A Randomized Trial of Zoledronic Acid to Prevent Bone Loss in the First Year after Kidney Transplantation.

BACKGROUND: Bone and mineral disorders commonly affect kidney transplant (KTx) recipients and have been associated with a high risk of fracture. Bisphosphonates may prevent or treat bone loss in such patients, but there is concern that these drugs might induce adynamic bone disease (ABD). METHODS: In an open label, randomized trial to assess the safety and efficacy of zoledronate for preventing bone loss in the first year after kidney transplant, we randomized 34 patients before transplant to receive zoledronate or no treatment. We used dual-energy x-ray absorptiometry (DXA), high-resolution peripheral quantitative computed tomography (HR-pQCT), and bone biopsies to evaluate changes in bone in the 32 evaluable participants between the time of KTx and 12 months post-transplant. RESULTS: Both groups of patients experienced decreased bone turnover after KTx, but zoledronate itself did not affect this outcome. Unlike previous studies, DXA showed no post-transplant bone loss in either group; we instead observed an increase of bone mineral density in both lumbar spine and total hip sites, with a significant positive effect of zoledronate. However, bone biopsies showed post-transplant impairment of trabecular connectivity (and no benefit from zoledronate); HR-pQCT detected trabecular bone loss at the peripheral skeleton, which zoledronate partially attenuated. CONCLUSIONS: Current immunosuppressive regimens do not contribute to post-transplant central skeleton trabecular bone loss, and zoledronate does not induce ABD. Because fractures in transplant recipients are most commonly peripheral fractures, clinicians should consider bisphosphonate use in patients at high fracture risk who have evidence of significantly low bone mass at these sites at the time of KTx.

Parathyroidectomy: still the best choice for the management of severe secondary hyperparathyroidism.

INTRODUCTION: Management of secondary hyperparathyroidism (SHPT) is a challenging endeavor with several factors contruibuting to treatment failure. Calcimimetic therapy has revolutionized the management of SHPT, leading to changes in indications and appropriate timing of parathyroidectomy (PTX) around the world. METHODS: We compared response rates to clinical vs. surgical approaches to SHPT in patients on maintenance dialysis (CKD 5D) and in kidney transplant patients (Ktx). A retrospective analysis of the one-year follow-up findings was carried out. CKD 5D patients were divided into 3 groups according to treatment strategy: parathyroidectomy, clinical management without cinacalcet (named standard - STD) and with cinacalcet (STD + CIN). Ktx patients were divided into 3 groups: PTX, CIN (cinacalcet use), and observation (OBS). RESULTS: In CKD 5D we found a significant parathormone (PTH) decrease in all groups. Despite all groups had a higher PTH at baseline, we identified a more pronounced reduction in the PTX group. Regarding severe SHPT, the difference among groups was evidently wider: 31%, 14% and 80% of STD, STD + CIN, and PTX groups reached adequate PTH levels, respectively (p<0.0001). Concerning the Ktx population, although the difference was not so impressive, a higher rate of success in the PTX group was also observed. CONCLUSION: PTX still seems to be the best treatment choice for SHPT, especially in patients with prolonged diseases in unresourceful scenarios.

Osteoporosis after transplantation.

Transplantation is an established therapy for end-stage diseases of kidney, lung, liver, and heart among others. Osteoporosis and fragility fractures are serious complications of organ transplantation, particularly in the first post-transplant year. Many factors contribute to the pathogenesis of osteoporosis following organ transplantation. This review addresses the mechanisms of bone loss that occurs both in the early and late post-transplant periods, including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac, and bone marrow transplantation. Prevention and treatment for osteoporosis in the transplant recipient are also discussed.

Iron-based phosphorus chelator: Risk of iron deposition and action on bone metabolism in uremic rats.

