RESUMEN
Human leukocyte antigen typing of 2578 donor-recipient pairs whose transplantation was facilitated by the National Marrow Donor Program allowed for an in-depth analysis of the accuracy of high-volume allele level testing data. The methods employed provided allele level typing at DRB1/3/5, DQA1, DQB1, DPA1, and DPB1 using sequence-specific oligonucleotide probe hybridization (SSOPH), polymerase chain reaction (PCR) restriction fragment length polymorphism analysis, sequence specific PCR, and direct sequence-based typing (SBT). Each typing was independently tested by two laboratories in Phase 1, and in subsequent phases targeted samples were typed in duplicate by SBT to monitor typing quality. Comparison with prior transplant center typing was also evaluated. SSOPH detected discrepancies ranged from 0.6% at DPB1 to 5.1% at DQB1 in Phase 1. The majority of discrepancies, 62%, resulted from human error such as sample handling, result interpretation, or clerical errors. Alleles that are frequently discrepant have been identified in this predominantly white population.
Asunto(s)
Trasplante de Médula Ósea , Antígenos HLA-D/genética , Prueba de Histocompatibilidad/métodos , Alelos , Humanos , Hibridación de Ácido Nucleico , Sondas de Oligonucleótidos , Reacción en Cadena de la Polimerasa , Polimorfismo Genético , Polimorfismo de Longitud del Fragmento de Restricción , Reproducibilidad de los Resultados , Estudios Retrospectivos , Análisis de Secuencia de ADN/métodosRESUMEN
We studied the effect of fluvastatin (XU 62-320), a new HMG-CoA reductase inhibitor, on the distribution of low density lipoprotein (LDL) subspecies and composition in humans. As expected, fluvastatin significantly lowered serum LDL levels (25% after 6 weeks of therapy). In addition, treatment with fluvastatin changed the LDL subspecies. In the group treated with fluvastatin, 38.5% of the individuals showed changes in the shape of LDL absorbance profile obtained from density gradient ultracentrifugation and 54% of the group showed changes in the electrophoretic mobility of the LDL bands. Of those showing changes in electrophoretic mobility, the majority (78%) shifted to slightly larger, less dense LDL after drug therapy. However, the LDL-cholesterol/apo B ratio changes were relatively small in all fluvastatin-treated individuals including the group with changes in electrophoretic mobility, confirming that HMG-CoA reductase inhibitor causes relatively small and subtle changes in the distribution of LDL subspecies.
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Ácidos Grasos Monoinsaturados/farmacología , Inhibidores de Hidroximetilglutaril-CoA Reductasas , Indoles/farmacología , Lipoproteínas LDL/sangre , Apolipoproteínas B/sangre , Centrifugación por Gradiente de Densidad , Colesterol/sangre , LDL-Colesterol/sangre , Método Doble Ciego , Electroforesis en Gel de Poliacrilamida , Ácidos Grasos Monoinsaturados/uso terapéutico , Femenino , Fluvastatina , Humanos , Hipercolesterolemia/sangre , Hipercolesterolemia/tratamiento farmacológico , Indoles/uso terapéutico , Lipoproteínas LDL/química , Masculino , Persona de Mediana EdadRESUMEN
The World Marrow Donor Association has formulated guidelines for establishing the extent and quality of histocompatibility testing for unrelated donor registries, umbilical cord blood banks, and transplant centers involved in international exchange of hematopoietic stem cells for allogeneic transplantation. Registry and cord blood bank guidelines suggest that, at a minimum, initial HLA typing should be performed for three HLA loci, HLA-A, -B, and -DR, at low resolution/split antigen level. DNA-based testing methods should be utilized for HLA-DR typing. DNA-based testing for HLA-A and -B should replace serologic testing of new volunteer donors and cord blood units as robust protocols and reagents become available to the laboratories. Transplant center guidelines for typing of patient, family and to confirm the HLA types of potential unrelated donors should include, at the minimum, typing HLA-A, B, and -DR loci using primarily DNA-based testing methods at allele level resolution for DRB1 and low resolution/split antigen level for HLA-A and -B. It is strongly recommended that the typing of a patient and the selected donor be performed using the same set of reagents, methodology, and interpretation criteria with fresh tissue samples to ensure HLA identity. Guidelines for laboratory accreditation, approaches to quality assurance and quality control for HLA testing, and suggestions for the format of the HLA database of donor types are also outlined.