this study shows that long-term stable kidney allograft survival without maintenance IS can be achieved following transient mixed chimerism induction.


Assuntos
Transplante de Medula Óssea , Sobrevivência de Enxerto/imunologia , Terapia de Imunossupressão , Nefropatias/cirurgia , Transplante de Rim , Complicações Pós-Operatórias , Tolerância ao Transplante/imunologia , Adulto , Feminino , Seguimentos , Humanos , Imunossupressores/uso terapêutico , Isoanticorpos/sangue , Nefropatias/imunologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Quimeras de Transplante , Condicionamento Pré-Transplante , Transplante Homólogo , Adulto Jovem
3.
World J Transplant ; 13(2): 44-57, 2023 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-36908306

RESUMO

BACKGROUND: As Hepatitis C virus infection (HCV+) rates in kidney donors and transplant recipients rise, direct-acting antivirals (DAA) may affect outcomes. AIM: To analyze the effects of HCV+ in donors, recipients, or both, on deceased-donor (DD) kidney transplantation (KT) outcomes, and the impact of DAAs on those effects. METHODS: The Organ Procurement and Transplantation Network data of adult first solitary DD-KT recipients 1994-2019 were allocated into four groups by donor and recipient HCV+ status. We performed patient survival (PS) and death-censored graft survival (DCGS) pairwise comparisons after propensity score matching to assess the effects of HCV+ in donors and/or recipients, stratifying our study by DAA era to evaluate potential effect modification. RESULTS: Pre-DAA, for HCV+ recipients, receiving an HCV+ kidney was associated with 1.28-fold higher mortality (HR 1.151.281.42) and 1.22-fold higher death-censored graft failure (HR 1.081.221.39) compared to receiving an HCV- kidney and the absolute risk difference was 3.3% (95%CI: 1.8%-4.7%) for PS and 3.1% (95%CI: 1.2%-5%) for DCGS at 3 years. The HCV dual-infection (donor plus recipient) group had worse PS (0.56-fold) and DCGS (0.71-fold) than the dual-uninfected. Donor HCV+ derived worse post-transplant outcomes than recipient HCV+ (PS 0.36-fold, DCGS 0.34-fold). In the DAA era, the risk associated with HCV+ in donors and/or recipients was no longer statistically significant, except for impaired PS in the dual-infected vs dual-uninfected (0.43-fold). CONCLUSION: Prior to DAA introduction, donor HCV+ negatively influenced kidney transplant outcomes in all recipients, while recipient infection only relatively impaired outcomes for uninfected donors. These adverse effects disappeared with the introduction of DAA.

4.
Am J Transplant ; 12(10): 2608-22, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22958872

RESUMO

An increasing number of patients older than 65 years are referred for and have access to organ transplantation, and an increasing number of older adults are donating organs. Although short-term outcomes are similar in older versus younger transplant recipients, older donor or recipient age is associated with inferior long-term outcomes. However, age is often a proxy for other factors that might predict poor outcomes more strongly and better identify patients at risk for adverse events. Approaches to transplantation in older adults vary across programs, but despite recent gains in access and the increased use of marginal organs, older patients remain less likely than other groups to receive a transplant, and those who do are highly selected. Moreover, few studies have addressed geriatric issues in transplant patient selection or management, or the implications on health span and disability when patients age to late life with a transplanted organ. This paper summarizes a recent trans-disciplinary workshop held by ASP, in collaboration with NHLBI, NIA, NIAID, NIDDK and AGS, to address issues related to kidney, liver, lung, or heart transplantation in older adults and to propose a research agenda in these areas.


Assuntos
Transplante de Órgãos , Idoso , Alocação de Recursos para a Atenção à Saúde , Humanos , Imunossupressores/uso terapêutico , Seleção de Pacientes , Justiça Social , Doadores de Tecidos , Resultado do Tratamento
5.
Am J Transplant ; 11(8): 1712-8, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21672159

RESUMO

In 2003, the US kidney allocation system was changed to eliminate priority for HLA-B similarity. We report outcomes from before and after this change using data from the Scientific Registry of Transplant Recipients (SRTR). Analyses were based on 108 701 solitary deceased donor kidney recipients during the 6 years before and after the policy change. Racial/ethnic distributions of recipients in the two periods were compared (chi-square); graft failures were analyzed using Cox models. In the 6 years before and after the policy change, the overall number of deceased donor transplants rose 23%, with a larger increase for minorities (40%) and a smaller increase for non-Hispanic whites (whites) (8%). The increase in the proportion of transplants for non-whites versus whites was highly significant (p < 0.0001). Two-year graft survival improved for all racial/ethnic groups after implementation of this new policy. Findings confirmed prior SRTR predictions. Following elimination of allocation priority for HLA-B similarity, the deficit in transplantation rates among minorities compared with that for whites was reduced but not eliminated; furthermore, there was no adverse effect on graft survival.