Phosphate chelators are frequently used in patients with chronic kidney disease (CKD). New iron-based chelators remain understudied and offer a promising therapeutic option for the control of bone and mineral disorders of chronic kidney disease (BMD-CKD). We assessed the effect of the phosphorus chelator, chitosan-iron III (CH-FeCl), compared to calcium carbonate (CaCO3) in BMD-CKD and the potential iron overload in uremic rats. Thirty-two animals were divided into four groups, namely the control, CKD, CKD/CH-FeCl, and CKD/CaCO3 groups. CKD was induced by adding 0.75% (4 weeks) and 0.1% (3 weeks) adenine to the diet. The chelators were administered from week 3 through week 7. The renal function, BMD-CKD markers, and histomorphometry of the femur were assessed at week 7. The CKD group showed a significant increase in creatinine (83.9 ± 18.6 vs. 41.5 ± 22.1 µmol/L; P = 0.001), phosphate (3.5 ± 0.8 vs. 2.2 ± 0.2 mmol/L; P = 0.001), fractional excretion of phosphorus (FEP) (0.71 ± 0.2 vs. 0.2 ± 0.17; P = 0.0001), and FGF23 (81.36 ± 37.16 pg/mL vs. 7.42 ± 1.96; P = 0.011) compared to the control group. There was no accumulation of serum or bone iron after the use of CH-FeCl. The use of chelators reduced the FEP (control: 0.71 ± 0.20; CKD/CH-FeCl: 0.40 ± 0.16; CKD/CaCO3 0.34 ± 0.15; P = 0.001), without changes in the serum FGF23 and parathyroid hormone levels. Histomorphometry revealed the presence of bone disease with high remodeling in the uremic animals without changes with the use of chelators. The CH-FeCl chelator was efficient in reducing the FEP without iron accumulation, thereby paving the way for the use of this class of chelators in clinical settings in the future.

Effects of time on ultrastructural integrity of parathyroid tissue before cryopreservation.

BACKGROUND: Cryopreservation of parathyroid tissue is used in the surgical treatment of secondary hyperparathyroidism. After surgical resection, the tissue is temporarily maintained in a cell culture solution until it arrives at the specialized laboratory where the cryopreservation process will take place. The present study evaluates the time that the human hyperplastic parathyroid gland tissue can wait before cryopreservation, based on parathyroid cell ultrastructural integrity. METHODS: This prospective study included 11 patients who underwent total parathyroidectomy with heterotopic autotransplantation and cryopreservation of parathyroid tissue fragments. Part of the tissue was kept in cell culture solution at 4 °C. Five time periods between 2 and 24 h were defined, and parathyroid fragments were kept in the solution for that length of time. At the end of each period, the fragments were removed from the transport solution, fixed, and prepared for ultrathin sections. RESULTS: Of the 11 cases studied, 10 showed ultrastructural findings consistent with cellular viability in tissue fragments that remained in the transport solution up to 12 h. Electron microscopy revealed that cell adhesion and the integrity of plasma membranes, nuclei, and mitochondria were preserved in one case for up to 24 h. Changes in mitochondrial structure represented the most constant ultrastructural damage seen in the cases studied, in addition to the presence of edema and cell vacuoles. CONCLUSIONS: Analysis of the ultrastructure of hyperplastic parathyroid gland tissue showed that ultrastructural integrity was in most cases properly maintained in fragments stored up to 12 h in a cell culture solution at 4 °C.

Parathyroid hormone levels after parathyroidectomy for secondary hyperparathyroidism.

OBJECTIVE: The parathormone level after parathyroidectomy in dialysis patients are of interest. Low levels may require cryopreserved tissue implantation; however, the resection is necessary in case of recurrence. We analyzed post parathyroidectomy parathormone levels in renal hyperparathyroidism. METHODS: Prospective observation of postoperative parathormone levels over defined periods in a cohort of dialysis patients that underwent total parathyroidectomy and immediate forearm autograft from 2008 to 2010, at a single tertiary care hospital. RESULTS: Of 33 patients, parathormone levels until 36 months could be divided into four patterns. Patients with stable function (Pattern 1) show relatively constant levels after two months (67% of the cases). Early function and later failure (Pattern 2) were an initial function with marked parathormone reduction before one year (18%). Graft recurrence (Pattern 3) showed a progressive increase of parathormone in four cases (12%). Complete graft failure (Pattern 4) was a nonfunctioning implant at any period, which was observed in one patient (3%). Parathormone levels of Pattern 3 became statistically different of Pattern 1 at 36 months. CONCLUSIONS: Patients that underwent the total parathyroidectomy and autograft present four different graft function patterns with a possible varied therapeutic management.

