Influence of hydroxyurea on tubular phosphate handling in sickle cell nephropathy.

OBJECTIVE: This study aims to evaluate the markers of tubular phosphate handling in adults with sickle cell anemia (SCA) and the influence of hydroxyurea (HU), the degree of anemia and Hb F concentration on these markers. METHODS: Eighty-eight steady state SCA patients in outpatient follow-up in Fortaleza, Ceara, Brazil and 31 healthy individuals were included in this study. Vitamin D (25OHD) was measured by enzyme-bound fluorescence assay, intact parathyroid hormone (iPTH) by electrochemiluminescence, and serum and urinary phosphate and creatinine by colorimetric methods. Details of Hb F and HU use were obtained from clinical records. Tubular reabsorption of phosphate (TRP) and maximum tubular reabsorption of phosphate (MTRP) were calculated. SCA patients were stratified according to the use of HU, degree of anemia and percentage of Hb F. The significance level was set for p-values <0.05. RESULTS: Compared to controls the 25OHD level (25 ± 11 vs. 30 ± 9 pg/mL) was lower in SCA, while serum phosphate and MTRP were higher (3.86 ± 0.94 vs. 3.46 ± 0.72 and 3.6 ± 1.21 vs. 3.21 ± 0.53, respectively). There was no significant difference in iPTH, TRP and phosphaturia. Serum phosphate showed correlation with TRP (r = 0.32; p-value = 0.008) and MTRP (r = 0.9; p-value <0.001) in SCA. Patients taking HU, especially those with Hb F >10 % presented reduced serum phosphate levels, and TRP and MTRP rates. Those with mild anemia presented reduced serum phosphate levels and MTRP rates. CONCLUSION: Serum phosphate levels and renal phosphate reabsorption rate were increased in SCA. HU use, high Hb F concentration and total Hb were associated with better control of tubular phosphate handling markers.

Diets with high carbohydrate contents were associated with refeeding hypophosphatemia: A retrospective study in Japanese inpatients with anorexia nervosa.

OBJECTIVE: Refeeding hypophosphatemia (RH) is a potentially fatal complication in patients with anorexia nervosa (AN), and its dietary preventive strategy is not well established. We aimed to examine the association between carbohydrate content in the diet and the occurrence of RH in inpatients with AN via retrospective medical chart review. METHOD: We performed a chart review to collect data of patients with AN hospitalized at the Department of Psychosomatic Medicine of the University of Tokyo Hospital between April 1, 2012, and February 29, 2020. Receiver operating characteristic (ROC) analysis was performed to determine the cutoff point of the percentage of carbohydrate content in the diet for the occurrence of RH. Multivariate logistic regression analysis was performed with occurrence of RH as the dependent variable and the carbohydrate content of more than the identified cutoff point as the independent variable adjusting for the risk factors for RH. RESULTS: The percentage of carbohydrate content that is higher than the cutoff point obtained from the ROC analysis (58.4%) was significantly associated with the occurrence of RH, even after adjusting for variables associated with RH in univariate logistic regression analysis (age and body mass index) as well as the average daily calorie intake (odds ratio, 5.37; 95% confidence interval, 1.60-18.1; p = .0066). DISCUSSION: We identified that diets with higher carbohydrate contents were associated with RH in inpatients with AN, even after adjusting for known risk factors. Our findings may promote the development of dietary preventive strategies against RH in inpatients with AN.

Pseudohipoparatiroidismo de presentación tardía: reporte de dos casos / Pseudohypoparathyroidism: report of two cases of late presentation

Pseudohypoparathyroidism (PHP) is a group of rare genetic disorders that share organ targeted resistance to the action of parathyroid hormone (PTH) as a common feature. Biochemically, they may present with hypocalcemia, hyperphosphatemia and elevated PTH. Some forms present with a specific phenotype: short stature, round facies, short neck, obesity, brachydactyly and subcutaneous calcifications, called Albrigth's Hereditary Osteodystrophy (AHO). This spectrum of disorders are caused by several alterations in the gene coding for the alpha subunit of the G protein (GNAS): an ubiquitous signaling protein that mediates the action of numerous hormones such as PTH, TSH, gonadotropins, and ACTH, among others. According to their inheritance with maternal or paternal imprinting, they may manifest in a diversity of clinical forms. Although most commonly diagnosed during childhood, PHP may manifest clinically during adolescence or early adulthood. We report two late presenting cases of pseudohypoparathyroidism. A 21-year-old female with biochemical abnormalities characteristic of pseudohypoparathyroidism who was misdiagnosed as epilepsy and a 13-year-old boy with the classic AHO phenotype but without alterations in phospho-calcium metabolism, compatible with pseudopseudohypoparathyrodism.

