Expanded hemodialysis: Is anticoagulation of the dialysis circuit different from online hemodiafiltration and high-flux hemodialysis?

Expanded hemodialysis (HDx) has a high capacity for removing medium and medium-large molecules; however, there are no specific recommendations during HDx for anticoagulation of the dialysis circuit. We aimed to evaluate the differences in the efficacy of anticoagulation procedures using the venous port and 40 mg enoxaparin in HDx compared to high-flux hemodialysis (HF-HD) and postdilution online hemodiafiltration (HDF). We compared anticoagulant activity in 11 patients in HDx, HF-HD, and HDF under similar dialysis conditions. In the 33 dialysis sessions, 40 mg enoxaparin was administered through the venous port, and pre- and postdialysis antifactor Xa activity (aXa) and activated partial thromboplastin time (APTT), postdialysis clotting time of the vascular access, visual clotting score of the dialyzer, and any complications with the extracorporeal circuit or bleeding were registered. APTT postdialysis in HDx was not significantly different from that in HF-HD and HDF. Postdialysis aXa in HDx was not significantly different from that in HF-HD and HDF. We found no significant differences in visual clotting score of the dialyzer. Enoxaparin administered through the venous port was sufficient for anticoagulation within the extracorporeal circuit in HDx, HF-HD, and HDF. There were no differences in postdialysis aXa or APTT, most likely because when low molecular-weight heparin is applied through venous port, lesser enoxaparin concentration reaches the dialyzer. Thus, we conclude that the dose of enoxaparin administered through the venous port should not be adjusted according to dialysis technique.

Intradialytic hypotension and relationship with cognitive function and brain morphometry

Background

The haemodynamic stress brought about by dialysis could justify the loss of structural and functional integrity of the central nervous system (CNS). The main objective of this study was to analyse the relationship between intradialytic hypotension (IDH) and cognitive function and brain morphometry.

Methods

The cross-sectional KIDBRAIN study (Cohort Study of Morphological Changes of the Brain by MRI in Chronic Kidney Disease Patients) included 68 prevalent patients with no history of neurological disorders (cerebrovascular disease and cognitive impairment) undergoing haemodialysis (HD). We analysed 18 non-consecutive dialysis sessions (first three of each month over a 6-month period) and various definitions of IDH were recorded. Global cognitive function (GCF) was assessed using the Mini-Mental State Examination (MMSE) and parameters of structural integrity of the CNS were obtained using volume morphometry magnetic resonance imaging analysis [grey matter (GM), white matter (WM) and hippocampus).

Results

A greater number of sessions with IDH were associated with less volume of WM (r = −0.359,P = 0.003) and hippocampus (r = −0.395, P = 0.001) independent of cardiovascular risk factors according to multivariable linear regression models (β = −0.198, P = 0.046 for WM; β = −0.253, P = 0.017 for hippocampus). The GCF by the MMSE was 27.3 ± 7.3.1 and was associated with WM volume (β = 0.403, P = 0.001) independent of GM and hippocampus volume. Symptomatic IDH was associated with GCF (r = −0.420, P < 0.001) in adjusted analysis (β = −0.339, P = 0.008).

Conclusions

Even when asymptomatic, IDH is associated with a lower WM and hippocampus volume and reduced GCF in patients undergoing HD, thus suggesting greater vulnerability of the brain to the haemodynamic stress that may be generated by a dialysis session.

Efficacy of enoxaparin in preventing coagulation during high-flux haemodialysis, expanded haemodialysis and haemodiafiltration

Background

Low-molecular-weight heparins (LMWHs) are easily dialysable with high-flow membranes; however, it is not clear whether the LMWH dose should be adjusted according to the membrane type and dialysis technique. This study aimed to evaluate the influence of the dialyser on anticoagulation of the extracorporeal dialysis circuit.

Methods

Thirteen patients received the same dose of LMWH through the arterial port via three dialysis techniques: high-flux haemodialysis (HF-HD), online haemodiafiltration (HDF) and expanded haemodialysis (HDx). All dialysis was performed under similar conditions: duration, 4 h; blood flow, 400 mL/min; and dialysate flow, 500 mL/min. Antifactor Xa (aXa) activity and activated partial thromboplastin time (APTT) were measured before and after the dialysis. Clotting time of the vascular access site after haemodialysis, visual clotting score of the dialyser and any complications with the extracorporeal circuit or bleeding were registered.

Results

Post-dialysis aXa activity in HF-HD (0.26 ± 0.02 U/mL) was significantly different from that in HDF (0.21 ± 0.02 U/mL, P = 0.024), and there was a trend in HDx (0.22 ± 0.01 U/mL, P = 0.05). APTT post-dialysis in HF-HD (30.5 ± 0.7 s) was significantly different from that in HDx (28.2 ± 0.64 s, P = 0.009) and HDF (28.8 ± 0.73 s, P = 0.009).

Conclusions

AXa activity in HDF was significantly lower than that in HF-HD, possibly because of more losses of LMWH through the dialyser. Given the higher anticoagulant loss in HDF and probably in HDx than in HF-HD, the enoxaparin dose administered may be adjusted according to the dialysis technique.

Vascular access clinic results before and after implementing a multidisciplinary approach adding routine Doppler ultrasound

BACKGROUND

A multidisciplinary approach and Doppler ultrasound (DU) assessment for the creation and maintenance of arteriovenous fistulas (AVF) for haemodialysis can improve prevalence and patency. The aim of this study was to analyse the impact of a new multidisciplinary vascular access (VA) clinic with routine DU.

MATERIAL AND METHODS

We analysed the VA clinic results from 2014 and 2015, before and after the implementation of a multidisciplinary team protocol (vascular surgeon/nephrologist) with routine DU in preoperative mapping and prevalent AVF.

RESULTS

We analysed 345 and 364 patients from 2014 and 2015 respectively. The number of surgical interventions was similar in both periods (p=.289), with a trend towards an increase in preventive surgical repair of AVF in 2015 (17 vs. 29, p=.098). 155 vs. 169 new AVF were performed in 2014 and 2015, with a significantly lower primary failure rate in 2015 (26.4 vs. 15.3%, p=.015), and a non-significant increase in radiocephalic AVF, 25.8 vs. 33.2% (n=40 vs. 56), p=.159. The concordance between the indication at the clinic and the surgery performed also increased (81.3 vs. 93.5%, p=.001). Throughout 2015 fewer complementary imaging test were requested from the clinic (78 vs. 35, p <.001), with a corresponding reduction in costs (€87,716 vs. €59,445).

