RESUMO
Single antigen bead based assays (SAB) to identify antibodies to HLA are marketed as a qualitative test, however often used as a quantitative test as the results provide mean fluorescence intensity (MFI) which is found to correlate with the strength/avidity of the antibody. We studied the between and within laboratory variability in performing the SAB from one manufacturer. Ten samples were tested at four laboratories according to the manufacturer's suggested protocol. Additionally same samples were tested on four consecutive days in one laboratory. All tests were performed using the same lot of beads and secondary antibody. Results were classified as positive at four different MFI cutoffs: 1000, 5000, 8000 and 10,000. MFI values across and within the laboratory were compared in a pair-wise fashion with Pearson's correlations. Overall concordance for Class-I was 97% between laboratories and 98% within laboratory at all cutoffs. Pair-wise Pearson correlation between laboratories was 0.989-0.99, while within laboratory it was 0.998-0.999. For Class-II, overall concordance between and within laboratory was 98%. Pair-wise Pearson correlation between laboratories was 0.991-0.997, while within laboratory it was 0.997-0.999. There is good correlation between laboratories and within laboratory using the same manufacturer, same lot and same protocol while performing SAB.
Assuntos
Anticorpos/imunologia , Antígenos HLA/imunologia , Técnicas Imunológicas/normas , Laboratórios/normas , Anticorpos/sangue , Especificidade de Anticorpos/imunologia , Teste de Histocompatibilidade/métodos , Teste de Histocompatibilidade/normas , Humanos , Técnicas Imunológicas/métodos , Microesferas , Reprodutibilidade dos TestesRESUMO
The number of highly sensitized patients on the transplant waiting list continues to rise. HLA allosensitization has profound effects on the wait time to transplant, rejection rates, and long-term outcomes. While technological advances with high sensitivity and specificity have facilitated the detection of donor specific antibodies, there is no consensus on diagnostic and prognostic values of these tests. Recently, multiple desensitization protocols have been developed that comprise high dose IVIG, low dose IVIG with plasmapheresis, rituximab and more novel agents including Bortezomib. Although these preconditioning protocols have led to successful transplantation of sensitized patients, long-term outcomes are limited and suboptimal. Randomized clinical trials are needed to determine optimal treatment and monitoring strategies in patients that are highly sensitized across the HLA barrier.
Assuntos
Dessensibilização Imunológica/métodos , Antígenos HLA/imunologia , Imunoglobulinas Intravenosas/uso terapêutico , Transplante de Rim/imunologia , Plasmaferese/métodos , Anticorpos Monoclonais Murinos/uso terapêutico , Ácidos Borônicos/uso terapêutico , Bortezomib , Feminino , Citometria de Fluxo , Humanos , Masculino , Pirazinas/uso terapêutico , Rituximab , Sensibilidade e Especificidade , Fatores Sexuais , Resultado do TratamentoRESUMO
BACKGROUND: We have demonstrated that immunodominant donor-specific antibody (DSA) more than 100 mean fluorescence intensity (MFI) at the time of transplant is associated with a significantly higher risk of rejection. We now present short-term outcomes of DSA-based desensitization (DSZ) strategies in patients with a negative complement-dependent cytotoxicity crossmatch. METHODS: Between January 1, 2009, and January 1, 2010, live-donor kidney transplant recipients were divided into three protocols based on their immunodominant DSA MFI pretransplant (D1: 100-500, D2: 501-1000, and D3: 1001-3000). Deceased donor kidney transplant recipients were stratified into two protocols (D4: 501-1000 and D5: 1001-3000). The intensity of the conditioning treatment increased with DSA levels and included thymoglobulin induction, plasmapheresis, and intravenous immunoglobulin in the highest risk groups. We compared outcomes between desensitized patients (DSZ) and those undergoing no DSZ (or D0) during the same interval. RESULTS: Forty-eight of 249 (23%) kidney transplants underwent DSZ (n=20, 4, 3, 4, and 17 in D1-D5 protocols, respectively). There was more retransplantation (50% vs. 18%, P<0.001) and live donor transplantation (56% vs. 30%, P<0.001) in the DSZ group. In this group, mean peak panel reactive antibody and MFI at transplant were 51% ± 7% and 960 ± 136, respectively. The incidence of antibody-mediated rejection (25% vs. 12.5%, P=0.008) and acute cellular rejection (23% vs. 14%, P=0.02) was greater in the DSZ group. However, mixed rejection (8%), graft loss (0 vs. 6), patient death (0 vs. 3), cytomegalovirus infection (15% vs. 12%), and 1-year serum creatinine (1.4 ± 0.5 and 1.4 ± 0.4 mg/dL) were similar between DSZ and no-DSZ groups. CONCLUSION.: Long-term follow-up is needed to determine the role of Luminex-based strategies in current preconditioning regimens.