Reversal of uremic tumoral calcinosis by optimization of clinical treatment of bone and mineral metabolism disorder / Reversão da calcinose tumoral urêmica pela otimização do tratamento clínico da desordem do metabolismo ósseo e mineral

Abstract Tumoral calcinosis is an uncommon type of extraosseous calcification characterized by large rubbery or cystic masses containing calcium-phosphate deposits. The condition prevails in the periarticular tissue with preservation of osteoarticular structures. Elevated calcium-phosphorus products and severe secondary hyperparathyroidism are present in most patients with uremic tumoral calcionosis (UTC). Case report of an obese secondary to chronic glomerulonephritis, undergoing continuous ambulatory peritoneal dialysis (CAPD) reported the appearance of painless tumors in the medial surface of fifth finger and left arm. Tumoral calcinosis was confirmed by left biceps biopsy. Poor adherence to CAPD. The patient was transferred to the "tidal" modality of peritoneal dialysis and after was treated by hemodialysis, despite the persistence of severe hyperparathyroidism progressive reduction of UTC until near to its complete disappearance. Nowadays, one year after patient received deceased-donor kidney transplantation, he presents with an improvement in secondary hyperparathyroidism. UTC should be included in the elucidation of periarticular calcification of every patient on dialysis. Relevant laboratory findings such as secondary hyperparathyroidism and elevated calcium- phosphorus products in the presence of periarticular calcification should draw attention to the diagnosis of UTC.

Resumo A calcinose tumoral é um tipo raro de calcificação extraóssea caracterizada por grandes massas císticas e elásticas contendo depósitos de fosfato de cálcio. A condição é mais prevalente no tecido periarticular e preserva estruturas osteoarticulares. A elevação do produtos cálcio-fósforo e o hiperparatireoidismo secundário grave estão presentes na maioria dos pacientes com calcinose tumoral urêmica (UTC). O relato de caso em questão refere-se a um homem de 22 anos, branco, obeso, com doença renal crônica secundária à glomerulonefrite crônica, em diálise peritoneal ambulatorial contínua (CAPD), que apresentou aparecimento de tumores indolores na face medial do quinto quirodáctilio e braço esquerdo. A calcinose tumoral foi confirmada por biópsia do bíceps esquerdo. O paciente apresentava baixa adesão à CAPD. Foi transferido para a modalidade de diálise peritoneal e depois iniciou tratamento por hemodiálise. Apesar da persistência do hiperparatireoidismo grave, houve redução progressiva da UTC, com resolução próxima do seu desaparecimento completo. Há 1 ano o paciente foi submetido a transplante renal, doador falecido, e apresentou melhora do hiperparatiroidismo secundário. A UTC deve ser incluída na elucidação de calcificação periarticular de pacientes em diálise. Os achados laboratoriais relevantes, tais como hiperparatiroidismo secundário e elevação dos produtos cálcio-fósforo na presença de calcificação periarticular, devem chamar a atenção para o diagnóstico da UTC.

Modifications to bicarbonate conductivity: A way to increase phosphate removal during hemodialysis? Proof of concept.

