Forming a new perspective: Post-structural approaches to determination of donor compatibility and post-transplant assessment of allograft health.

The purpose of this review is to encourage a new perspective on the question of donor-recipient compatibility and post-transplant assessment of graft health based on functional measures. The premise is that we should be better sighted on what (and how) the immune system responds toward rather than what is merely there. Continuance of the pursuit of further and better definition of antigens and antibodies is not however discouraged but seen as necessary to improved understanding of the structural correlates of functional immunity. There currently exists, in the opinion of the authors, an opportunity for histocompatibility and immunogenetics laboratories to develop and widen their scope of involvement into these new areas of laboratory activity in support and to the benefit of the transplant programmes they serve.

Assessment of immunosuppression induction with basiliximab compared to antithymocyte-globulin in adult heart transplant patients.

BACKGROUND: Patients undergoing heart transplants are at risk of rejection which can have significant morbidity and mortality. Induction immunosuppression at the time of transplant reduces the early risk and has additional benefits. The induction agent of choice within our program was changed from rabbit antithymocyte-globulin (rATG) to basiliximab, so it was necessary to evaluate whether this had any impact on patient outcomes. OBJECTIVES: Our primary objective was to describe rejection, infection, and other outcomes in adult heart transplant patients at the University of Alberta Hospital in Edmonton, Canada. METHODS: This study was a nonrandomized, retrospective cohort study. RESULTS: Sixty-three patients were included with median ages 50 years versus 54 years. More female patients received rATG (20% vs. 42.4%). The most common indication for transplant in both cohorts was ICM (63.3% vs. 57.6%). Patients who received rATG had significantly higher PRA (0% vs. 43%, p < .001). Acute rejection episodes were similar between basiliximab and rATG at 3 months (16.7% vs. 15.1%; p = 1.0) and 6-months (30.0% vs. 18.1%; p = .376). Infections were not statistically different with basiliximab compared to rATG at 3-months, 43.3% vs. 63.6% and at 6-months 60.0% vs. 66.7%). There were no fatalities in either group. CONCLUSIONS: Our study did not demonstrate differences in rejection with basiliximab compared to rATG. Mortality did not differ, but basiliximab-treated patients had fewer infections and infection-related hospitalizations than those treated with rATG. Larger studies with longer durations are needed to more completely describe the differences in rejection and infectious outcomes.

Assessment of biological organ age using molecular pathology in pre-transplant kidney biopsies.

Organ shortage is a major challenge in kidney transplantation but the use of older donors, often with co-morbidities, is hampered by inconsistent outcomes. Methods of accurately stratifying marginal donor organs by clinical and histological assessment are lacking. To better understand organ variability, we profiled the transcriptomes of 271 kidneys from deceased donors at retrieval. Following correction for biopsy composition, we assessed molecular pathways that associated with delayed, and sub-optimal one-year graft function. Analysis of cortical biopsies identified an adaptive immune gene-rich module that significantly associated with increasing age and worse outcomes. Cellular deconvolution using human kidney reference single cell transcriptomes confirmed an increase in kidney-specific B and T cell signatures, as well as kidney macrophage, myofibroblast and fibroblast gene sets in this module. Surprisingly, innate immune pathway and neutrophil gene signature enrichment was associated with better outcomes. Thus, our work uncovers cellular molecular features of pathological organ ageing, identifiable at kidney retrieval, with translational potential.

Maximizing matching, equity and survival in kidney transplantation using molecular HLA immunogenicity quantitation.

HLA matching improves long-term outcomes of kidney transplantation, yet implementation challenges persist, particularly within the African American (Black) patient demographic due to donor scarcity. Consequently, kidney survival rates among Black patients significantly lag behind those of other racial groups. A refined matching scheme holds promise for improving kidney survival, with prioritized matching for Black patients potentially bolstering rates of HLA-matched transplants. To facilitate quantity, quality and equity in kidney transplants, we propose two matching algorithms based on quantification of HLA immunogenicity using the hydrophobic mismatch score (HMS) for prospective transplants. We mined the national transplant patient database (SRTR) for a diverse group of donors and recipients with known racial backgrounds. Additionally, we use novel methods to infer survival assessment in the simulated transplants generated by our matching algorithms, in the absence of actual target outcomes, utilizing modified unsupervised clustering techniques. Our allocation algorithms demonstrated the ability to match 87.7% of Black and 86.1% of White recipients under the HLA immunogenicity threshold of 10. Notably, at the lowest HMS threshold of 0, 4.4% of Black and 12.1% of White recipients were matched, a marked increase from the 1.8% and 6.6% matched under the prevailing allocation scheme. Furthermore, our allocation algorithms yielded similar or improved survival rates, as illustrated by Kaplan-Meier (KM) curves, and enhanced survival prediction accuracy, evidenced by C-indices and Integrated Brier Scores.

Current approaches for risk assessment of intestinal transplant patients: A view from the histocompatibility laboratory.

