Rapidly progressive interstitial renal fibrosis in young women: association with slimming regimen including Chinese herbs

Two similar cases of rapidly progressive fibrosing interstitial nephritis in young women who followed the same slimming regimen prompted us to conduct an epidemiological survey of the nephrology centres of Brussels and to further investigate the exact nature of this slimming treatment. Seven other women under the age of 50 in terminal or preterminal renal failure were admitted for dialysis in 1991 and 1992. They had all followed a slimming regimen in the same medical clinic. Renal biopsy samples in eight of the nine cases showed extensive interstitial fibrosis without glomerular lesions. Two of the patients were seen for the first time in terminal renal failure and were started immediately on dialysis. For the seven other women, the nephropathy was characterised by a rapid deterioration in renal function, with initial serum creatinine doubling within about 3 months. The clinic had specialised in slimming treatments for the previous 15 years without any problems. In May, 1990, therapy was changed, with the introduction of two Chinese herbs (Stephania tetrandra and Magnolia officinalis). In June, 1992, three of twenty-five randomly selected women who had followed the same regimen during at least 3 months from 1990 had impaired renal function. Chemical analysis of some brands of these Chinese herbs did not show nephrotoxic contaminants of fungal or plant origin (ochratoxin or aristolochic acid) or adulteration by diuretics or antiinflammatory drugs. However, the medicinal preparation of the capsules taken by patients had different alkaloid profiles from those expected in Chinese plants. The striking relation between a specific type of fibrosing interstitial nephritis in young women and a slimming treatment involving Chinese herbs adds support to the arguments against uncontrolled therapy with herbal preparations.

Factor H mutations in hemolytic uremic syndrome cluster in exons 18-20, a domain important for host cell recognition

Several recent studies have established an association between abnormalities of complement factor H (FH) and the development of hemolytic uremic syndrome (HUS). To identify the relative importance of mutations in FH as a cause of HUS, we have undertaken mutation screening of the FH gene in 19 familial and 31 sporadic patients with FH. Mutations were found in two familial and three sporadic patients, and these clustered in exons 18-20, a domain important for host recognition. Moreover, this study demonstrates that familial HUS is likely to be a heterogeneous condition.

Fibrate-induced increase in blood urea and creatinine: is gemfibrozil the only innocuous agent?

BACKGROUND

Some reports indicate that fibrates can induce renal dysfunction. However, the clinical characteristics of these episodes, and the respective nephrotoxicity of the four main fibrates used-namely, fenofibrate, bezafibrate, ciprofibrate, and gemfibrozil-remain ill defined.

METHODS

To better characterize this side-effect, we first reviewed the charts of 27 patients from our institution who developed an impairment of renal function during fibrate therapy. We next analysed the articles (n=24) that contained data on renal function in patients taking fibrates (n=2676).

RESULTS

Among our 27 patients, 25 were on fenofibrate therapy, one was taking bezafibrate, and one ciprofibrate. Nineteen were recipients of solid-organ transplants (kidney recipients, n=15; heart or heart-lung recipients, n=4), and eight were non-transplanted patients with some impairment of renal function. Baseline plasma creatinine ranged from 0.9 to 2.9 mg/dl. It increased by a mean of 40% after the start of fibrate therapy. There was a concomitant increase of blood urea values (mean 36%) in most of the patients. Renal function returned to baseline in 18/24 patients after fibrate discontinuation. However, six patients, all transplant recipients, experienced a permanent increase in plasma creatinine. The incidence of fibrate-induced renal dysfunction among our series of kidney transplant recipients was 60%, as it occurred in 15 of the 25 patients who had ever taken fibrates. An increase of mean creatinine values during therapy was described in all papers on fenofibrate (n=7) and bezafibrate (n=8) (range 8-18% and 8-40% respectively), and in three of four papers dealing with ciprofibrate (range 6-16%). No significant renal impairment was described in any of the eight articles reporting data on gemfibrozil therapy.

CONCLUSION

Therapy with fenofibrate, bezafibrate, and ciprofibrate may induce renal dysfunction. Gemfibrozil appears to be devoid of this side-effect.

Anaphylactoid reactions during hemodialysis on AN69 membranes in patients receiving ACE inhibitors

We report five life-threatening anaphylactoid reactions occurring within the very first minutes of hemodialysis on polyacrylonitrile (AN69) capillary dialyzers in three patients receiving ACE inhibitors. Such reactions were not observed either in patients treated with ACE inhibitors but dialyzed on other membranes (N = 9), nor in patients on AN69 who did not receive ACE inhibitors (N = 19). These anaphylactoid reactions could be due to bradykinin accumulation, as a result of both increased synthesis--by interaction of blood with the AN69 polymer--and catabolism blockade by ACE inhibitors.

