C4d-positive chronic rejection: a frequent entity with a poor outcome.

BACKGROUND: Chronic rejection (CR) is an important cause of kidney graft loss. Some studies have suggested the role of antibodies mediating chronic graft dysfunction. In this context, C4d identification is an important tool to evaluate antibody-mediated rejection. METHOD: This is a retrospective study that analyzed 80 patients with histological diagnosis of chronic allograft nephropathy (CAN) according Banff 97 and no evidence of transplant glomerulopathy. These patients had renal biopsies available for C4d immunoperoxidase staining at the time of diagnosis. Cases were reclassified by the presence of C4d in peritubular capillaries. RESULTS: C4d was negative in 30 cases (37.5%) and positive in 50 (62.5%). C4d+ group had more female and highly sensitized patients (PRA) at transplant. All variables were similar between C4d- and C4d+ cases at diagnosis time, but more C4d+ patients presented proteinuria (>0.3 g/L). Patients were submitted to various immunosuppression regimens after the CAN diagnosis. Four years after the diagnosis, death-censored graft survival was 87% for C4d- and 50% for C4d+ (P=0.002). In the multivariate Cox regression analysis, C4d+, PRA>10%, and vascular intimal proliferation were the variables that present higher relative risk for graft loss. CONCLUSION: These data indicate that C4d positive chronic rejection is very common, associated with proteinuria, and has a poor outcome. A larger study is warranted to identify which immunosuppressive regimen may modify the poor course of this entity.

Decréscimo transitório da função renal no pós-operatório imediato de paratireoidectomia: uma observação clínica indicativa da ação hemodinâmica renal do hormônio da paratireóide? / Transitory decrease of renal function after parathyroidectomy: a clinical observation indicating the renal hemodynamic effect of parathyroid hormone?

Introdução: a hipocalcemia recebe grande atenção após paratireoidectomia no tratamento do hiperparatireoidismo (HPT). Há evidência de decréscimo da função renal após paratireoidectomia em transplantados renais. Essa alteração é pouco estudada após o tratamento do HPT primário. Objetivo: avaliar a variação da creatinina no pós-operatório de diferentes modalidades de operações em Cirurgia de Cabeça e Pescoço. Casuística e Método: estudo retrospectivo de 1997 a 2007 da variação da creatinina após operações em doentes com HPT primário, HPT após transplante renal bem sucedido, ressecção de tumores de cabeça e pescoço em transplantados renais, tireoidectomia e ressecção de neoplasias em cabeça e pescoço. Analisaram-se a creatinina pré-operatória e as medidas pós-operatórias próximas. Calculou-se a diferença percentual do valor pós-operatório em relação ao pré, pela diferença pós e pré, dividida pelo valor préoperatório. Resultados: Houve elevação da creatinina pósoperatória superior a 10% em 77 de 105 casos de HPT primário, em 32 de 38 doentes transplantados renais após paratireoidectomia, em um de sete transplantados renais operados por outros tumores, em 11 de 22 indivíduos submetidos à tireoidectomia total e em três casos de 18 portadores de câncer de mucosa ou pele de cabeça e pescoço. As médias de variação percentual foram de +30,8%, +39,5%, -2,7%, +18,7% e -6,4%, respectivamente, nos grupos citados. Não houve diferença significativa entre os transplantados renais com HPT, os tireoidectomizados e portadores de HPT primário. Houve diferença significativa entre os transplantados renais entre si (p<0,05, Kruskal-Wallis) e entre os portadores de HPT primário e os tratados por câncer de cabeça e pescoço (p<0,001, Kruskal-Wallis). Quando os tireoidectomizados foram estratificados de acordo com a ocorrência de hipocalcemia pósoperatória (possível hipoparatireoidismo), houve diferença significativa, com média de elevação da creatinina média 28,5% nos hipocalcêmicos e de 1,2% nos não hipocalcêmicos (p=0,02, Teste t não pareado). Conclusão: Em operações com redução aguda do nível de paratormônio há elevação do nível de creatinina também de modo agudo. Essa observação é compatível com estudos em animais que mostraram diminuição da função renal após paratireoidectomia em ratos.