Introduction Hyperphosphatemia and cardiovascular mortality are associated particularly with end-stage renal disease. Available therapeutic strategies (i.e., diet restriction, calcium [or not]-based phosphate binders, calcimimetics) are associated with extrarenal blood purification. Compartmentalization of phosphate limits its depuration during hemodialysis. Several studies suggest that plasmatic pH is involved in the mobilization of phosphate from intracellular to extracellular compartments. Consequently, the efficiency of modified bicarbonate conductivity to purify blood phosphate was tested. Methods Ten hemodialysis patients with chronic hyperphosphatemia (>2.1 mmol/L) were included in the two three-sessions-per week periods. Bicarbonate concentration was fixed at 40 mmol/L and 30 mmol/L in the first and second periods, respectively. Phosphate depuration was evaluated by phosphate mobilization clearance (KM ). Findings Although bicarbonatemia was lower during the second period (21.0 ± 2.7 vs. 24.4 ± 3.1 mmol/L, P < 0.01), no difference was observed in phosphatemia (2.4 ± 0.5 vs. 2.3 ± 0.4 mmol/L, P = NS). The in-session variation of phosphate was lower (-1.45 ± 0.42 vs. -1.58 ± 0.44 mmol/L, P < 0.05) and KM was higher during the second period (82.94 ± 38.00 vs. 69.74 ± 24.48 mL/min, P < 0.05). Discussion The decrease of in-session phosphate and the increase in KM reflect phosphate refilling during hemodialysis. Thus, modulation of serum bicarbonate may play a role in controlling the phosphate pool. Even though correcting metabolic acidosis during hemodialysis remains important, alkaline excess can impair phosphate mobilization clearance. Clinical trials are needed to test the efficiency and relevance of a strategy where bicarbonatemia is corrected less at the beginning of sessions.

Comparison of on -line hemodiafiltration and high -flux hemodialysis for correcting calcium and phosphate metabolic disorder in uremia patients / 中国基层医药

Objective To compare the effect on correcting calcium and phosphate metabolic disorder and the impact on quality of life in uremia patients between on -line hemodiafiltration and high -flux hemodialysis.Methods 90 patients with uremia,digital watches were randomly divided into QL -HDF group and HFHD group,Ca2 +,P3 +, serum parathyroid hormone(PTH)level were measured before and after dialysis blood.The survival quality of patients were evaluated by the KDQOL -SFTM1.3 scale.The incidence of adverse reactions were collected.The similarities and differences of two groups were compared.Results The comparison of Ca2 + levels in the two groups before and after dialysis showed no significant difference(P >0.05);Of the QL -HDF group after treatment,P3 + was (1.82 ± 0.19)mmol/L,PTH was (401.6 ±16.7)pg/L,which were significantly lower than those of QL -HDF group[P3 +(2.14 ±0.22)mmol/L,PTH(425.0 ±17.2)pg/L](t =24.256,21.059,all P 0.05 );6 cases of adverse reactions was in the QL -HDF group (13.33%),14 cases of adverse reactions was in the HFHD group(31.11%),there was significant difference between the two groups(χ2 =5.361,P <0.05).Conclusion The two methods can improve the metabolic disorders of calcium and phosphorus in patients with uremia,and QL -HDF showed stronger ability to remove the ability,and the quality of life is higher,it is worth promoting in clinical practice.

Fibroblast Growth Factor 23: A New Dimension to Diseases of Calcium-Phosphorus Metabolism.

Traditionally, control of phosphorus in the body has been considered secondary to the tighter control of calcium by parathyroid hormone and vitamin D. However, over the past decade, substantial advances have been made in understanding the control of phosphorus by the so-called phosphatonin system, the lynchpin of which is fibroblast growth factor 23 (FGF23). FGF23 binds to the klotho/FGFR1c receptor complex in renal tubular epithelial cells, leading to upregulation of Na/Pi cotransporters and subsequent excretion of phosphorus from the body. In addition, FGF23 inhibits parathyroid hormone and the renal 1α-hydroxylase enzyme, while it stimulates 24-hydroxylase, leading to decreased 1,25-dihydroxyvitamin D3. FGF23 is intimately involved in the pathogenesis of a number of diseases, particularly the hereditary hypophosphatemic rickets group and chronic kidney disease, and is a target for the development of new treatments in human medicine. Little work has been done on FGF23 or the other phosphatonins in veterinary medicine, but increases in FGF23 are seen with chronic kidney disease in cats, and increased FGF23 expression has been found in soft tissue sarcomas in dogs.