Digital radiography as an alternative method in the evaluation of bone density in uremic rats.

INTRODUCTION: Digital radiography (DRx) may provide a suitable alternative to investigate mineral and bone disorder (MBD) and loss of bone density (BD) in rodent models of chronic kidney disease (CKD). The objective of this study was to use DRx to evaluate BD in CKD rats, and to evaluate the correlation between DRx findings and serum MBD markers and bone histomorphometry. METHODS: Uremia was induced by feeding Wistar rats an adenine-enriched diet (0.75% for 4 weeks/0.10% for 3 weeks); outcomes were compared to a control group at experimental weeks 3, 4, and 7. The following biochemical markers were measured: creatinine clearance (CrC), phosphate (P), calcium (Ca), fractional excretion of P (FeP), alkaline phosphatase (ALP), fibroblast growth factor-23 (FGF-23), and parathyroid hormone (PTH). DRx imaging was performed and histomorphometry analysis was conducted using the left femur. RESULTS: As expected, at week 7, uremic rats presented with reduced CrC and higher levels of P, FeP, and ALP compared to controls. DRx confirmed the lower BD in uremic animals (0.57±0.07 vs. 0.68 ± 0.06 a.u.; p = 0.016) compared to controls at the end of week 7, when MBD was more prominent. A severe form of high-turnover bone disease accompanied these biochemical changes. BD measured on DRx correlated to P (r=-0.81; p = 0.002), ALP (r = -0.69, p = 0.01), PTH (r = -0.83, p = 0.01), OS/BS (r = -0.70; p = 0.02), and ObS/BS (r = -0.70; p = 0.02). CONCLUSION: BD quantified by DRx was associated with the typical complications of MBD in CKD and showed to be viable in the evaluation of bone alterations in CKD.

Parathyroidectomy: still the best choice for the management of severe secondary hyperparathyroidism / Paratireoidectomia: ainda a melhor escolha para o tratamento do hiperparatireoidismo secundário grave

Abstract Introduction: Management of secondary hyperparathyroidism (SHPT) is a challenging endeavor with several factors contruibuting to treatment failure. Calcimimetic therapy has revolutionized the management of SHPT, leading to changes in indications and appropriate timing of parathyroidectomy (PTX) around the world. Methods: We compared response rates to clinical vs. surgical approaches to SHPT in patients on maintenance dialysis (CKD 5D) and in kidney transplant patients (Ktx). A retrospective analysis of the one-year follow-up findings was carried out. CKD 5D patients were divided into 3 groups according to treatment strategy: parathyroidectomy, clinical management without cinacalcet (named standard - STD) and with cinacalcet (STD + CIN). Ktx patients were divided into 3 groups: PTX, CIN (cinacalcet use), and observation (OBS). Results: In CKD 5D we found a significant parathormone (PTH) decrease in all groups. Despite all groups had a higher PTH at baseline, we identified a more pronounced reduction in the PTX group. Regarding severe SHPT, the difference among groups was evidently wider: 31%, 14% and 80% of STD, STD + CIN, and PTX groups reached adequate PTH levels, respectively (p<0.0001). Concerning the Ktx population, although the difference was not so impressive, a higher rate of success in the PTX group was also observed. Conclusion: PTX still seems to be the best treatment choice for SHPT, especially in patients with prolonged diseases in unresourceful scenarios.

