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1.
Am J Transplant ; 14(11): 2545-55, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25225081

RESUMO

Persistent hyperparathyroidism (HPT) after kidney transplantation (KTx) is associated with hypercalcemia, hypophosphatemia and abnormally high levels of parathyroid hormone (PTH). In this randomized trial, cinacalcet was compared to placebo for the treatment of hypercalcemia in adult patients with persistent HPT after KTx. Subjects were randomized 1:1 to cinacalcet or placebo with randomization stratified by baseline corrected total serum calcium levels (≤11.2 mg/dL [2.80 mmol/L] or >11.2 mg/dL [2.80 mmol/L]). The primary end point was achievement of a mean corrected total serum calcium value<10.2 mg/dL (2.55 mmol/L) during the efficacy period. The two key secondary end points were percent change in bone mineral density (BMD) at the femoral neck and absolute change in phosphorus; 78.9% cinacalcet- versus 3.5% placebo-treated subjects achieved the primary end point with a difference of 75.4% (95% confidence interval [CI]: 63.8, 87.1), p<0.001. There was no statistical difference in the percent change in BMD at the femoral neck between cinacalcet and placebo groups, p=0.266. The difference in the change in phosphorus between the two arms was 0.45 mg/dL (95% CI: 0.26, 0.64), p<0.001 (nominal). No new safety signals were detected. In conclusion, hypercalcemia and hypophosphatemia were effectively corrected after treatment with cinacalcet in patients with persistent HPT after KTx.


Assuntos
Hipercalcemia/tratamento farmacológico , Hiperparatireoidismo/complicações , Transplante de Rim , Naftalenos/uso terapêutico , Adulto , Densidade Óssea , Remodelação Óssea , Cálcio/sangue , Cinacalcete , Método Duplo-Cego , Feminino , Humanos , Hipercalcemia/complicações , Masculino , Pessoa de Meia-Idade , Naftalenos/efeitos adversos , Fósforo/sangue , Placebos
2.
Osteoporos Int ; 22(1): 281-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20229199

RESUMO

UNLABELLED: This study evaluates the efficacy of low doses of pamidronate after renal transplantation to prevent bone loss in osteopenic patients. Results show that pamidronate is safe and significantly reduced spinal bone loss when administered immediately after renal transplantation. INTRODUCTION: The purpose of this work is to evaluate the efficacy of two intravenous infusions of pamidronate in the immediate post-transplant period in a renal transplant (RT) population. METHODS: In this 12-month, randomized, double-blind, multicenter trial, 39 kidney recipients with diagnosed osteopenia received two doses of 30 mg of disodium pamidronate (n = 24) or placebo (n = 15), at surgery and 3 months post-RT. All patients received calcium and vitamin D. Bone density of the lumbar spine and total femur was measured by dual-energy X-ray absorptiometry (DXA) and X-rays were performed at RT, 6 and 12 months post-RT. Biochemical and hormonal determinations were performed before and after treatment. RESULTS: Pamidronate significantly reduced spinal bone loss, but no significant benefit was found for the incidence of fractures. Elevated baseline intact parathyroid hormone (iPTH) and bone remodeling markers returned to normal levels 3 months post-RT. However, normal procollagen type I N propeptide (PINP) concentrations were only maintained in the pamidronate group. After RT, a comparable graft function was observed in both groups according to creatinine values, 25-hydroxyvitamin-D (25-OH-D) levels were improved, and serum calcium levels normalized after a transient fall during the first 3 months. CONCLUSION: A low dose of pamidronate prevents bone loss in osteopenic patients when administered immediately after RT.


Assuntos
Conservadores da Densidade Óssea/administração & dosagem , Doenças Ósseas Metabólicas/tratamento farmacológico , Difosfonatos/administração & dosagem , Transplante de Rim/efeitos adversos , Adulto , Idoso , Densidade Óssea/efeitos dos fármacos , Conservadores da Densidade Óssea/efeitos adversos , Conservadores da Densidade Óssea/uso terapêutico , Doenças Ósseas Metabólicas/etiologia , Doenças Ósseas Metabólicas/fisiopatologia , Remodelação Óssea/efeitos dos fármacos , Creatinina/sangue , Difosfonatos/efeitos adversos , Difosfonatos/uso terapêutico , Métodos Epidemiológicos , Feminino , Fêmur/fisiopatologia , Colo do Fêmur/fisiopatologia , Humanos , Infusões Intravenosas , Vértebras Lombares/fisiopatologia , Masculino , Pessoa de Meia-Idade , Fraturas por Osteoporose/prevenção & controle , Pamidronato , Cuidados Pós-Operatórios/métodos , Resultado do Tratamento
3.
Nephrol Dial Transplant ; 25(7): 2356-63, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20139064

RESUMO

The outcome of patients with cirrhosis and chronic kidney disease treated with combined liver-kidney transplantation (CLKT) is not well known because most series of patients treated with CLKT include not only patients with cirrhosis but also patients with inherited diseases without cirrhosis. To evaluate to what extent the combined kidney transplantation impairs posttransplantation outcome compared to liver transplantation (LT) alone, the outcome of patients with cirrhosis and chronic kidney disease treated with CLKT (n = 20) was compared to that of a group of patients with cirrhosis without chronic kidney disease treated with LT alone matched by age, sex, year of transplantation and severity of cirrhosis (n = 60). The primary end point of the study was survival, and secondary end points were outcome of renal function and complications within 6 months of transplantation. Patients with CLKT had a higher incidence of bacterial infections and transfusion requirements compared to LT patients. The incidence of acute renal failure during the first 6 months was similar, yet the severity of renal failure was greater in patients with CLKT. Hospital and intensive care unit (ICU) stays were longer in the CLKT group. One- and three-year survival probabilities in patients treated with CLKT were 80 and 75% compared to 97 and 88%, respectively, in patients treated with LT. In conclusion, CLKT for patients with cirrhosis and chronic kidney disease is associated with a relatively high frequency of postoperative complications that moderately impairs short-term survival. However, 3-year survival of patients with cirrhosis treated with CLKT is excellent.