Perfil dos níveis de cálcio iônico, fósforo, produto cálcio-fósforo e paratormônio em pacientes hemodializados / Prolife of the levels of the ionized calcium, phosphorus, calcium-phosphorus product and parathyroid hormone in hemodialisys patients

Objetivo: avaliar os níveis de cálcio iônico (Cai), fósforo (P), produto cálcio-fósforo (CaxP) eparatormônio (PTH) em conformidade com as Diretrizes Brasileiras de Prática Clínica para oDistúrbio Mineral e Ósseo (DMO) na Doença Renal Crônica (DRC), assim como, correlacionar essesvalores com o tempo de hemodiálise e presença de diabetes mellitus. Método: foram pesquisados 74pacientes renais crônicos em tratamento hemodialítico no Hospital Ophir Loyola em maio de 2011.Utilizados os resultados dos níveis séricos de Cai, P, CaxP e PTH, e coletadas informações sobre otempo no qual o paciente realiza hemodiálise e se é diabetico. Resultados: os níveis de Caiencontraram-se entre 1,12-1,25 mmol/L em 68,92% dos pacientes.; 51,35% apresentaram valores de Pentre 3,5-5,5 mg/mL; o CaxP < 55 mg2/dL2 foi observado em 72,97% e 39,19% possuíam valores dePTH adequados. Houve correlação positiva entre o PTH e o tempo de hemodiálise. A associação entreo PTH e presença de diabetes mellitus demonstrou que os diabéticos possuíam valores inferiores dePTH em relação aos não diabéticos. Conclusão: os níveis de Cai, P, CaxP e PTH se encontraramdentro das recomendações das Diretrizes em 68,92%, 51,35%, 72,97% e 39,19% respectivamente.Verificou-se correlação positiva entre níveis de PTH e tempo de hemodiálise, assim como associaçãoentre diabetes mellitus e baixos níveis desse hormônio

Objective: this study aimed to evaluate the ionized calcium (Cai), phosphorus (P), calciumphosphorusproduct (CaxP) and parathyroid hormone (PTH) levels in accordance with the BrazilianGuidelines for Clinical Practice for the Mineral and Bone Disorders (MBD) in Chronic KidneyDisease (CKD), thus to correlate these with the duration of hemodialysis treatment, and the presenceof diabetes mellitus. Methods: 74 hemodialysis patients were surveyed in the Ophir Loyola Hospitalin May of 2011. We used the results of serum Cai, P, CaxP and PTH, and collected information on thetime at which the patient undergoes hemodialysis and if they have diabetes. Results: the values of Caiwere between 1.12-1.25 mmol/L in 68.92% of the patients. 51.35% had P values between 3.5?5.5mg/mL. CaxP <55mg2/dL2 was observed in 72.97%, and 39.19% presented appropriate values of PTH.There was a positive correlation between PTH and the duration of hemodialysis treatment. Theassociation between PTH and diabetes mellitus presence showed that diabetics had lower values ofPTH in relation to non-diabetics. Conclusion: it is concluded that the levels of Cai, P, CaxP and PTHwere within the recommendations of the Guidelines in 68.92%, 51.35%, 72.97% and 39.19%,respectively. There was a positive correlation between PTH and the duration of hemodialysistreatment, as well as the association between diabetes mellitus and low levels of this hormone

KDIGO CKD-MBD Discussion forum: the Brazilian perspective / Fórum nacional de discussão das diretrizes do KDIGO para o distúrbio mineral e ósseo da doença renal crônica (DMO-DRC): uma análise crítica frente à relidade Brasileira

No dia 14 de novembro de 2009, a Sociedade Brasileira de Nefrologia promoveu um fórum de discussão das novas diretrizes do KDIGO (Kidney Disease: Improving Global Outcomes). O objetivo desse encontro, onde estiveram presentes 64 participantes, foi discutir estas novas diretrizes diante da realidade brasileira. Esse encontro teve o patrocínio da Empresa de Biotecnologia Genzyme, que não teve acesso à sala de discussão e tampouco aos temas tratados durante o evento. Este artigo traz um resumo das diretrizes do KDIGO e das discussões realizadas pelos participantes.

On November 14th, 2009, the Brazilian Society of Nephrology coordinated the Brazilian Discussion Meeting on the new KDIGO (Kidney Disease: Improving Global Outcomes) guidelines. The purpose of this meeting, which was attended by 64 nephrologists, was to discuss these new guidelines from the Brazilian perspective. This meeting was supported by an unrestricted grant of the biotechnology company Genzyme, which did not have access to the meeting room or to the discussion sections. This article brings a summary of the KDIGO guidelines and of the discussions by the attendees.