CONCLUSIONS

Multidisciplinary approach with routine DU can improve VA results, with a decrease in primary failure rate, higher likelihood of radiocephalic AVF, better management of dis-functioning AVF and lower radiological test costs.

Is High-Volume Online Hemodiafiltration Associated With Malnutrition?

Chronic malnutrition is a common problem in patients with end-stage renal disease on hemodialysis. Some studies have reported albumin loss into dialysis fluid during postdilution online hemodiafiltration (OL-HDF). The aim of the study was to assess the nutritional status of patients on high-volume OL-HDF and to demonstrate that higher convective clearances are not associated with malnutrition due to possible loss of nutrients with ultrafiltration. Demographic and clinical data, corporal composition with bioimpedance spectroscopy, dialysis features, albumin loss into dialysis fluid and laboratory parameters were collected in twenty-eight patients with ESRD undergoing postdilution OL-HDF with stable convective volumes over 28 L/session. Convective volume (CV) in the last six months was 32.51 ± 3.52 L per session. Cross-sectional analysis of dialysis features showed 32.7 ± 3.34 L of CV and high reduction rates of beta-2-microglobulin (84.2 ± 3.8%) and cystatin-C (81.6 ± 3.47%). Beta-2-microglobulin reduction showed a positive correlation with prealbumin levels (P = 0.048). CV was only correlated with cystatin-C reduction (P = 0.025). Estimated albumin loss into dialysis fluid (1.82 ± 1.05 g/session) was not related to laboratory or bioimpedance nutritional parameters, or to CV. Among patients with higher CV, serum albumin levels maintained more stability during the observational period. High volume OL-HDF results in better convective clearances and is not associated with malnutrition. Albumin and nutrients loss into dialysis fluid should not be a limiting factor of the substitution volume.

Low lean tissue mass is an independent risk factor for mortality in patients with stages 4 and 5 non-dialysis chronic kidney disease

Background: Mortality in patients with stages 4 and 5 chronic kidney disease (CKD) is higher than in the general population. Body composition predicts mortality. Our objective was to evaluate the effect of body composition on mortality in patients with stages 4 and 5 non-dialysis CKD. Methods: We performed a prospective study of 356 patients with stages 4 and 5 non-dialysis CKD. At baseline, we recorded general characteristics, history of cardiovascular events, body composition, serum inflammatory markers, nutrition and cardiac biomarkers. Body composition was analysed using bioimpedance spectroscopy. We recorded the lean tissue index (LTI), fat tissue index (FTI) and overhydration (OH). During a median (range) follow-up of 22 (3-49) months, we recorded mortality, cardiovascular events and progress to renal replacement therapy. Results: At baseline, mean (± standard deviation) age was 67 ± 13 years (men 64%; diabetes 36%). Mean body mass index was 28.2 ± 12.8 kg/m2, the FTI was 12.3 ± 5.6 kg/m2, the LTI was 15.7 ± 3.4 kg/m2 and median (interquartile range) OH was 0.6 (-0.4 to 1.5) L. Sixty-four (18%) patients died during follow-up. The univariate Cox analysis showed an association between mortality and age, low LTI, high Charlson comorbidity index, previous cardiovascular events, OH, low albumin and prealbumin levels, and high C-reactive protein levels. Kaplan-Meier analysis revealed higher survival in patients with a higher LTI (log-rank, 9.47; P = 0.002). The multivariate Cox analysis confirmed an association between mortality and low LTI (P = 0.031), previous cardiovascular events (P = 0.003) and high Charlson comorbidity index (P = 0.01). We did not find any association between body composition and cardiovascular events or renal replacement therapy. Conclusions: A low LTI is an independent factor for mortality in patients with stages 4 and 5 CKD.

Pulmonary Hypertension Is Associated with Mortality and Cardiovascular Events in Chronic Kidney Disease Patients

BACKGROUND

We evaluated the prevalence, determinants and prognosis value of pulmonary hypertension (PH) in non-dialysis chronic kidney disease (CKD) patients.

METHODS

This is a prospective study with stages 3-5 non-dialysis-dependent CKD patients. PH was estimated by Doppler echocardiography and defined as a pulmonary artery systolic pressure above 35 mm Hg.

RESULTS

Three hundred fifty-three patients were recruited, of whom 94 (26.6%) had PH. Prevalence of PH increased with the decline of renal function: 21.6, 24.1, and 31.7% in stages 3, 4, and 5, respectively. Independent predictors of PH were age, estimated glomerular filtration rate (eGFR), history of cardiovascular (CV) events, the presence of an arteriovenous fistulae (AVF), and left ventricular (systolic and diastolic) dysfunction. Over a median follow-up of 22 months, 71 patients died (20%). After multivariate adjustment for age, gender, previous CV disease, diastolic and systolic dysfunction, PH remained as an independent predictor of all-cause mortality (hazards ratio [HR] 1.84, 95% CI 1.06-3.18, p = 0.02). One hundred patients (28%) had a new onset CV event. After adjustment for age, gender, previous CV disease, systolic and diastolic dysfunction, PH maintains its independent association with CV events (HR 2.77, 95% CI 2.00-3.25, p < 0.001).

CONCLUSIONS

PH prevalence rises as kidney function declines. Main determinants of PH are age, eGFR, previous CV disease, the presence of an AVF and left ventricular systolic or diastolic dysfunction. PH is an independent predictor of all-cause mortality and CV events.