Resumo Introdução: O manejo do hiperparat-ireoidismo secundário (HPTS) é uma tarefa desafiadora com diversos fatores que contribuem para o fracasso do tratamento. A terapia calcimimética revolucionou o manejo do HPTS, levando a alterações nas indicações e no momento apropriado da paratireoidectomia (PTX) em todo o mundo. Métodos: Comparamos taxas de resposta às abordagens clínica vs. cirúrgica do HPTS em pacientes em diálise de manutenção (DRC 5D) e pacientes transplantados renais (TxR). Foi realizada uma análise retrospectiva dos achados de um ano de acompanhamento. Pacientes com DRC 5D foram divididos em 3 grupos de acordo com a estratégia de tratamento: paratireoidectomia, manejo clínico sem cinacalcete (denominado padrão - P) e com cinacalcete (P + CIN). Os pacientes com TxR foram divididos em 3 grupos: PTX, CIN (uso de cinacalcete) e observação (OBS). Resultados: Na DRC 5D, encontramos uma redução significativa do paratormônio (PTH) em todos os grupos. Apesar de todos os grupos apresentarem um PTH mais elevado no início do estudo, identificamos uma redução mais acentuada no grupo PTX. Com relação ao HPTS grave, a diferença entre os grupos foi evidentemente maior: 31%, 14% e 80% dos grupos P, P + CIN e PTX atingiram níveis adequados de PTH, respectivamente (p< 0,0001). Com relação à população TxR, embora a diferença não tenha sido tão impressionante, também foi observada uma taxa maior de sucesso no grupo PTX. Conclusão: A PTX ainda parece ser a melhor escolha de tratamento para o HPTS, especialmente em pacientes com doenças prolongadas em cenários sem recursos.

Bone biopsy in nephrology practice.

Renal osteodystrophy (ROD), a group of metabolic bone diseases secondary to chronic kidney disease (CKD), still represents a great challenge to nephrologists. Its management is tailored by the type of bone lesion - of high or low turnover - that cannot be accurately predicted by serum biomarkers of bone remodeling available in daily clinical practice, mainly parathyroid hormone (PTH) and alkaline phosphatase (AP). In view of this limitation, bone biopsy followed by bone quantitative histomorphometry, the gold-standard method for the diagnosis of ROD, is still considered of paramount importance. Bone biopsy has also been recommended for evaluation of osteoporosis in the CKD setting to help physicians choose the best anti-osteoporotic drug. Importantly, bone biopsy is the sole diagnostic method capable of providing dynamic information on bone metabolism. Trabecular and cortical bones may be analyzed separately by evaluating their structural and dynamic parameters, thickness and porosity, respectively. Deposition of metals, such as aluminum and iron, on bone may also be detected. Despite of these unique characteristics, the interest on bone biopsy has declined over the last years and there are currently few centers around the world specialized on bone histomorphometry. In this review, we will discuss the bone biopsy technique, its indications, and the main information it can provide. The interest on bone biopsy should be renewed and nephrologists should be capacitated to perform it as part of their training during medical residency.

Chitosan-Fe (III) Complex as a Phosphate Chelator in Uraemic Rats: A Novel Treatment Option.

Phosphate retention and hyperphosphataemia are associated with increased mortality in patients with chronic kidney disease (CKD). We tested the use of cross-linked iron chitosan III (CH-FeCl) as a potential phosphate chelator in rats with CKD. We evaluated 96 animals, divided equally into four groups (control, CKD, CH-FeCl and CKD/CH-FeCl), over 7 weeks. We induced CKD by feeding animals an adenine-enriched diet (0.75% in the first 4 weeks and 0.1% in the following 3 weeks). We administered 30 mg/kg daily of the test polymer, by gavage, from the third week until the end of the study. All animals received a diet supplemented with 1% phosphorus. Uraemia was confirmed by the increase in serum creatinine in week 4 (36.24 ± 18.56 versus 144.98 ± 22.1 µmol/L; p = 0.0001) and week 7 (41.55 ± 22.1 versus 83.98 ± 18.56 µmol/L; p = 0.001) in CKD animals. Rats from the CKD group treated with CH-FeCl had a 54.5% reduction in serum phosphate (6.10 ± 2.23 versus 2.78 ± 0.55 mmol/L) compared to a reduction of 25.6% in the untreated CKD group (4.75 ± 1.45 versus 3.52 ± 0.74 mmol/L, p = 0.021), between week 4 and week 7. At week 7, renal function in both CKD groups was similar (serum creatinine: 83.98 ± 18.56 versus 83.10 ± 23.87 µmol/L, p = 0.888); however, the CH-FeCl-treated rats had a reduction in phosphate overload measured by fractional phosphate excretion (FEPi) (0.71 ± 0.2 versus 0.4 ± 0.16, p = 0.006) compared to the untreated CKD group. Our study demonstrated that CH-FeCl had an efficient chelating action on phosphate.

