RESUMO

Evaluation of patients for kidney transplant candidacy is a comprehensive process that involves a detailed assessment of medical and surgical issues, psychosocial factors, and patients' physical and cognitive abilities with an aim of balancing the benefits of transplantation and potential risks of surgery and long-term immunosuppression. There is considerable variability among transplant centers in their approach to evaluation and decision-making regarding transplant candidacy. The 2020 KDIGO (Kidney Disease: Improving Guidelines Outcome) clinical practice guideline on the evaluation and management of candidates for kidney transplantation provides practice recommendations that can serve as a useful reference guide to transplant professionals. The guideline, covering a broad range of topics, was developed by an international group of experts from transplant and nephrology through a review of literature published until May 2019. A work group of US transplant nephrologists convened by NKF-KDOQI (National Kidney Foundation-Kidney Disease Quality Initiative) chose key topics for this commentary with a goal of presenting a broad discussion to the US transplant community. Each section of this article has a summary of the key KDIGO guideline recommendations, followed by a brief commentary on the recommendations, their clinical utility, and potential implementation challenges. The KDOQI work group agrees broadly with the KDIGO recommendations but also recognizes and highlights the decision-making challenges that arise from lack of high-quality evidence and the need to balance equity with utility of organ transplantation.

Assuntos

RESUMO

El éxito de un trasplante hepático en gran parte radica en la selección del candidato óptimo y del mejor órgano. En los últimos años se ha trabajado de forma importante hacia la elaboración de criterios de selección y de asignación basados en la evidencia. La evaluación histopatológica de las biopsias hepáticas desempeña un papel importante en el contexto del trasplante hepático, tanto en la evaluación pretrasplante de órganos considerados como marginales y en el diagnóstico y el tratamiento del paciente que ha recibido un trasplante. El uso de la biopsia intraoperatoria para evaluar órganos marginales en la evaluación pretrasplante es debatido por unos grupos y apoyado por otros. Por otra parte, los cambios morfológicos que ocurren en el postrasplante como el rechazo agudo celular y el rechazo crónico están muy bien reconocidos y la biopsia hepática sigue siendo considerada el patrón oro para el diagnóstico de estas condiciones, no así la biopsia del posible donante, sin embargo su precisión ha sido cuestionada debido en gran parte a la gran variabilidad y subjetividad, dadas principalmente por las dificultades diagnósticas que plantea esta patología y a la experiencia del patólogo (1). En esta revisión se discutirán los tópicos más importantes y frecuentes, así como algunos que pueden crear problemas de diagnóstico en patología del trasplante, se hará énfasis en las características patológicas y el diagnóstico diferencial. Los temas serán tratados en tres partes, esta primera entrega corresponde a los aspectos relevantes de la biopsia del donante.

The success of liver transplantation depends largely on the selection of the optimal donor and the best organ. In recent years significant work has been done to develop selection criteria and evidence-based organ assignments. Histopathological evaluation of liver biopsies plays an important role both in pretransplant evaluation of possibly marginal organs and in the diagnosis and treatment of patients who receive transplants. The use of intraoperative biopsies to evaluate organs found to be marginal in the pretransplant evaluation is opposed by some groups and supported by others. On the other hand, in contrast to the debate about the use of liver biopsies to evaluate donor organs, liver biopsies are still considered to be the “gold standard” for diagnosis of morphological changes such as acute rejection and chronic rejection that occur following transplantation. Nevertheless, the accuracy of biopsies has been questioned due to the variability and subjectivity of these evaluations which is caused primarily by the diagnostic difficulties posed by this disease and by the experience of the pathologist (1). The most important and frequent topics in this area will be discussed in this review. In addition, issues that can cause problems for diagnosing pathologies of the donor organ will be discussed. The article emphasizes pathological features and differential diagnosis. It is organized into three installments. This installment, the first, is about issues relevant aspects to biopsies of the donor organ.

Assuntos