Effectiveness of direct-acting antivirals in Hepatitis C virus infection in haemodialysis patients

Hepatitis C virus (HCV) infection is highly prevalent among patients on haemodialysis and leads to a poorer prognosis compared to patients who do not have said infection. Treatment with interferon and ribavirin is poorly tolerated and there are limited data on the experience with new direct-acting antivirals (DAAs). The aim of this study is to retrospectively analyse the current prevalence of HCV infection and efficacy and safety results with different DAA regimens in the haemodialysis population of 2hospital areas. This is a multicentre, retrospective and observational study in which HCV antibodies were analysed in 465 patients, with positive antibody findings in 54 of them (11.6%). Among these, 29 cases (53.7%) with genotypes 1 and 4 were treated with different DAA regimens, including combinations of paritaprevir/ritonavir, ombitasvir, dasabuvir, sofosbuvir, simeprevir, daclatasvir and ledipasvir, with/without ribavirin. Mean age was 53.3±7.9 years, 72.4% of patients were male and the most important aetiology of chronic kidney disease involved glomerular abnormalities. In 100% of cases, a sustained viral response was achieved after 24 weeks, regardless of DAA regimen received. Adverse effects were not relevant and no case required stopping treatment. In 15 cases, ribavirin was combined with the DAA. In these cases, the most significant adverse effect was anaemic tendency, which was reflected in the increase of the dose of erythropoietin stimulating agents, although none required transfusions. In summary, we conclude that new DAAs for the treatment of HCV in haemodialysis patients are highly effective with minimal adverse effects; it is a very important advance in HCV management. These patients are therefore expected to have a much better prognosis than they have had until very recently.

Crescentic glomerulonephritis: data from the Spanish Glomerulonephritis Registry

BACKGROUND

Crescentic glomerulonephritis (CGN) is a histological finding that implies rapid deterioration of renal function and can be related to different diseases, such as type 1 or anti-glomerular basement membrane antibody (Goodpasture) disease, type 2 or immune complex CGN and type 3 or pauci-immune disease.

AIM

The present study describes CGN and its characteristics based on the data from the Spanish Glomerulonephritis Registry.

METHODS

An analysis was made of all native renal biopsies obtained from patients during 1994-2013 and classified as CGN. A patient epidemiological and clinical data questionnaire was completed by the 120 centres involved.

RESULTS

A total of 21,774 biopsies was performed, of which 2089 (8.1%) corresponded to CGN (211 type 1, 177 type 2 and 1701 type 3). Renal function was poorer in type 1 compared with types 2 and 3, and proteinuria was higher in type 2 compared to types 1 and 3. Patients diagnosed with CGN type 3 were older than those with types 1 and 2, but less hypertensive than the type 2 patients. No differences in the urine test findings were found between types 1 and 2. Microhaematuria was the most frequent feature in general, as well as in type 3 compared with types 1 and 2. The main indication for biopsy was acute renal injury. Age was the only difference between type 1 patients with and without alveolar haemorrhage (53 [33-67] vs 64 [46-73], P = 0.008).

CONCLUSION

Although classified as the same entity, the different types of CGN have different features that must be taken into account.

Haematuria on the Spanish Registry of Glomerulonephritis

Recent studies suggest a pathogenic role for glomerular haematuria among renal function. However, there is no data on the prevalence of haematuria from a large renal biopsy registry. We analysed the prevalence of gross (GH) and microscopic (mH) haematuria in 19,895 patients that underwent native renal biopsies from the Spanish Registry of Glomerulonephritis. Haematuria's overall incidence was 63% (GH 8.6% and mH 55.1%), being more frequent in males (64.7% vs. 62.4%). GH was more prevalent in patients <18 years (21.3% vs. 7.7%). The commonest clinical presentation associated with GH was acute kidney injury (31.5%) and IgA Nephropathy (IgAN) (33.6%) was the most frequent histological finding. GH patients showed a significantly (p < 0.05) lower eGFR and proteinuria levels as compared with patients with mH and without haematuria. Moreover, mH was more prevalent in adults (56.3%). Nephrotic syndrome was the commonest clinical presentation in mH patients (32.2%) and IgAN (18.5%) the most frequent histological finding. In conclusion, haematuria, is a frequent urinalysis finding in patients underwent native renal biopsy. The most frequent histological finding in both GH and mH is IgAN. Whereas, GH is more frequent in young males with acute kidney injury, mH is commoner among adults with nephrotic syndrome.

Creatine-kinase and dialysis patients, a helpful tool for stratifying cardiovascular risk?

BACKGROUND AND AIMS

Hemodialysis patients have an enhanced risk for cardiovascular events. Cardiac biomarkers provide useful information for stratifying their risk. However the prognosis value of creatine kinase MB isoenzyme (CKMB) has not yet been validated in this population. The aim of the present study is to determine the predictable value of CK-MB in hemodialysis.

METHODS

A cohort of 211 hemodialysis patients (58.3% male, median age 73 (60-80) years) were followed for 39 (19-56) months. Cardiac biomarkers including CKMB were recorded at baseline. Factors associated to CKMB and prognosis value of this biomarker was studied.

RESULTS

The median value of CKMB was 1 (1-2) ng/mL with no patient exceeding normal laboratory values. Previous heart disease, diabetes mellitus, peripheral vascular disease and systolic and diastolic dysfunction were associated with higher levels of CKMB. Ninety-four patients (44.5%) cardiovascular events were recorded. CKMB levels ≥2ng/mL was independently associated to cardiovascular events during the follow up after adjusting. Adding CKMB to a model including several variables for predicting cardiovascular events, resulted in 17% improvement in risk discrimination (IDI) with a relative IDI of 9.9% (p=0.04).

CONCLUSIONS

CKMB is a good marker for stratifying cardiovascular risk in hemodialysis patients and adds prognosis information to other well known independent predictors for cardiovascular events.

Haematuria increases progression of advanced proteinuric kidney disease

Background

Haematuria has been traditionally considered as a benign hallmark of some glomerular diseases; however new studies show that haematuria may decrease renal function.

Objective

To determine the influence of haematuria on the rate of chronic kidney disease (CKD) progression in 71 proteinuric patients with advanced CKD (baseline eGFR <30 mL/min) during 12 months of follow-up.