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas/métodos , Trasplante de Células Madre Hematopoyéticas/normas , Prueba de Histocompatibilidad/métodos , Prueba de Histocompatibilidad/normas , Sistema de Registros , Donantes de Tejidos , Voluntarios , Trasplante de Médula Ósea/métodos , Trasplante de Médula Ósea/normas , Sangre Fetal/inmunología , Marcadores Genéticos , Antígenos HLA/genética , Hospitales Especializados , Humanos , Laboratorios de Hospital/normas , Registros Médicos/normas , Núcleo Familiar , Garantía de la Calidad de Atención de Salud , Reproducibilidad de los Resultados , Factores de Tiempo , Organización Mundial de la SaludRESUMEN
As the demand for undifferentiated stem cells for the treatment of leukemia and other cancers has increased, new methods for their collection have been developed. One of these new methods, allogeneic peripheral blood stem cell (PBSC) donation, involves the administration of a granulocyte colony-stimulating factor (G-CSF, filgrastim), and a 1-2 day apheresis collection procedure. Our goal in the current study was to examine donors' psychosocial and physical experiences of PBSC vs marrow donation. Potential participants included 80 donors from the National Marrow Donor Program (NMDP) who donated a second time between 1991 and 1997. All of these donors had previously donated marrow. A final cohort of 70 donors (25 PBSC and 45 marrow) participated in a retrospective questionnaire study of their donation experiences. In general, all second-time donors reported low levels of concern about the physical consequences of donation. However, PBSC donors were more likely to have postponed the decision to donate a second time. Despite their reservations, PBSC donors reported fewer donation-related side-effects than did marrow donors. Finally, PBSC donors reported that marrow donation was more physically difficult, time-consuming, and inconvenient, and that they preferred PBSC to marrow donation.
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Eliminación de Componentes Sanguíneos/psicología , Donantes de Tejidos/psicología , Adulto , Eliminación de Componentes Sanguíneos/efectos adversos , Eliminación de Componentes Sanguíneos/métodos , Células de la Médula Ósea , Recolección de Datos , Toma de Decisiones , Femenino , Movilización de Célula Madre Hematopoyética/métodos , Movilización de Célula Madre Hematopoyética/psicología , Células Madre Hematopoyéticas , Humanos , Masculino , Persona de Mediana Edad , Estudios RetrospectivosRESUMEN
A prospective survey involving 544 searches of the US National Marrow Donor Program (NMDP) Registry was conducted to identify reasons why many patients who have apparent HLA-matched donors do not proceed to transplant. Coordinators at NMDP transplant centers, patients and referring physicians were surveyed shortly after the initial search, and follow-up surveys were sent to the coordinators as the search was ongoing. The death of the patient, worsening of the patient's medical condition and length of the search process were the most commonly cited barriers to transplantation. Other times a decision was made not to transplant through the NMDP due to the use of a donor from another source, a preference for chemotherapy or immunotherapy, hesitancy on the part of the transplant physician or patient, or because the patient did not require a transplant. Responses differed between U.S. and international cases. An unrelated donor outside the NMDP was the most common reason cited by international coordinators (46%), whereas the death of the patient was the most common reason among US coordinators (13%). The death of the patient was the second most common reason cited by international coordinators at 9%. Financial problems were listed by 41% of US coordinators as a potential barrier at the time of initial search, but only 5% indicated this as an actual barrier on a follow-up survey. Finances were cited as the most important reason 3% of the time overall, and 6% for African Americans and Asian/Pacific Islanders.
