Jorge Paulo Strogoff de Matos

Effects of dialyzer reuse on the permeability of low-flux membranes★

Little attention has been given to the effects of reuse on the permeability of low-flux membranes, especially regarding middle molecules. We studied two different types of low-flux membranes at reuses 0, 6, and 12 in five patients undergoing hemodialysis with the following combinations of membrane and sterilant: cellulose diacetate membrane and formaldehyde, polysulfone membrane and formaldehyde, cellulose diacetate membrane and peracetic acid, and polysulfone and peracetic acid. The permeability of the membranes was assessed through the hydraulic ultrafiltration coefficient (K(UF)), sieving coefficient for beta(2)-microglobulin (B2M), and vitamin B(12) and albumin concentrations in ultrafiltrate. After 12 reuses, total cell volume (TCV) tended to be reduced in both cellulose diacetate and polysulfone dialyzers irrespective of the sterilant used, but significance was only found for the first set of dialyzers. Cellulose diacetate dialyzers reprocessed with either formaldehyde or peracetic acid showed an important reduction in K(UF) (31% [P < 0.05] and 23% [P < 0.05], respectively). A significant elevation in K(UF) was found in polysulfone membranes reprocessed with peracetic acid (41%; P < 0.05), but no alterations in K(UF) were found in polysulfone membranes reprocessed with formaldehyde. Cellulose diacetate membranes were intrinsically more permeable to B2M than polysulfone membranes (sieving coefficient, 6. 85 +/- 2.53 versus 0.04 +/- 0.02 x 10(-2); P < 0.001), which was not modified by any of the sterilants. Vitamin B(12) levels in ultrafiltrate decreased to an undetectable level in four of five samples collected after 12 reuses in polysulfone membranes reprocessed with peracetic acid (90 +/- 71 to 3 +/- 8 pg/mL; P < 0. 05 versus reuse 0). Albumin leakage occurred in two of five samples after the 12th reuse, but only in polysulfone membranes reprocessed with peracetic acid. Our findings suggest that reuse of low-flux polysulfone dialyzers reprocessed with peracetic acid is associated with structural damage of the membrane and a reduced permeability to middle molecules.

Assessment of a five-year survival on hemodialysis in Brazil: a cohort of 3,082 incident patients

Brazil has the third largest contingent of patients on maintenance hemodialysis (HD) worldwide. However, little is known regarding survival rate and predictors of mortality risk in that population, which are the purposes of this study. A total of 3,082 patients incident on HD, from 2000 to 2004, at 25 dialysis facilities distributed among 7 out of 26 states of Brazil were followed-up until 2009. Patients were 52 ± 16 years-old, 57.8% men, and 20.4%, diabetics. The primary outcome was all causes of mortality. Data were censored at five years of follow-up. The global five-year survival rate was 58.2%. In the Cox proportional model, variables associated with risk of death were: age (hazard ratio - HR = 1.44 per decade, p < 0.0001), diabetes (HR = 1.51, p < 0.0001), serum albumin (HR = 0.76 per g/dL, p = 0.001), creatinine (HR = 0.92 per mg/dL, p < 0.0001), and phosphorus (HR = 1.06 per mg/dL, p = 0.04). The present results show that the mortality rate on HD in this Brazilian cohort was relatively low, but the population is younger and with a lower prevalence of diabetes than the ones reported for developed countries.

Effects of citrate-enriched bicarbonate based dialysate on anticoagulation and dialyzer reuse in maintenance hemodialysis patients