Results

The mean rate of decline in eGFR was higher in patients with both haematuria and proteinuria (haemoproteinuria, HP, n=31) than in patients with proteinuria alone (P patients, n=40) (-3.8±8.9 vs 0.9±9.5 mL/min/1.73m2/year, p<0.05, respectively). The deleterious effect of haematuria on rate of decline in eGFR was observed in patients <65 years (-6.8±9.9 (HP) vs. 0.1±11.7 (P) mL/min/1.73m2/year, p<0.05), but not in patients >65 years (-1.2±6.8 (HP) vs. 1.5±7.7 (P) mL/min/1.73m2/year). Furthermore, the harmful effect of haematuria on eGFR slope was found patients with proteinuria >0.5 g/24 h (-5.8±6.4 (HP) vs. -1.37± 7.9 (P) mL/min/1.73m2/year, p<0.05), whereas no significant differences were found in patients with proteinuria < 0.5 g/24 h (-0.62±7.4 (HP) vs. 3.4±11.1 (P) mL/min/1.73m2/year). Multivariate analysis reported that presence of haematuria was significantly and independently associated with eGFR deterioration after adjusting for traditional risk factors, including age, serum phosphate, mean proteinuria and mean serum PTH (β=-4.316, p=0.025).

Conclusions

The presence of haematuria is closely associated with a faster decrease in renal function in advanced proteinuric CKD patients, especially in younger CKD patients with high proteinuria levels; therefore this high risk subgroup of patients would benefit of intensive medical surveillance and treatment.

Body Composition Affects Urea Distribution Volume Estimated by Watson's Formula

OBJECTIVE

Dialysis machines use the Watson formula (Vwatson) to estimate the urea distribution volume (UDV) to calculate the online Kt/V for each dialysis session. However, the equation could give rise to inaccuracies. The present study analyzes whether body composition affects UDV estimated by Vwatson in comparison to bioimpedance spectroscopy (Vbis) as the reference method.

DESIGN

This is a transversal study performed in the setting of a hemodialysis unit.

SUBJECTS

Prevalent hemodialysis patients.

INTERVENTION

The same day, UDV was measured using Vwatson and Vbis. We compared their results.

MAIN OUTCOME MEASURE

Differences between UDV using Watson equation and Vbis.

RESULTS

We included 144 prevalent patients. Vwatson overestimated the volume with regard to Vbis (Vwatson - Vbis) by 2.5 L (1.8 L; P = .001). We found an excellent correlation between the 2 methods. A higher mean Vwatson - Vbis value was correlated to older age (P = .03), body mass index (P = .01), fat tissue index (P = .001), lower lean tissue index (P = .001), lower extracellular water (P = .01), and intracellular water (P = .001).

CONCLUSION

Body composition affects UDV estimated by Vwatson, thus modifying the result of Kt/V. In young patients who present more lean tissue and less fat tissue, Kt/V is underestimated with Vwatson.

Dose equivalence between continuous erythropoietin receptor activator (CERA), Darbepoetin and Epoetin in patients with advanced chronic kidney disease

BACKGROUND

Anemia is a prevalent situation in patients with chronic kidney disease (CKD) and can be well managed with erythropoiesis-stimulating agents (ESAs). Continuous erythropoietin receptor activator (CERA) has a long half-life that allows to be administered once monthly. The lowest recommended dose for patients with non dialysis CKD is 120 μg per month. The objectives were to assess the efficacy of subcutaneous monthly dosing of CERA in CKD stages 4 and 5 not on dialysis, and to determine the equivalent dose to epoetin β and darbepoetin α.

METHODS

This is a cohort study. A 30-patient group that ESAs was changed to CERA (μg/month) was used as treatment group. We used the following clinically-based equivalent dosing: epoetin β (IU/week) and darbepoetin α (μg/week): 3000/15= 50; 4000/20=75; 6000/30=100; 8000/40=150. Another group of 30 patients with similar characteristics was used as control group and received the same epoetin β and darbepoetin α doses.

RESULTS

The mean CERA initial dose and at 6 months was 81.9 ± 35.2 and 82.0 ± 37.82 μg/month (p=0.37). The mean erythropoietin resistance index (ERI) and hemoglobin at baseline and at 6 months in the CERA group and in the control group were not statistically significant.

CONCLUSION

Monthly dosing treatment with CERA is safe and effective. A dose of 75-100 μg/month is enough to maintain stable levels of hemoglobin. Hippokratia 2014; 18 (4): 315-318.

Risk factors for renal failure in patients with lupus nephritis: data from the spanish registry of glomerulonephritis

BACKGROUND

Lupus nephritis (LN) is a severe complication of systemic lupus erythematosus. Data from national registries based on renal biopsies are scarce. The aim of our study was to analyze the demographic characteristics, clinicopathological correlations, and risk factors associated with renal failure in patients with LN at the time of renal biopsy.

METHODS

We performed a cross-sectional observational study based on data from the Spanish Registry of Glomerulonephritis for the years 1994-2009. The outcome measure was the presence of renal failure (eGFR <60 ml/min/1.73 m(2)). We also recorded age, gender, proteinuria levels, hypertension, and histological class.

RESULTS

We collected 17,525 native renal biopsies, of which 1,648 biopsies showed LN lesions. In total, 609 patients (37%) showed renal failure at the time of renal biopsy. The univariate analysis showed that these patients were older, had higher levels of proteinuria, and a higher prevalence of hypertension than the group with eGFR ≥60 ml/min/ 1.73 m(2). The histological class of LN was recorded for 566 patients, and multivariate logistic regression analysis showed that the independent risk factors for renal failure at the time of renal biopsy were age (OR 1.03; 95% CI 1.01-1.04), male gender (OR 1.94; 95% CI 1.12-3.10), hypertension (OR 3.18; 95% CI 2.16-4.67), proteinuria (OR 1.15; 95% CI 1.08-1.24), and histological classes III and IV (OR 1.82; 95% CI 1.16-2.87).

CONCLUSIONS

Data from the Spanish Registry of Glomerulonephritis provide valuable information about risk factors for renal failure in patients with LN at the time of renal biopsy.

[Clinical and analytical changes in hemodialysis without acetate]

BACKGROUND

the purpose of this study was to evaluate blood acetate levels and its correlation with clinical and analytical changes in hemodialysis patients treated with standard bicarbonate dialysate compared to treatment with acetate-free bicarbonate dialysate.

