Uremic neuropathy: an overview of the current literature

SUMMARY INTRODUCTION: Peripheral neuropathy is a disorder that affects the cell body, axon or myelin of motor or peripheral sensory neurons and occurs in 60-100% of patients who are submitted to dialysis due to chronic kidney disease. Uremic neuropathy is attributed to the accumulation of organic waste, evident in patients with reduced glomerular filtration rate. Objectives: This review aims to make clinical characteristics of uremic neuropathy evident enabling early diagnosis and treatment. Methods: This is a literature review of articles published on PubMed over the last 10 years using "Uremic Neuropathy" as "Title/Abstract". Results: A total of nine articles that met the inclusion criteria were included. UN is a distal symmetric sensorimotor polyneuropathy that occurs due to the accumulation of uremic toxins associated with an oxidative stress-related free radical activity. Hyperkalemia is thought to play an important role in its pathophysiology. Diagnosis depends on nerve conduction studies, and treatment includes dialysis or renal transplant. Conclusion: Clinical presentations of UN are broad and non-specific; nonetheless, it is important to detect early changes in order to avoid its progression. The earlier UN is diagnosed and treated, the more successful are the clinical outcomes.

RESUMO INTRODUÇÃO: A neuropatia periférica (NU) é um distúrbio que afeta o corpo celular, o axônio ou a mielina do motor ou neurônios sensoriais periféricos e ocorre em 60%-100% dos pacientes que são submetidos à diálise por doença renal crônica. A neuropatia urêmica é atribuída à acumulação de resíduos orgânicos, evidente em pacientes com taxa de filtração glomerular reduzida. Objetivo: O objetivo desta revisão é fazer com que as características clínicas da neuropatia urêmica sejam evidenciadas, permitindo o diagnóstico e tratamento precoce. Método: Esta é uma revisão da literatura de artigos publicados no PubMed nos últimos dez anos usando "Neuropatia Urêmica" como "Título/Resumo". Resultados: No total, foram incluídos nove artigos que atendem aos critérios de inclusão. A NU é uma polineuropatia sensório-motora simétrica distal que ocorre devido ao acúmulo de toxinas urêmicas associadas à atividade de radicais livres relacionados ao estresse oxidativo. A hipercalemia tem um papel importante na sua fisiopatologia. O diagnóstico depende de estudos de condução nervosa e o tratamento inclui diálise ou transplante renal. Conclusão: As apresentações clínicas das NU são amplas e não específicas; no entanto, é importante detectar mudanças iniciais para evitar sua progressão. Quanto mais precoce for a detecção e tratamento da NU, melhor será o resultado clínico.

Effects of renal dysfunction on healing of colonic anastomosis: experimental study in wistar rats / Efeitos da disfunção renal na cicatrização de anastomoses colônicas: estudo experimental em ratos wistar

ABSTRACT Background: Chronic kidney disease affects more than 500 million people worldwide. In this context, the uremic toxins present are related to worsening in tissue healing. Aim: Evaluate on healing of colonic anastomosis in uremic rats, serum and anatomopathological indicators, which may be related to the change tissue repair process. Methods: Twenty Wistar rats, were randomly separated into two groups. In the sham group they were submitted to 5/6 nephrectomy simulation in left kidney, simulation right nephrectomy, median laparotomy, colotomy and colorraphy. In the uremia group, they were submitted to 5/6 nephrectomy of the left kidney, total nephrectomy of the right kidney and median laparotomy, colotomy and colorraphy. Were collected for serum urea, creatinine and CRP dosages and the colonic segments were studied for evaluation of granulation tissue, collagen maturation, microvascular and myofibroblasts density, and cell viability. Through histochemical processing, microvascular density was evaluated by anti-CD34 monoclonal antibody marking, cell viability by cell proliferation nuclear antigen screening and myofibroblasts density with monoclonal anti-α-actin antibody. Computerized histometry was used for evaluations of collagens type I and III by the coloration of picrosirius. Results: The group submitted to nephrectomy 5/6, compared to the sham group, show urea increase (p<0.0000) and higher C reactive protein (p=0.0142). Decrease of granulation tissue formation (border reepithelialization p=0,0196, angiofibroblast proliferation p=0.0379), mean collagen I (p=0,0009) and collagen III (p=0,016), microvascular density (p=0,0074), cell proliferation nuclear antigen (p<0,0000) and myofibroblasts (p<0,0001). Conclusion: The uremia induced by nephrectomy 5/6 model establishes negative impact in the colonic wound healing.