Effect of cross-linked chitosan iron (III) on vascular calcification in uremic rats.

Cross-linked chitosan iron (III) is a chitin-derived polymer with a chelating effect on phosphorus, but it is untested in vascular calcification. We evaluated this compound's ability to reduce hyperphosphatemia and its effect on vascular calcification in uremic rats using an adenine-based, phosphorus-rich diet for seven weeks. We used a control group to characterize the uremia. Uremic rats were divided according the treatment into chronic kidney disease, CKD-Ch-Fe(III)CL (CKD-Ch), CKD-calcium carbonate, or CKD-sevelamer groups. We measured creatinine, phosphorus, calcium, alkaline phosphatase, phosphorus excretion fraction, parathyroid hormone, and fibroblast growth factor 23. Vascular calcification was assessed using the aortic calcium content, and a semi-quantitative analysis was performed using Von Kossa and hematoxylin-eosin staining. At week seven, rats in the chronic kidney disease group had higher creatinine, phosphorus, phosphorus excretion fraction, calcium, alkaline phosphatase, fibroblast growth factor 23, and aortic calcium content than those in the Control group. Treatments with cross-linked chitosan iron (III) and calcium carbonate prevented phosphorus increase (20%-30% reduction). The aortic calcium content was lowered by 88% and 85% in the CKD-Ch and CKD-sevelamer groups, respectively. The prevalence of vascular changes was higher in the chronic kidney disease and CKD-calcium carbonate (62.5%) groups than in the CKD-Ch group (37.5%). In conclusion, cross-linked chitosan iron (III) had a phosphorus chelating effect similar to calcium carbonate already available for clinical use, and prevented calcium accumulation in the aorta. Impact statement Vascular calcification (VC) is a common complication due to CKD-related bone and mineral disorder (BMD) and is characterized by deposition of calcium in vessels. Effective therapies are not yet available but new phosphorus chelators can prevent complications from CV. We tested the effect of chitosan, a new phosphorus chelator, on the VC of uremic animals. It has recently been proposed that chitosan treatment may be effective in the treatment of hyperphosphataemia. However, its action on vascular calcification has not been investigated yet. In this study, we demonstrated that chitosan reduced the calcium content in the aorta, suggesting that this may be a therapeutic approach in the treatment of hyperphosphatemia by preventing CV.

Early postoperative parathormone sampling and prognosis after total parathyroidectomy in secondary hyperparathyroidism.

INTRODUCTION: There is possibility of a supernumerary hyperplastic parathyroid gland in dialysis patients after total parathyroidectomy and autograft in dialysis patients. OBJECTIVE: To test if the early postoperative measure of parathyroid hormone (PTH) can identify persistent hyperparathyroidism. METHODS: A prospective cohort of dialysis patients submitted to parathyroidectomy had PTH measured up to one week after operation. The absolute value and the relative decrease were analyzed according to clinical outcome of satisfactory control of secondary hyperparathyroidism or persistence. RESULTS: Of 51 cases, preoperative PTH varied from 425 to 6,964 pg/mL (median 2,103 pg/mL). Postoperatively, PTH was undetectable in 28 cases (54.9%). In eight individuals (15.7%) the PTH was lower than 16 pg/mL, in 10 (19.6%) the PTH values were between 16 and 87pg/mL, and in five (9.8%), PTH was higher than 87 pg/mL. Undetectable PTH was more common in patients with preoperative PTH below the median (p = 0.0002). There was a significant correlation between preoperative PTH and early postoperative PTH (Spearman R = 0.42, p = 0.002). A relative decrease superior to 95% was associated to satisfactory clinical outcome. A relative decrease less than 80% was associated to persistent disease, despite initial postoperative hypocalcemia. CONCLUSION: Measurement of PTH in the first days after parathyroidectomy in dialysis patients may suggest good clinical outcome if a decrease of at least 95% of the preoperative value is observed. Less than 80% PTH decrease is highly suggestive of residual hyperfunctioning parathyroid tissue with persistent hyperparathyroidism, and an early reintervention may be considered.

