HLA antigenic and haplotype frequencies estimated in hematopoietic progenitor cell donors from Argentina.

BACKGROUND: Hematopoietic progenitor cell transplantation is considered a standard-of-care treatment for defined hematological and non-hematological conditions affecting bone marrow-derived cells. METHODS: Patients and potential donors are HLA typed for their HLA-A, -B, -C, -DRB1, and -DQB1 alleles. The best allogeneic donor is one for which each allele matches the patient at HLA-A, -B, -C, and -DRB1 (8/8). For patients with no related donor, the transplant physician will start a search for unrelated donors. The search is performed through a local registry and often includes the search for donors worldwide. The Argentinean HPC Donors Registry was established in 2003. Our National HPC Donor Registry has already typed more than 31,000 donors for HLA-A, -B, and -DR. RESULTS: We present the analysis of HLA frequencies and haplotypes estimates for the subset of our donor database that is additionally typed for HLA-C. We analyzed HLA data from 2657 donors. Antigen and haplotype frequencies were estimated through the use of expectation maximization. CONCLUSIONS: Our analysis showed for the first time the antigenic HLA frequency distribution from HPC donors in Argentina. Knowing haplotype frequencies in our population will help us to select potential donors for high-resolution typing for the patients.

Factors associated with patient and graft survival using kidneys from cadaveric donors in transplant patients under 18 years of age in Argentina.

BACKGROUND: Thanks to advances in surgical techniques and immune system suppression, the mortality rate in children with end-stage renal disease (ESRD) has dramatically declined. Kidney transplantation has become the primary method to treat ESRD in the pediatric population. MATERIALS AND METHODS: Information was obtained from SINTRA (National Information System of Orrgan Procurement and transplantation in Argentina) for the period 1998-2009. We used the Kaplan-Meier curve, survival was measured at 30 days, 1, 5, and 10 years. The Cox regression variables taken for patient and graft survival were gender and age of both donor and recipient, ischemia time (> or <24 hr), etiology of chronic renal failure, time on dialysis (> or <3 years) of the recipient, cause of donor's death (stroke, head trauma, anoxia, other causes of coma, tumor and others). We coded the value of mismatch. For each HLA, it was 0 when they shared the 2. Adding the 3 types of antigens, the possible mismatch values ranged between 0 and 6. However, all had values between 5 and 6. We used SPSS statistical software Medcalc 17. RESULTS: We analyzed 345 (54%) men and 290 (46%) women. The average age was 12.5 + 3.9 years. The median follow-up time was 4 years (maximum 13 years). Patient survival rates at 30 days were 99.4%, at 1 year 96.8%, at 5 years 91.1%, and at 10 years 82.5%. Cox regression for patient survival: being a female and receiving HR 1.88 (95% CI 1.09-3.25) P = .023 or donor HR 1.86 (95% CI 1.06-3.25) P = .030. Tumor HR 17.19 (95% CI 4.48-65.98) P = <.0001. For recipient's age compared with <12 years >12 years HR 1.99 (95% CI 1.11-3.65) P = <.024. Graft survival rate at 30 days was 97.2%, at 1 year was 91.9%, at 5 years was 79.3% and at 10 years was 61.8%. Compared with donor's age <18 years: 45-59 years HR 2.52 (95% CI 1.42-4.47) P = .002. Glomerulonephritis HR 1.71 (95% CI 1.10-2.77) P = .018. Tumor as the cause of donor's death HR 4.39 (95% CI 1.28-2.28) P = .012. Time on dialysis > 3 years HR 1.59 (95% CI 1.11-2.28) P = .012. CONCLUSIONS: Being a female, receiving a kidney from a woman and tumor as the cause of donor's death and age >12 years were associated with worse patient survival. Donor's age between 45 and 59, glomerulonephritis as the etiology of renal failure, tumor as the cause of death and time on dialysis >3 years were associated with lower graft survival.

Analysis of mortality while on waiting list for kidney transplant in adults in Argentina 2005-2009.