METHODS

fourteen patients on hemodialysis (11 male) with mean age of 61 15 years, were treated with conventional bicarbonate dialysate for 1 month and then switched to acetate-free bicarbonate dialysate for another month. Blood samples were drawn at the third session of first and fourth week of each type of dialysis.

RESULTS

Pre-dialysis blood acetate levels were similar in both groups, whereas post-dialysis blood acetate levels were higher in patients treated with conventional bicarbonate dialysate (0.48+/- 0.64 vs. 0.18+/-0.23 mmol/L, p=0.024). Moreover, both periods had similar percentage of patients with pre-dialysis blood acetate levels in the pathologic range, whereas this percentage was higher in post-dialysis samples from patients treated with conventional bicarbonate dialysate respect to acetate-free dialysate (67% vs. 21%, p=0.001). Serum levels of interleukin-6 were statistically higher in the period with conventional bicarbonate dialysate (31.7+/- 24.7 vs. 18.7+/- 10.3 pg/ml, p=0.014), even though other inflammatory markers such as LBP, TNF- and CRP failed to increase in the same period. We didn't found significant differences in the other parameters studied except for the changes in serum concentrations of sodium, chloride and bicarbonate.

CONCLUSIONS

Acetate-free bicarbonate dialysate does not expose patients to a big amount of acetate and allows that the majority of patients finished hemodialysis with blood acetate levels in the physiologic ranges. Acetate-free dialysate was safe and well tolerated by our hemodialysis patients, although clinical advantages derived from its use should be evaluated in long-term prospective studies.

[Resistance index to epoetin alpha and to darbepoetin-alpha in chronic hemodialysis patients: a cohort study]

The effectiveness of the erythropoietic response can be evaluated using the resistance index (RI) to erythropoietic agents (EA) that measures the relationship between the dose administered and the hemoglobin levels attained. In a hemodialysis population, the RI is associated with several clinical and biochemical parameters, such as albumin levels, C-reactive protein (CRP), body mass index (BMI) and Kt/V. This index therefore reflects an important group of parameters that indicate comorbidities and measures the effectiveness of the treatment received. A substantial proportion of chronic hemodialysis patients show a relative resistance to human recombinant erythropoietin (rHuEPO) and require high doses to reach hemoglobin levels above 11 g/dl. Darbepoetin alpha is a new erythropoietic agent with a longer half-life than rHuEPO and greater biological activity in vivo. Furthermore, it remains at clinically effective plasma levels for much longer than rHuEPO. This study evaluated the effect on RI of switching from epoetin alpha to darbepoetin alpha in hemodialysis patients requiring i.v. rHuEPO at either high ( >10,000 UI/w) or low ( <4,000 UI/w) doses, compared to a control group receiving epoetin alpha. Unlike the control group, both groups of patients who switched to darbepoetin alpha showed a reduction in RI and a progressive reduction in the dose required of darbepoetin alpha with respect to the equivalent dose at treatment conversion. In the group requiring high doses, darbepoetin alpha RI (DRI) at week 24 was a significant 23.9% lower than epoetin alpha RI (ERI) at conversion (week 0) (p <0.01). In the group requiring low doses, DRI at week 24 was 13.4% lower than the ERI at conversion (p = NS). In both control groups, ERI at week 24 was higher than ERI at week 0. All groups showed stable hemoglobin levels across the study, with mean levels between 11.5 and 13.3 g/dl. CRP at week 24 was significantly related to albumin levels (p <0.001). In conclusion, switching hemodialysis patients from epoetin alpha to darbepoetin alpha was associated with a significant improvement in RI in the group of patients with high doses of EA, which we consider to be an important indicator of the effectiveness and quality of the treatment administered.

A prospective multicentre study of the role of anaemia as a risk factor in haemodialysis patients: the MAR Study

BACKGROUND

Retrospective studies have shown hospitalization and mortality rates during haemodialysis (HD) to be associated with anaemia.

METHODS

The prospective, multicentre Morbidity-and-mortality Anaemia Renal (MAR) study was designed to establish the burden of anaemia by controlling for other risk factors. Charlson index was used for comorbid adjustment. Finally, 1428 patients from 119 centres (60% men, aged 64.4 years, time on HD 15.3 months, Charlson comorbidity index 6.5 +/- 2.3) completed follow-up. They had hypertension (75.8%), diabetes mellitus (25.9%), heart failure (13.9%) and coronary disease (16.7%). Of the total patients, 94.8% were receiving erythropoietin (111.6 +/- 70.6 U/kg/week) and 76.7% i.v. iron, and haemoglobin (Hb) at inclusion was 11.7 +/- 1.5 g/dl.

RESULTS

Hospitalization rate was 1.1 admissions/patient/year. Yearly mortality was 12% [35% cardiovascular (CV)]. The relative risk and confidence interval (CI) for hospitalization and death were 0.86 (0.81-0.91) and 0.82 (0.73-0.91), respectively, per 1 g/dl increase in initial Hb after adjustment for comorbidity, vintage, aetiology, access type, albumin and Kt/V. The probability of remaining free from hospitalization (CI) was 0.34 (0.27-0.41) for initial Hb <10 g/dl, 0.47 (0.41-0.53) for Hb 10-11 g/dl, 0.54 (0.49-0.59) for Hb 11-12 g/dl, and 0.63 (0.59-0.67) for Hb >12 g/dl. Same analysis for patient survival was 0.77 (0.71-0.83) for Hb <10 g/dl vs 0.82 (0.77-0.87) for Hb 10-11 vs 0.89 (0.86-0.92) for Hb 11-12 vs 0.92 (0.90-0.94) for Hb > 12 g/dl, P < 0.001. The Cox regression model for hospitalization-free survival included the risk factors initial Hb (relative risk 0.86 per 1 g/dl increase, P < 0.001) Charlson, albumin and prior CV event.

CONCLUSION

Hb level predicted 1-year-survival and hospitalization. This effect persisted after adjustment for comorbidity and other prognostic factors.