Persistent disorders of mineral metabolism after one year of kidney transplantation.

INTRODUCTION:: The persistence of mineral metabolism disorders after renal transplant (RT) appears to possess a negative impact over graft and patient's survival. OBJECTIVES:: To evaluate the parameters of mineral metabolism and the persistence of hyperparathyroidism (HPT) in transplanted patients for a 12-month period after the procedure. METHODS:: Retrospective analysis of 41 transplants (18 women- 44%, mean age of 39 ± 15 years) performed in a University Hospital, evaluating changes of calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) and the prevalence of persistent HPT. The patients were divided into two groups accordingly to PTH levels prior to Tx: Group 1 with PTH ≤ 300 pg/mL (n = 21) and Group 2 with PTH > 300 pg/mL (n = 20). The persistency of HPT after transplant was defined as PTH ≥ 100 pg/mL. The evolution of biochemical parameters and the persistency of HPT were analyzed in each group after 1 year of transplant. RESULTS:: After a one-year of follow up, 5% of the patients presented hypophosphatemia (p < 2.7 mg/dL), 24% hypercalcemia (Ca > 10.2 mg/dL) and 48% persistency of HPT (PTH ≥ 100 pg/mL). There was a positive correlation between the PTH pre and post Tx (r = 0.42/p = 0.006) and a negative correlation between PTH and Ca pre-Tx (r = -0.45/p = 0.002). However, there was no significant difference among groups 1 and 2 regarding PTH levels pre and post Tx. CONCLUSION:: The findings in this article suggest that mineral metabolism alterations and the persistency of HPT may occur after one year of renal Tx, mainly in patients which present high PTH levels prior toTx. INTRODUÇÃO:: A persistência de distúrbios do metabolismo mineral ósseo após o transplante renal (Tx) parece possuir um impacto negativo sobre a sobrevida do enxerto e do paciente. OBJETIVOS:: avaliar os parâmetros do metabolismo mineral e a persistência de hiperparatiroidismo (pHPT) 12 meses após o Tx. MÉTODOS:: Análise retrospectiva de 41 transplantes (18 mulheres- 44%, idade de 39 ± 15 anos) realizados em um Hospital Universitário, avaliando cálcio (Ca), fósforo (P), hormônio da paratireóide (PTH) e a prevalência de pHPT. Pacientes foram divididos em dois grupos de acordo com os níveis de PTH pré Tx: Grupo 1: PTH ≤ 300 pg/ml (n = 21) e Grupo 2: PTH > 300 pg/ml (n = 20). pHPT foi definida como PTH ≥ 100pg/mL após o Tx. A evolução dos parâmetros bioquímicos e a pHPT foram analisadas após 1 ano de Tx. Resultados: após um ano, 5% dos pacientes apresentaram hipofosfatemia (p < 2,7mg/dL), 24% hipercalcemia (Ca > 10,2 mg/dL) e 48% persistência de HPT (PTH ≥ 100 pg/mL ). Houve correlação positiva entre PTH pré e pós Tx (r = 0,42/p = 0,006) e correlação negativa entre PTH e Ca pré-Tx (r = -0,45/p = 0,002). Entretanto, não houve diferença significativa entre os grupos 1 e 2 em relação aos níveis de PTH pré e pós-Tx. CONCLUSÃO:: Os resultados sugerem que alterações do metabolismo mineral e a pHPT podem ocorrer após um ano do Tx, principalmente em pacientes com níveis elevados de PTH pré-Tx.