INTRODUCTION: Comparison of survival after renal transplant patients on the waiting list is an important factor to evaluate this therapy. OBJECTIVE: To measure the magnitude of deceased donor kidney transplant on patient survival compared to patients on dialysis and on waiting lists in over 18 years in Argentina. MATERIAL AND METHODS: The information was obtained from SINTRA for the period January 2003 to December 2009. The follow-up period ended in December 2010. Survival was considered as the time from the entrance to the waiting list until death, the end of the study (June 2009), or last follow-up available, whichever came first. The Kaplan-Meir method was used. The survival rate was recorded at 30 days, 1, 5 and 10 years. Log-rank was used to compare the curves and their statistical significance. The Cox regression model was used to consider the variables for both patient and graft survival, such as gender and age, time on dialysis, etiology of end-stage renal disease (ESRD), and presence of comorbidities. The MedCalc and SPSS 17 statistical packages were used. RESULTS: We analyzed 1682 patients transplanted average age 48.14 + 13.48 years and 3647 patients on waiting lists average age 47.88 + 14.32 years. For patients transplanted 30-day survival was 99.8% at 1 year 96.2% and 5 years of 79.9%. For patients on the waiting list survival at 30 days was 99.7% at 1 year and 5 years 94.6% 66.6%. Chi-square was 42.77, P = <.0001. HR 0.64 (95% CI 0.56 to 0.73). Cox regression for patients on waiting lists HR 1.40 (95% CI 1.20-1.63) P = <.0001. The time dependent Cox regression showed for patients transplanted at 30 days, <1 year >1 year showed HR 4.18 (95% CI 2.88-6.06) P = <.0001, HR 0.40 (95% CI 0.27 to 0.61) P = <.0001 and HR 0.19 (95% CI 1.12-0.29) P = <.0001, respectively. CONCLUSIONS: Survival, both at baseline and in the long term, is better in transplant patients as compared to patients on waiting list. In Cox time-dependant regression the risk of death during the first 30 days is 4 times higher in transplant patients. This reverses and at 1 year, transplant patients are 60% less likely to die, and after one year this probability is 81% lower (P =<.0001).

Factors associated with patient and graft survival using kidneys from cadaveric donors in transplanted patients over 18 years of age in Argentina.

BACKGROUND: With improvements in short-term kidney graft and patient survival, focus has shifted to understand patient and graft features that affect long-term survival. MATERIALS AND METHODS: This retrospective analysis from January 1998 to December 2009 employed Kaplan-Meier analysis to evaluate survival ratios at 30 days as well as 1, 5, and 10 years. A multivariable Cox regression model considered variables of donor and recipient, gender and age, cold ischemia time (CIT), chronic renal failure etiology, time on dialysis (TD) and cause of donor death. The mismatch (MM) value was coded according to the number of antigens shared by both the donor and the recipient for HLA-A, B, and DR. The MM values ranged between 0 and 6. Two groups were analyzed according the number of shared antigens: 0 to 3 versus 4 to 6. RESULTS: Among 3030 (55.85%) males and 2395 (44.15%) females, the overall mean age was 46.9 ± 13.9 years. Median follow-up was 4 years (max 13 years). Patient survival rate (SR) was 97.5% at 30 days, 87.5% at 1 year, 74.5% at 5 years, and 59.2% at 10 years. Using Cox analysis, patient SR was affected by: diabetic nephropathy (DN) hazard ratio (HR) 1.55 (95% confidence interval [CI 95%] 1.21-1.97) P = .0005; head trauma (HT) cause of donor death HR 0.83 (0.73-0.95) P = .0005 and donor age (DA) compared by 18 to 44 years: 45 to 59 years HR 1.44 (CI95% 1.00-1.30) P = .043, >60 years HR 1.41 (CI95% 1.17-1.70) P = .0004. In addition relevant factors were recipient age (RA) compared by 18 to 44 years: 45 to 59 HR 1.99 (CI95% 1.74-2.27) P < .0001, >60 years HR 3.24 (CI95% 2.79-3.75) P < .0001 and DT >7 years HR 1.33 (CI95% 1.19-1.48) P = .0001. MM HLA 0 to 3 level HR 0.78 (CI95% 0.69-0.88) P < .0001. Graft SR was 95% at 30 days, 81.6% at 1 year, 64.7% at 5 years, and 47.3% at 10 years. The relevant factors were: DN HR 1.26 (CI95% 1.01-1.57) P = .04; HT HR 0.82 (0.74-0.91) P = .0004; DA compared by 18 to 44 years: 45-59 years HR 1.19 (CI95% 1.07-1.32) P = .002, >60 years HR 1.53 (CI95% 1.30-1.80) P < .0001; RA compared by 18 to 44 years: 45-59 HR 1.33 (CI95% 1.19-1.47) P < .0001, >60 years HR 1.84 (CI95% 1.63-2.09) P < .0001; DT > 7 years HR 1.22 (CI95% 1.11-1.35) P = .0001; CIT >24 hours HR 1.13 (CI95% 1.03-1.23) P = .009 and MM HLA 0 to 3 HR 0.82 (CI95% 0.74-0.91) P = .0002. CONCLUSION: HT as the cause of donor death and MM between 0 and 3 were associated with better patient and graft SR, DN, TD over 7 years, DA and RA over 45 were associated with lower patient SR. CIT > 24 hours, DN, TD over 7 years, as well as donor and recipient ages over 45 yr were associated with a lower graft SR.

