Low bone remodeling and relatively low serum parathyroid hormone (PTH) levels characterize adynamic bone disease (ABD). The impact of renal transplantation (RT) on the course of ABD is unknown. We studied prospectively 13 patients with biopsy-proven ABD after RT. Bone histomorphometry and bone mineral density (BMD) measurements were performed in the 1st and 12th months after RT. Serum PTH, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and osteocalcin were measured regularly throughout the study. Serum PTH levels were slightly elevated at transplantation, normalized at the end of the third month and remained stable thereafter. Bone biopsies performed in the first month after RT revealed low bone turnover in all patients, with positive bone aluminum staining in 5. In the 12th month, second biopsies were performed on 12 patients. Bone histomorphometric dynamic parameters improved in 9 and were completely normalized in 6, whereas no bone mineralization was detected in 3 of these 12 patients. At 12 months post-RT, no bone aluminum was detected in any patient. We also found a decrease in lumbar BMD and an increase in femoral BMD. Patients suffering from ABD, even those with a reduction in PTH levels, may present partial or complete recovery of bone turnover after successful renal transplantation. However, it is not possible to positively identify the mechanisms responsible for the improvement. Identifying these mechanisms should lead to a better understanding of the physiopathology of ABD and to the development of more effective treatments.
PURPOSE: To assess the agreement between clinical and histopathological diagnosis in a renal transplantation center, 40 episodes of acute renal failure were studied. METHODS: Kidney biopsies were performed at the moment that a clinical diagnosis was made by the staff. RESULTS: Nineteen episodes of acute tubular necrosis (ATN), eighteen episodes of acute cellular rejection (ACR), 2 humoral rejections and 1 acute cyclosporin nephrotoxicity episodes were diagnosed. ATN episodes were confirmed by renal biopsy in 84.21%, ACR episodes in 83.33%, humoral rejections in 100%. Renal biopsy showed ATN in the occurrence of clinical cyclosporin nephrotoxicity. Total agreement was 82.5%. CONCLUSION: There is a good relationship between clinical and histopathological diagnosis in the post-transplantation period. Diagnostic mistakes occurred mainly when oliguria was present.
OBJETIVO: Para determinar o acerto obtido pelos diagnósticos efetuados em uma unidade de transplante renal, foram analisados 40 episódios de disfunção renal aguda que ocorreram no período pós-transplante. MÉTODOS: Os pacientes foram submetidos a biópsia renal por ocasião do episódio de insuficiência renal ao mesmo tempo em que o diagnóstico clínico era realizado pelos membros da equipe. RESULTADOS: Foram realizados 19 diagnósticos de necrose tubular aguda (NTA), 18 de rejeição celular aguda (RCA), dois de rejeição humoral (RH) e um de nefrotoxicidade (NTX) pela ciclosporina A (CyA). O diagnóstico de NTA foi confirmado pela histologia em 84,21%, o de RCA, em 83,33%, o de RH em 100% e o único diagnóstico de NTX realizado se apresentou como NTA à biópsia. No total, a clínica foi concordante com a histologia em 82,5% das vezes. CONCLUSÃO: Os autores concluíram que existe uma boa acurácia nos diagnósticos clínicos de RCA, NTA e RH realizados em um centro experiente em transplante renal.