Assuntos
Transplante de Rim/imunologia , Transplante de Rim/métodos , Condicionamento Pré-Transplante/métodos , Adulto , Soro Antilinfocitário/uso terapêutico , Protocolos Clínicos , Feminino , Teste de Histocompatibilidade , Hospitais Universitários , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Isoanticorpos/sangue , Isoanticorpos/isolamento & purificação , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Plasmaferese , Estudos Retrospectivos , Doadores de Tecidos , Resultado do Tratamento , WisconsinRESUMO
Response to immunocytokine (IC) therapy is dependent on natural killer cells in murine neuroblastoma (NBL) models. Furthermore, killer immunoglobulin-like receptor (KIR)/KIR-ligand mismatch is associated with improved outcome to autologous stem cell transplant for NBL. Additionally, clinical antitumor response to monoclonal antibodies has been associated with specific polymorphic-FcγR alleles. Relapsed/refractory NBL patients received the hu14.18-IL2 IC (humanized anti-GD2 monoclonal antibody linked to human IL2) in a Children's Oncology Group phase II trial. In this report, these patients were genotyped for KIR, HLA, and FcR alleles to determine whether KIR receptor-ligand mismatch or specific FcγR alleles were associated with antitumor response. DNA samples were available for 38 of 39 patients enrolled: 24 were found to have autologous KIR/KIR-ligand mismatch; 14 were matched. Of the 24 mismatched patients, 7 experienced either complete response or improvement of their disease after IC therapy. There was no response or comparable improvement of disease in patients who were matched. Thus KIR/KIR-ligand mismatch was associated with response/improvement to IC (P = 0.03). There was a trend toward patients with the FcγR2A 131-H/H genotype showing a higher response rate than other FcγR2A genotypes (P = 0.06). These analyses indicate that response or improvement of relapsed/refractory NBL patients after IC treatment is associated with autologous KIR/KIR-ligand mismatch, consistent with a role for natural killer cells in this clinical response.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Interleucina-2/uso terapêutico , Neuroblastoma/tratamento farmacológico , Receptores de IgG/genética , Receptores KIR/genética , Adolescente , Criança , Pré-Escolar , Genótipo , Antígenos HLA/genética , Antígenos HLA-B/genética , Antígenos HLA-C/genética , Humanos , Lactente , Células Matadoras Naturais/metabolismo , Ligantes , Neuroblastoma/genética , Polimorfismo Genético , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: With adoption of Model for End-Stage Liver Disease, the number of simultaneous liver-kidney transplants (SLK) has greatly increased. A recent registry study questioned the equity of allocating kidney transplants (KTx) simultaneously with liver transplantation due to poor outcomes (Locke et al., Transplantation 2008; 85: 935). METHODS: To investigate outcome of KTx in SLK, all SLK (n=36) performed at our center from January 2000 to December 2007 were reviewed and KTx outcomes compared with those of kidney transplant alone (KTA) performed during that period (n=1283). We also reviewed whether pretransplant panel reactive antibody and donor-specific antibody affected KTx outcome in SLK. RESULTS: One- and 3-year KTx and patient survival were not different between KTA and SLK regardless of sensitization level. There were 348 (27%) KTx failures in KTA vs. 6 (17%) in SLK (NS). Overall freedom from acute cellular rejection (ACR) and antibody-mediated rejection (AMR) in SLK was 93 and 96% at 3 years, compared with 72 and 78% in KTA (P=0.0105 and P=0.0744, respectively). Sensitized KTx recipients had more ACR and AMR (32 and 38%) at 3 years compared with nonsensitized recipients (28 and 20%) (P=0.23 and 0.0001, respectively). No differences in ACR and AMR were observed when SLK was divided and level of sensitization compared (P=0.17 and 0.65, respectively). CONCLUSION: SLK is a life-saving procedure with excellent patient and graft survival. AMR incidence in the KTx appears reduced in SLK compared with KTA regardless of level of preoperative panel reactive antibody. A high level of donor-specific antibody should not preclude simultaneous transplantation when clinically indicated.