Introduction: hypocalcemia is the major concern after parathyroid operations. Notwithstanding, there are some reports of decreased renal function after parathyroidectomy after renal transplantation. Little attention was given to creatinine levels after primary hyperparathyroidism operation. Objective: to evaluate the creatinine levels after the surgical treatment of different head and neck patients groups. Patients and methods: retrospective analysis of creatinine levels of patients operated on from 1997 to 2007 for primary hyperparathyroidism, hyperparathyroidism after successful renal transplantation, head and neck neoplasms in both renal transplant and non transplant patients and thyroid disorders. Creatinine values before and close after surgical treatment were evaluated. Percent creatinine variation was calculated by subtracting preoperative from postoperative value and dividing this result by the preoperative level. Results: More than 10% creatinine elevation occurred in 77 of 105 patients with primary hyperparathyroidism, in 32 of 38 cases of parathyroidectomy after renal transplantation, in 1 of 7 renal transplant patients with other head and tumors, in 11 of 22 individuals after thyroidectomy and in 3 of 18 submitted to major head and neck surgery for cancer. Mean percent variations of creatinine were +30.8%, +39.5%, -2.7%, +18.7% e - 6.4%, respectively for those groups. No significant differences were observed between hyperparathyroidism transplant renal cases, thyroid patients and primary hyperparathyroidism individuals. Significant difference occurred between transplant patients with and without hyperparathyroidism (p<0.05, Kruskal-Wallis), and among those with primary hyperparathyroidism and head and neck neoplasms (p<0.001, Kruskal-Wallis). When thyroidectomy patients were stratified according to the postoperative hypocalcemia and presumed hypoparathyroidism, a significant difference was observed. Mean creatinine increase was of 28.5% for those with hypocalcemia and only 1.2% on the other group (p=0.02, non paired t test). Conclusion: Acute elevation of creatinine was observed in operations with acute reduction of parathyroid hormone. This clinical observation is in accordance with previous animals studies showing renal function reduction after parathyroidectomy.

Screening for significant coronary artery disease in high-risk renal transplant candidates.

BACKGROUND: Renal transplant candidates are at an increased risk for coronary artery disease (CAD), a strong predictor of cardiovascular events [major adverse coronary events (MACE)]. Coronary angiography is a costly, risky, invasive procedure. We sought to determine clinical predictors of significant CAD (stenosis > or =70%) in high-risk renal transplant candidates. METHODS: Clinical evaluation and coronary angiography were performed in 301 patients (57+/-8 years, 73% men) on hemodialysis for 32 months (median). Patients were followed-up for 22 months (median). Inclusion criteria were diabetes (type 1 or 2), evidence of cardiovascular disease, or age > or =50 years. Risk factors included hypertension (93.7%), overweight/obesity (54.3%), dyslipidemia (44.9%), diabetes (42.1%), and smoking (24.3%). Cardiovascular disease was found as follows: peripheral arterial disease (PAD) (31.2%), angina (28.1%), stroke (12.9%), myocardial infarction (MI) (10.3%), and heart failure (9.3%). RESULTS: Significant CAD was found in 136 individuals (45.2%). Diabetes [odds ratio (OR)=1.82; 95% confidence interval (CI)=1.08-3.07], PAD (OR=2.50; 95% CI=1.44-4.37), and previous MI (OR=7.75; 95% CI=3.03-23.98) were associated with significant CAD. The prevalence of significant CAD increased with the number of clinical predictors from 26% (none) to 100% (all present) (P<0.0001). The incidence of fatal/nonfatal MACE increased two, four, and sixfold in those with diabetes, PAD, or previous MI, respectively (P<0.0001). CONCLUSIONS: In high-risk patients with end-stage renal disease, the prevalence of CAD and the incidence of MACE were high. Significant CAD or cardiovascular complications were not related to the majority of classic risk factors. Patients with diabetes, PAD, or previous MI are at higher risk of CAD, MACE, or both and, thus, must be referred for invasive diagnostic procedures.

Renal cell carcinoma in renal transplant patients.