Assuntos
Antígenos HLA-B/imunologia , Política de Saúde , Teste de Histocompatibilidade , Transplante de Rim , Sobrevivência de Enxerto , Humanos , Grupos Populacionais , Doadores de Tecidos , Estados Unidos
6.
J Clin Invest ; 97(4): 1056-63, 1996 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-8613529

RESUMO

Studies in the rat have pointed to a role for intercellular adhesion molecule-1 (ICAM-1) in the pathogenesis of acute tubular necrosis. These studies used antibodies, which may have nonspecific effects. We report that renal ICAM-1 mRNA levels and systemic levels of the cytokines IL-1 and TNF-alpha increase 1 h after ischemia/ reperfusion in the mouse. We sought direct proof for a critical role for ICAM-1 in the pathophysiology of ischemic renal failure using mutant mice genetically deficient in ICAM-1. ICAM-1 is undetectable in mutant mice in contrast with normal mice, in which ICAM-1 is prominent in the endothelium of the vasa recta. Mutant mice are protected from acute renal ischemic injury as judged by serum creatinine, renal histology, and animal survival . Renal leukocyte infiltration, quantitated morphologically and by measuring tissue myeloperoxidase, was markedly less in ICAM-1-deficient than control mice. To evaluate whether prevention of neutrophil infiltration could be responsible for the protection observed in the mutant mice, we treated normal mice with antineutrophil serum to reduce absolute neutrophil counts to < 100 cells/mm3. These neutrophil-depleted animals were protected against ischemic renal failure. Anti-1CAm-1 antibody protected normal mice against renal ischemic injury but did not provide additional protection to neutrophil-depleted animals. Thus, ICAM-1 is a key mediator of ischemic acute renal failure likely acting via potentiation of neutrophilendothelial interactions.


Assuntos
Molécula 1 de Adesão Intercelular/fisiologia , Isquemia/complicações , Nefropatias/fisiopatologia , Rim/irrigação sanguínea , Animais , Nefropatias/patologia , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Neutrófilos/fisiologia , Peroxidase/metabolismo
7.
Curr Opin Immunol ; 13(5): 577-81, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11544007

RESUMO

The detection of anti-donor-HLA antibodies in a renal allograft recipient's serum, either at the time of or after transplantation, is usually associated with specific antibody-mediated clinical syndromes. These can be divided temporally into three categories: hyperacute rejection, acute humoral rejection and chronic humoral rejection. With the identification of new immunosuppressive drug combinations, more-effective control of alloantibody production has been recently achieved in humans. Thus, prevention and/or treatment of antibody-mediated allograft injury are now possible. Ultimately, the induction of mixed hematopoietic chimerism may allow us to overcome the problem of allosensitization and accept an allograft without chronic immunosuppression.


Assuntos
Linfócitos B/imunologia , Antígenos HLA/imunologia , Imunossupressores/uso terapêutico , Tolerância ao Transplante/imunologia , Animais , Humanos , Imunização/efeitos adversos , Isoanticorpos/biossíntese
8.
J Bone Joint Surg Br ; 88(11): 1524-6, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17075103

RESUMO

We describe a case of lumbosacral plexopathy caused by an isolated aneurysm of the common iliac artery. The patient presented with worsening low back pain, progressive numbness and weakness of the right leg in the L2-L4 distribution. This had previously been diagnosed as sciatica. A CT scan showed an aneurysm of the right common iliac artery which measured 8 cm in diameter. Despite being listed for emergency endovascular stenting, the aneurysm ruptured and the patient died. It is important to distinguish a lumbosacral plexopathy from sciatica and to bear in mind its treatable causes which include aneurysms of the common and internal iliac arteries.