Asunto(s)
Antígenos HLA/análisis , Trasplante de Células Madre Hematopoyéticas , Adolescente , Adulto , Anciano , Niño , Preescolar , Contraindicaciones , Recolección de Datos , Toma de Decisiones , Femenino , Enfermedades Hematológicas/terapia , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Aceptación de la Atención de Salud , Estudios Prospectivos , Negativa al Tratamiento , Sistema de Registros , Donantes de TejidosRESUMEN
During its 10-year existence, the National Marrow Donor Program (NMDP) has been extremely successful at recruiting potential bone marrow donors to join the volunteer registry. Due in part to successful recruitment and the longevity of the registry, the focus of the NMDP has now shifted to decreasing potential attrition when volunteers are recontacted for additional testing to determine whether they would be the optimal donor for a specific patient. Our own interest in the bone marrow donation process led us to examine four domains of variables - demographic characteristics, volunteer history, recruitment-related characteristics and donation-related concerns - that we hypothesized would be associated with increased likelihood of donor attrition at a key donor decision-point (DR-stage blood typing). Questionnaires were mailed to potential donors after they were contacted at the DR-stage, and had made the decision of whether or not to continue with blood typing. Our final sample included 756 volunteers who decided to continue with typing, and 258 individuals who declined further participation in the registry. In the bivariate analyses, factors in three of the four domains (all except demographic characteristics) were found to be substantially correlated with likelihood of attrition. Logistic regression indicated that nine central variables across the three domains produced the majority of increased attrition likelihood. Finally, a dose-response analysis suggested that as the number of attrition-related factors endorsed by an individual increased, his/her likelihood of dropping out of the registry also increased. Implications for future research and interventions to reduce potential donor attrition are discussed.
Asunto(s)
Trasplante de Médula Ósea , Sistema de Registros , Donantes de Tejidos/psicología , Adulto , Femenino , Prueba de Histocompatibilidad , Humanos , MasculinoRESUMEN
The World Marrow Donor Association has formulated guidelines for establishing the extent and quality of histocompatibility testing for unrelated donor registries, umbilical cord blood banks, and transplant centers involved in international exchange of hematopoietic stem cells for allogeneic transplantation. The ability to identify unrelated stem cell donors in one country for patients in another country requires cooperation and standardization in many areas. The adoption of guidelines for histocompatibility testing, such as those summarized in this report, will facilitate these opportunities and rapidly provide accurately typed donors for patients in need.
Asunto(s)
Donantes de Sangre , Guías como Asunto , Trasplante de Células Madre Hematopoyéticas , Prueba de Histocompatibilidad/normas , Adulto , Niño , Preescolar , Humanos , Trasplante HomólogoRESUMEN
A comprehensive analysis of the HLA-D region loci, DRB1, DRB3, DRB5, DQA1, DQB1, DPA1 and DPB1, was performed to determine allelic diversity and underlying HLA disparity in 1259 bone marrow recipients and their unrelated donors transplanted through the National Marrow Donor Program. Although 43.0% of DRB1 alleles known to exist at the beginning of the study were found in this predominantly Caucasian transplant population, a few alleles predominated at each locus. In recipients, 67.1% of DRB1 alleles identified were one or two of six common DRB1 alleles. Only 118 (9.4%) donor-recipient pairs were matched for all alleles of DRB1, DQA1, DQB1, DPA1 and DPB1. While 79.4% of the pairs were matched for DRB1, only 13.2% were matched for DPB1 alleles. Almost 66% of pairs differed by more than one allele mismatch and 59.0% differed at more than one HLA-D locus. DQB1 was matched in 85.9% of DRB1-matched pairs. In contrast, only 13.9% of the pairs matched for DRB1, DQA1 and DQB1 were also matched for DPA1 and DPB1. This database, highlighting the underlying HLA disparity within the pairs, forms the foundation of an ongoing study to establish the relationship between HLA matching and successful outcome in unrelated allogeneic stem cell transplant.