OBJECTIVES: To report our experience with renal cell carcinoma in patients with end-stage renal failure receiving dialysis at two institutions that perform a large number of transplantations. Renal cell carcinoma is more frequent in patients with end-stage renal failure treated with dialysis and in renal transplant patients than in the population at large. METHODS: We reviewed the case histories of 1375 consecutive patients who had transplanted kidneys functioning for more than 1 year. RESULTS: Eleven renal tumors were found in 10 patients (1.37%); 10 of the tumors (90%) were in the native kidney (9 unilateral and 1 bilateral) and 1 (10%) was in the transplanted kidney. The tumors in the native kidneys were discovered incidentally. Three were in organs removed for treatment of arterial hypertension and the other seven were found by ultrasonography. The tumor in the transplanted kidney was found after nephrectomy for the treatment of hematuria. The tumor types were clear cell in six, papillary in four, and chromophobe in one. Of the 9 patients who were treated with radical nephrectomy, 7 were alive with no evidence of the disease and 2 had died of other causes, also with no evidence of the disease. One patient who already had metastases at the diagnosis did not undergo surgery and died 4 months later. CONCLUSIONS: The native kidneys of renal transplant patients should be examined by ultrasonography annually because they are at greater risk of renal cell carcinoma. Radical nephrectomy cures those cases in which the tumors are clinically localized and 6 cm or less in size.

Diabetes and coronary artery disease impose similar cardiovascular morbidity and mortality on renal transplant candidates.

BACKGROUND: In renal transplant candidates (RTC), diabetes and coronary artery disease (CAD) are commonly observed. However, whether diabetes imparts a cardiovascular risk equivalent to that of CAD and whether CAD adds to the cardiovascular risk associated with diabetes is unknown. METHODS: To assess the interplay between diabetes and CAD as a determinant of major adverse cardiovascular events (MACE), 288 high-risk RTC (56.4+/-8.1 years old, 72% males) underwent a comprehensive cardiovascular evaluation including coronary angiography. Patients were divided into four groups based on the diagnoses of diabetes and CAD (>70% narrowing), and followed up for 1-60 months (median, 17). The primary endpoint was the composite incidence of fatal/non-fatal MACE. RESULTS: During follow-up, 80 MACE occurred. Patients with diabetes (P=0.03) or CAD (P<0.0001) had a worse long-term prognosis. However, only in patients without diabetes was CAD associated with an increased incidence of MACE (10.6% vs 45.9%, P<0.0001). In patients with diabetes, the endpoints were not different between those with and without CAD. No difference occurred in the long-term prognosis of patients with diabetes (with or without CAD) and patients without diabetes with CAD. CONCLUSIONS: We concluded that in high-risk RTC, diabetes confers a cardiovascular risk comparable to that of CAD in patients without diabetes, independent of coronary obstruction. In patients with diabetes, concomitant CAD does not add to the already very high cardiovascular risk of this population.

Recorrência de glomerulosclerose segmentar e focal em rins transplantados / Recurrence of segmental and focal glomerulosclerosis in transplanted kidneys

Relatamos a evoluçäo de 16 pacientes com glomerulosclerose segmentar e focal (GESF), que receberam transplante de rim. Dez dos 16 (grupo 1) tinham o diagnóstico confirmado histologicamente nos rins nativos. Em seis (grupo 2) o diagnóstico foi sugerido em virtude do aparecimento precoce de GESF no enxerto, o qual foi considerado com recidiva da doença primária. O percentual e recidiva (grupo 1) foi de 40%, sendo o principal marcador clínico a proteinúria, de nível nefrótico e de aparecimento precoce em todos os casos, isto é, em tempo menor do que 60 dias. Naqueles pacientes que apresentaram evoluçäo mais rápida da doença primitiva, em tempo menor que quatro anos, o percentual de recorrência da glomerulosclerose focal. Por outro lado, aqueles pacientes com tempo maior de evoluçäo da doença primária apresentaram evoluçäo mais benigna da glomerulosclerose recidivada, näo se observando nenhuma perda do enxerto pela recidiva. Acreditamos que o transplante renal, com doador vivo, deva ser evitado para aqueles pacientes com GESF de rápida evoluçäo