Assuntos
Aneurisma Roto/complicações , Aneurisma Ilíaco/complicações , Plexo Lombossacral , Doenças do Sistema Nervoso Periférico/etiologia , Idoso , Aneurisma Roto/diagnóstico por imagem , Evolução Fatal , Humanos , Aneurisma Ilíaco/diagnóstico por imagem , Plexo Lombossacral/diagnóstico por imagem , Masculino , Doenças do Sistema Nervoso Periférico/diagnóstico por imagem , Radiografia
9.
Arch Intern Med ; 154(19): 2209-14, 1994 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-7944842

RESUMO

BACKGROUND: To prevent serious pneumococcal infections, 23-valent pneumococcal polysaccharide vaccine is recommended for individuals over 24 months of age with chronic predisposing diseases and for healthy older adults. This nonrandomized controlled study in rural Alaska assessed the immunogenicity of revaccination in adults. METHODS: Twenty-six adults, 33 to 88 years of age, vaccinated a mean of 7.4 years before this study, were matched to 26 previously unvaccinated subjects by age, number of chronic diseases, sex, and ethnicity. One or more chronic diseases were validated in 62% of subjects (32 of 52). All received a first or second intramuscular dose of pneumococcal vaccine. Antibody levels were determined by radioimmunoassay for 12 pneumococcal capsular serotypes immediately before and 20 to 84 days after vaccination. RESULTS: Six to 9 years after primary vaccination, over one third of serotype-specific antibody levels were below 500 ng of antibody nitrogen per milliliter, equal to the percentage in unvaccinated subjects of similar age. Antibody levels against all pneumococcal serotypes rose to similar levels after primary vaccination and revaccination, and 54% and 55%, respectively, of subjects who received primary vaccination and revaccination had at least a 1.4-fold increase in antibody levels. Only the antibody level for serotype 4 remained low. Neither gender nor age affected peak response. For those with chronic diseases, there was a trend toward fewer low antibody levels against three or more serotypes after revaccination (two subjects [13%]) than after primary vaccination (five subjects [31%]). CONCLUSIONS: Following the initial immunization of high-risk and elderly patients with pneumococcal polysaccharide, pneumococcal antibody levels appear to wane with time. Primary vaccination and revaccination 6 or more years after a first dose of pneumococcal vaccine stimulate comparable mean antibody levels.


Assuntos
Anticorpos Antibacterianos/sangue , Doença Crônica , Imunização Secundária , Inuíte , Infecções Pneumocócicas/prevenção & controle , Streptococcus pneumoniae/imunologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Alaska/epidemiologia , Causalidade , Seguimentos , Humanos , Análise por Pareamento , Pessoa de Meia-Idade , Infecções Pneumocócicas/epidemiologia , Infecções Pneumocócicas/microbiologia , População Rural , Sorotipagem , Streptococcus pneumoniae/classificação
10.
Arch Intern Med ; 142(11): 2000-5, 1982 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-6215008

RESUMO

One hundred seven patients were treated with either piperacillin (56) or carbenicillin (51) in an open randomized trial of hospitalized patients with pleuropulmonary (40), urinary tract (26), gynecologic (21), skin and soft-tissue (eight), joint (five), bone (three), and miscellaneous other infections (four). Patients with urinary tract infections were given 150 mg/kg/day of piperacillin sodium or 200 mg/kg/day or carbenicillin sodium in divided doses every six hours intravenously. Patients with other infections were given 250 mg/kg/day of piperacillin sodium and 450 mg/kg/day of carbenicillin sodium; 53/56 (95%) patients treated with piperacillin and 45/51 (88%) patients treated with carbenicillin were cured clinically. In general, the drugs were well tolerated. There were, however, more adverse experiences in the groups taking carbenicillin. Of special interest was the finding of liver function test abnormalities in 17/78 (21%) carbenicillin recipients (evaluative and nonevaluative cases). We concluded that piperacillin was effective and safe. It has potential for use in a great variety of infections.