Assuntos
Sobrevivência de Enxerto/fisiologia , Nefropatias/cirurgia , Transplante de Rim/fisiologia , Cirrose Hepática/cirurgia , Transplante de Fígado/fisiologia , Adulto , Doença Crônica , Feminino , Humanos , Nefropatias/mortalidade , Transplante de Rim/mortalidade , Cirrose Hepática/mortalidade , Transplante de Fígado/mortalidade , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/epidemiologia , Prevalência , Insuficiência Renal/epidemiologia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
4.
Nefrologia ; 30(3): 288-96, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20514097

RESUMO

Bisphosphonates are synthetic compounds similar to organic pyrophosphates. The bioavailability of intravenous preparations is 100%, whereas the availability of oral therapy ranges from 1 to 5%. About 50% to 80% of free bisphosphonates are incorporated into bone. Because of their urinary elimination, bisphosphonates must be carefully administered in chronic kidney disease (CKD) patients. In spite of this, bisphosphonates can safely be used in all CKD stages, including dialysis and kidney transplant. The renal toxicity seems different among these compounds, and it is due basically to their protein binding and the average lifespan in renal tissues. In practice, renal toxicity have been associate to the infusion velocity and excessive dosage In patients with CKD, it is very relevant to maintain the time of infusion and in haemodialysis patients we recommend the administration during the haemodialysis session. When bisphosphonates are given to 4-5 CKD patients it seems reasonable to reduce the dose to 50%. No renal pathology has been associated to oral administration. The indications of bisphosphonates in CKD include: hypercalcemia episodes, prevention of bone loss after renal transplantation, treatment of low bone mineral density in all CKD stage including transplantation. They are too a promising therapy of calciphylaxis and to prevent vascular calcifications. When suppressed bone turnover is suspected, bone biopsy is mandatory before bisphosphonates therapy.


Assuntos
Difosfonatos/uso terapêutico , Nefropatias/metabolismo , Disponibilidade Biológica , Biópsia , Densidade Óssea/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Osso e Ossos/efeitos dos fármacos , Osso e Ossos/metabolismo , Osso e Ossos/patologia , Calcinose/tratamento farmacológico , Calcinose/prevenção & controle , Calciofilaxia/tratamento farmacológico , Calciofilaxia/prevenção & controle , Doença Crônica , Distúrbio Mineral e Ósseo na Doença Renal Crônica/tratamento farmacológico , Distúrbio Mineral e Ósseo na Doença Renal Crônica/prevenção & controle , Difosfonatos/efeitos adversos , Difosfonatos/química , Difosfonatos/classificação , Difosfonatos/farmacocinética , Humanos , Doenças Maxilomandibulares/induzido quimicamente , Nefropatias/induzido quimicamente , Nefropatias/complicações , Transplante de Rim , Taxa de Depuração Metabólica , Osteonecrose/induzido quimicamente , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle , Doenças Vasculares/tratamento farmacológico , Doenças Vasculares/prevenção & controle
5.
Nefrologia ; 30(2): 158-67, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20098464

RESUMO

For patients with chronic renal failure who develop secondary hyperparathyroidism (SHPT), imaging techniques can be useful, especially to evaluate the location, size and functional status of parathyroid glands. This review analyzes all available imaging procedures in the context of SHPT. We evaluate: 1) Cervical ultrasound (B-mode, Doppler, colour-Doppler and power-Doppler), 2) Scintigraphic studies (Tallium, 99mTc-MIBI and 99mTc-tetrofosmin), including non-standard image acquisition techniques (Pinhole, SPECT), 3) Positron emission tomography (PET), 4) Computed tomography (CT) and magnetic resonance imaging (MRI) and 5) hybrid scanners (SPECT/CT and PET/CT). Our recommendation is that SHPT patients who are initially non responders to medical therapy should be investigated using parathyroid scintigraphy and cervical ultrasound. 99mTc-MIBI uptake can be graded in a semiquantitative scale. Intense uptake indicates a low probability of success using medical treatment and parathyroidectomy should be considered. A moderate to faint uptake indicates that a more intensive medical therapy would probably be beneficial. In the case of no uptake of 99mTc-MIBI, PET should be performed. Where this is not available, MRI could be a possible alternative.