Muerte encefálica en Iberoamérica / Brain death in Latin America

Objetivo: Analizar el diagnóstico de muerte encefálica (ME) en Iberoamérica. Fundamento: La ME se ha aceptado como la muerte del individuo desde hace décadas, pero existen diferencias legales y gran variabilidad en los criterios diagnósticos de cada país. Método: Encuesta sobre el diagnóstico médico y legal de la ME en los 21 países que forman la Red/Consejo Iberoamericano de Donación y Trasplante. Resultados: Todos los países iberoamericanos, excepto Nicaragua, reconocen legalmente la ME como la muerte de la persona. Para declarar el fallecimiento, en la mayoría se necesitan 2 o 3 médicos. En todos los países es obligatoria la presencia de un coma arreactivo, ausencia de reflejos de tronco y de respiración espontánea. Los niveles de presión parcial de dióxido de carbono requerida en el test de apnea oscilan entre 50-60mmHg. La temperatura mínima requerida para la exploración neurológica oscila entre 32-35°C. El test de atropina es obligatorio en 7 países (35%). El período de observación más recomendado es de 6h, pero hay gran variabilidad, que llega hasta 24h. En 8 países (40%) es obligatorio realizar siempre un test instrumental, en el resto solamente en circunstancias especiales. En algunos países, si no hay donación de órganos para trasplante no se retiran las medidas de soporte, este hecho es más frecuente en los niños. Conclusiones: Existe uniformidad en los criterios diagnósticos fundamentales, pero se observan diferencias en los prerrequisitos clínicos, la exploración neurológica, el tiempo de observación, los test instrumentales y las decisiones clínicas tras la declaración de ME. Sería recomendable la homogeneización de los criterios diagnósticos (AU)

Objective: To examine the diagnosis of brain death (BD) in Latin America. Background: The term BD has long been used to define the death of an individual despite legal differences and variations in the diagnostic criteria applied in each country. Method: A survey was conducted to gain information on the medical and legal diagnosis of BD in the 21 countries that make up the Latin American Network/Council of Donation and Transplant. Results: All the Latin American countries except for Nicaragua legally recognize BD as the death of the person. To declare a person dead, 2 or 3 doctors are required in most countries. In all the countries, the requirements that must be fulfilled are unresponsive coma, lack of brainstem reflexes and of spontaneous breathing. Partial pressure of arterial carbon dioxide levels required in the apnea test vary from 50-60mm Hg. The minimum temperature required for a neurological examination ranges from 32°-35°C. The atropine test is mandatory in 7 (35%) countries. The most recommended observation period is 6h, but there is great variation and can be up to 24h. In 8 countries (40%), an instrumental test is obligatory, while in the remaining countries this is only undertaken under special circumstances. In some countries, when organs are not donated for transplant, support measures are not withdrawn, this being more frequent in children. Conclusions: There seems to be some uniformity in the main diagnostic criteria applied, with differences observed in clinical prerequisites, neurological exams, observation time, instrumental tests and the clinical decisions made following a declaration of BD. It is recommended that diagnostic criteria be standardized (AU)