Assuntos
Infecções Bacterianas/tratamento farmacológico , Carbenicilina/uso terapêutico , Penicilinas/uso terapêutico , Adulto , Carbenicilina/efeitos adversos , Avaliação de Medicamentos , Feminino , Humanos , Testes de Função Hepática , Masculino , Testes de Sensibilidade Microbiana , Penicilinas/efeitos adversos , Piperacilina , Distribuição Aleatória
11.
Transplantation ; 64(9): 1361-4, 1997 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-9371681

RESUMO

BACKGROUND: Hepatic artery thrombosis (HAT) remains a devastating complication after liver transplantation. Various factors have been implicated in the pathogenesis of HAT, such as clotting abnormalities, increased hematocrit, and technical complications, but the role of anticardiolipin antibodies has not been evaluated. We investigated the possible association between HAT and anticardiolipin antibodies in adult patients who underwent liver transplantation. METHODS: Seven patients with HAT after orthotopic liver transplantation, 28 liver recipients without HAT, and 35 normal blood donors were evaluated. Determination of IgM and IgG anticardiolipin antibodies was performed by enzyme-linked immunosorbent assay using pretransplant serum from all allograft recipients. Clinical information was obtained from chart review. Fisher's exact test and Wilcoxon rank sum test were used for statistical analysis, and all P-values were two-tailed. RESULTS: Overall, 22 of 35 (63%) liver recipients had a positive anticardiolipin antibody test (either IgG or IgM titer >4 SD from the normal controls). The test was positive in 7 liver recipients (100%) with HAT compared with 15 out of 28 patients (54%) without HAT (P=0.031). As compared with liver recipients without HAT, patients with HAT also tended to have a higher mean anticardiolipin titer of IgG and IgM and a lower pretransplant platelet count; however, these differences were not significant. CONCLUSIONS: Our findings indicate that anticardiolipin antibodies are frequently elevated in patients with liver failure and may contribute to the pathogenesis of HAT after liver transplantation. Other potential consequences of anticardiolipin antibodies in end-stage liver disease remain to be determined.


Assuntos
Cardiolipinas/imunologia , Artéria Hepática , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Transplante de Fígado/efeitos adversos , Trombose/sangue , Trombose/etiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
12.
Transplantation ; 64(7): 1073-6, 1997 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9381532

RESUMO

In recent years, hepatitis C virus infection has been reported to be typically associated with membranoproliferative glomerulonephritis and less frequently with membranous nephropathy. Treatment of hepatitis C with interferon-alpha can reduce viremia and improve renal disease. After liver transplantation for hepatitis C virus-associated liver failure, standard immunosuppressive protocols result in a significant increase in hepatitis C viremia. In this report we describe a patient with end-stage liver disease and biopsy-proven hepatitis C-associated glomerulonephritis who underwent liver transplantation. Within 1 month after transplantation, he developed a severe nephrotic syndrome that paralleled a marked increase in viremia. We discuss the possible pathogenic relationship between hepatitis C virus infection and the nephrotic syndrome that followed liver transplantation.


Assuntos
Glomerulonefrite/complicações , Hepatite C/complicações , Transplante de Fígado , Síndrome Nefrótica/etiologia , Complicações Pós-Operatórias , Viremia/complicações , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Creatinina/sangue , Enalapril/uso terapêutico , Feminino , Glomerulonefrite/virologia , Hepacivirus/isolamento & purificação , Hepatite C/cirurgia , Hepatite C/terapia , Humanos , Transplante de Rim , Transplante de Fígado/fisiologia , Pessoa de Meia-Idade , Proteinúria , RNA Viral/sangue , Reoperação , Fatores de Tempo
13.
Transplantation ; 67(5): 737-41, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10096531