Asunto(s)
Alelos , Trasplante de Médula Ósea , Antígenos de Histocompatibilidad Clase II/genética , Prueba de Histocompatibilidad , Variación Genética , Antígenos de Histocompatibilidad Clase II/inmunología , Humanos , Polimorfismo Genético , Inmunología del Trasplante , Trasplante HomólogoRESUMEN
A single-blind study was conducted to investigate the effect of multiple doses of finasteride, a 5 alpha-reductase inhibitor for the treatment of benign prostatic hyperplasia, on the single-dose pharmacokinetics of antipyrine. Twelve patients with benign prostatic hyperplasia received a total of four single oral doses of 18 mg/kg antipyrine before, during, and after treatment with 10 mg/day of finasteride for 28 days. Finasteride had no effect on antipyrine concentration profiles. There were also no changes in urinary excretion of three principal antipyrine metabolites. A slight increase in renal clearance of antipyrine was observed; however, this is not considered relevant because excretion of unchanged antipyrine represents a minor fraction of total elimination and is not directly related to oxidative metabolism. These results imply that significant interactions between finasteride and drugs metabolized by these cytochrome P-450 enzymes are unlikely.
Asunto(s)
Antipirina/farmacocinética , Finasterida/farmacología , Hiperplasia Prostática/tratamiento farmacológico , Administración Oral , Anciano , Antipirina/administración & dosificación , Antipirina/sangre , Finasterida/administración & dosificación , Finasterida/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Método Simple CiegoRESUMEN
This article describes the recruitment of elderly black subjects into the Cholesterol Reduction in Seniors Program (CRISP), a federal, multi-center, randomized, double-masked feasibility study of cholesterol intervention in the elderly. The study tested the feasibility of recruiting significant numbers of hypercholesterolemic black men, black women, and white women over the age of 65, groups previously underrepresented in federal trials. The study involved dietary modification and drug intervention with either 20 mg or 40 mg of lovastatin or placebo. Maximum follow-up was 18 months. Over the 12-month screening and recruitment period, 431 subjects (108% of the recruitment goal) were randomized. A total of 311 (72% of the study cohort) was female; 105 subjects (24% of the total cohort) were minorities. Media sources were most effective in recruiting white subjects. Church screening was an effective strategy in the black community, although such an approach required considerable resources s and time. The CRISP feasibility study demonstrated that a large cohort of elderly black subjects could be recruited in a cholesterol intervention trial, although the use of community-based approaches required substantial resources and staff time.
Asunto(s)
Población Negra , Ensayos Clínicos como Asunto , Método Doble Ciego , Selección de Paciente , Ensayos Clínicos Controlados Aleatorios como Asunto , Anciano , Estudios de Cohortes , Femenino , Estudios de Seguimiento , Humanos , Hipercolesterolemia/dietoterapia , Hipercolesterolemia/tratamiento farmacológico , Lovastatina/uso terapéutico , MasculinoRESUMEN
We are reporting the results of HLA-A typing by PCR-SSOP complemented by PCR-SSP of samples obtained from the National Marrow Donor Program (NMDP). These samples were a representative group from 2486 tested in duplicate by serology. A total of 390 samples gave HLA-A discrepant results. Comparing the molecular typing results of 238 samples (samples with available DNA) with the serological typing results, 54 homozygotes and 184 heterozygotes produced a total of 422 assignments by molecular methods. We found assignment discrepancies in 147/422 (35%) in laboratory 1 and 144/422 (34%) in laboratory 2 (a combined group of 4 NMDP laboratories; laboratory 1 is not included). The serological discrepancies found were of 3 categories: a) false negatives, b) incomplete typing (discrepancies due to the level of resolution within a cross-reactive or CREG group) and c) false positives. Major problems were identified using serology for typing HLA-A antigens: a) inability to identify all WHO-recognized specificities, more frequently in non-Caucasians or in HLA-A specificities known to be found more frequently in non-Caucasians for laboratory 1 and incorrect assignments of A19 specificities in laboratory 2, b) incorrect assignments in cells with poor viability and c) false-positive assignments in homozygotes. We propose a possible strategy to type HLA-A specificities with two steps: a) a minimum of serology for typing specificities for common CREG groups: A1, A2, A3, A11, A9, A10, A28, A19. However, a given laboratory can determine the level of serological assignments needed as a first step. And b) molecular methods to identify splits: A23, A24, A29, A30, A31, A32, A33, A34, A36, A66, A74 and A80. The technique described is useful for large-scale bone marrow donor typings for cells with poor viability, and for resolving ambiguous results including false-positive assignments of homozygous cells.