Anemia management and treatment response in patients on hemodialysis: the MAR study

BACKGROUND

Anemia management guidelines describe the importance of anemia as a risk factor in hemodialysis and the need for clinical prospective studies focused on this role of anemia. Response to treatment with iron and epoetin is multifactorial, and results are still far from the targets set by the guidelines. The Morbidity and Mortality Anemia Renal study (MAR) is a multicenter prospective cohort study of hemodialysis (HD), designed to assess the burden of anemia on morbidity and mortality. We report here a cross-sectional analysis of the management of anemia, and response-to-treatment factors.

METHODS

A total of 1,710 patients were included (60% male, mean age 64.4 +/- 13.6 years, mean 16.2 +/- 11.1 months on HD) with a high comorbidity (hypertension 75.8%, diabetes 25.9%, heart failure 13.9% and coronary disease 16.7%) and a mean Charlson Index of 6.5 +/- 2.3.

RESULTS

There were 28.7% of patients who had started epoetin before end-stage renal disease (pre-ESRD), 81.4% of patients displayed Hb <11 g/dL when initiating HD with a mean Hb of 9.7 g/dL. Only 67.9% of prevalent HD patients attained a hemoglobin (Hb) level above 11 g/dL, 89.5% achieved a ferritin level above 100 ng/mL, 76.7% a transferrin saturation index (TSI) above 20%, and 61.1% met all 3 objectives. The multivariate analysis identified the following risk factors for Hb <11g/dL: low albumin (odds ratio, OR = 1.75), HD efficacy below objectives (OR = 1.44) and female sex (OR = 1.36), corrected for comorbidity, epoetin treatment, transfusion, surgery or hospital admission.

CONCLUSIONS

As compared with previous surveys, we found an improved but still inadequate anemia management in Spanish HD patients. Our results are comparable with those of Euro-DOPPS. Several modifiable factors related to a lower Hb concentration were assessed. On behalf of the MAR Study Group.

Psychosocial Factors and Health-Related Quality of Life in Hemodialysis Patients

Several sociodemographic and clinical variables are known to influence the health-related quality of life (HRQOL) of patients with kidney disease, yet the relationship between psychological factors and the HRQOL measured by the Kidney Disease Quality of Life Short-Form (KDQOL-SF) is incompletely understood. The objective of this study was to examine the relationship between psychosocial status (depressive symptoms, trait anxiety, and social support) and KDQOL-SF scales in hemodialysis (HD) patients by controlling the effects of sociodemographic and clinical variables. The HRQOL of 194 patients from 43 dialysis centers in Spain was assessed by completing the KDQOL-SF, and evaluating depressive Symptoms (Cognitive Depression Index), trait anxiety (Trait Anxiety Inventory) and degree of social support (Scale of Perceived Social Support). We also recorded several sociodemographic and clinical variables. Two regression models were estimated for each of the 19 scales in the KDQOL-SF. In the first model, we only included sociodemographic and clinical-factors, while the second model also took into consideration psychosocial variables. These last factors (trait anxiety and depressive symptoms, not social support) were found to increase the proportion of explained variability, with highest standardized regression coefficients observed for most KDQOL-SF scales. Depressive symptoms were related to a poor HRQOL when there was a strong physical component, while trait anxiety was mainly related to emotional upset and social relationships. We were able to conclude that trait anxiety and depressive symptoms are strongly associated with the HRQOL assessed by the KDQOL-SF in HD patients. The effects of these factors should therefore be considered when evaluating the quality of life of this type of patient.

[Cardiovascular risk in hemodialysis in Spain: prevalence, management and target results (MAR study)]

Cardiovacular disease is the main cause of morbidity and mortality in hemodialysis (HD) patients. However, there are no reliable data neither on the prevalence of cardiovacular disease nor its risk factors in Spain. The Morbidity and mortality Anemia Renal study (MAR) is a two-year multicenter, open-label, prospective cohorts study. Its main objective is to assess the general morbidity and mortality, particularly of a cardiovascular cause, and its relationship with the degree of anemia. Secondary objectives are: a/ the description of current clinical practices in anemia, dialysis, vascular access, and CV risk factor management; and b/ the description of hospitalization and mortality causes. This paper describes the prevalence of cardiovascular disease and risk factors of the HD population in Spain. A total of 1.710 patients were included (60% male, aged 64.4 years, 16.2 months on HD). The mean co-morbidity Charlson index was 6.5 +/- 2.3. Cardiovascular disease was the most prevalent comorbidity, 16.7% had a coronary disease, and 13.9% had different degrees of heart failure, while 11.6% had arrhythmia, 1.7% stroke and 5.5% peripheral artery disease. The prevalence of hypertension was 75.8%, 74.4% of patients received antihypertensive drugs, and still 40% of patients had an inadequate blood pressure control. The investigators considered as dyslipidemic 34.1% of patients, and prescribed treatment to 69.5% of them, while the remaining 30.5% (10.4% of the total) had hyperlipidemia with no drug therapy. Eleven percent was active smoker, and 26.6% former smoker. There was 47.4% of patients with a corporal mass index above 25. Secondary hyperparathyroidism with PTH above of 300 pg/ml was present in 22.2% of patients. Despite the EBPG and K-DOQI recommendations, only 68.8% of prevalent hemodialysis patients attained a hemoglobin (Hb) above 11 g/dl, 89.4% ferritin levels above 100 ng/ml, 66.5 degrees/a a transferrin saturation index (TSI) above 20%, and 61.1% met all three objectives. In summary, this first cross-sectional analysis has allowed us to know in detail the standard practice in multiple aspects of management of HD population in Spain. It has also established clear differences in the prevalence of cardiovascular disease and risk factors from the US registries. Last but not least we have identified therapeutic opportunities to improve the course and prognosis of our patients.

Clinicopathologic correlations of renal pathology in Spain

BACKGROUND

There are not enough large epidemiologic population-based studies of biopsy-proven nephropathies with detailed clinicopathologic correlations.

METHODS

The Glomerulonephritis Registry of the Spanish Society of Nephrology has obtained data from 9378 cases with native biopsy-proven renal diseases and well-known clinical syndrome between 1994 and 2001, investigating clinicopathologic correlations. Patients were divided in three groups according to age: children (<15 years old), adults (15 to 65 years), and elderly (>65 years).