RESUMO

BACKGROUND: The renal allograft biopsy is generally accepted as the gold standard for clarifying the cause of renal dysfunction. However, the clinical usefulness of this procedure has rarely been studied prospectively, nor have most studies included follow-up of patients to delineate the influence of the biopsy on clinical outcome. In this study, we evaluated prospectively the clinical usefulness of the allograft biopsy in renal transplant recipients receiving cyclosporine (CyA). METHODS: During a 21-month period, 82 biopsies were performed. In 54 instances (47 patients), we outlined a presumed diagnosis and tentative treatment plan before the procedure. After the biopsy, a definitive diagnosis was made and an appropriate patient management approach was instituted. We analyzed the incidence of change in patient management that resulted from histological findings. All patients were followed to monitor their response to treatment and allograft survival. In cases of biopsy-proven acute cellular rejection (ACR) or cyclosporine (CyA) toxicity, clinical and laboratory data from the day of the biopsy were reviewed to determine their diagnostic value. RESULTS: One biopsy specimen was inadequate for definitive interpretation. The biopsy findings resulted in a change in patient management in 22 (41.5%) of the remaining 53 cases (change group). The incidence of altered patient management was 38.7% in biopsy specimens taken in the first month, 55.6% between 1 and 12 months, and 38.5% after 1 year posttransplantation. A change in management was required in 2 of 2 patients with chronic allograft dysfunction, in 44.4% of the 45 patients with acute allograft dysfunction, and in none of the patients with delayed graft function (n=6). Within the first week of treatment 19 of 22 (86.4%) in the change group and 25 of 31 (80.6%) in the no change group had a positive response to therapy. The 1-year allograft survival rate was also similar between the two groups. None of the clinical and laboratory data was useful in distinguishing ACR from CyA toxicity. CONCLUSIONS: Renal allograft biopsy findings alter patient management recommendations in approximately 40% of patients in whom a presumptive diagnosis had been made on the basis of clinical and laboratory findings. Patients who had a change in patient management because of biopsy findings demonstrated a response to therapy and allograft survival similar to those of patients who had no alteration in management plan after the biopsy.


Assuntos
Ciclosporina/uso terapêutico , Imunossupressores/uso terapêutico , Transplante de Rim/patologia , Rim/patologia , Adulto , Biópsia , Ciclosporina/efeitos adversos , Feminino , Sobrevivência de Enxerto , Humanos , Imunossupressores/efeitos adversos , Rim/efeitos dos fármacos , Masculino , Estudos Retrospectivos , Transplante Homólogo
14.
Transplantation ; 65(9): 1192-7, 1998 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-9603167

RESUMO

BACKGROUND: Collapsing glomerulopathy is a recently described form of glomerular injury characterized by capillary collapse and visceral epithelial hypercellularity associated with nephrotic range proteinuria and a rapid, progressive decline in renal function. The lesion has rarely been described in allografts. METHODS: We reviewed 892 allograft biopsies from a population of 1079 recipients who received renal transplants between 1978 and 1996. RESULTS: Five cases of de novo collapsing glomerulopathy were identified (0.6% of biopsies; 3.2% since 1993). None occurred before 1993. The patients were 31 to 66 years of age and they presented 6 to 25 months after transplantation. The 24-hr urinary protein ranged from 1.8 to 11.8 g. All patients and donors were negative for the human immunodeficiency virus and had no risk factors for human immunodeficiency virus infection. Diffuse or focal, global or segmental collapse of glomerular capillaries, swelling and hypercellularity of the visceral epithelium, hyaline arteriolosclerosis, and interstitial fibrosis were characteristic histologic features. Two cases had concomitant glomerular immune complex deposits. Progressive decline in allograft function occurred within 2-24 months after diagnosis, culminating in return to dialysis in all patients. CONCLUSION: Collapsing glomerulopathy can arise in renal allografts as a de novo disease. Although its pathogenesis remains to be clarified, it is important to distinguish this lesion in allografts as it can be associated with rapidly progressive graft failure.


Assuntos
Glomerulosclerose Segmentar e Focal/etiologia , Transplante de Rim , Complicações Pós-Operatórias , Adulto , Idoso , Biópsia , Feminino , Imunofluorescência , Glomerulosclerose Segmentar e Focal/metabolismo , Glomerulosclerose Segmentar e Focal/patologia , Humanos , Incidência , Rim/metabolismo , Rim/patologia , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Transplante Homólogo
15.
Transplantation ; 71(9): 1308-11, 2001 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-11397968

RESUMO

BACKGROUND: Complement activation has recently been implicated as a contributing factor to early and late allograft dysfunction in cardiac transplantation. The current study was designed to determine whether measurement of plasma complement fragments C4d and SC5b-9 would be useful in detecting acute rejection or accelerated graft atherosclerosis (AGA) in cardiac allograft recipients. METHODS: We measured complement activation products, C4d (classical pathway) and SC5b-9 (terminal pathway), at the time of routine endomyocardial biopsy in heart transplant recipients. Ten patients in the immediate posttransplantation period (0-100 days) and 19 patients more than 6 months after transplantation were studied. RESULTS: No correlation was found between plasma levels of complement activation fragments and the presence of biopsy-proven acute allograft rejection or AGA (assessed by coronary angiography). However, plasma C4d and SC5b-9 were significantly elevated in 9 of 10 and 7 of 10 patients, respectively, in the immediate posttransplantation period. This was followed by progressive decrease in the levels of C4d and SC5b-9 fragments during the first 4-6 weeks after transplantation. CONCLUSION: We conclude that measuring plasma levels of fragments C4d and SC5b-9 is not a useful noninvasive method for detecting acute rejection or AGA after heart transplantation. However, this study provides further evidence that early complement activation after heart transplantation may play a pathogenic role in allograft injury.