Use of phosphate-binding agents is associated with a lower risk of mortality

Hyperphosphatemia has been associated with higher mortality risk in CKD 5 patients receiving dialysis. Here, we determined the association between the use of single and combined phosphate-binding agents and survival in 6797 patients of the COSMOS study: a 3-year follow-up, multicenter, open-cohort, observational prospective study carried out in 227 dialysis centers from 20 European countries. Patient phosphate-binding agent prescriptions (time-varying) and the case-mix-adjusted facility percentage of phosphate-binding agent prescriptions (instrumental variable) were used as predictors of the relative all-cause and cardiovascular mortality using Cox proportional hazard regression models. Three different multivariate models that included up to 24 variables were used for adjustments. After multivariate analysis, patients prescribed phosphate-binding agents showed a 29 and 22% lower all-cause and cardiovascular mortality risk, respectively. The survival advantage of phosphate-binding agent prescription remained statistically significant after propensity score matching analysis. A decrease of 8% in the relative risk of mortality was found for every 10% increase in the case-mix-adjusted facility prescription of phosphate-binding agents. All single and combined therapies with phosphate-binding agents, except aluminum salts, showed a beneficial association with survival. The findings made in the present association study need to be confirmed by randomized controlled trials to prove the observed beneficial effect of phosphate-binding agents on mortality.

Comparison of cellulose diacetate and polysulfone membranes in the outcome of acute renal failure. A prospective randomized study

BACKGROUND

Whether the nature of haemodialysis (HD) membranes can influence the outcome of acute renal failure (ARF) remains debatable. Recent studies have suggested that dialysis with bioincompatible unsubstituted cellulosic membranes is associated with a less favourable patient outcome than dialysis with biocompatible synthetic membranes. Since we generally use a modified cellulosic membrane with substantially lower complement- and leukocyte-activating potential than cuprophane, for dialysis of patients with ARF, and because there are no data in the literature regarding the influence of modified cellulosic membranes on the outcome of patients with ARF, we compared the outcome of ARF patients dialysed either with cellulose diacetate or with a synthetic polysulfone membrane. We also investigated the potential role of permeability by comparing membranes with high-flux versus low-flux characteristics.

METHODS

This prospective, randomized, single centre study included 159 patients with ARF requiring HD. Patients were stratified according to age, gender, and APACHE II score and then randomized in chronological order to one of three dialysis membranes: low-flux polysulfone, high-flux polysulfone and meltspun cellulose diacetate.

RESULTS

Aetiologies of ARF and the prevalence of oliguria were similarly distributed among the three groups. There was no significant difference between the three groups for survival (multivariate Cox's proportional hazards model, P=0.57), time necessary to recover renal function (P=0.82), and number of dialysis sessions required before recovery (P=0.86). Multivariate analysis showed that survival was significantly influenced only by the severity of the disease state (APACHE III score, P<0.0001), but not by the nature of the dialysis membrane (P=0.57) or the presence of oliguria (P=0.24).

CONCLUSIONS

Among patients with ARF requiring HD survival and recovery time are not significantly influenced by the use of either meltspun cellulose diacetate or the more biocompatible high-flux or low-flux polysulfone. Dialysis using modified cellulose membranes is just as effective as dialysis using synthetic polysulfone membranes, but at a lower cost. In addition, the flux of the membrane did not influence patient outcome.

Effects of steroids on the progression of renal failure in chronic interstitial renal fibrosis: a pilot study in Chinese herbs nephropathy

Chinese herbs nephropathy is characterized by an extensive interstitial fibrosis and by a rapid evolution to end-stage renal failure. We thus decided to try steroid therapy (prednisolone 1 mg/kg for 1 month, tapered off 0.1 mg/kg every 2 weeks) in cases with moderate renal failure and evidence of deterioration in renal function. Our steroid group (SG) consisted of 12 female patients with biopsy-proven renal fibrosis who were followed for at least 12 months after the initiation of steroids. Plasma creatinine level (Pcreat) ranged from 1.8 to 3.9 mg/dL (mean +/- SEM, 2.8 +/- 0.2 mg/dL) when steroids were initiated at t = 0. Renal failure was in progression since Pcreat was 2.1 +/- 0.1 mg/dL (P = 0.022) 3 months before t = 0. Our control group (CG; N = 23) was selected retrospectively from among the 81 patients in the Belgian Register of Chinese Herbs Nephropathy. Compared with the CG, renal function was better preserved in the SG (Pcreat; mean +/- SEM): SG v CG, 2.9 +/- 0.3 mg/dL v 5.3 +/- 0.5 mg/dL at 6 months (P = 0.0024) and 4.0 +/- 0.7 mg/dL v 7.1 +/- 0.5 mg/dL at 1 year (P = 0.001). The slope of the reciprocal serum creatinine concentration was similar in both groups before t = 0 (-0.0463 mg/dL/mo in the SG v -0.0438 mg/dL/mo in the CG; P = 0.83), but it became less steep after initiation of steroid therapy (between 0 and 6 months, -0.000742 mg/dL/mo in the SG v -0.0284 mg/dL/mo in the CG; P < 0.001). Finally, only two of the 12 patients in the SG required dialysis at 1 year compared with 16 of the 23 patients in the CG (P = 0.0045). We conclude that steroid therapy slows the progression of renal failure in a disease characterized by an interstitial fibrosis that progresses quickly despite the fact that the insulting agent has been withdrawn. This supports the hypothesis that renal interstitial fibrosis may be an immune-mediated process.