RESUMO Racional: A doença renal crônica atinge mais de 500 milhões de pessoas em todo o mundo. Neste contexto, as toxinas urêmicas estão relacionadas ao comprometimento da cicatrização tecidual. Objetivo: Avaliar, na cicatrização de anastomoses colônicas de ratos urêmicos indicadores séricos e anatomopatológicos que possam estar relacionados com alteração do processo de reparação tissular. Métodos: Utilizaram-se 20 ratos Wistar divididos aleatoriamente em dois grupos. No grupo simulação eles foram submetidos à simulação da nefrectomia 5/6 do rim esquerdo, simulação de nefrectomia total do rim direito, laparotomia mediana, colotomia e colorrafia. No grupo uremia, eles foram submetidos à nefrectomia 5/6 do rim esquerdo, nefrectomia total do rim direito, laparotomia mediana, colotomia e colorrafia. Coletaram-se amostras de sangue para dosagens séricas da ureia, creatinina e proteína C reativa, e do cólon para processamentos histológicos e histoquímicos na avaliação do tecido de granulação, maturação de colágeno, densidade microvascular e de miofibroblastos, viabilidade celular cicatricial. Empregou-se a histometria computadorizada para as avaliações de colágenos tipos I e III, densidade microvascular pela marcação com anticorpo monoclonal anti-CD34, viabilidade celular pela pesquisa do antígeno nuclear de proliferação celular e a densidade de miofibroblastos com anticorpo monoclonal anti-α-actina. Resultados: O grupo submetido à nefrectomia 5/6, em comparação ao grupo simulação, demonstraram aumentos da ureia sérica (p<0,0000) e proteína C reativa (p=0,0142), redução da formação de tecido de granulação (reepitelização de bordas p=0,0196, proliferação angiofibroblástica p=0,0379), porcentagens de colágeno I (p=0,0009) e colágeno III (p=0,016), densidade microvascular (p=0,0074) e miofibroblastos (p<0,0001) e antígeno nuclear de proliferação celular (p<0,0000). Conclusão: A uremia induzida pelo modelo de nefrectomia 5/6 determina impacto negativo no processo de cicatrização colônico.

Study of erythropoeitin on IGM serum levels in HCV positive patients on regular HD

Both uremia and HD process cause immunosuppression in HD patients. There was significant increase of total serum IgG and IgM levels found in patients with chronic HCV compared with healthy controls. There is evidence pointing to direct effect of rHuEPO upon B cells. High doses of recombinant human erythropoietin [rHu EPO] enhanced in vitro Ig production and proliferation of various plasma cell lines, as well as human plasma cells generated in vitro. Study was conducted at hemodialysis Unit of Shubra Municipal hospital between August 2010 to February 2011. 30 HCV positive patients on regular hemodialysis were included in study, using bicarbonate dialysate and polysulfone membrane dialyser, for 4 hours 3 times weekly. Patients were divided into 2 groups: first group: 15 patients on EPO therapy. 4000 IU/week and second group not taking EPO for all patients full clinical examination was done, CBC, BUN, serum creatinine, ALT, AST, serum albumin and serum IgM by ELISA [quantitative assay], were done. There was no significant difference between 2 groups as regards age, sex distribution, WBC count, ALT, AST, serum creatinine, BUN and IgM serum level. First group had borderline significant higher Hgb and Hct than second group [p = 0.056]. Females didn't have higher serum IgM level than males [p = 0.403]. All correlations of IgM serum level to other parameters of study were irrelevant. Uremia seems to protect ESRD patients on regular HD from complications of HCV and also EPO effect on Ig serum levels

Colonic Mucosal Necrosis Following Administration of Calcium Polystryrene Sulfonate (Kalimate) in a Uremic Patient

Colonic necrosis is known as a rare complication following the administration of Kayexalate (sodium polystryrene sulfonate) in sorbitol. We report a rare case of colonic mucosal necrosis following Kalimate (calcium polystryrene sulfonate), an analogue of Kayexalate without sorbitol in a 34-yr-old man. He had a history of hypertension and uremia. During the management of intracranial hemorrhage, hyperkalemia developed. Kalimate was administered orally and as an enema suspended in 20% dextrose water to treat hyperkalemia. Two days after administration of Kalimate enema, he had profuse hematochezia, and a sigmoidoscopy showed diffuse colonic mucosal necrosis in the rectum and sigmoid colon. Microscopic examination of random colonic biopsies by two consecutive sigmoidoscopies revealed angulated crystals with a characteristic crystalline mosaic pattern on the ulcerated mucosa, which were consistent with Kayexalate crystals. Hematochezia subsided with conservative treatment after a discontinuance of Kalimate administration.