Assuntos
Transplante de Rim/fisiologia , Transplante de Fígado/fisiologia , Doença Aguda , Adulto , Infecções por Citomegalovirus/epidemiologia , Etnicidade , Feminino , Rejeição de Enxerto/epidemiologia , Rejeição de Enxerto/prevenção & controle , Humanos , Transplante de Rim/imunologia , Transplante de Rim/mortalidade , Transplante de Fígado/imunologia , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros , Taxa de Sobrevida , Transplante Homólogo/imunologia , Transplante Homólogo/mortalidade , Transplante Homólogo/fisiologia , Resultado do TratamentoRESUMO
BACKGROUND: To determine the impact at a single center of the United Network for Organ Sharing-mandated sharing program for human leukocyte antigen (HLA)-A/-B/-DR 0-mismatched (0MM) kidneys, we analyzed the results of 264 kidney transplants from 0MM distant donors between 1993 and 2006, with a follow-up through January 31, 2007. We compared these results with that of concurrent kidneys transplanted from HLA more than 0MM local donors and with shipped more than 0MM kidneys from "payback" donors. RESULTS: Despite a significantly longer preservation time, we found an 11% increase in 8-year graft survival (63% vs. 52%; P<0.003) of 0MM shipped versus locally procured, >0MM donor kidneys. Graft survival of 0MM shipped kidneys at 8 years was significantly better in nonsensitized (<20% panel reactive antibodies; 68% vs. 55%; P<0.0005) but not in sensitized (>or=20% panel reactive antibodies) recipients, who showed an early (2 years) but short-lived benefit. The benefit of receiving a HLA-A, -B, and -DR 0MM shipped kidney remained strong and statistically significant (0.71 relative risk of graft loss vs. local; P<0.02) when adjusted for 22 potentially confounding variables in a Cox proportional hazards analysis. CONCLUSIONS: The recent change in United Network for Organ Sharing policy restricting mandated sharing of 0MM kidneys to sensitized and pediatric recipients will give greater flexibility to the local organ procurement organization in allocating organs. However, the survival benefit to nonsensitized patients is real and long lasting and will be lost.
Assuntos
Isquemia Fria , Seleção do Doador , Sobrevivência de Enxerto , Antígenos HLA/imunologia , Teste de Histocompatibilidade , Transplante de Rim , Preservação de Órgãos , Universidades , Adulto , Idoso , Feminino , Antígenos HLA-A/imunologia , Antígenos HLA-B/imunologia , Antígenos HLA-DR/imunologia , Alocação de Recursos para a Atenção à Saúde , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Wisconsin , Adulto JovemRESUMO
BACKGROUND: The clinical significance of pretransplant donor-specific antibodies (pre-Tx DSAs) detected by single-antigen bead flow cytometry (SAB-FC) remains unclear. METHODS: To investigate the impact that pre-Tx DSAs detected by SAB-FC have on early clinical outcomes, we tested pre-Tx sera from all consecutive deceased-donor kidney transplants performed between January 2005 and July 2006 (n=237). RESULTS: In the study population of which 66% had a high-immunologic risk, mean fluorescence intensity (MFI) more than or equal to 100 for class I and more than or equal to 200 for class II were the lowest DSA thresholds associated with inferior antibody-mediated rejection-free graft survival (75% vs. 90%, P=0.004 and 76% vs. 87%, P=0.017, respectively). The hazard ratio for antibody-mediated rejection increased linearly with higher class II DSA from MFI 100 to 800 (1.7[0.8-3.2], P=0.1 for MFI ≥100 vs. 4.7[2.4-8.8], P<0.001 for MFI ≥ 800). Differences in graft function were only evident in patients with class II MFI more than or equal to 500 (estimated glomerular filtration rate: 47.6 vs. 54.3, P=0.02 and proteinuria: 0.6 ± 0.6 vs. 0.4 ± 0.3, P=0.03). A difference in death-censored graft survival was detected in patients with class II MFI more than or equal to 1000 (75% vs. 91.9%, P=0.055). CONCLUSION: High-pre-Tx DSAs detected by SAB-FC are associated with incrementally poor graft outcomes in deceased-donor kidney transplant with high-immunologic risk.