Assuntos
Ativação do Complemento/fisiologia , Complemento C4b , Proteínas do Sistema Complemento/metabolismo , Transplante de Coração , Fragmentos de Peptídeos/sangue , Complemento C4/análise , Complemento C5/análise , Complemento C5b , Humanos , Fragmentos de Peptídeos/análise , Fatores de Tempo
16.
Transplantation ; 67(2): 253-8, 1999 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-10075589

RESUMO

BACKGROUND: OKT3 monoclonal antibody therapy results in an acute clinical syndrome (ACS) associated with the release of tumor necrosis factor and sequestration of neutrophils in the lungs. We have previously shown that inhibition of tumor necrosis factor does not completely eliminate OKT3-ACS, suggesting that other factors also contribute to the ACS. The current studies analyzed complement activation in vivo during the first hour after OKT3 administration. METHODS: Renal (n=4) and lung (n=4) transplant recipients received OKT3 as treatment for rejection and induction therapy, respectively. Complement activation products C4d, Bb, iC3b, and SC5b-9 were measured by ELISA. Hemodynamic parameters were also monitored in the lung transplant recipients. Neutrophil expression of CD11a, CD11b, and CD18 was monitored by flow cytometry. Controls included patients receiving methylprednisolone for rejection (n=4), two adults with adult respiratory distress syndrome who received extracorporeal membrane oxygenation, and normal volunteers (n=5). P values less than 0.05 (*) were considered significant. RESULTS: Increases in the plasma levels of C4d, Bb, iC3b, and SC5b-9 were observed in seven of eight patients after OKT3 administration. Mean values (n=8) at 0, 15, and 60 min (in microg/ml) were as follows-C4d: 1.865, 2.644*, and 2.607*; Bb: 0.245, 0.411, and 0.385; iC3b: 10.881, 17.242*, and 15.145*; and SC5b-9: 0.232, 0.269, and 0.302*. An increase in CD11b and CD18 and a decrease of CD11a on neutrophils in parallel with complement activation was observed. In lung transplant recipients, C3 activation correlated with increases in mean pulmonary and central venous pressures (P<0.05). As compared with extracorporeal membrane oxygenation, which activated classical and alternative pathways, OKT3 predominantly activated complement by the classical pathway. Methylprednisolone pulses did not activate complement. CONCLUSIONS: Complement activation is an early event after OKT3 administration and is associated with the increased expression of adhesion molecules on neutrophils and with pulmonary hemodynamic changes. Effective therapeutic approaches to the control of early monoclonal antibody side effects may require measures that limit complement activation in addition to reducing cytokine activity.


Assuntos
Complemento C3b/biossíntese , Complemento C4/biossíntese , Complemento C4b , Complexo de Ataque à Membrana do Sistema Complemento/biossíntese , Hemodinâmica , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Transplante de Pulmão/imunologia , Muromonab-CD3/uso terapêutico , Fragmentos de Peptídeos/biossíntese , Adulto , Idoso , Pressão Sanguínea , Ativação do Complemento , C3 Convertase da Via Alternativa do Complemento , Ensaio de Imunoadsorção Enzimática , Feminino , Frequência Cardíaca , Humanos , Transplante de Rim/fisiologia , Transplante de Pulmão/fisiologia , Masculino , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Modelos Químicos
17.
Transplantation ; 66(11): 1460-4, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9869086

