The pathogenesis of osteodystrophy after renal transplantation as detected by early alterations in bone remodeling

The pathogenesis of osteodystrophy after renal transplantation as detected by early alterations in bone remodeling.BackgroundLoss of bone mass after transplantation begins in the early periods after transplantations and may persist for several years, even in patients with normal renal function. While the pathogenesis of these abnormalities is still unclear, several studies suggest that preexisting bone disease, glucocorticoid therapy, and alterations in phosphate metabolism may play important roles. Recent studies indicate that osteoblast apoptosis and impaired osteoblastogenesis play important roles in the pathogenesis of glucocorticoid-induced osteoporosis.ObjectivesTo examine the early alterations in osteoblast number and surfaces during the period following renal transplantation.MethodsTwenty patients with a mean age of 36.5 ± 12 years were subjected to bone biopsy 22 to 160 days after renal transplantation. In 12 patients, a control biopsy was performed on the day of transplantation. Bone sections were evaluated by histomorphometric analysis and cell DNA fragmentation by the methods of terminal deoxynucleotidyl transferase-mediated uridine triphosphate nick end labeling (TUNEL), using immunoperoxidase and direct immunofluorescence techniques.ResultsThe main alterations in posttransplant biopsies were a decrease in osteoid and osteoblast surfaces, adjusted bone formation rate, and prolonged mineralization lag time. Peritrabecular fibrosis was markedly decreased. None of the pretransplant biopsies revealed osteoblast apoptosis. In contrast, TUNEL-positive cells in the proximity of osteoid seams or in the medullary space were observed in nine posttransplant biopsies of which four had mixed bone disease, two had adynamic bone disease, one had osteomalacia, one had osteitis fibrosa, and one had mild hyperparathyroid bone disease. Osteoblast number in posttransplant biopsies with apoptosis was lower as compared with posttransplant biopsies without apoptosis. In addition, most of them showed a marked shift toward quiescence from the cuboidal morphology of active osteoblasts. Serum phosphorus levels were lower in patients showing osteoblast apoptosis and correlated positively with osteoblast number and negatively with the number of apoptotic osteoblasts. In addition, posttransplant osteoblast surface correlated positively with parathyroid hormone (PTH) levels and negatively with glucocorticoid cumulative dose.ConclusionThe data suggest that impaired osteoblastogenesis and early osteoblast apoptosis may play important roles in the pathogenesis of posttransplant osteoporosis. The possible mechanisms involved in the pathogenesis of theses alterations include posttransplant hypophosphatemia, the use of glucocorticoids, and the preexisting bone disease. PTH seems to have a protective effect by preserving osteoblast survival

