Recomendaciones para el manejo de la lisis tumoral / Recommendations for tumor lysis syndrome management

El síndrome de lisis tumoral representa una complicación potencialmente letal provocada por la liberación masiva de ácidos nucleicos, potasio y fosfato hacia la circulación como resultado de la lisis de células neoplásicas, las cuales se caracterizan por una rápida capacidad de proliferación y alta sensibilidad a fármacos. Esto puede ocurrir de forma espontánea antes del inicio del tratamiento y agravarse luego de haberse iniciado la quimioterapia. Presenta una alta mortalidad. Su prevención continúa siendo la medida terapéutica más importante. El cuadro clínico se caracteriza por la existencia de trastornos del metabolismo hidroelectrolítico, en particular, hipercalemia, hiperfosfatemia e hiperuricemia y por la aparición de una lesión renal aguda. Una adecuada intervención terapéutica implica hidratación intravenosa y medidas para prevenir o corregir las alteraciones metabólicas. En este artículo, se proponen lineamientos para seguir tanto en la etapa diagnóstica como en el tratamiento de esta complicación.

The tumor lysis syndrome represents a potentially lethal complication caused by the massive release of nucleic acids, potassium and phosphate into the circulation as a result of the lysis of neoplastic cells, which are characterized by a rapid proliferation capacity and high sensitivity to drugs. This may occur spontaneously prior to the start of treatment, becoming worse after the initiation of chemotherapy. It presents a high mortality; its prevention continues being the most important therapeutic measure. The clinical picture is characterized by the existence of hydroelectrolytic metabolism disorders, in particular hyperkalemia, hyperphosphatemia and hyperuricemia and by the appearance of an acute renal lesion. Adequate therapeutic intervention involves intravenous hydration and measures to prevent or correct metabolic alterations. This article proposes guidelines to follow both in the diagnostic stage and in the treatment of this complication.

The impact of cinacalcet in the mineral metabolism markers of patients on dialysis with severe secondary hyperparathyroidism / Impacto de cinacalcete em marcadores do metabolismo mineral de pacientes em diálise portadores de hiperparatireoidismo secundário grave

Abstract Introduction: Treating secondary hyperparathyroidism (SHPT), a common condition associated with death in patients with chronic kidney disease, is a challenge for nephrologists. Calcimimetics have allowed the introduction of drug therapies no longer based on phosphate binders and active vitamin D. This study aimed to assess the safety and effectiveness of cinacalcet in managing chronic dialysis patients with severe SHPT. Methods: This retrospective study included 26 patients [age: 52 ± 12 years; 55% females; time on dialysis: 54 (4-236) months] on hemodialysis (N = 18) or peritoneal dialysis (N = 8) with severe SHPT (intact parathyroid hormone (iPTH) level > 600 pg/mL) and hyperphosphatemia and/or persistent hypercalcemia treated with cinacalcet. The patients were followed for 12 months. Their serum calcium (Ca), phosphorus (P), alkaline phosphatase (ALP), and iPTH levels were measured at baseline and on days 30, 60, 90, 180, and 365. Results: Patients with hyperphosphatemia (57.7%), hypercalcemia (23%), or both (19.3%) with iPTH > 600 pg/mL were prescribed cinacalcet. At the end of the study, decreases were observed in iPTH (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0.001), Ca (9.5 ± 1.0 vs. 9.1 ± 0.6 mg/dl; p = 0.004), P (6.0 ± 1.3 vs. 4.9 ± 1.1 mg/dl; p < 0.001), and ALP (202 ± 135 vs. 155 ± 109 IU/L; p = 0.006) levels. Adverse events included hypocalcemia (26%) and digestive problems (23%). At the end of the study, 73% of the patients were on active vitamin D and cinacalcet. Three (11.5%) patients on peritoneal dialysis did not respond to therapy with cinacalcet, and their iPTH levels were never below 800 pg/mL. Conclusion: Cinacalcet combined with traditional therapy proved safe and effective and helped manage the mineral metabolism of patients with severe SHPT.

Resumo Introdução: O tratamento do hiperparatireoidismo secundário (HPTs), patologia comum e associada à mortalidade na doença renal crônica, é um desafio para o nefrologista. Advento dos calcimiméticos propiciou terapêutica medicamentosa diferente da usual, baseada em quelantes de fósforo e vitamina D ativa. O objetivo deste estudo foi avaliar segurança e efetividade de cinacalcete no controle do HPTs grave de pacientes em diálise crônica. Métodos: Estudo retrospectivo 26 pacientes [idade: 52 ± 12 anos; 55% mulheres; tempo em diálise: 54 (4-236) meses], em hemodiálise (N = 18) ou diálise peritoneal (N = 8), com HPTs grave (nível de paratormônio intacto (PTHi) > 600 pg/mL), com hiperfosfatemia e/ou hipercalcemia persistentes, em tratamento com cinacalcete. Período de seguimento de 12 meses. Avaliados níveis séricos de cálcio (Ca), fósforo (P), fosfatase alcalina (FA) e PTHi no início do seguimento, 30, 60, 90, 180 e 365 dias. Resultados: Indicações para início do cinacalcete: hiperfosfatemia (57,7%), hipercalcemia (23%), ou ambos (19,3%) com PTH > 600 pg/mL. Ao final do seguimento, observada redução dos níveis PTHi (1348 ± 422 vs. 440 ± 210 pg/mL; p < 0,001), Ca (9,5 ± 1,0 vs. 9,1 ± 0,6 mg/dl; p = 0,004), P (6,0 ± 1,3 vs. 4,9 ± 1,1 mg/dl; p < 0,001) e FA (202 ± 135 vs. 155 ± 109 UI/L; p = 0,006). Eventos adversos: hipocalcemia (26%) e queixas digestivas (23%). No fim do estudo, 73% pacientes utilizavam vitamina D ativada associada ao cinacalcete. Três (11,5%) pacientes, todos em DP, não responderam ao cinacalcete, mantendo níveis PTHi > 800 pg/mL. Conclusão: Utilização de cinacalcete, associado à terapia tradicional, em pacientes com HPTs grave foi segura, eficiente e associada a melhor controle do metabolismo mineral.