Asunto(s)
Sondas de ADN de HLA/genética , Antígenos HLA-A/análisis , Prueba de Histocompatibilidad/métodos , Reacción en Cadena de la Polimerasa/métodos , Pruebas Serológicas , ADN/genética , Errores Diagnósticos , Estudios de Evaluación como Asunto , Genes MHC Clase I , Genotipo , Antígenos HLA-A/genética , Humanos , Grupos Raciales/genética , Sensibilidad y EspecificidadRESUMEN
Information obtained by DNA-based HLA typing assays is more detailed and of higher quality than that obtained by conventional serological techniques. Nevertheless, it is common for data acquired in this way to be presented in the more familiar serological format. In many cases this representation can lead to significant loss of information, which may only become apparent at a later time, with the discovery of novel allele sequences. DNA-based typing methods, such as sequence-specific oligonucleotide probing (SSOP) or sequence-specific priming (SSP) generate fragmentary sequence data which is information rich. An alternative to assigning allele names to these fragments is to simply store the sequence data itself without interpretation. Bone marrow donor repositories can then be searched directly with sequence information, which though complex is more complete, rather than searching by derivative allele names.
Asunto(s)
Secuencia de Bases , Trasplante de Médula Ósea , Prueba de Histocompatibilidad , Sistema de Registros/normas , Cartilla de ADN , HumanosRESUMEN
Unrelated volunteer donors (69) recruited by the National Marrow Donor Program were HLA typed by DNA-based methods for both the HLA-A and -B loci. Each donor had been previously typed by serology by at least two independent laboratories. Of the 69 samples, all serologic laboratories were in concordance for HLA-A in 62 typed samples and for HLA-B in 48 typed samples. Of the serologically concordant samples, 5 samples typed for HLA-A and 7 samples typed for HLA-B received DNA and serology types differing in their level of resolution. One sample typed for HLA-A and 3 samples typed for HLA-B by DNA methods gave different results from their serologic assignments. Of the samples exhibiting disparities among the different serologic typing laboratories, the DNA-defined types of 7 samples typed for HLA-A and 18 samples typed for HLA-B were consistent with at least one of the serologic assignments. The DNA types for the remaining 3 HLA-B typed samples did not agree with the serologic assignments and their alleles were subsequently sequenced. One of these sequences was a previously undefined allele, B*1537. Sharing of polymorphic sequences among HLA allelic products creates difficulties for consistent serologic assignments of some types complicating the process of identifying potential donors from bone marrow registries. Thus, the use of DNA-based typing techniques for characterization of donor class I types should allow a more consistent definition of types and should speed the donor selection process.