Systemic anticoagulation with unfractionated heparin is commonly used in maintenance hemodialysis (HD), but it increases the risk of bleeding complications. We investigated whether the use of citrate‐enriched bicarbonate based dialysate (CD) would reduce systemic anticoagulation without compromising the efficacy of reprocessed dialyzers. This is a crossover study in which half of a total of 30 patients initially underwent HD with acetate‐enriched bicarbonate based dialysate and a standard heparin dose of ∼100 IU/kg (Treatment A), whereas the remaining patients were treated with CD and a 30% reduced heparin dose (Treatment B). After 12 consecutive HD sessions in each treatment, the dialysate and heparin doses were reversed, then followed for another period of 12 HD sessions. The two treatment phases were split by a washout period of six HD sessions using acetate‐enriched bicarbonate based dialysate and standard heparin dose. Systemic anticoagulation was higher in Treatment A. The activated partial thromboplastin time at the end of HD session was 68 ± 36 seconds in Treatment A and 47 ± 16 seconds in Treatment B (P = 0.005). Sixty‐eight percent of the dialyzers remained adequate until the 12th use in Treatment A and 61% did so in Treatment B (P = 0.63). Patients had three and 24 cramps episodes during Treatment A and B, respectively (P < 0.001). Nine and 26 symptomatic intradialytic hypotension episodes were seen in Treatment A and B, respectively, (P = 0.003). In conclusion, the use of CD had a favorable effect on anticoagulation in the extracorporeal circuit in patients on maintenance HD, but it was also associated with more hypotension and cramps.

Comparison of serum creatinine levels in different color/race categories in a Brazilian population

Serum creatinine (sCr) is usually higher among black people in the United States due to increased muscle mass, justifying the addition of race adjustment in creatinine-based formulas to estimate glomerular filtration rate (eGFR). We aimed to assess if sCr levels are different in low-income communities in Brazil according to their race. A total of 1,303 participants were enrolled (58% females, 50±14 years-old, 33% self-defined as white, 41% as mixed race, and 26% as black). No significant differences in sCr were found between racial groups and no influence of race on sCr was seen in the linear regression analysis. The eGFR, calculated using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula with no race adjustment, was no different between whites, mixed race and blacks. However, using such adjustment, eGFR for mixed race and black individuals was significantly higher than for whites (p < 0.001). In conclusion, no significant differences in sCr levels were found between racial groups, raising doubts as to whether race adjustment in eGFR formula should be used in that population.

BK polyomavirus in Kidney transplant recipients: screening, monitoring and clinical management

BK polyomavirus (BKPyV) is a causal agent of nephropathy, ureteral stenosis and hemorrhagic cystitis in kidney transplant recipients, and is considered an important emerging disease in transplantation. Regular screening for BKPyV reactivation mainly during the first 2 years posttransplant, with subsequent pre-emptive reduction of immunosuppression is considered the best option to avoid disease progression, since successful clearance or reduction of viremia is achieved in the vast majority of patients within 6 months. The use of drugs with antiviral properties for patients with persistent viremia has been attempted despite unclear benefits. Clinical manifestations of BKPyV nephropathy, current strategies for diagnosis and monitoring of BKPyV infection, management of immunosuppressive regimen after detection of BKPyV reactivation and the use of antiviral drugs are discussed in this review.

Prevalência e correlatos de doença vascular no exame de ultrassom em pacientes em hemodiálise