Alemtuzumab induction in kidney transplant recipients

INTRODUCTION: Induction therapy has been used in sensitized patients, re-transplants, and in patients who have high risk to delayed graft function (DGF) after renal transplantation. METHODS: Retrospective study with aim to compare transplant endpoints between recipients of deceased donors which have received induction with alemtuzumab (n = 9) versus thymoglobulin (n = 18). Patients were matched for age, duration of dialysis treatment and cold ischemia time. RESULTS: There were no differences at demographic characteristics. All patients received kidney grafts from deceased donors and 67% of these donors met the expanded criteria. The incidence of DFG was similar in alemtuzumab and thymoglobulin groups, 55% and 56%. At 12 months, rates of rejection free survival (67% versus 89%, p = 0,13), graft survival (62,5% versus 76,6%; p = 0,73), graft with death censored (62,5% versus 76,6%; p = 0,82) and patient survival (83,3% versus 81,2%; p = 0,63) were similar between the two groups. Viral infections and renal function were similar between groups. At the end of the first month, alemtuzumab patients displayed a fewer lymphocyte number (135 ± 78 versus 263 ± 112 N/mm³, p < 0,05) followed by a more rapid recovery after 3 months (day 90: 683 ± 367 versus 282 ± 72 N/mm³; p < 0,05). Cost associated with alemtuzumab and thymoglobulin inductions therapies were R$1,388.00 and R$ 7,398.00. CONCLUSION: In this cohort of patients, alemtuzumab induction showed efficacy and safety comparable to thymoglobulin but with significant cost reduction.INTRODUÇÃO: Terapias de indução são usualmente utilizadas em receptores sensibilizados contra antígenos HLA, retransplantes e pacientes com risco de apresentar função tardia do enxerto (FTE). MÉTODO: Estudo retrospectivo com objetivo de avaliar os desfechos do transplante renal com doador falecido em pacientes que receberam indução com alentuzumabe (n = 9). Os pacientes do grupo controle, pareados conforme idade do receptor, tempo em diálise e tempo de isquemia fria, receberam timoglobulina (n = 18). RESULTADOS: Não houve diferença nas características demográficas entre os grupos. A idade média dos receptores foi de 47 anos e dos doadores, de 59 anos. Entre os doadores, 67% apresentavam critério expandido. A incidência de FTE foi de 55% e 56%, respectivamente. Ao final do primeiro ano, não houve diferença nas sobrevidas livre de rejeição aguda comprovada por biópsia (67,0% e 84,6%, p = 0,26), do paciente (83,3% e 81,2%; p = 0,63), do enxerto (62,5% e 66,7%; p = 0,82), do enxerto com óbito censorado (62,5% e 76,6%; p = 0,73) e na função renal (depuração de creatinina: 61,6 ± 18,2 versus 52,7 ± 26,1 mL/min, p = 0,503). Houve maior redução na contagem de linfócitos no sangue periférico no grupo alentuzumabe (dia 14:172 ± 129 versus 390 ± 195 N/mm³, p < 0,05; dia 30: 135 ± 78 versus 263±112 N/mm³, p < 0,05), porém com retorno mais rápido a valores normais após o transplante (dia 90: 683 ± 367 versus 282 ± 72 N/mm³, p < 0,05; dia 360: 1269 ± 806 versus 690±444 N/mm³, p < 0,05). O custo do tratamento com alentuzumabe foi de R$1.388,00, enquanto que o custo médio com timoglobulina foi de R$ 7.398,00. CONCLUSÃO: Essa experiência com alentuzumabe não demonstrou eficácia e/ou segurança superiores aos regimes com timoglobulina, apesar do custo ser em média cinco vezes menor.Universidade Federal de São Paulo (UNIFESP) Departamento de Medicina Hospital do Rim e HipertensãoUniversidade Federal de São Paulo (UNIFESP) Departamento de Patologia, Transplante Renal e NefropatologiaUNIFESP, Depto. de Medicina Hospital do Rim e HipertensãoUNIFESP, Depto. de Patologia, Transplante Renal e NefropatologiaSciEL

EPIC Trial: education programme impact on serum phosphorous control in CKD 5D patients on hemodialysis

Abstract Introduction: In stage 5D chronic kidney disease (CKD 5D) patients, the encouragement of treatment adherence by health professionals is a significant clinical challenge. Objectives: This study evaluates the impact of a nutritional education programme on hyperphosphatemia, utilizing the transtheoretical model of behavior change (TMBC). Subjects and Methods: A prospective interventional study comprising 179 CKD 5D patients with hypophosphatemia. The 4-month educational programme took place during dialysis sessions. Demographic and laboratory data were evaluated, whilst the TMBC was utilized both pre- and post-intervention. Results: 132 patients showed a positive change and significant reduction in phosphate levels, whilst 47 patients showed a negative change and little reduction in phosphate levels. Positive changes were identified at different levels of literacy. 117/179 participants had ongoing treatment with sevelamer throughout the trial period. 61 patients with intact parathyroid hormone (iPTH) 300 pg/ml also showed a decrease in phosphate levels. Conclusions: Nutritional education programmes can achieve excellent results when appropriately applied. An education programme may be effective across different literacy levels