Assuntos
Diagnóstico por Imagem , Hiperparatireoidismo Secundário/diagnóstico , Diagnóstico por Imagem/métodos , Humanos , Hiperparatireoidismo Secundário/diagnóstico por imagem , Hiperparatireoidismo Secundário/etiologia , Hiperparatireoidismo Secundário/cirurgia , Falência Renal Crônica/complicações , Imageamento por Ressonância Magnética , Glândulas Paratireoides/diagnóstico por imagem , Paratireoidectomia , Tomografia por Emissão de Pósitrons , Radiologia Intervencionista , Compostos Radiofarmacêuticos , Tecnécio Tc 99m Sestamibi , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Ultrassonografia Doppler/métodos , Ultrassonografia de Intervenção
6.
Nefrologia ; 30(4): 413-9, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20651882

RESUMO

AIM: To compare the dynamics of calcium-regulated PTH secretion in vitro from adenomatous versus hyperplastic glands and to investigate the relationship between the parathyroid cell cycle and the calcium-regulated PTH secretion in these glands. MATERIALS AND METHODS: A total of 31 parathyroid glands (8 adenomatous and 23 hyperplastic) from 8 patients with primary hyperparathyroidism and 7 with secondary hyperparathyroidism respectively were studied. For the evaluation of calcium-regulated PTH secretion, small parathyroid pieces of 1 mm were sequentially transferred to wells with varying Ca concentrations: 0.4, 0.6, 0.8, 1, 1.25 and 1.35 or 1.5 mM. PTH concentrations were determined in the medium. For the parathyroid cell cycle studies, parathyroid cells were isolated without the use of enzymes and cell cycle was analyzed using the method described by Vindelov. The nuclei were acquired by flow cytometer and analyzed using the CELLFIT software. RESULTS: In parathyroid tissues from hyperplastic glands, the increase in extracellular calcium produced a decrease in PTH secretion which was apparent with a calcium level as low as 0.8 mM and the maximal inhibition of PTH secretion was obtained with a calcium of 1.25 mM, by the contrary, adenomatous glands required a calcium of 1.2 mM to produce a minimal decrease in PTH secretion. In hyperplastic parathyroid glands but not in parathyroid adenomas there was a significant correlation between the percentage of cells in G0/G1 phase with the set point (r = 0.914; P < 0.005) and the basal serum Ca (r = 0.862; P < 0.02). CONCLUSIONS: The control of the extracellular calcium-PTH release in vitro is less sensitive in parathyroid adenomas than hyperplasic parathyroid glands. In parathyroid hyperplasia the cell proliferation may be regulated by the extracellular calcium concentration (higher calcemia less proliferation).


Assuntos
Adenoma/metabolismo , Cálcio/fisiologia , Ciclo Celular/fisiologia , Glândulas Paratireoides/metabolismo , Glândulas Paratireoides/patologia , Hormônio Paratireóideo/metabolismo , Neoplasias das Paratireoides/metabolismo , Feminino , Humanos , Hiperplasia , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade
7.
Nefrologia ; 30(1): 73-7, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20098472

RESUMO

AIM: To compare the dynamics in vivo and in vitro calcium-PTH release of uremic patients with secondary hyperparathyroidism and their hyperplasic parathyroid glands after parathyroidectomy. MATERIALS AND METHODS: Seven patients with secondary HPT and their 23 hyperplasic glands obtained after surgical parathyroidectomy were evaluated. In vivo studies of the PTH secretion curve were obtained by induction of hypocalcemia and hypercalcemia with a continuous endovenous infusion of sodium EDTA and Ca gluconate, respectively. For the in vitro studies, small parathyroid pieces of 1 mm were sequentially transferred to wells with varying Ca concentrations: 0.4, 0.6, 0.8, 1, 1.25 and 1.5 mM. iPTH concentrations were determined in the medium. RESULTS: The in vivo set point did not correlate with the basal, maximal or minimal PTH concentrations, although it correlated significantly with the basal serum Ca concentration (r = 0.62, p < 0.02). Both in vivo and in vitro PTH secretion curves were sigmoidal, although the in vivo set point was higher than the in vitro (1.57 +/- 0.05 vs. 1.27 +/- 0.07 mM, p < 0.001). The degree of maximal PTH inhibition were similar in both circumstances (30.5 +/- 8.1 vs. 33.6 +/- 5.4 %; p = NS) with a significant direct correlation (r = 0.901; p < 0.01). CONCLUSIONS: The in vivo set point of calcium is more closely related to serum calcium concentration than to basal iPTH concentration. Although there are differences between the in vivo and in vitro calcium set point the maximal degree of PTH inhibition was similar in both circumstances.


Assuntos
Cálcio/fisiologia , Hiperparatireoidismo Secundário/metabolismo , Hormônio Paratireóideo/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Tecidos
8.
Nefrologia ; 30(1): 54-63, 2010.
Artigo em Espanhol | MEDLINE | ID: mdl-20038970