Asunto(s)
Trasplante de Médula Ósea/inmunología , Sondas de ADN de HLA/genética , Antígenos HLA-A/análisis , Antígenos HLA-B/análisis , Prueba de Histocompatibilidad/métodos , Reacción en Cadena de la Polimerasa , Análisis de Secuencia de ADN , Donantes de Tejidos , Obtención de Tejidos y Órganos/métodos , Errores Diagnósticos , Estudios de Evaluación como Asunto , Genes MHC Clase I , Antígenos HLA-B/genética , Humanos , Sistema de Registros , Sensibilidad y Especificidad , Alineación de Secuencia , Homología de Secuencia , Pruebas SerológicasRESUMEN
DNA typing of HLA class II alleles of the DRB1/3/4 and DQB1 loci using sequence-specific oligonucleotide probes and polymerase chain reaction-amplified DNA was used for the large-scale typing of donors for the National Marrow Donor Program unrelated donor registry. The results of quality control analysis for the first 7 months of the project show the typing to be highly accurate, specific, and reliable. The percent of correctly classified HLA oligotypes based on 1652 DRB1 and 1652 DQB1 assignments was greater than 99% for DRB1/DRB3/DRB4 and greater than 98% for DQB1. This level of accuracy is particularly remarkable because the quality control samples could not be distinguished from 9011 donor samples tested at the same time by the laboratories.
Asunto(s)
Antígenos HLA-DQ/inmunología , Antígenos HLA-DR/inmunología , Antígenos de Histocompatibilidad Clase II/inmunología , Sondas de Oligonucleótidos , Oligonucleótidos/inmunología , Alelos , ADN/genética , Antígenos HLA-DQ/genética , Cadenas beta de HLA-DQ , Antígenos HLA-DR/genética , Cadenas HLA-DRB1 , Cadenas HLA-DRB3 , Cadenas HLA-DRB4 , Antígenos de Histocompatibilidad Clase II/genética , Prueba de Histocompatibilidad/normas , Humanos , Reacción en Cadena de la Polimerasa , Control de Calidad , Sistema de Registros , Donantes de TejidosRESUMEN
The National Marrow Donor Program (NMDP) maintains a registry of approximately 4 million volunteer unrelated donors for patients in need of a stem cell transplant. When several comparably HLA-matched volunteers are identified for a patient, various criteria are used to select a donor. A retrospective analysis of 6978 bone marrow transplantations facilitated by the NMDP from 1987 to 1999 was conducted to study the effects of various donor characteristics on recipient outcome. The evaluation addressed possible effects of donor age, cytomegalovirus serologic status, ABO compatibility, race, sex, and parity on overall and disease-free survival, acute and chronic graft-versus-host disease (GVHD), engraftment, and relapse. Age was the only donor trait significantly associated with overall and disease-free survival. Five-year overall survival rates for recipients were 33%, 29%, and 25%, respectively, with donors aged 18 to 30 years, 31 to 45 years, and more than 45 years (P =.0002). A similar effect was observed among HLA-mismatched cases (28%, 22%, and 19%, respectively). A race mismatch between recipient and donor did not affect outcome. The cumulative incidences of grade III or IV acute GVHD were 30%, 34%, and 34%, respectively, with donors aged 18 to 30 years, 31 to 45 years, and more than 45 years (P =.005). The corresponding incidences of chronic GVHD at 2 years were 44%, 48%, and 49% (P = 0.02). Recipients with female donors who had undergone multiple pregnancies had a higher rate of chronic GVHD than recipients with male donors (54% versus 44%; P <.0001). The use of younger donors may lower the incidence of GVHD and improve survival after bone marrow transplantation. Age should be considered when selecting among comparably HLA-matched volunteer donors.