BACKGROUND Patients on hemodialysis present an increased risk of cardiovascular death. Intimal media thickness (IMT) and presence of arterial calcifications are well-known risk factors for cardiovascular death in hemodialysis patients. OBJECTIVE To assess the prevalence of IMT and arterial calcifications in HD patients and to correlate image findings with clinical and laboratory data. METHODS Cross-sectional study involving 75 patients on dialysis for >12 months. Patients underwent B-mode ultrasound scan (US) for determination of IMT of the distal third of the common carotid arteries. Arterial calcifications were assessed by US of carotids, femoral and tibial arteries, and labeled positive if calcification was found in any arterial site. RESULTS Patients were 52±13 years old, 57% were males and 16% were diabetics. IMT > 0.9 mm was found in 57% of cases and arterial calcifications at US in 48%. Aging (decades) and smoking were associated with both increased IMT (adjusted odds ratio [aOR] = 3.4, p < 0.001; aOR = 4.4, p = 0.045, respectively) and presence of vascular calcifications (aOR = 3.0, p < 0.001; aOR = 6.8, p = 0.011, respectively). High intact parathyroid hormone levels (per each 100 pg/ml) were significantly associated with increased IMT (aOR = 1.7, p = 0.021), but not with vascular calcification. In contrast, Diabetes and time on dialysis (years) were significant determinants for calcifications at US (aOR = 15.0, p = 0.009; aOR = 1.39, p = 0.020), but not for increased IMT. CONCLUSION Increased IMT and calcifications at US are common findings in hemodialysis patients. Aging and smoking are consistent determinants for both image alterations. Parathyroid hormone elevation is associated with increased IMT. Diabetes and time on dialysis substantially increase the risk for arterial calcification.FUNDAMENTO: Pacientes en hemodialisis (HD) presentan riesgo aumentado de muerte cardiovascular. El espesor intima-media (EIM) y la presencia de calcificaciones arteriales son factores de riesgo bien conocidos de muerte cardiovascular en pacientes en HD. OBJETIVO:Evaluar la prevalencia de EIM y calcificaciones en pacientes en HD y correlacionar hallazgos de imagen con datos clinicos y de laboratorio. METODOS:Estudio transversal de 75 pacientes en HD por >12 meses. Los pacientes fueron sometidos a ultrasonografia (US) modo-B para determinacion de la EIM del tercio distal de las arterias carotidas comunes. Las calcificaciones arteriales fueron evaluadas por US de arterias carotidas, femorales y tibiales y consideradas positivas si fuesen encontradas calcificaciones en cualquier sitio arterial. RESULTADOS:Los pacientes tenian 52±13 anos, 57% eran del sexo masculino y 16% eran diabeticos. EIM > 0,9mm fue encontrada en 57% de los casos y calcificaciones arteriales en la US en 48%. Envejecimiento (decadas) y tabaquismo estaban asociados a aumento de la EIM (odds ratio ajustado [aOR] = 3,4, p < 0,001; aOR = 4,4, p = 0,045, respectivamente) y presencia de calcificaciones vasculares (aOR = 3,0, p < 0,001; aOR = 6,8, p = 0,011, respectivamente). Altos niveles de hormona paratiroidea intacta (iPTH) (por 100 pg/ml) estaban asociados de forma significativa a aumento en la EIM (aOR = 1,7, p = 0,021), pero no a calcificacion vascular. En contraste, diabetes y tiempo de dialisis (anos) fueron determinantes significativos para calcificaciones en la US (aOR = 15,0, p = 0,009; aOR = 1,39, p = 0,020), pero no para el aumento de la EIM. CONCLUSION:EIM aumentada y calcificaciones en la US son hallazgos comunes en pacientes en HD. Envejecimiento y tabaquismo son determinantes consistentes para ambas alteraciones de imagen. Aumento en los niveles de iPTH esta asociado a aumento en la EIM. Diabetes y tiempo de dialisis aumentan de forma sustancial el riesgo de calcificacion arterial.

Detection of Autonomic Dysfunction in Hemodialysis Patients Using the Exercise Treadmill Test: The Role of the Chronotropic Index, Heart Rate Recovery, and R-R Variability

Autonomic dysfunction is highly prevalent in hemodialysis patients and has been implicated in their increased risk of cardiovascular mortality. Objective To evaluate the ability of different parameters of exercise treadmill test to detect autonomic dysfunction in hemodialysis patients. Methods Cross-sectional study involving hemodialysis patients and a control group. Clinical examination, blood sampling, echocardiogram, 24-hour Holter, and exercise treadmill test were performed. A ramp treadmill protocol symptom-limited with active recovery was employed. Results Forty-one hemodialysis patients and 41 controls concluded the study. There was significant difference between hemodialysis patients and controls in autonomic function parameters in 24h-Holter and exercise treadmill test. Probability of having autonomic dysfunction in hemodialysis patients compared to controls was 29.7 at the exercise treadmill test and 13.0 in the 24-hour Holter. Chronotropic index, heart rate recovery at the 1st min, and SDNN at exercise were used to develop an autonomic dysfunction score to grade autonomic dysfunction, in which, 83% of hemodialysis patients reached a scoring ≥2 in contrast to 20% of controls. Hemodialysis was independently associated with either altered chronotropic index or autonomic dysfunction scoring ≥2 in every tested model (OR=50.1, P=0.003; and OR=270.9, P=0.002, respectively, model 5). Conclusion The exercise treadmill test was feasible and useful to diagnose of the autonomic dysfunction in hemodialysis patients. Chronotropic index and autonomic dysfunction scoring ≥2 were the most effective parameters to differentiate between hemodialysis patients and controls suggesting that these variables portrays the best ability to detect autonomic dysfunction in this setting.