RESUMO

INTRODUCTION: During the last years the number of patients on waiting list for kidney transplantation has been stable. Living donor kidney transplantation is nowadays a chance to increase the pool of donors. However, there are a group of patients with ABO incompatibility, making impossible the transplant until now. The aim of the present study is to describe the experience of Hospital Clinic Barcelona on ABO incompatible living transplantation. METHODS: A retrospective- descriptive study was made based on 11 living donor kidney recipients with ABO incompatibility in Hospital Clinic of Barcelona from October'06 to January'09. Selective blood group, antibody removal with specific immunoadsortion, immunoglobulin and anti- CD 20 antibody were made until the immunoglobulin (IgG) and isoaglutinine (IgM) antibody titters were 1/8 or lower. Immunosuppressive protocol was adjusted to particular recipient characteristics. Isoaglutinine titters were set before, during and post desensitization treatment and two weeks after transplant. Immunological, medical and surgical evaluation was the standard in living donor kidney transplant program. RESULTS: Medium age of donors and recipients were 47.8 +/- 12.4 and 44.4 +/- 14.1 years, respectively. 90% of donors were females and 73% of recipients males. Follow-up time was 10.2 +/- 10.2 months. Siblings and spouses were the most frequent relation (n=4, 36.4%, respectively). Chronic glomerulonephritis, adult polycystic kidney disease and Alport syndrome, the most frequent cause of end-stage renal disease. All the patients acquire appropriate isoaglutinine titters pre transplant (< 1/8), requiring 5.54 +/- 2.6 immunoadsorption sessions pretransplant and 2.82 posttransplant. One patient didn t need any immunoadsorption session (incompatibility blood group B) and another patient plasma exchange instead of immunoadsorption for being hypersensitized with positive flow cytometry crossmatch. Posttransplant isoaglutinine titters remained low. Two patients had cellular acute rejection episode (type IA and IB of Banff classification) with good response to corticosteroid treatment. Patient and graft survival were 91% at first year and remain stable during the follow-up. A graft lost by death of patient in relation to haemorrhagic shock developed within the first 72 hours after transplantation. Renal graft function at first year was excellent with serum creatinine of 1.3 +/- 0.8 mg/dl, creatinine clearance of 62.6 ml/min/1.73 m2 and proteinuria of 244.9 mg/U-24h. CONCLUSION: ABO incompatible living donor kidney transplantation represent an effective and safe alternative in certain patients on waiting list for renal transplant, obtaining excellent results in patient and graft survival, with good renal graft function.


Assuntos
Sistema ABO de Grupos Sanguíneos/imunologia , Incompatibilidade de Grupos Sanguíneos , Transplante de Rim/imunologia , Doadores Vivos , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
9.
Nephron Clin Pract ; 108(2): c141-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18259100

RESUMO

BACKGROUND: Secondary hyperparathyroidism remains a serious problem in hemodialysis patients. The therapy of renal osteodystrophy is mainly based on lowering phosphate levels and administering vitamin D(3) metabolites and calcimimetic agents. METHODS: An observational, prospective, multicenter study was made to evaluate the efficacy of alfacalcidol in 185 chronic hemodialysis patients with secondary hyperparathyroidism (i-PTH >150 pg/ml). Patients with a CaxP product >70 were excluded. Intermittent therapy with intravenous alfacalcidol was observed for 6 months. RESULTS: The mean dose of alfacalcidol per week was 3.63 +/- 1.71 microg. Patients previously treated with vitamin D(3) metabolites needed higher doses of alfacalcidol (4.0 +/- 1.7 vs. 3.2 +/- 1.6; p = 0.01). Only 50.8% of the patients had received vitamin D(3) metabolites prior to the start of the study and at baseline they had higher i-PTH levels (600.3 +/- 360.5 vs. 489.9 +/- 292.6, p = 0.02). i-PTH levels decreased from 546 +/- 332.6 to 332.4 +/- 274.5 pg/ml (p < 0.001). 60.5% of the patients had i-PTH < 300 pg/ml at the last observation. Serum calcium increased (9.4 +/- 0.8 to 9.97 +/- 1.0 mg/l, p < 0.001). CONCLUSION: Alfacalcidol reduced the levels of i-PTH and produced a slight increase in serum calcium and phosphate levels. In mild or moderate hyperparathyroidism the doses needed were lower than in severe hyperparathyroidism.


Assuntos
Hidroxicolecalciferóis/uso terapêutico , Hiperparatireoidismo Secundário/tratamento farmacológico , Falência Renal Crônica/terapia , Diálise Renal/efeitos adversos , Idoso , Análise de Variância , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Seguimentos , Humanos , Hiperparatireoidismo Secundário/etiologia , Infusões Intravenosas , Falência Renal Crônica/complicações , Falência Renal Crônica/diagnóstico , Masculino , Pessoa de Meia-Idade , Hormônio Paratireóideo/sangue , Estudos Prospectivos , Valores de Referência , Diálise Renal/métodos , Medição de Risco , Resultado do Tratamento
10.
Minerva Endocrinol ; 33(3): 203-12, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18846026

RESUMO

Preoperative imaging has proved its use successful in the localization of solitary parathyroid adenomas in patients with suspected primary hyperparathyroidism. However, due to multiglandular disease at presentation patients with renal hyperparathyroidism need to be analyzed separately, making the usefulness of imaging techniques controversial. Recently, improved methods of functional imaging like parathyroid scan with 99mTc-sestamibi or positron emission tomography, especially when combined with computed tomography, can provide additional quantitative and qualitative information that has yet to be assessed. Nuclear medicine procedures could prove useful not only in preoperative diagnosis, but also in the selection of medical or surgical therapeutic alternatives in secondary hyperparathyroidism patients. There is evidence that 99mTc-sestamibi uptake in parathyroid hyperplasia or adenoma is related to biochemical markers of parathyroid function. We are only beginning to identify the factors involved in radiotracer uptake by parathyroid cells and how it can be modulated to obtain more accurate results. This review analyzes the current use of non-invasive imaging modalities in patients with secondary hyperparathyroidism, taking into account the latest trends in the field combining anatomic and functional modalities and the relevant factors linked to radiotracer uptake in abnormal hyperfunctioning parathyroid glands.