Prurido urêmico / Uremic pruritus

A insuficiência renal crônica produz várias manifestaçöes dermatológicas, como a hiperceratose folicular, xerose, unhas ®half-and-half¼, hiperpigmentaçäo e prurido. Dessas, a que mais pode comprometer a qualidade de vida do paciente urêmico é, sem dúvida, o prurido. De etiologia näo completamente compreendida, o prurido urêmico acomete grande parte dos pacientes renais e seu tratamento envolve vários aspectos do gerenciamento da síndrome urêmica como diálise, controle do hiperparatireoidismo e correçäo da anemia. Esta revisäo discorre sobre os principais aspectos da fisiopatologia e tratamento desta freqüente manifestaçäo da uremia.

La baja del ácido urico sérico aumenta o mantiene la filtración glomerular en la insuficiencia renal crónica moderada (IRC) / Decrease of uric acid increase glomerular filtration in mild chronic uremia

Estudiamos 80 pacientes con insuficiencia renal crónica (IRC), durante un promedio de 21 ñ 7 meses (rango 6-89 meses), con edad promedio de 52 años. Recibieron dieta isocalórica, con 0.5 g de proteínas por kg (50 por ciento de alto valor biológico), baja en purinas y fosfatos; normal en sodio, potasio y líquidos. Medicamentos. Alopurinol 10 mg por kg de peso cada 24 horas, furosemide a dosis bajas, hipotensores y quelantes del fósforo. Los pacientes fueron vistos cada dos meses por observadores diferentes.En todos los pacientes disminuyó el ácido úrico plasmático y se evitó que cayera rápidamente la filtración glomerular (FG). Se tuvieron dos tipos de respuestas: GRUPO 1: en 49 pacientes aumentó la (FG) 34 por ciento y GRUPO II: en 31 pacientes disminuyó la FG a 9.7 por ciento. Los resultados mostraron que la única variable que influyó en el aumento de la FG fue la baja del ácido úrico plasmático, R. de 0.886 (P<0.001). Se concluye que en IRC moderada, la baja de ácido úrico plasmático mediante la restricción de purinas de la dieta y dosis altas de alopurinol, es un factor que influye en la elevación hasta de un 34 por ciento de la FG, o en la caída lenta de la FG de lapsos de dos o más años. El mecanismo está en discusión. Recomendamos disminuir la hiperuricemia secundaria a la IRC.

periodontal status of Egyptian children on hemodialysis and prospective

The periodontal condition of 45 uremic children and 35 prospective [on hemodialysis]; was compared with that of systemically healthy children, matched for age, teeth present and sex. The two renal groups had significantly [p < 0.05] higher plaque scores than the control group. The hemodialysis group showed significantly [p < 0.05] fewer gingival bleeding points than their respective controls. Progressive uremia; thus; entailed less clinical gingivitis. The mean attachment loss as judged from clinical measurements was similar among the paired groups. It is a must that a special program of periodontal disease prevention for such children is quite needed. Over the last two decades renal allotransplantation and treatment have saved many patients with chronic renal failure with immunosuppressive agents. There is no exaggeration to mention that, so many children are included to share the same aforementioned problem. The drug regimen creates a life-long susceptibility to infections, even by the commensal flora [1]. To minimize this risk the periodontist should reduce dental plaque as a source of noxious bacterial products. The progressive nature of chronic periodontal disease has been well documented in epidemiological studies [2]. It is suggested that the gingival inflammatory reaction to dental plaque released mediators that may initiate destructive activities in the periodontium [3]. Moreover, the gingival response to dental plaque can be modulated by the host's medical status and by drugs [4]. If chronic inflammatory periodontal disease, in part at least, reflects local immune-based inflammatory reactions, then patients with reduced immune capacity might show less severe periodontal disease than otherwise healthy subjects [5, 6]. However, others found about the same degree of periodontal destruction in patients on hemodialysis and in systemically healthy subjects [6]. They pointed out that substances released from dental plaque may also directly cause periodontal breakdown. Since local immune reactions provide an important barrier against invading toxins and antigens, lack of proper immune responses might well accentuate the loss of tooth support. Moreover, children with renal problems provide an opportunity to study the pathogenesis of periodontal diseases, because these individuals have an altered immune system [7]. The aim of the present study was to compare the relationship between plaque and gingival inflammation under uremia and immunosuppression; added to the assessment of periodontal disease progression in such patients

Histochemical study of the skeletal muscle in children with chronic failure in dialysis treatment

Among the modifications occurring in the uremic organism,in addition to the consequences of dialysis, myophathy and peripheral neuropathy are very significant. Children are particularly affected, as their growth and development are jeopardized. Histochemistry of muscular biopsy was used to study eighteen children with end-stage renal failure under dialysis during a ten-month period. According to our results, the skeletal muscular tissue presented the following types of alterations: atrophy, type grouping, lipidosis, glycogen depletion and mitochondrial proliferation.