Alterações dermatológicas nos pacientes em hemodiálise e em transplantados

Recently, the world is facing an escalate in the incidence of chronic kidney disease (CKD). Databases containing information about patients in end stage renal disease (ESRD), especially in the United States, were the sources of initial information about it. Brazil has the third largest population on dialysis in the world, and there are about 680 dialysis centers, spread across all units of the federation in the present, providing treatment to an estimated population of almost 90,000 patients. Cutaneous involvement in the chronic renal failure is characterized by a number of manifestations, which may be related to three processes: the primary renal disease, the uremic state, or the therapeutic measures used in their handling. The skin changes in these two classes of patients, dialysis and transplant recipients, have been the subject of several studies. n recent years, however, great progress has been achieved in these two therapeutic modalities, which may have changed not only the type of the dermatologic disorders associated with these two conditions, but also their intensity or frequency. This article aims to yield an update as to the topic skin diseases in hemodialysis and kidney transplant patients.

Associação do índice tornozelo-braço com inflamação e alterações minerais ósseas em pacientes em hemodiálise

BACKGROUND: Reduced ankle-arm index (AAI), inflammation and mineral bone disorder (MBD) are all associated with increased risk of death and cardiovascular complications in patients on hemodialysis (HD), but the association between them deserves clarification. OBJECTIVE: To evaluate the association between abnormal AAI with MBD and inflammation in patients on HD. METHODS: This was a cross-sectional analysis of 478 patients on hemodialysis for at least one year. The AAI was evaluated using a portable Doppler and mercury column manometer. Patients were divided into 3 groups, according to AAI (low: 1.3). C-reactive protein measurement was used as an inflammatory marker, whereas MBD was evaluated by calcium, phosphorus and intact parathyroid hormone levels. RESULTS: Participants were 54 (18 to 75) years old, 56% males, 17% diabetics, and had been on hemodialysis for a mean of 5 (1 to 35) years. The prevalence of low, normal and high AAI was 26.8%, 64.6% and 8.6%, respectively. Using a backward conditional logistic regression model, age (p 6 mg/L (p= 0.006) were associated with the presence of low AAI, whereas male gender (p<0.001), diabetes (p= 0.001) and elevated calcium x phosphorus product (p= 0.026) were associated with high AAI. CONCLUSION: In patients on hemodialysis, the presence of diabetes was associated with both low and high AAI. The risk of having low AAI seems to be increased by aging and inflammation, whereas BMD was associated with high AAI.BACKGROUND Reduced ankle-arm index (AAI), inflammation and mineral bone disorder (MBD) are all associated with increased risk of death and cardiovascular complications in patients on hemodialysis (HD), but the association between them deserves clarification. OBJECTIVE To evaluate the association between abnormal AAI with MBD and inflammation in patients on HD. METHODS This was a cross-sectional analysis of 478 patients on hemodialysis for at least one year. The AAI was evaluated using a portable Doppler and mercury column manometer. Patients were divided into 3 groups, according to AAI (low: <0.9, normal: 0.9 to 1.3, and high: >1.3). C-reactive protein measurement was used as an inflammatory marker, whereas MBD was evaluated by calcium, phosphorus and intact parathyroid hormone levels. RESULTS Participants were 54 (18 to 75) years old, 56% males, 17% diabetics, and had been on hemodialysis for a mean of 5 (1 to 35) years. The prevalence of low, normal and high AAI was 26.8%, 64.6% and 8.6%, respectively. Using a backward conditional logistic regression model, age (p<0.001), diabetes (p= 0.001), and C-reactive protein levels >6 mg/L (p= 0.006) were associated with the presence of low AAI, whereas male gender (p<0.001), diabetes (p= 0.001) and elevated calcium x phosphorus product (p= 0.026) were associated with high AAI. CONCLUSION In patients on hemodialysis, the presence of diabetes was associated with both low and high AAI. The risk of having low AAI seems to be increased by aging and inflammation, whereas BMD was associated with high AAI.