Assuntos
Diagnóstico por Imagem/métodos , Hiperparatireoidismo Secundário/diagnóstico por imagem , Cálcio/uso terapêutico , Humanos , Hiperparatireoidismo Secundário/tratamento farmacológico , Hiperparatireoidismo Secundário/cirurgia , Hipocalcemia/complicações , Hipocalcemia/tratamento farmacológico , Compostos Organofosforados , Compostos de Organotecnécio , Paratireoidectomia , Tomografia por Emissão de Pósitrons , Cuidados Pré-Operatórios , Compostos Radiofarmacêuticos/farmacocinética , Tecnécio Tc 99m Sestamibi/farmacocinética , Distribuição Tecidual , Tomografia Computadorizada de Emissão de Fóton Único , Tomografia Computadorizada por Raios X , Ultrassonografia
11.
J Nephrol ; 31(2): 287-296, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29350348

RESUMO

BACKGROUND: Cardiovascular calcification (CVC) is a major concern in hemodialysis (HD) and the loss of endogenous modulators of calcification seems involved in the process. Phytate is an endogenous crystallization inhibitor and its low molecular mass and high water solubility make it potentially dialyzable. SNF472 (the hexasodium salt of phytate) is being developed for the treatment of calciphylaxis and CVC in HD patients. We aimed to verify if phytate is lost during dialysis, and evaluate SNF472's behaviour during dialysis. METHODS: Dialyzability was assessed in vitro using online-hemodiafiltration and high-flux HD systems in blood and saline. SNF472 was infused for 20 min and quantified at different time points. RESULTS: Phytate completely dialyzed in 1 h at low concentrations (10 mg/l) but not when added at 30 or 66.67 mg/l SNF472. In bypass conditions, calcium was slightly chelated during SNF472 infusion but when the system was switched to dialysis mode the calcium in the bath compensated this chelation. CONCLUSION: Phytate dialyses with a low clearance. The administration of SNF472 as an exogenous source of phytate allows to attain supra-physiological levels required for its potential therapeutic properties. As SNF472 is infused during the whole dialysis session, the low clearance would not affect the drug's systemic exposure.


Assuntos
Ácido Fítico/sangue , Diálise Renal/efeitos adversos , Calcificação Vascular/prevenção & controle , Cálcio/química , Creatinina/sangue , Soluções para Diálise , Hemodiafiltração/instrumentação , Humanos , Ácido Fítico/administração & dosagem , Ácido Fítico/farmacologia , Diálise Renal/instrumentação , Calcificação Vascular/etiologia
12.
J Clin Invest ; 97(9): 2092-100, 1996 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-8621799

RESUMO

Erythropoietin (rHuEPO) has proven to be effective in the treatment of anemia of chronic renal failure (CRF). Despite improving the quality of life, peak oxygen uptake after rHuEPO therapy is not improved as much as the increase in hemoglobin concentration ([Hb)] would predict. We hypothesized that this discrepancy is due to failure of O2 transport rates to rise in a manner proportional to [Hb]. To test this, eight patients with CRF undergoing regular hemodialysis were studied pre- and post-rHuEPO ([Hb] = 7.5 +/- 1.0 vs. 12.5 +/- 1.0 g x dl-1) using a standard incremental cycle exercise protocol. A group of 12 healthy sedentary subjects of similar age and anthropometric characteristics served as controls. Arterial and femoral venous blood gas data were obtained and coupled with simultaneous measurements of femoral venous blood flow (Qleg) by thermodilution to obtain O2 delivery and oxygen uptake (VO2). Despite a 68% increase in [Hb], peak VO2 increased by only 33%. This could be explained largely by reduced peak leg blood flow, limiting the gain in O2 delivery to 37%. At peak VO2, after rHuEPO, O2 supply limitation of maximal VO2 was found to occur, permitting the calculation of a value for muscle O2 conductance from capillary to mitochondria (DO2). While DO2 was slightly improved after rHuEPO, it was only 67% of that of sedentary control subjects. This kept maximal oxygen extraction at only 70%. Two important conclusions can be reached from this study. First, the increase in [Hb] produced by rHuEPO is accompanied by a significant reduction in peak blood flow to exercising muscle, which limits the gain in oxygen transport. Second, even after restoration of [Hb], O2 conductance from the muscle capillary to the mitochondria remains considerably below normal.


Assuntos
Anemia/tratamento farmacológico , Eritropoetina/uso terapêutico , Falência Renal Crônica/fisiopatologia , Músculo Esquelético/metabolismo , Oxigênio/metabolismo , Adulto , Anemia/complicações , Anemia/metabolismo , Anemia/fisiopatologia , Transporte Biológico/efeitos dos fármacos , Gasometria , Exercício Físico , Humanos , Falência Renal Crônica/complicações , Falência Renal Crônica/metabolismo , Masculino , Músculo Esquelético/irrigação sanguínea , Consumo de Oxigênio/efeitos dos fármacos
13.
J Clin Invest ; 97(9): 2101-10, 1996 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-8621800