Despite its recent decline in volumes, intestinal transplantation remains an important option for patients with irreversible intestinal failures. The long-term outcome of an intestinal transplant has stagnated. The major cause of graft loss is rejection, resulting from mismatches in human leukocyte antigens (HLA) and the presence of antibodies to mismatched donor-specific HLA antigens (DSA). Literature has reported that DSAs, either preformed before transplantation or developed de novo after transplantation, are harmful to intestinal grafts, especially for those without combined liver grafts. A comprehensive assessment of DSA by the histocompatibility laboratory is critical for successful intestinal transplantation and its long-term survival. This paper briefly reviews the history and current status of different methods for detecting DSA and their clinical applications in intestinal transplantation. The focus is on applying different antibody assays to manage immunologically challenging intestinal transplant patients before and after transplantation. A clinical case is presented to illustrate the complexity of HLA tests and the necessity of multiple assays. The review of risk assessment by the histocompatibility laboratory also highlights the need for close interaction between the laboratory and the intestinal transplant program.

Hospitalizations for cardiovascular diseases and the coverage by the family health strategy / Internações por doenças cardiovasculares e a cobertura da estratégia saúde da família / Internaciones por enfermedades cardiovasculares y la cobertura de la estrategia salud de la familia

AbstractObjective: to verify the correlation between the rates of hospitalization for primary care-sensitive cardiovascular diseases and the coverage by the Family Health Strategy of residents of the State of Paraná, by regional health divisions, from 2000 to 2011.Method: ecological study developed from data of the Hospital Information System of the Brazilian Unified Health System (SUS) and the Department of Primary Care of the Ministry of Health. The rates of hospitalization for cardiovascular diseases were correlated with the annual coverage by the Family Health Strategy using Pearson's and Spearman's correlation coefficients.Result: there was a strong and negative correlation in the State of Paraná (r=-0.91; p <0.001) and in most regional health divisions, with the highest correlations observed in the Metropolitan and Toledo (r =-0.93; p<0.001) and Paranaguá (r=-0.92, p<0.001) regional health divisions.Conclusion: the results suggest that the increase in the coverage by the Family Health Strategy was an important factor for decrease in the hospitalizations for cardiovascular conditions among residents of the State of Paraná and in most regional health divisions. Other studies should be performed to analyze the factors and causes in regional health divisions where there was no correlation with increase in the Family Health Strategy.

ResumoObjetivo:verificar a correlação entre taxas de internação por doenças cardiovasculares sensíveis à atenção primária e a cobertura da Estratégia Saúde da Família de residentes no estado do Paraná, por regionais de saúde, no período de 2000 a 2011.Método:estudo ecológico, desenvolvido a partir de dados do Sistema de Informações Hospitalares do Sistema Único de Saúde e do Departamento de Atenção Básica do Ministério da Saúde. Correlacionaram-se as taxas de internação por doenças cardiovasculares com as coberturas anuais da Estratégia Saúde da Família, utilizando-se os coeficientes de correlação de Pearson e Spearman.Resultado:houve correlação negativa e forte no estado do Paraná (r=-0,91; p<0,001) e na maioria das regionais de saúde, sendo maior na Metropolitana e Toledo (r=-0,93; p<0,001) e Paranaguá (r=-0,92; p<0,001).Conclusão:os resultados sugerem que o aumento da cobertura da Estratégia Saúde da Família foi fator importante para a diminuição das internações por condições cardiovasculares em residentes no estado do Paraná e na maioria das regionais de saúde. Outros estudos devem ser realizados para analisar fatores e causas nas regiões do estado onde não houve correlação com incremento da Estratégia Saúde da Família.

ResumenObjetivo:verificar la correlación entre tasas de internación por enfermedades cardiovasculares sensibles a la atención primaria y la cobertura de la Estrategia Salud de la Familia de residentes en el estado de Paraná, por regionales de salud, en el período de 2000 a 2011.Método:estudio ecológico, desarrollado a partir de datos del Sistema de Informaciones Hospitalarias del Sistema Único de Salud y del Departamento de Atención Básica del Ministerio de la Salud. Se correlacionaron las tasas de internación por enfermedades cardiovasculares con las coberturas anuales de la Estrategia Salud de la Familia, utilizando los coeficientes de correlación de Pearson y Spearman.Resultado:hubo correlación negativa y fuerte en el estado de Paraná (r=-0,91; p<0,001) y en la mayoría de las regionales de salud, siendo mayor en la Metropolitana y Toledo (r=-0,93; p<0,001) y Paranaguá (r=-0,92; p<0,001).Conclusión:los resultados sugieren que el aumento de la cobertura de la Estrategia Salud de la Familia fue un factor importante para la disminución de las internaciones por condiciones cardiovasculares en residentes en el estado de Paraná y en la mayoría de las regionales de salud. Otros estudios deben ser realizados para analizar factores y causas en las regiones del estado en donde no hubo correlación con incremento de la Estrategia Salud de la Familia.