Parathyroid hormone levels after parathyroidectomy for secondary hyperparathyroidism

SUMMARY OBJECTIVE: The parathormone level after parathyroidectomy in dialysis patients are of interest. Low levels may require cryopreserved tissue implantation; however, the resection is necessary in case of recurrence. We analyzed post parathyroidectomy parathormone levels in renal hyperparathyroidism. METHODS: Prospective observation of postoperative parathormone levels over defined periods in a cohort of dialysis patients that underwent total parathyroidectomy and immediate forearm autograft from 2008 to 2010, at a single tertiary care hospital. RESULTS: Of 33 patients, parathormone levels until 36 months could be divided into four patterns. Patients with stable function (Pattern 1) show relatively constant levels after two months (67% of the cases). Early function and later failure (Pattern 2) were an initial function with marked parathormone reduction before one year (18%). Graft recurrence (Pattern 3) showed a progressive increase of parathormone in four cases (12%). Complete graft failure (Pattern 4) was a nonfunctioning implant at any period, which was observed in one patient (3%). Parathormone levels of Pattern 3 became statistically different of Pattern 1 at 36 months. CONCLUSIONS: Patients that underwent the total parathyroidectomy and autograft present four different graft function patterns with a possible varied therapeutic management.

The deceptive concept of hypoparathyroidism and recurrence after parathyroidectomy in dialysis patients: are we offering a Procrustean bed to some patients?

OBJECTIVE:: to analyze the frequency of hypoparathyroidism and of its recurrence after parathyroidectomy in dialysis patients according to different existing classifications. METHODS:: we conducted a retrospective study of 107 consecutive dialysis patients undergoing total parathyroidectomy with immediate autograft in a tertiary hospital from 2006 to 2010. We studied the changes in PTH levels in the postoperative period over time. Were grouped patients according to different PTH levels targets recommended according to the dosage method and by the American and Japanese Nephrology Societies, and by an International Experts Consortium. RESULTS:: after parathyroidectomy, there was sustained reduction in serum calcium and phosphatemia. The median value of PTH decreased from 1904pg/ml to 55pg/ml in 12 months. Depending on the considered target level, the proportion of patients below the target ranged between 17% and 87%. On the other hand, the proportion of patients with levels above the target ranged from 3% to 37%. CONCLUSION:: the application of different recommendations for PTH levels after parathyroidectomy in dialysis patients may lead to incorrect classifications of hypoparathyroidism or recurrent hyperparathyroidism and resultin discordant therapeutic conducts. OBJETIVO:: analisar as frequências de hipoparatireoidismo e de recidiva do hiperparatireoidismo após paratireoidectomia em pacientes dialíticos de acordo com diferentes classificações existentes. MÉTODOS:: estudo retrospectivo de 107 pacientes dialíticos consecutivamente submetidos à paratireoidectomia total com autoenxerto imediato em um hospital terciário no período de 2006 a 2010. A variação dos níveis de PTH no pós-operatório foi estudada ao longo do tempo. Os pacientes foram agrupados de acordo com diferentes metas de níveis de PTH recomendados de acordo com o método de dosagem e pelas sociedades de nefrologia americana, japonesa e de um consórcio internacional de especialistas. RESULTADOS:: após a paratireoidectomia, houve redução sustentada da calcemia e fosfatemia. O valor mediano do PTH reduziu-se de 1904pg/ml para 55pg/ml, em 12 meses. Dependendo do nível alvo considerado, a proporção de pacientes abaixo da meta variou entre 17% e 87%. Ao contrário, a proporção de pacientes com níveis acima da meta variou de 3% a 37%. CONCLUSÃO:: O emprego de diferentes recomendações de níveis de PTH em pacientes dialíticos após paratireoidectomia pode levar a classificações incorretas de hipoparatireoidismo ou hiperparatireoidismo recidivado e implicar em condutas terapêuticas discordantes.

Bone disease after transplantation: osteoporosis and fractures risk.

Organ transplantation is the gold standard therapy for several end-stage diseases. Bone loss is a common complication that occurs in transplant recipients. Osteoporosis and fragility fractures are serious complication, mainly in the first year post transplantation. Many factors contribute to the pathogenesis of bone disease following organ transplantation. This review address the mechanisms of bone loss including the contribution of the immunosuppressive agents as well as the specific features to bone loss after kidney, lung, liver, cardiac and bone marrow transplantation. Prevention and management of bone loss in the transplant recipient should be included in their post transplant follow-up in order to prevent fractures.