RESUMO

After erythropoietin (rHuEPO) therapy, patients with chronic renal failure (CRF) do not improve peak O2 uptake (VO2 peak) as much as expected from the rise in hemoglobin concentration ([Hb]). In a companion study, we explain this phenomenon by the concurrent effects of fall in muscle blood flow after rHuEPO and abnormal capillary O2 conductance observed in CRF patients. The latter is likely associated with a poor muscle microcirculatory network and capillary-myofiber dissociation due to uremic myopathy. Herein, cellular bioenergetics and its relationships with muscle O2 transport, before and after rHuEPO therapy, were examined in eight CRF patients (27 +/- 7.3 [SD] yr) studied pre- and post-rHuEPO ([Hb] = 7.8 +/- 0.7 vs. 11.7 +/- 0.7 g x dl-1) during an incremental cycling exercise protocol. Eight healthy sedentary subjects (26 +/- 3.1 yr) served as controls. We hypothesize that uremic myopathy provokes a cytosolic dysfunction but mitochondrial oxidative capacity is not abnormal. 31P-nuclear magnetic resonance spectra (31P-MRS) from the vastus medialis were obtained throughout the exercise protocol consisting of periods of 2 min exercise (at 1.67 Hz) at increasing work-loads interspersed by resting periods of 2.5 min. On a different day, after an identical exercise protocol, arterial and femoral venous blood gas data were obtained together with simultaneous measurements of femoral venous blood flow (Qleg) to calculate O2 delivery (QO2leg) and O2 uptake (VO2leg). Baseline resting [phosphocreatine] to [inorganic phosphate] ratio ([PCr]/[Pi]) did not change after rHuEPO (8.9 +/- 1.2 vs. 8.8 +/- 1.2, respectively), but it was significantly lower than in controls (10.9 +/- 1.5) (P = 0.01 each). At a given submaximal or peak VO2leg, no effects of rHuEPO were seen on cellular bioenergetics ([PCr]/[Pi] ratio, %[PCr] consumption halftime of [PCr] recovery after exercise), nor in intracellular pH (pHi). The post-rHuEPO bioenergetic status and pHi, at a given VO2leg, were below those observed in the control group. However, at a given pHi, no differences in 31P-MRS data were detected between post-rHuEPO and controls. After rHuEPO, at peak VO2, Qleg fell 20% (P < 0.04), limiting the change in QO2leg to 17%, a value that did not reach statistical significance. The corresponding O2 extraction ratio decreased from 73 +/- 4% to 68 +/- 8.2% (P < 0.03). These changes indicate that maximal O2 flow from microcirculation to mitochondria did not increase despite the 50% increase in [Hb] and explain how peak VO2leg and cellular bioenergetics (31P-MRS) did not change after rHuEPO. Differences in pHi, possibly due to lactate differences, between post-rHeEPO and controls appear to be a key factor in the abnormal muscle cell bioenergetics during exercise observed in CRF patients.


Assuntos
Anemia/tratamento farmacológico , Metabolismo Energético/efeitos dos fármacos , Eritropoetina/uso terapêutico , Falência Renal Crônica/metabolismo , Músculo Esquelético/metabolismo , Oxigênio/metabolismo , Adulto , Anemia/complicações , Anemia/metabolismo , Feminino , Humanos , Falência Renal Crônica/complicações , Espectroscopia de Ressonância Magnética , Masculino
14.
Transplant Proc ; 39(7): 2254-5, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17889155

RESUMO

Persistent hyperparathyroidism is the most frequent cause of hypercalcemia after renal transplantation, namely, hypercalcemia is observed in about 10% of patients at 1 year. This prospective study evaluated the effect of cinacalcet, a second-generation calcimimetic, on serum calcium and parathyroid hormone (PTH) blood levels among recipients with hypercalcemia due to persistent hyperparathyroidism. Thirteen renal transplanted patients (10 women and 3 men) were included based upon: a total serum calcium >10.5 mg/dL; intact PTH (iPTH) blood levels >65 pg/mL; graft function >6 months, and stable maintenance immunosuppressive therapy. After inclusion, patients initially received 30 mg of cinacalcet once daily. The mean time of initiation was 64 +/- 7 months after transplantation. The follow-up was 6 months. The median dose of cinacalcet was 30 mg/d (5 patients received 60 mg/d). During the study period, renal function remained stable. Serum calcium levels decreased significantly from 11.7 +/- 0.39 to 10.35 +/- 0.8 mg/dL (P < .001). Serum phosphate levels increased from 2.82 +/- 0.34 mg/dL to 3.2 +/- 0.41 mg/dL (P < .05). The mean iPTH levels significantly decreased from 308 +/- 120 to 210 +/- 80 pg/mL (P < .05). There were no significant change in 25-hydroxyvitamin D3 blood levels (from 17.7 +/- 9 to 17.4 +/- 6 ng/mL), but the 1,25-dihydroxyvitamin D3 blood levels decreased from 53.8 +/- 18.2 to 32.6 +/- 9.2 pg/mL (P < .01). There were no significant changes in blood levels of alkaline phosphatase, magnesium, bicarbonate, calciuria, phosphaturia, and immunosuppressive drugs. Cinacalcet was well tolerated in all patients except one who had gastrointestinal discomfort. In summary, cinacalcet corrected hypercalcemia and improved phosphatemia in patients with persistent hyperparathyroidism after transplantation with no negative effects on renal function.