Asunto(s)
Trasplante de Médula Ósea/efectos adversos , Donantes de Tejidos , Adolescente , Adulto , Factores de Edad , Análisis de Varianza , Trasplante de Médula Ósea/normas , Femenino , Supervivencia de Injerto , Enfermedad Injerto contra Huésped/etiología , Histocompatibilidad , Humanos , Masculino , Persona de Mediana Edad , Embarazo , Grupos Raciales , Recurrencia , Sistema de Registros , Factores de Riesgo , Tasa de Supervivencia , Trasplante Homólogo/efectos adversos , Trasplante Homólogo/normasRESUMEN
BACKGROUND: Chronic myelogenous leukemia (CML) is an indolent but ultimately fatal disease. Because the natural history of CML varies and quality of life with CML may be excellent until shortly before death, deciding whether and when to pursue unrelated donor bone marrow transplantation is often difficult. OBJECTIVE: To compare early transplantation, delayed transplantation, and no transplantation for patients with chronic-phase CML on the basis of discounted, quality-adjusted life expectancy. DESIGN: A markov model comparing different strategies was constructed. This model considers patient age, quality of life, risk aversion, and the competing risks for CML progression and transplant toxicity. SETTING: Therapeutic decision at the time of diagnosis of CML. PATIENTS: The base case is a 35-year-old patient with intermediate-prognosis CML. Younger and older patients with better and worse prognoses are also evaluated. INTERVENTION: Early transplantation, delayed transplantation, and no transplantation. MEASUREMENTS: Quality-adjusted, discounted life expectancy. RESULTS: For patients with newly diagnosed CML, transplantation within the first year provides the greatest quality-adjusted expected survival, although this benefit decreases with increasing patient age. For a 35-year-old patient with intermediate-prognosis CML, transplantation within the first year results in 53 more discounted, quality-adjusted years of life expectancy than does no transplantation. This finding is robust even with varying baseline assumptions. CONCLUSIONS: These results support the use of early unrelated donor bone marrow transplantation for most patients with CML.
Asunto(s)
Trasplante de Médula Ósea , Técnicas de Apoyo para la Decisión , Leucemia Mielógena Crónica BCR-ABL Positiva/terapia , Factores de Edad , Antineoplásicos/uso terapéutico , Progresión de la Enfermedad , Humanos , Interferón-alfa/uso terapéutico , Leucemia Mielógena Crónica BCR-ABL Positiva/mortalidad , Masculino , Cadenas de Markov , Persona de Mediana Edad , Pronóstico , Años de Vida Ajustados por Calidad de Vida , Sensibilidad y Especificidad , Factores de Tiempo , Donantes de Tejidos , Trasplante HomólogoRESUMEN
The World Marrow Donor Association has formulated guidelines for establishing the extent and quality of histocompatibility testing for unrelated donor registries, umbilical cord blood banks, and transplant centers involved in international exchange of hematopoietic stem cells for allogeneic transplantation. Registry and cord blood bank guidelines suggest that, at a minimum, initial HLA typing should be performed for three HLA loci, HLA-A, -B, and -DR, at low resolution/split antigen level. DNA-based testing methods should be utilized for HLA-DR typing. DNA-based testing for HLA-A and -B should replace serologic testing of new volunteer donors and cord blood units as robust protocols and reagents become available to the laboratories. Transplant center guidelines for typing of patient, family and to confirm the HLA types of potential unrelated donors should include, at the minimum, typing HLA-A, B, and -DR loci using primarily DNA-based testing methods at allele level resolution for DRB1 and low resolution/ split antigen level for HLA-A and -B. It is strongly recommended that the typing of a patient and the selected donor be performed using the same set of reagents, methodology, and interpretation criteria with fresh tissue samples to ensure HLA identity. Guidelines for laboratory accreditation, approaches to quality assurance and quality control for HLA testing, and suggestions for the format of the HLA database of donor types are also outlined.