Assuntos
Isoanticorpos/sangue , Transplante de Rim/imunologia , Doadores de Tecidos , Adulto , Especificidade de Anticorpos , Feminino , Taxa de Filtração Glomerular , Rejeição de Enxerto/imunologia , Sobrevivência de Enxerto/imunologia , Humanos , Estimativa de Kaplan-Meier , Transplante de Rim/efeitos adversos , Transplante de Rim/mortalidade , Transplante de Rim/fisiologia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoAssuntos
Ácidos Borônicos/uso terapêutico , Resistência a Múltiplos Medicamentos/efeitos dos fármacos , Rejeição de Enxerto/tratamento farmacológico , Transplante de Rim/imunologia , Inibidores de Proteases/uso terapêutico , Pirazinas/uso terapêutico , Doença Aguda , Adulto , Bortezomib , Creatinina/urina , Diabetes Mellitus Tipo 1/cirurgia , Nefropatias Diabéticas/cirurgia , Diurese/efeitos dos fármacos , Rejeição de Enxerto/patologia , Humanos , Imunização , Transplante de Rim/patologia , Masculino , Transplante de PâncreasAssuntos
Complemento C4b/análise , Rejeição de Enxerto/imunologia , Antígenos HLA-DP/imunologia , Isoanticorpos/sangue , Transplante de Rim/imunologia , Transplante de Rim/patologia , Fragmentos de Peptídeos/análise , Adulto , Atrofia , Hospitais Universitários , Humanos , Isoanticorpos/imunologia , Glomérulos Renais/patologia , Túbulos Renais/patologia , Masculino , WisconsinRESUMO
BACKGROUND: Organs procured from deceased donors emanate from individuals with diverse genetic backgrounds. Donor organs, therefore, may vary in their response to injury and immune stimuli in a genetically determined manner. We assessed polymorphisms from 244 renal allograft donors to better understand the impact of donor polymorphisms on selected transplant outcomes. METHODS: Donor genomic DNA restriction fragment length polymorphisms were assayed for evidence of common cytokine [interleukin (IL)-2, IL-6, IL-10, tumor necrosis factor (TNF)-alpha, TGF-beta, interferon (IFN)-gamma] and chemokine (CCR2, CCR5) polymorphisms. Associations between donor polymorphisms and graft events were determined using chi-square, linear regression, and Kaplan-Meier analyses. RESULTS: Several genotypic polymorphisms demonstrated a modest association with acute rejection, including the transforming growth factor (TGF)-beta T/C codon 10 (P= 0.027) and the CCR5 G/A 59029 (P= 0.039) genes by chi-square analysis. Notably, the presence of the T allele in the IFN-gamma gene (+874) demonstrated a highly significant association with biopsy-proven chronic allograft nephropathy (P < 0.008). This association remained highly significant in a multiple linear regression model that incorporated biopsy-proven acute rejection as a covariate. CONCLUSION: These data suggest that many of the donor polymorphisms studied in this analysis may influence a recipient's immune response to a renal allograft. However, their greatest impact may be demonstrated in long-term outcomes.