Assuntos
Hipercalcemia/prevenção & controle , Hiperparatireoidismo Secundário/tratamento farmacológico , Falência Renal Crônica/complicações , Transplante de Rim/efeitos adversos , Naftalenos/uso terapêutico , Adulto , Cinacalcete , Feminino , Humanos , Hipercalcemia/etiologia , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Estudos Prospectivos
15.
Transplant Proc ; 39(7): 2251-3, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17889154

RESUMO

Posttransplant diabetes mellitus (PTDM) occurs in approximately 15% to 20% of renal transplant patients. It has important clinical implications for graft function and survival. Anticalcineurin drugs are associated with an increased risk of developing PTDM. There is a little evidence that conversion from tacrolimus to cyclosporine (CsA)-based immunosuppression improves glucose metabolism and reverses diabetes. This prospective study included nine renal transplant patients (mean age of 34 +/- 20) with PTDM under immunosuppression with tacrolimus. Five were switched directly to CsA and the other four (glycemia > 250 mg/dL) required insulin and were simultaneously switched to CsA. Basal blood levels of tacrolimus were 7.9 +/- 1.9 ng/dL. Conversion was associated with an early, significant improvement of glycemia and HbA1c blood levels (P < .01). At the end of the follow-up, the glycemia (105 +/- 20 mg/dL) and Hb1Ac (5.1 +/- 0.4 mg/dL) were normal. Insulin was discontinued between 3 and 6 months in all patients who required it at the beginning. Cholesterol did not change significantly and triglycerides decreased significantly (basal 210 +/- 85 mg/dL, at 12 months 125 +/- 29, P < .01). Graft function was stable with a mean serum creatinine of 1.7 +/- 0.2 mg/dL. CsA blood levels remained stable during all follow-up periods (P = NS). There were neither episodes of acute rejection nor secondary effects related to the medication. In summary, renal transplant patients receiving tacrolimus who develop PTDM may display better control of hyperglycemia by a switch to CsA.


Assuntos
Ciclosporina/uso terapêutico , Diabetes Mellitus/prevenção & controle , Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Transplante de Rim/imunologia , Tacrolimo/uso terapêutico , Adolescente , Adulto , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Ciclosporina/administração & dosagem , Esquema de Medicação , Feminino , Humanos , Imunossupressores/administração & dosagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Estudos Prospectivos , Tacrolimo/administração & dosagem
16.
Transplant Proc ; 39(7): 2157-9, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17889123

RESUMO

Everolimus (Eve) has shown good efficacy and safety profiles in clinical trials in combination with low doses of cyclosporine but there is limited experience in other modes, especially with calcineurin inhibitor elimination. We developed a retrospective study to analyze its clinical use after approval in Europe in 2005. Herein we have presented the results of a series of 272 patients followed for the first 6 months after Eve introduction. In 93.8% of cases Eve was introduced after the first month posttransplantation (conversion use), and 6 months after introduction, the CNI had been eliminated in 75% of cases. The main indication for Eve introduction was the diagnosis of a malignant neoplasm (42%), whereas the combined indication of prevention and/or treatment of toxicity, especially nephrotoxicity, accounted for 46.3% of cases. Initial doses were low (1.37 mg/d), but were progressively increased up to 2 mg/d at 6 months. Renal function remained unchanged during the follow-up period, whereas proteinuria moderately increased. Only 5 cases (2%) of acute rejection episodes were observed with excellent patient and graft survivals at 6 months after conversion. Further analysis of this extensive series of patients with a longer follow-up is needed.


Assuntos
Imunossupressores/uso terapêutico , Transplante de Rim/imunologia , Sirolimo/análogos & derivados , Adulto , Idoso , Inibidores de Calcineurina , Divisão Celular/efeitos dos fármacos , Everolimo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias/complicações , Sistema de Registros , Estudos Retrospectivos , Sirolimo/uso terapêutico , Espanha
17.
Nefrologia ; 27(2): 209-13, 2007.
Artigo em Espanhol | MEDLINE | ID: mdl-17564567

RESUMO

Parathyroid carcinoma (PC) is an infrequent disease with a subtle initial presentation and a variable course, necessitating a high index of suspicion to make the correct diagnosis. In chronic failure patients on haemodialysis it becomes even more difficult to suspect this entity since the high prevalence of secondary hyperparathyroidism(SHP). Two patients with PC out of a series of 160 patients with moderate-to-severe SHP submitted for parathyroidectomy are reported. Their clinical features are compared with those of the twenty-two cases previously reported in the literature with a discussion of this pathology. Patients with PC showed higher blood levels of iPTH, total calcium, phosphate and total alkaline phosphatase than the SHP population. The final diagnosis of PC was made after histological study revealing capsular or blood vessel invasion.


Assuntos
Hiperparatireoidismo Secundário/etiologia , Neoplasias das Paratireoides/complicações , Diálise Renal , Adulto , Feminino , Humanos
18.
Rev Esp Med Nucl ; 25(5): 289-93, 2006 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-17173774

RESUMO

AIM: To evaluate the usefulness of 111In-oxine-labelled platelet scan in the therapeutic management of prolonged febrile syndrome in dialysis patients with a non-functional renal allograft. MATERIAL AND METHODS: One hundred and fifty-eight patients (94 men, 64 women; mean age 44 +/- 9 years) were studied. Duration of fever was 42 days (range 7-112). A total of 68 % of the patients (107/158) were on low doses of corticosteroids (<10 mg/day). Platelet scans were performed 48 hours after reinjection of 111In-ixone-labelled platelets. A platelet uptake index (PUI) was calculated by dividing the cpm/pixel in the allograft by the cpm/pixel in a mirror background. A PUI > or = 1.5 was considered as threshold for immunological fever. The final diagnosis of immunological fever was established when it disappeared after transplantectomy, embolization or high doses of corticosteroid therapy. Fever of non-immunological origin was established when it disappeared after antibiotic therapy. RESULTS: In 102/158 patients the fever was considered of immunological origin. In 56/158 patients the fever was considered of non immunological origin. Sensitivity and the specificity of the platelet scan was 80 % and 100 %, respectively. All those patients considered as having fever of immunological origin who had PUI <1.5 had been using corticosteroids during platelet scan. CONCLUSION: 111In-labelled platelet scintigraphy is a useful technique in the therapeutic management of prolonged febrile syndrome in dialysis patients with non-functional renal allograft. The use of corticosteroids can reduce the sensitivity of 111In- labelled platelet scan.