Asunto(s)
Trasplante de Células Madre Hematopoyéticas , Prueba de Histocompatibilidad/métodos , Prueba de Histocompatibilidad/normas , Guías de Práctica Clínica como Asunto , Donantes de Tejidos , Células Madre Hematopoyéticas/inmunología , Humanos , Trasplante HomólogoRESUMEN
The National Marrow Donor Program (NMDP) has instituted an approach to address the impact of new alleles on the DNA-based HLA assignments obtained during volunteer donor typing. This approach was applied to the DRB typing results from 371,187 donors received from 14 laboratories in 1999. Samples were tested with a standardized set of sequence specific oligonucleotide reagents and the positive and negative hybridization results transmitted electronically to the NMDP. A software program interpreted the primary data into HLA assignments and rejected assignments which did not produce a result at the specified level of resolution. Comparison of the HLA assignments derived by the NMDP software to the assignments made by the laboratories using several local software prograins showed 90.5% of the assignments to be identical. Differences in assignments were explained by varying levels of typing resolution, variation in the inclusion of the second expressed DRB loci, disparity arising when alternative assignments were summarized, and failure to submit correct information. When the primary data collected in 1999 were interpreted into HLA assignments using the set of alleles defined in July 2000, 74% of the HLA-DRB assignments were altered by the description of new alleles, justifying the development of this software.
Asunto(s)
Antígenos HLA/genética , Trasplante de Células Madre Hematopoyéticas , Sistema de Registros , Donantes de Tejidos , Secuencia de Bases , Antígenos HLA-DR/genética , Cadenas HLA-DRB1 , Prueba de Histocompatibilidad/normas , Prueba de Histocompatibilidad/estadística & datos numéricos , Humanos , Sondas de Oligonucleótidos/genética , Programas Informáticos , Trasplante HomólogoRESUMEN
A total of 42,160 individuals were typed for HLA-A and HLA-B by both serology and PCR-based typing. The HLA assignments included all of the known serological equivalents. The majority of the individuals (99.9%) were from U.S. minority population groups. The serologic typing was performed between 1993 and 1997 at the time of recruitment for the National Bone Marrow Program (NMDP) registry. The polymerase chain reaction (PCR)-based typing was carried out in two phases. In phase I, DNA typing was performed by PCR using sequence-specific oligonucleotide probes (PCR-SSOP) or PCR using sequence-specific primers (PCR-SSP) without knowledge of the serologic assignments. Discrepancies were identified between the serologic and DNA assignments in 24% of the volunteers (8% of volunteers differed for only HLA-A assignments, 13% for HLA-B, and 3% for both HLA-A and -B) and a potential explanation was assigned each discrepant serology/DNA pair. In phase II, a random sampling scheme was used to select a statistically significant number of individuals for repeat DNA typing from each of these categories. The categories included antigens missed by serology, nonexpressed (null) alleles, PCR amplification failures, misassignment of antigens and nomenclature issues. Only a single individual was found to carry a null allele. DNA-based testing correctly typed nearly 99% of the donors at HLA-A, more than 98% at HLA-B, and more than 97% at both HLA-A and -B validating this methodology for registry typing.
Asunto(s)
Trasplante de Médula Ósea , Pruebas Inmunológicas de Citotoxicidad/métodos , ADN , Antígenos HLA-A/genética , Antígenos HLA-B/genética , Prueba de Histocompatibilidad/métodos , Sistema de Registros , Donantes de Tejidos , Examen de la Médula Ósea/métodos , ADN/análisis , ADN/sangre , Antígenos HLA-A/sangre , Antígenos HLA-B/sangre , Humanos , Reacción en Cadena de la Polimerasa , Reproducibilidad de los ResultadosRESUMEN
DNA-based typing of HLA class I alleles of the HLA-A and HLA-B loci using sequence-specific oligonucleotide primers and/or probes has been used for the large-scale typing of individuals for the National Marrow Donor Program unrelated donor registry. Typing was performed by 16 laboratories at a low level of resolution (e.g. A*01, B*07). The results of blinded quality control analysis for the first 12 months of the project show the typing to be highly accurate, specific and reliable. The total error rate based on 11,545 HLA-A and 11,428 HLA-B assignments was 1.1% for HLA-A and 1.9% for HLA-B. This level of accuracy is particularly remarkable because the quality control samples could not be distinguished from 64,180 donor samples tested at the same time by the laboratories.