RESULTS

The most common clinical syndrome at any age is nephrotic syndrome (35.5%), followed by asymptomatic urinary abnormalities (25.9%), acute renal failure (12.9%), chronic renal failure (12.1%), nephritic syndrome (4.5%), macroscopic haematuria (4.5%), and arterial hypertension (3.0%). A male predominance is observed at any age (3:2). The frequencies of histologic findings are statistically different in all syndromes according to age. Minimal change disease is the most frequent finding in children with nephrotic syndrome (39.5%), whereas in adults and elderly, membranous nephropathy is the most prevalent (24.2% and 28.0%, respectively). Ig A nephropathy (IgAN) is the most frequent glomerulonephritis in patients with asymptomatic urinary abnormalities at any age. Acute renal failure is an important cause for performing a kidney biopsy in elderly and vasculitis is the main histologic finding. The clinical manifestations of focal segmental glomerulosclerosis, non-IgA mesangial nephropathy, lupus nephritis, vasculitis, and nephroangiosclerosis are statistically different according to age.

CONCLUSION

The findings of clinicopathologic correlations obtained from the Spanish Registry of Glomerulonephritis on native biopsy-proven renal diseases add valuable information to previous reports and it can be the initial step for follow-up and prospective studies.

[Differences in health-related quality of life between male and female hemodialysis patients]

BACKGROUND

Previous studies in renal patients have reported that women perceive a lower health-related quality of life (HRQOL) than men: however, these studies have been carried out without taking into account the gender-related differences shown in general population samples. The aims of the present study are: a) to define the HRQOL dimensions in which there are differences between men and women on chronic hemodialysis (HD), correcting then the differences on the generic dimensions by means of standardization by age and gender of the obtained scores, using Spanish normative data, and b) to identify the variables that cause these possible gender-related differences on HRQOL.

METHODS

A cross-sectional multi-center study was carried out with 152 patients (69 men and 83 women) receiving HD treatment in 43 Spanish centers, using the KDQOL-SF to evaluate their HRQOL. The generic KDQOL-SF scores were standardized by age and gender using Spanish normative data. Sociodemographic, clinical and psychosocial variables were also collected on each patient. A MANOVA was carried out to study the variables associated with the gender-related differences on HRQOL. The sociodemographic, clinical and psychosocial variables showing significant differences between men and women in the previous univariate analysis were entered as covariates.

RESULTS

The KDQOL-SF scores showed statistically significant differences between men and women in four scales: physical functioning, emotional role limitation, social function and emotional well-being. In contrast, standardized scores showed no differences between men and women in the profile or degree of HRQOL impairment. Although statistically significant gender-related differences were shown in educational level, employment, haemoglobin, Kt/V, trait anxiety and depressive symptoms, only the last two variables showed an independent effect on the differences in HRQOL.

CONCLUSION

Impaired HRQOL in women on HD reflects the gender-related differences that are also shown in the general population, and they are related to the higher prevalence of trait anxiety and depressive symptoms in women.

Frequency of renal pathology in Spain 1994-1999

BACKGROUND

There are not enough large epidemiological population-based studies of biopsy-proven nephropathies with detailed clinical and histopathological data.

METHODS

The Glomerulonephritis Registry of the Spanish Society of Nephrology has obtained data from 7016 patients with biopsied renal diseases between 1994 and 1999, investigating prevalence, incidence and clinical and histopathological data. Biopsies of transplant kidneys have not been considered.

RESULTS

The observed biopsy rate for all ages is 4.8 per 100 000 inhabitants. A male predominance is seen for all age groups. The most common clinical syndrome at any age is nephrotic syndrome. The prevalence of hypertension is higher in adults and elderly patients. The most common pathologies are IgA nephropathy, focal glomerulosclerosis, membranous nephropathy and lupus nephritis. The mean annual incidence (per million of population) of the most common nephropathies is IgA nephropathy 7.9, focal segmental glomerulosclerosis 6.4, membranous nephropathy 6.2, lupus nephritis 5.6, minimal-change disease 4.8, nephroangiosclerosis 4.6, vasculitis 4.3, membranoproliferative glomerulonephritis 3.6 and amyloidosis 3.3. In children, the most frequent causes are minimal-change disease, IgA nephropathy and focal glomerulosclerosis. In adults, the most common diagnoses are IgA nephropathy, lupus nephritis, and focal glomerulosclerosis. In elderly patients, the most frequently reported pathologies are vasculitis, membranous nephropathy and amyloidosis. Membranous nephropathy has increased in incidence in recent years.

CONCLUSIONS

We provide representative population-based descriptive data on native biopsy-proven renal diseases in Spain.

Quality of life in end-stage renal disease patients

Health-related quality of life (QOL) refers to the measure of a patient's functioning, well-being, and general health perception in each of three domains: physical, psychological, and social. Along with survival and other types of clinical outcomes, patient QOL is an important indicator of the effectiveness of the medical care they receive. QOL of patients with end-stage renal disease is influenced by the disease itself and by the type of replacement therapy. Numerous studies have identified the effect of such factors as anemia, age, comorbidity, and depression on QOL. Most of these factors appear during the predialysis period, and the adequate management of some of them could influence patient outcomes. Among replacement therapies, transplantation appears to give the best QOL for large groups of patients. No conclusive data exist to prove differences in QOL between hemodialysis patients and peritoneal dialysis patients. In the case of elderly patients or those with a high degree of comorbidity, the best treatment option should be assessed in each individual case, taking all possible factors into account. Finally, it has been proven that physical and mental function are inversely correlated with the risk for hospitalization and mortality.

Quality of life in end-stage renal disease patients

Health-related quality of life (QOL) refers to the measure of a patient's functioning, well-being, and general health perception in each of three domains: physical, psychological, and social. Along with survival and other types of clinical outcomes, patient QOL is an important indicator of the effectiveness of the medical care they receive. QOL of patients with end-stage renal disease is influenced by the disease itself and by the type of replacement therapy. Numerous studies have identified the effect of such factors as anemia, age, comorbidity, and depression on QOL. Most of these factors appear during the predialysis period, and the adequate management of some of them could influence patient outcomes. Among replacement therapies, transplantation appears to give the best QOL for large groups of patients. No conclusive data exist to prove differences in QOL between hemodialysis patients and peritoneal dialysis patients. In the case of elderly patients or those with a high degree of comorbidity, the best treatment option should be assessed in each individual case, taking all possible factors into account. Finally, it has been proven that physical and mental function are inversely correlated with the risk for hospitalization and mortality.