RESUMO

BACKGROUND: Acute renal allograft rejection associated with the development of donor-specific alloantibody (acute humoral rejection, AHR) typically carries a poor prognosis. The best treatment of this condition remains undefined. METHODS: During a 14-month period, 73 renal transplants were performed. During the first postoperative month, five recipients (6.8%) with AHR were identified. The diagnosis was based on: (1) evidence of severe rejection, resistant to steroid and antilymphocyte therapy; (2) typical pathologic features; and (3) demonstration of donor-specific alloantibody (DSA) in recipient's serum at the time of rejection. Pretransplant donor-specific T- and B-cell cross-matches were negative. RESULTS: Plasma exchange (PE, four to seven treatments per patient) significantly decreased circulating DSA to almost pretransplant levels in four of five patients, and improvement in renal function occurred in all patients. One patient had recurrent renal dysfunction in the setting of an increase in circulating DSA. A second series of five PE treatments decreased DSA and reversed the rejection episode. Rescue therapy with tacrolimus (initial mean dose: 0.14+/-0.32 mg/kg/day) and mycophenolate mofetil (2 g/day) was used in five of five and four of five patients, respectively. With a mean follow-up of 19.6+/-5.6 months, patient and allograft survival are 100%. Renal function remains excellent with a mean current serum creatinine of 1.2+/-0.3 mg/dl. (range: 0.9-1.8 mg/dl). CONCLUSIONS: Our findings suggest that a therapeutic approach combining PE and tacrolimus-mycophenolate mofetil rescue has the potential to improve the outcome of AHR.


Assuntos
Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Ácido Micofenólico/análogos & derivados , Troca Plasmática , Tacrolimo/uso terapêutico , Doença Aguda , Formação de Anticorpos , Biópsia , Feminino , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Rejeição de Enxerto/prevenção & controle , Antígenos HLA/imunologia , Humanos , Imunoglobulina G/análise , Isoanticorpos/imunologia , Rim/patologia , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/uso terapêutico
18.
Transplantation ; 71(5): 652-8, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11292296

RESUMO

BACKGROUND: Acute rejection (AR) associated with de novo production of donor-specific antibodies (DSA) is a clinicopathological entity that carries a poor prognosis (acute humoral rejection, AHR). The aim of this study was to determine the incidence and clinical characteristics of AHR in renal allograft recipients, and to further analyze the antibodies involved. METHODS: During a 4-year period, 232 renal transplants (Tx) were performed at our institution. Assays for DSA included T and B cell cytotoxic and/or flow cytometric cross-matches and cytotoxic antibody screens (PRA). C4d complement staining was performed on frozen biopsy tissue. RESULTS: A total of 81 patients (35%) suffered at least one episode of AR within the first 3 months: 51 had steroid-insensitive AR whereas the remaining 30 had steroid-sensitive AR. No DSA were found in patients with steroid-sensitive AR. In contrast, circulating DSA were found in 19/51 patients (37%) with steroid-insensitive AR, and widespread C4d deposits in peritubular capillaries were present in 18 of these 19 (95%). In at least three cases, antibodies were against donor HLA class II antigens. DSA were not found in the remaining 32 patients but C4d staining was positive in 2 of 32. The DSA/C4d positive (n=18) and DSA/C4d negative (n=30) groups differed in pre-Tx PRA levels, percentage of re-Tx patients, refractoriness to antilymphocyte therapy, and outcome. Plasmapheresis and tacrolimus-mycophenolate mofetil rescue reversed rejection in 9 of 10 recipients with refractory AHR. CONCLUSION: More than one-third of the patients with steroid-insensitive AR had evidence of AHR, often resistant to antilymphocyte therapy. Most cases (95%) with DSA at the time of rejection had widespread C4d deposits in peritubular capillaries, suggesting a pathogenic role of the circulating alloantibody. Combined DSA testing and C4d staining provides a useful approach for the early diagnosis of AHR, a condition that often necessitates a more intensive therapeutic rescue regimen.


Assuntos
Complemento C4b , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/fisiopatologia , Transplante de Rim , Doença Aguda , Adulto , Anticorpos/análise , Anticorpos/uso terapêutico , Formação de Anticorpos , Complemento C4/análise , Complemento C4/uso terapêutico , Resistência a Medicamentos , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/imunologia , Humanos , Imunidade Celular , Incidência , Rim/imunologia , Pessoa de Meia-Idade , Fragmentos de Peptídeos/análise , Fragmentos de Peptídeos/uso terapêutico , Período Pós-Operatório , Esteroides/uso terapêutico , Doadores de Tecidos , Estados Unidos
19.
Transplantation ; 72(1): 77-83, 2001 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-11468538