Prevalence and correlates of vascular disease at ultrasound examination in patients on hemodialysis.

BACKGROUND Patients on hemodialysis present an increased risk of cardiovascular death. Intimal media thickness (IMT) and presence of arterial calcifications are well-known risk factors for cardiovascular death in hemodialysis patients. OBJECTIVE To assess the prevalence of IMT and arterial calcifications in HD patients and to correlate image findings with clinical and laboratory data. METHODS Cross-sectional study involving 75 patients on dialysis for >12 months. Patients underwent B-mode ultrasound scan (US) for determination of IMT of the distal third of the common carotid arteries. Arterial calcifications were assessed by US of carotids, femoral and tibial arteries, and labeled positive if calcification was found in any arterial site. RESULTS Patients were 52±13 years old, 57% were males and 16% were diabetics. IMT > 0.9 mm was found in 57% of cases and arterial calcifications at US in 48%. Aging (decades) and smoking were associated with both increased IMT (adjusted odds ratio [aOR] = 3.4, p < 0.001; aOR = 4.4, p = 0.045, respectively) and presence of vascular calcifications (aOR = 3.0, p < 0.001; aOR = 6.8, p = 0.011, respectively). High intact parathyroid hormone levels (per each 100 pg/ml) were significantly associated with increased IMT (aOR = 1.7, p = 0.021), but not with vascular calcification. In contrast, Diabetes and time on dialysis (years) were significant determinants for calcifications at US (aOR = 15.0, p = 0.009; aOR = 1.39, p = 0.020), but not for increased IMT. CONCLUSION Increased IMT and calcifications at US are common findings in hemodialysis patients. Aging and smoking are consistent determinants for both image alterations. Parathyroid hormone elevation is associated with increased IMT. Diabetes and time on dialysis substantially increase the risk for arterial calcification.FUNDAMENTO: Pacientes en hemodialisis (HD) presentan riesgo aumentado de muerte cardiovascular. El espesor intima-media (EIM) y la presencia de calcificaciones arteriales son factores de riesgo bien conocidos de muerte cardiovascular en pacientes en HD. OBJETIVO:Evaluar la prevalencia de EIM y calcificaciones en pacientes en HD y correlacionar hallazgos de imagen con datos clinicos y de laboratorio. METODOS:Estudio transversal de 75 pacientes en HD por >12 meses. Los pacientes fueron sometidos a ultrasonografia (US) modo-B para determinacion de la EIM del tercio distal de las arterias carotidas comunes. Las calcificaciones arteriales fueron evaluadas por US de arterias carotidas, femorales y tibiales y consideradas positivas si fuesen encontradas calcificaciones en cualquier sitio arterial. RESULTADOS:Los pacientes tenian 52±13 anos, 57% eran del sexo masculino y 16% eran diabeticos. EIM > 0,9mm fue encontrada en 57% de los casos y calcificaciones arteriales en la US en 48%. Envejecimiento (decadas) y tabaquismo estaban asociados a aumento de la EIM (odds ratio ajustado [aOR] = 3,4, p < 0,001; aOR = 4,4, p = 0,045, respectivamente) y presencia de calcificaciones vasculares (aOR = 3,0, p < 0,001; aOR = 6,8, p = 0,011, respectivamente). Altos niveles de hormona paratiroidea intacta (iPTH) (por 100 pg/ml) estaban asociados de forma significativa a aumento en la EIM (aOR = 1,7, p = 0,021), pero no a calcificacion vascular. En contraste, diabetes y tiempo de dialisis (anos) fueron determinantes significativos para calcificaciones en la US (aOR = 15,0, p = 0,009; aOR = 1,39, p = 0,020), pero no para el aumento de la EIM. CONCLUSION:EIM aumentada y calcificaciones en la US son hallazgos comunes en pacientes en HD. Envejecimiento y tabaquismo son determinantes consistentes para ambas alteraciones de imagen. Aumento en los niveles de iPTH esta asociado a aumento en la EIM. Diabetes y tiempo de dialisis aumentan de forma sustancial el riesgo de calcificacion arterial.