Helicobacter gastroduodenitis in uraemic patients with endoscopic and histopathological correlation

The aim of this study was to determine the prevalence of helicobacter pylori gastroduodentitis in uraemic patients on maintenance dialysis treatment. Forty patients underwent endoscopy and gastroduodenal biopsy. Endoscopic gastroduodentitis was found in twenty patients [50%]. On the other-hand histological gastritis was found in 65% of patients and duodenitis in 30% of patients. The analysis of the results demonstrated no correlation, between histological and endoscopic gastritis or duodenitis. Helicobacter pylori occurred in the stomach body or antrum in twelve patients [30%]. Their presence was insignificantly associated with gastritis in particular acute and acute on chronic rather than chronic gastritis

Uremic toxins, the blood brain barrier and uraemic encephalopathy in experimental uraemic rats

The pathophysiology of uremic encephalopathy and the various cerebral disorders associated with uremia are poorly understood. The aim of the present work was to study the role played by the major uremic toxins [non protein nitrogen, urea, uric acid, creatinine and phenols] in this regard. This was achieved by determining their concentrations in the plasma, the cerebrum, cerebellum, brain stem and skeletal muscles of rats with experimental uremia induced by bilateral ligation of both ureters for 48 hours. Results revealed that uremic rats showed an apparent alteration in alertness and appeared drowsy compared with their pre-fed controls suggesting an early stage of metabolic encephalopathy. It was evident from the study that the blood brain barrier was broken in uremia as there was high concentration of the studied uremic metabolites in the brain parts of uremic animals compared with controls. However, this barrier was not totally ruptured because the concentration of any given metabolite was higher in the skeletal muscle than the brain parts. The affinity of the different brain parts to the same metabolite was also different. So, it was justified to postulate that the composite picture of the uremic patients may be due to the variability in the concentrations of these studied toxins and/or others in the different parts of the brain resulting in disturbance of their normal function. The effect of the metabolites studied on the nervous system was also reviewed

Coagulopatia urêmica pós-traumática: fisiopatologia e terapêutica / Post-traumatic uremic bleeding: physiopathology and treatment

Este artigo aborda os mecanismos fisiopatológicos envolvidos na uremia pós-traumática, assim como os recursos terapêuticos atualmente disponíveis. O aparecimento de fenômenos hemorrágicos, nesse grupo de pacientes, é relativamente freqüente. O interesse do estudo detalhado dessa complicaçäo pós-traumática é muito importante, sobretudo nos casos em que a necessidade de reintervençäo cirúrgica se impöe. A visäo atualizada da fisiopatologia e da terapêutica da uremia pós-traumática será de grande valia na conduçäo clínica e cirúrgica desses pacientes

Toxinas urémicas y función plaquetaria / Uremic toxins and platelet function

Se hizo un estudio de la función plaquetaria en nueve pacientes con insuficiencia renal crónica, siete de los cuales mostraron alteración de dicha función, y sólo en dos ésta fue normal. Ambos grupos fueron comparados con un grupo control normal. Con cada uno de los tres grupos estudiados se hizo un pool de suero. Una cromatografía de columna, para la que se utilizó Sephadex G-25, separó a cada pool en tres fracciones de diferentes pesos moleculares (moléculas pequeñas, moléculas medias y grandes moléculas). Se probó si estas fracciones eran posibles. Agentes inhibidores de la agregación plaquetaria frente a un grupo de agentes agregantes: adenosindifosfato (ADP), epinefrina y colágeno. Sólo en el grupo con trastornos de la función plaquetaria se detectó un efecto inhibidor sobre la agregación, fundamentalmente en el rango de las moléculas medias que presentan un poderoso efecto inhibidor sobre dicho proceso

Disminución de la contractilidad miocárdica en pacientes con síndrome urémico / Decreased myocardial contractility in patients with uremic syndrome

El ecocardiograma produce información digna de confianza sobre las dimensiones de las paredes y las cavidades y sobre la dinámica del corazón. En este artículo se presenta un estudio de las variables ecocardiográficas en pacientes de insuficiencia renal crónica terminal y sobre la mejoría de la actividad cardiaca después de la diálisis peritoneal. Los pacientes de insuficiencia renal crónica terminal manifestaron aumento de tamaño del ventrículo izquierdo (p < 0.001) e hipertrofia del mismo (p < 0.001), disminución de la contractilidad miocárdica (p < 0.001), falta de hipovolemia estadísticamente importante (p > 0.2) e hiperdinamia (p < 0.001); la diálisis peritoneal disminuye el índice del volumen sanguíneo total (p < 0.01), produce mejoría pequeña de la contractilidad cardiaca y no mejora el estado hiperdinámico. Se concluye que el índice del volumen sanguíneo total tiene una pequeña función en la fisiopatología de la insuficiencia del ventrículo izquierdo en pacientes de insuficiencia renal crónica terminal