Consideraciones generales sobre la muerte encefálica y recomendaciones sobre las decisiones clínicas tras su diagnóstico / General considerations on brain death and recommendations on the clinical decisions after its diagnosis

El objetivo de la Red/Consejo Iberoamericano de Donación y Trasplantes es desarrollar la cooperación entre los países miembros en todos los aspectos relacionados con la donación y el trasplante de órganos, tejidos y células. Considerando que el diagnóstico de muerte encefálica (ME) es una de las claves fundamentales en la obtención de órganos para trasplante, uno de los objetivos prioritarios de la Red/Consejo es contribuir a la divulgación y a la formación del concepto y el diagnóstico de ME entre los profesionales sanitarios. En el presente trabajo se presentan las consideraciones generales sobre la ME y las recomendaciones sobre las decisiones clínicas tras su diagnóstico que la Red/Consejo Iberoamericano de Donación y Trasplantes elaboraron y aprobaron en su sexta reunión celebrada en mayo del año 2008 en La Habana, Cuba. Aunque existen diferencias legales y variabilidad en los criterios diagnósticos de ME en los países miembros, la ME se acepta como la muerte del individuo a efectos legales, éticos y científicos. El diagnóstico debe ser independiente de si existe o no donación de los órganos para trasplante. Una vez confirmado el diagnóstico de ME, se debe considerar siempre la posibilidad de donación de los órganos e iniciar las medidas oportunas de mantenimiento. Si la donación de órganos estuviera contraindicada, se procederá a la retirada de todas las medidas de soporte, incluida la ventilación mecánica. La decisión de retirar todas las medidas de soporte es consecuente con el diagnóstico clinico legal y diferentes sociedades científicas y bioéticas la apoyan (AU)

The objective of the Latin American Network/Council of Donation and Transplant is to develop cooperation among its member states in all aspects related to donation and transplant of organs, tissue and cells. Given that diagnosing brain death (BD) is one of the key issues for the procurement of organs for transplant, the Network/Council seeks to contribute to defining the accepted concept of BD and its diagnosis and to disseminate this information among healthcare workers. In this report, we present the general guidelines on brain death and recommendations for clinical decisions after its diagnosis established and approved by the Latin American Network/Council of Donation and Transplant at its sixth meeting held in La Havana, Cuba, in May 2008. Although there are legal differences and variations in the diagnostic criteria used to define BD among its member states, brain death is accepted as the death of an individual for all legal, ethical and scientific effects. The diagnosis of BD should be independent of the decision of whether to donor or not donate organs for transplant. Once a diagnosis of BD has been confirmed, the possibility of organ donation should always be considered and the appropriate organ maintenance measures initiated. If organ donation is contraindicated, all support measures should be withdrawn including mechanical respiration. The decision to withdraw all support measures is consistent with the clinical-legal diagnosis and supported by several scientific and bioethics societies (AU)

[General considerations on brain death and recommendations on the clinical decisions after its diagnosis. Red/Consejo Iberoamericano de Donación y Trasplante]. / Consideraciones generales sobre la muerte encefálica y recomendaciones sobre las decisiones clínicas tras su diagnóstico.

The objective of the Latin American Network/Council of Donation and Transplant is to develop cooperation among its member states in all aspects related to donation and transplant of organs, tissue and cells. Given that diagnosing brain death (BD) is one of the key issues for the procurement of organs for transplant, the Network/Council seeks to contribute to defining the accepted concept of BD and its diagnosis and to disseminate this information among healthcare workers. In this report, we present the general guidelines on brain death and recommendations for clinical decisions after its diagnosis established and approved by the Latin American Network/Council of Donation and Transplant at its sixth meeting held in La Havana, Cuba, in May 2008. Although there are legal differences and variations in the diagnostic criteria used to define BD among its member states, brain death is accepted as the death of an individual for all legal, ethical and scientific effects. The diagnosis of BD should be independent of the decision of whether to donor or not donate organs for transplant. Once a diagnosis of BD has been confirmed, the possibility of organ donation should always be considered and the appropriate organ maintenance measures initiated. If organ donation is contraindicated, all support measures should be withdrawn including mechanical respiration. The decision to withdraw all support measures is consistent with the clinical-legal diagnosis and supported by several scientific and bioethics societies.