Haemodialysis dose, extracellular volume control and arterial hypertension

Patients with chronic renal failure on periodical dialysis frequently are hypertensive. This frequency has increased in relation to the liberalization of diet and to short dialysis with a high sodium concentration in the dialysate. Although various factors influence the pathogenesis of this type of hypertension, volume overload is the most significant. The achievement of an optimal dry weight is still one of the most difficult and important tasks of a dialysis clinic. The reduction in extracellular volume in haemodialysis implies an improvement in dialysis tolerance. The time factor is one of the principal elements in this control, but it is possible, using other elements, to improve tolerance in 4-5 h sessions and to achieve the proper dry weight associated with normotension in most patients.

Increasing the hematocrit has a beneficial effect on quality of life and is safe in selected hemodialysis patients. Spanish Cooperative Renal Patients Quality of Life Study Group of the Spanish Society of Nephrology

Target hematocrit/hemoglobin values in dialysis patients are still controversial. The Spanish Cooperative Renal Patients Quality of Life Study Group (including 34 hemodialysis units) conducted a prospective, 6-mo study of the effect on patient functional status and quality of life of using epoetin to achieve normal hematocrit in hemodialysis patients with anemia. The possible adverse effects of increased hematocrit, patient hospitalization, and epoetin requirements were also studied. The study included 156 patients (age range, 18 to 65 yr). Given the minimal experience in the safety of increasing hematocrit in dialysis patients to normal levels with epoetin, stable patients on hemodialysis who had received epoetin treatment for at least 3 mo and had a stable hemoglobin level of > or = 9 g/dl were included in the study. Patients with antecedents of congestive cardiac failure, ischemic cardiopathy, diabetes mellitus, uncontrolled hypertension, cerebrovascular accident or seizures, malfunction of the vascular access or severe comorbidity (defined by a comorbidity index), and those over 65 yr of age were excluded from the study. Quality of life was measured with the Sickness Impact Profile (SIP) and Karnofsky scale. Patients completed questionnaires at home at onset and conclusion of the 6-mo study. Mean hematocrit increased from 30.9 to 38.4% and hemoglobin from 10.2 to 12.5 g/dl during the study. Health indicator scores improved significantly: mean Physical Dimension (SIP) from 5.38 to 4.1 (P < 0.005); mean Psychosocial Dimension from 9.2 to 7 (P < 0.001); mean global SIP from 8.9 to 7.25 (P < 0.001); mean Karnofsky scale score from 75.6 to 78.4 (P < 0.01). (SIP is scaled so that lower scores represent better functional status, and vice versa for the Karnofsky scale). Therefore, functional status and quality of life improved with increased hematocrit. No deaths occurred. Three patients (2%) were censored for hypertension and nine (5.7%) for thrombosis of the vascular access. The cumulative probability of thrombosis of the vascular access was 0.067. The average epoetin dose rose from 93 +/- 62 U/kg per wk at onset to 141 +/- 80 U/kg per wk at conclusion, a 51% increase. The number of patients hospitalized decreased and hospital lengths of stay were shorter during the study period than in the same patients in the 6-mo period preceding the study (P < 0.05). Nine patients (5.7%) had thrombosis of the vascular access. There were no changes in the prevalence of arterial hypertension, but three patients (2%) showed hypertension that was difficult to control. It is concluded that normalization of hematocrit in selected hemodialysis patients, i.e., nondiabetic patients without severe cardiovascular or cerebrovascular comorbidities, improves quality of life and decreases morbidity without significant adverse effects.

Changes in quality of life after renal transplantation

The objective of this study was to evaluate the modifications that renal transplantation produces on the quality of life (QOL) of patients with chronic renal failure (CRF) previously undergoing hemodialysis (HD) and to analyze the possible factors implicated. A multicenter study of QOL was performed on 1,023 patients undergoing dialysis, using as QOL indicators the Karnofsky Scale (KS) and the Sickness Impact Profile (SIP). Among this group, 93 patients received a renal transplant and QOL was re-studied in them; each subject, therefore, was his own control. In the 88 patients with a functioning graft, an improvement in QOL indices was globally observed; this improvement was much more marked in men than in women, for unclear reasons. Older age and greater prior comorbidity diminished the beneficial effects of transplantation.

[Prognostic value of anti-RNP/Sm and anti-Ro/La antibodies in lupus nephropathy]

With the aim to analyze the prognostic value of anti-RNP/Sm and anti-Ro/La antibodies (Ab) in lupus nephropathy, we have studied through Contraimmunoelectrophoresis (CIE) and Immunoblotting (IB) the serum of 63 patients diagnosed of systemic lupus erythematosus. Mean age was 36.5 years (15-71) and 90% were females. We have classified the patients into three subgroups: I, 25 patients without nephropathy; II, 26 patients with evidence of nephropathy (persistent proteinuria and/or microhematuria) and normal renal function; and III, 12 patients with renal failure (servu creatinine > 1.5 mg/dl). 21 patients had kidney biopsy. IB allows to identify a higher number of positive serum, specially in the case of anti-RNP (7.9% CIE vs 28.5% IB) and anti-Sm antibodies (6.3% vs 30.1%). Prevalence of anti-RNP Ab is lower in subgroup III (32% I vs 34% II vs 8% III) (p > 0.05). Anti-Sm Ab are more frequent in group II and are not associated with renal failure (16% vs 54% vs 8%) (p > 0.05). Anti-Ro Ab are related with the absence of nephropathy (52% vs 15% vs 0%) (p < 0.05). We conclude that IB is more sensitive than CIE in the detection of these Ab and its use in Systemic Lupus Erythematosus permits to identify patient subgroups with lesser risk to develop renal failure. Even though our data are preliminary, we suggest that the detection of anti-RNP/Sm and/or anti-Ro/La antibodies are a good prognostic factor in lupus nephropathy.