Effectiveness of sucroferric oxyhydroxide in patients on on-line hemodiafiltration in real-world clinical practice: A retrospective study / Eficácia do oxihidróxido sucroférrico em pacientes em hemodiafiltração on-line na realidade da prática clínica: um estudo retrospectivo

Abstract Introduction: Hyperphosphatemia is a serious consequence of chronic kidney disease and has been associated with an increased risk for cardiovascular disease. Controlling serum phosphorus levels in patients on dialysis is a challenge for the clinicians and implies, in most cases, the use of phosphate binders (PB). Part of the reason for this challenge is poor adherence to treatment because of the high pill burden in this patient group. Objective: To assess the real-world effectiveness of sucroferric oxyhydroxide (SO) in controlling serum phosphorus levels and determine the associated pill burden. Methods: A multicenter, quantitative, retrospective, before-after study was conducted with patients receiving online hemodiafiltration. Patients who switched to SO as a part of routine care were included in the study. PB treatment, number of pills, serum phosphorus levels, and intravenous iron medication and dosage were collected monthly during the six months of treatment with either PB or SO. Results: A total of 42 patients were included in the study. After switching from a PB to SO, the prescribed pills/day was reduced 67% from 6 pills/day to 2 pills/day (p < 0.001) and the frequency of pill intake was lowered from 3 times/day to 2 times/day (p < 0.001). During the treatment with SO, the proportion of patients with serum phosphorus ≤ 5.5 mg/dL increased from 33.3% at baseline to 45% after six months of treatment. Conclusion: During the six-month follow-up with SO, serum phosphorus levels were controlled with one third of the pills/day compared to other PB.

Resumo Introdução: A hiperfosfatemia é uma grave consequência da doença renal crônica associada a risco aumentado de doença cardiovascular. O controle dos níveis séricos de fósforo dos pacientes em diálise é um desafio que requer, na maioria dos casos, o uso de quelantes de fosfato (QF). Parte da dificuldade se deve à baixa adesão ao tratamento oriunda do grande número de medicamentos receitados para esse grupo de pacientes. Objetivo: Avaliar a real eficácia do oxihidróxido sucroférrico (OHS) no controle dos níveis séricos de fósforo e determinar a carga de comprimidos associada. Métodos: Estudo multicêntrico, quantitativo, retrospectivo, antes e depois conduzido com pacientes em hemodiafiltração on-line. Pacientes remanejados para OHS como parte dos cuidados de rotina foram incluídos no estudo. Tratamento com QF, número de comprimidos, níveis séricos de fósforo, reposição férrica endovenosa e dosagens foram registrados mensalmente durante seis meses de tratamento com QF ou OHS. Resultados: Foram incluídos 42 pacientes no estudo. Após a mudança de QF para OHS, o número de comprimidos prescritos por dia caiu em 67%, de seis para duas unidades diárias (p < 0,001). A frequência de ingestão de comprimidos caiu de três para duas vezes ao dia (p < 0,001). Durante o tratamento com OHS, o percentual de pacientes com fósforo sérico ≤ 5,5 mg/dL aumentou de 33,3% no início para 45% após seis meses de tratamento. Conclusão: Durante os seis meses de seguimento com OHS, os níveis séricos de fósforo foram controlados com um terço dos comprimidos por dia em relação aos tratamentos com outros QF.

Efficacy and safety of sevelamer. Comparison with calcium carbonate in thereatment of hyperphosphatemia in hemodialysis patients

Current phosphate binders used in hemodialysis patients include calcium-based binders that result in frequent hypercalcemia. The use of a calcium- and aluminum-free phosphate-binding polymer in hemodialysis [sevelamer] disclosed efficacy in the short and long-term studies. However, due to race differences we performed a short-term study on the Saudi hemodialysis patients and compared sevelamer with a standard calcium-based phosphate binder. An open-label, randomized, cross-over study was performed to evaluate the safety and effectiveness of sevelamer hydrochloride in controlling hyperphosphatemia in hemodialysis patients. After a 2-week phosphate binder washout period, stable hemodialysis patients were given either sevelamer or calcium carbonate, and the dosages were titrated to achieve phosphate control over an 8-week period. After a 2-week washout period, patients crossed over to the alternate agent for 8 weeks. Twenty patients from the Dialysis Unit of King Fahd Hospital, Jeddah, Kingdom of Saudi Arabia, were recruited for the study between March 2003 and June 2003. There was a similar decrease in serum phosphate values over the course of the study with both sevelamer [-3.3 +/- 2.2 mg/dL] and calcium carbonate [-3.9 +/- 2.8 mg/dL]. Fifty-two% of patients developed serum calcium greater than 2.75 mmol/L [11.0 mg/dL] while receiving calcium carbonate versus 26% of patients receiving sevelamer [p<0.05]. The incidence of hypercalcemia for sevelamer was not different from the incidence of hypercalcemia during the washout period. Patients treated with sevelamer also sustained a 13% mean decrease in serum cholesterol levels. Sevelamer was effective in controlling hyperphosphatemia without resulting in an increase in the incidence of hypercalcemia seen with calcium carbonate. This agent appears quite effective in the treatment of hyperphosphatemia in hemodialysis patients, and its usage may be advantageous in the treatment of dialysis patients