[Brain death in Ibero-America]. / Muerte encefálica en Iberoamérica.

OBJECTIVE: To examine the diagnosis of brain death (BD) in Latin America. BACKGROUND: The term BD has long been used to define the death of an individual despite legal differences and variations in the diagnostic criteria applied in each country. METHOD: A survey was conducted to gain information on the medical and legal diagnosis of BD in the 21 countries that make up the Latin American Network/Council of Donation and Transplant. RESULTS: All the Latin American countries except for Nicaragua legally recognize BD as the death of the person. To declare a person dead, 2 or 3 doctors are required in most countries. In all the countries, the requirements that must be fulfilled are unresponsive coma, lack of brainstem reflexes and of spontaneous breathing. Partial pressure of arterial carbon dioxide levels required in the apnea test vary from 50-60mm Hg. The minimum temperature required for a neurological examination ranges from 32 degrees -35 degrees C. The atropine test is mandatory in 7 (35%) countries. The most recommended observation period is 6h, but there is great variation and can be up to 24h. In 8 countries (40%), an instrumental test is obligatory, while in the remaining countries this is only undertaken under special circumstances. In some countries, when organs are not donated for transplant, support measures are not withdrawn, this being more frequent in children. CONCLUSIONS: There seems to be some uniformity in the main diagnostic criteria applied, with differences observed in clinical prerequisites, neurological exams, observation time, instrumental tests and the clinical decisions made following a declaration of BD. It is recommended that diagnostic criteria be standardized.

Matrix superhighways configurations: new concepts for complex organ regeneration.

New ideas and experimental models for tissue and organ regeneration are urgently needed. There are several exciting challenges in the field of organogenesis that need to be defined. The integrated signals and molecular repertoires that shape the particular architecture of specific organs like the kidney or the liver are not completely understood yet. To develop a new scientific platform to be able to build up complex organs we have established a research program using basically Acellular Xenogeneic Isomorphic Matrices (AXIMs) and mesenchymal stem cells (MSCs) generating the necessary concepts for the definition, production, and application of the specific configurations of these matrices for organ regeneration. New and interesting pathways for MSC differentiation were identified. We believe that all extracellular matrices were created fundamentally equal or at least very similar in nature. We also believe that there are true "matrix superhighway configurations" with different three-dimensional geometrical architectures as well as biochemical, electrical, and molecular properties that are tissue and organ specific that influence cell differentiation and organogenesis and will be fundamental for the in vitro regeneration of complex organs for transplantation.

Organ donation in Latin America.

Recently in Latin America, there has been a strong influence of the "Spanish model" of organ procurement. In 2001, The "Punta Cana Group" was created by Latin American transplantation coordinators with the objective of registering and improving the system of donation and procurement. In many countries there is no universal financial support from the government for medical treatment, including dialysis and transplantation. In other countries there is complete financial support for all of the population, including immunosuppressive drugs. Practically all countries have transplantation laws that follow ethical concepts, such as brain death diagnosis criteria, forms of consent, criteria of allocation, and inhibition of commerce. The rate of potential donors notified in countries that perform transplantations with deceased donors varied from 6 to 47 per million population yearly (pmp/y); The rate of effective donors varied from 1 to 20 pmp. In 2004, the mean rate of effective donors in Latin America was 5.4 pmp. The family refusal rate for the donation of organs varied from 28% in Uruguay to 70% in Peru. In some countries, such as Puerto Rico, Uruguay, and Cuba, it was more than 15 pmp, whereas in others countries deceased donors were practically not used. The number of patients on the waiting list for solid organ transplants in 12 Latin American countries is 55,000. Although the donation rate has increased by 100% during the last 10 years, it is lower than that in Europe (15 pmm/y) or the United States (20 pmp/y).

Glasgow coma scale 7 or less surveillance program for brain death identification in Argentina: Epidemiology and outcome.