Assuntos
Plaquetas , Febre/diagnóstico por imagem , Rejeição de Enxerto/diagnóstico por imagem , Radioisótopos de Índio , Transplante de Rim , Compostos Organometálicos , Oxiquinolina/análogos & derivados , Compostos Radiofarmacêuticos , Diálise Renal , Corticosteroides/uso terapêutico , Adulto , Antibacterianos/uso terapêutico , Infecções Bacterianas/complicações , Infecções Bacterianas/diagnóstico por imagem , Infecções Bacterianas/tratamento farmacológico , Diagnóstico Diferencial , Embolização Terapêutica , Feminino , Febre/tratamento farmacológico , Febre/etiologia , Febre/imunologia , Rejeição de Enxerto/complicações , Rejeição de Enxerto/tratamento farmacológico , Rejeição de Enxerto/cirurgia , Rejeição de Enxerto/terapia , Humanos , Rim/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Nefrectomia , Estudos Prospectivos , Cintilografia , Sensibilidade e Especificidade , Transplante Homólogo
19.
Transplant Proc ; 48(9): 2959-2961, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27932118

RESUMO

BACKGROUND: Malignancy is one of the most common long-term complications in renal transplant patients, often related to immunosuppressive treatment although other factors could be considered. Vitamin D plays an important role in reducing cancer risk. After kidney transplantation (KT), 25-hydroxyvitamin D (25OH-D, or calcidiol) insufficiency concerns >85%. The main aim of the present study was to determine the relationship between calcidiol blood levels and cancer development in KT recipients. METHODS: This was a retrospective observational case-control study including patients who received transplants in our hospital from 2003 to 2009 with a follow-up period to 2015. A total of 738 patients were included; 94 of them developed malignancy process, 80 of whose tumor data were analyzed in the cancer group, and the rest composed the control group. At the moment of cancer presentation, age, sex, primary kidney disease, time after surgery, immunosuppressant schedule, and 25OH-D blood levels were collected. RESULTS: The mean patient age was 57 years. The percentages of man and women were 59.5% and 41.5%. The predominant etiology of kidney disease was chronic glomerulonephritis in 31.9%. There were no significant differences between sex, primary kidney disease, immunosuppressant schedule, or incidence of neoplasm in each group of patients. There were no significant differences in 25OH-D blood levels. The incidence of cancer was 7.1%-13.7% per year. The mean time between the graft surgery and the event was 5.6 years. CONCLUSIONS: In patients with functioning KT, we found no correlation between blood levels of calcidiol and the incidence of cancer.


Assuntos
Nefropatias/sangue , Transplante de Rim/efeitos adversos , Neoplasias/etiologia , Complicações Pós-Operatórias , Vitamina D/análogos & derivados , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Seguimentos , Humanos , Imunossupressores/uso terapêutico , Incidência , Nefropatias/cirurgia , Masculino , Pessoa de Meia-Idade , Neoplasias/sangue , Neoplasias/epidemiologia , Estudos Retrospectivos , Vitamina D/sangue , Deficiência de Vitamina D/sangue , Deficiência de Vitamina D/etiologia
20.
Transplant Proc ; 37(9): 3836-8, 2005 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16386556

RESUMO

UNLABELLED: The increased incidence of Kaposi's sarcoma (KS) in organ transplantation has been related to the KS herpes virus and the permissive effect of immunosuppressive therapy. We postulated that conversion to SRL in renal recipients with KS favored regression of KS lesions without increasing the risk of graft rejection. METHODS: In this study we performed a retrospective chart review of 7 caucasian renal transplant recipients affected by KS to determine demographic data, etiology of ESRD, immunologic risk factors, immunosuppressive treatment, KS disease follow-up, and renal function before and after SRL conversion. RESULTS: All seven patients were under calcineurin inhibitor treatment at the onset of KS which was limited to the skin, without regression despite attempts to minimize immunosuppression. After conversion to SRL, six patients showed progressive regression of KS lesions, with only hyperpigmented atrophic cutaneous lesions remaining after a mean time of 8.1 months (2-18 months). The seventh patient has completed 9 months follow-up with a near complete regression of KS lesions. One patient returned to hemodialysis after 13 months following irreversible acute renal failure not directly related to SRL conversion; in the other six, renal function was stable. The mean serum creatinine was 1.87 +/- 0.64 versus 1.74 +/- 0.68 mg/dL, pre-conversion versus the end of follow up, respectively. Mean SRL blood level was 9.2 +/- 2.0 ng/mL. CONCLUSION: After SRL conversion, patients with KS showed progressive regression without an increased risk of acute rejection. SRL offers a promising approach to the management of posttransplantation KS and probably other malignancies in organ transplant recipients.


Assuntos
Transplante de Rim/imunologia , Sarcoma de Kaposi/imunologia , Sirolimo/uso terapêutico , Animais , Inibidores de Calcineurina , Feminino , Humanos , Imunossupressores/uso terapêutico , Transplante de Rim/efeitos adversos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
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