RESUMO

BACKGROUND: In renal transplantation, chronic rejection is a major cause of late allograft loss. Recent studies indicate that a subset of chronic rejection is associated with anti-HLA donor specific antibodies (DSA) and complement C4d deposition in peritubular capillaries (PTC). Since rescue therapy with tacrolimus and mycophenolate mofetil has been found to limit antidonor B-cell responses in recipients with acute humoral rejection, we sought to determine whether a similar immunosuppressive regimen might be effective in patients with 'chronic humoral rejection'. METHODS: Four renal allograft recipients with 'chronic humoral rejection' were prospectively identified. The diagnosis was based on: (1) progressive rise in serum creatinine over 12 months; (2) typical pathologic features by light microscopy (transplant arteriopathy and glomerulopathy); (3) widespread C4d deposits in PTC by immunofluorescence; (4) detection of 'de novo' DSA at the time of biopsy. Maintenance immunosuppression was CsA, prednisone and azathioprine (n=3) or prednisone and azathioprine (n=1). Rescue therapy with tacrolimus and mycophenolate mofetil was initiated in all patients, 12 hr after cyclosporine and azathioprine discontinuation. RESULTS: At diagnosis, the mean serum creatinine was 3.9 mg/dl (range: 3.3 to 5.4 mg/dl). DSA was an IgG directed against HLA class II (n=3) or class I (n=2), that is one patient had both anti-HLA class I and class II antibodies. Pretreatment antibody titers varied between 1:8 and 1:128. Rescue therapy was associated with a rapid and sustained decrease in antibody titers. In two patients, DSA became undetectable after 9 months and a repeat biopsy performed after 12 months revealed a decrease in C4d deposition in PTC. CONCLUSION: These results suggest that a decrease in DSA production can be induced in renal allograft recipients with 'chronic humoral rejection' by using an immunosuppressive regimen that combines tacrolimus and mycophenolate mofetil. Limitation of antidonor antibody synthesis may be important for the treatment or the prevention of chronic rejection in organ transplantation.


Assuntos
Anticorpos/imunologia , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/imunologia , Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Ácido Micofenólico/uso terapêutico , Tacrolimo/uso terapêutico , Doadores de Tecidos , Adulto , Formação de Anticorpos/efeitos dos fármacos , Especificidade de Anticorpos , Linfócitos B/imunologia , Doença Crônica , Quimioterapia Combinada , Humanos , Masculino , Pessoa de Meia-Idade , Ácido Micofenólico/análogos & derivados , Estudos Prospectivos , Transplante Homólogo
20.
Pediatrics ; 78(4): 591-600, 1986 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3763266

RESUMO

Three clusters of an unusual syndrome in premature infants were investigated in three intensive care nurseries in 1984. A retrospective cohort study of 68 infants weighing less than or equal to 1,250 g at birth and surviving at least 72 hours revealed that in 13 infants ascites developed and in four at least two of the following abnormal laboratory values were found within a seven-day period: serum direct bilirubin greater than or equal to 2 mg/dL, blood urea nitrogen greater than or equal to 40 mg/dL or serum creatinine greater than or equal to 2 mg/dL, and platelet count less than or equal to 60,000/microL. All cases occurred after the introduction and use of intravenous E-Ferol, a vitamin E preparation that was new on the market when the clusters were reported. All 17 case infants but only 23 of 51 (45%) noncase infants received E-Ferol (P less than .0001). Case and noncase infants were similar with respect to other complications and to receipt of medications and parenteral nutrition. A dose-response relationship was found; cases occurred in infants receiving E-Ferol dosages of greater than 20 U/kg/d. Case infants who had higher daily doses of E-Ferol had a shorter latency. No new cases were reported after use of E-Ferol was stopped. Results of these investigations led to a nationwide recall of intravenous E-Ferol.


Assuntos
Doenças do Prematuro/etiologia , Vitamina E/análogos & derivados , alfa-Tocoferol/análogos & derivados , Adulto , Ascite/induzido quimicamente , Ascite/mortalidade , Feminino , Seguimentos , Humanos , Recém-Nascido , Doenças do Prematuro/epidemiologia , Doenças do Prematuro/mortalidade , Injeções Intravenosas , Estudos Retrospectivos , Risco , Conglomerados Espaço-Temporais , Tocoferóis , Vitamina E/administração & dosagem , Vitamina E/efeitos adversos
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