BACKGROUND: In Argentina, the rate of cadaveric organ donation per million inhabitants has recently increased to 10.5 (it was previously <7). PURPOSE: To overcome this challenge, the National Institute for Organ Donation and Transplantation (INCUCAI) created a proactive donor detection plan performed by intensive care unit (ICU) physicians (hospital transplantation coordinators) from 90 selected hospitals across the country. METHODS: A prospective, observational study of patients in severe coma status was conducted from September 2003 to December 2005. We enrolled hospitalized patients who displayed a Glasgow Coma Scale (GCS) of 7 or less and who were admitted to ICUs. Data included demographics, etiology of coma, cardiac arrest, brain death, discharge or derivation, and positive/negative donation. RESULTS: Among 9841 enrolled patients, we excluded 498 who were discharged to another hospital or had unknown outcomes, leaving 9343 for analysis including 64% males and 36% females of overall mean age 50 +/- 19 years (adults) and 5 +/- 4 years (children). Herein, we have highlighted the high risk of death during the first 2 days in the ICU of patients with GCS 7 or less. Gunshot to the head-injured patients and those with hemorrhagic strokes were less likely to survive. In this study, cardiac arrest events and organ donors (OD) GCS 7 or less ratios emerged as quality control markers of ICU care, unraveling problems of potential donor maintenance or inadequate policies. CONCLUSIONS: The GCS 7 or less surveillance program seemed to be a valuable tool for identifying organ donors and potentially treatable events, such as the high rate of cardiac arrest observed in this study.

Bloodstream cells phenotypically identical to human mesenchymal bone marrow stem cells circulate in large amounts under the influence of acute large skin damage: new evidence for their use in regenerative medicine.

OBJECTIVES: Recent work has shown that human bone marrow contains mesenchymal stem cells (MSCs). However, little is known about their presence in peripheral blood. Since these cells are potentially responsible for tissue repair after injury, their number should be increased during these situations. To demonstrate their number during these situations, we measured MSCs in the peripheral blood of healthy donors and burn patients. MATERIALS AND METHODS: Blood samples were obtained from 15 acute burn patients and 15 healthy donors. We performed flow cytometric analysis, using a large monoclonal antibody panel: CD44, CD45, CD14, DR, CD34, CD19, CD13, CD29, CD105, CD1a, CD90, CD38, CD25. MSC phenotype was considered positive for CD44, CD13, CD29, CD90, and CD105, and negative for the other monoclonals. The testing was performed on day 3 after injury. We correlated the results with the age, sex, and size and type of burns. RESULTS: Cells expressing the MSC phenotype were detected in the peripheral blood of both groups. Noteworthy, compared with samples from healthy donors (0.0078 +/- 0.0044), blood obtained from burn patients showed a higher MSC percentage (0.1643 +/- 0.115; P < .001). The percentage of MSCs correlated with the size and severity of the burn. Increased values were also observed among younger patients. CONCLUSIONS: MSCs have an important role in regenerative processes of human tissues. We found cells phenotypically identical to MSCs circulating in physiological number in normal subjects, but in significantly higher amounts during acute large burns. Therefore, they may represent a previously unrecognized circulatory component to the process of skin regeneration.

Human mesenchymal stem cells are tolerized by mice and improve skin and spinal cord injuries.

INTRODUCTION: We sought to use human mesenchymal stem cells (HMSC) for skin and spinal cord repair in mice. MATERIALS AND METHODS: Human bone marrow obtained from a young healthy donor was used to separate and culture human mesenchymal stem cells (HMSC). Ten mice were included in each of four groups. A full-thickness skin defect was surgically performed on all mice in groups 1 and 2. A transverse complete medullar section was performed in groups 3 and 4. Groups 1 and 3 received HMSC IV infusion and local HMSC polymer implant. Groups 2 and 4 received only the IV HMSC infusion. Five control animals from each group went through the same lesions but they didn't receive treatment. RESULTS: After local administration of HMSC into the fibrin polymer combined with the IV infusion of HMSC, there was no immune rejection; all skin defects healed without scar or retraction at a median time of 14 days. Sixty percent of the animals treated with IV infusion and polymer with HMSC simultaneously had improved neurological activities, while all control mice with spinal cord injury experiments died or perpetuated their paralysis with worsening muscular atrophy and increasing propensity to skin damage. CONCLUSIONS: HMSC are not immunologically reactive and can trespass species defense barriers. Animals treated with these cells repaired injuries better than controls. In this way we propose that universal HMSC from donors can be cultured, expanded, and cryopreserved to be used in human organ or tissue regeneration.