Resistance to erythropoietin in iron-overloaded haemodialysis patients can be overcome by ascorbic acid administration

Haemodialysis patients with iron overload sometimes develop resistance to erythropoietin therapy due to 'functional iron deficiency'. It is known that this resistance may be overcome by iron supplementation; however, the latter could worsen haemosiderosis. Therefore, we treated four iron-overloaded haemodialysis patients who had developed relative resistance to erythropoietin (among whom three had features of 'functional iron deficiency') with ascorbic acid (500 mg intravenously after haemodialysis, 1-3 times a week). The erythropoietin doses were voluntarily kept unchanged during the study. After a latency of 2-4 weeks, haematocrit and haemoglobin had increased respectively from 26.5 +/- 0.7 to 32.7 +/- 0.4 vol% and from 8.8 +/- 0.3 to 10.8 +/- 0.2 g/dl (means +/- SEM, P < 0.001). While serum ferritin remained unchanged, transferrin saturation increased from 27 +/- 7 to 54 +/- 12% (P < 0.05), suggesting that ascorbic acid supplementation had allowed mobilization of iron from tissue burdens. In one patient, haematocrit declined after withdrawal of vitamin C and increased again after rechallenge. Also, ascorbate supplementation was continued after the study in two patients and allowed the erythropoietin doses to be decreased, 8 and 11 weeks, respectively, after the start of the trial. When a control group of seven patients with normal iron status and without resistance to erythropoietin were challenged in the same manner with ascorbate, no elevation of haematocrit or transferrin saturation was noted. We conclude that ascorbate supplementation may circumvent resistance to erythropoietin that sometimes occurs in iron-overloaded patients, in particular, in the setting of 'functional iron deficiency'.

Critical role of iron overload in the increased susceptibility of haemodialysis patients to bacterial infections. Beneficial effects of desferrioxamine

Iron overload, which is a common complication in haemodialysis patients, is known to enhance bacterial growth and virulence, and to alter phagocytosis. We reviewed the data of 61 haemodialysed patients to clarify the clinical relevance of iron status to the risk of bacterial infection. Increased concentrations of serum ferritin were associated with a greater infection rate (P less than 0.0025), which was already true for ferritin values between 500 and 1000 micrograms/l (P less than 0.025). Furthermore, in 21 iron-overloaded patients treated with an iron-chelator (desferrioxamine), the infection rate decreased from 1/19 patient-months to 1/112 (P less than 0.005), and returned to previous values when desferrioxamine was stopped. Our results demonstrate the importance of haemosiderosis in the increased susceptibility of haemodialysed patients to infections; this susceptibility is decreased by desferrioxamine therapy, which probably acts by restoring phagocytosis and reducing the bioavailability of iron for pathogens.

COSMOS: the dialysis scenario of CKD-MBD in Europe

BACKGROUND

Chronic kidney disease-mineral and bone disorders (CKD-MBD) are important complications of CKD5D patients that are associated with mortality.

METHODS

COSMOS is a multicentre, open cohort, prospective, observational 3-year study carried out in haemodialysis patients from 20 European countries during 2005-07. The present article describes the main characteristics of the European dialysis population, the current practice for the prevention, diagnosis and treatment of secondary hyperparathyroidism and the differences across different European regions.

RESULTS

The haemodialysis population in Europe is an aged population (mean age 64.8±14.2 years) with a high prevalence of diabetes (29.5%) and cardiovascular disease (76.0%), and 28.7% of patients have been on haemodialysis more than 5 years. Patients from the former Eastern countries are younger (59.3±14.3 versus 66.0±13.9), having a lower proportion of diabetics (24.1 versus 30.7%). There were relevant differences in the frequency of measurement of the main CKD-MBD biochemical parameters [Ca, P and parathyroid hormone (PTH)] and the Eastern countries showed a poorer control of these biochemical parameters (K/DOQI and K/DIGO targets). Overall, 48.0% of the haemodialysis patients received active vitamin D treatment. Calcitriol use doubled that of alfacalcidiol in the Mediterranean countries, whereas the opposite was found in the non-Mediterranean countries. The criteria followed to perform parathyroidectomy were different across Europe. In the Mediterranean countries, the level of serum PTH considered to perform parathyroidectomy was higher than in non-Mediterranean countries; as a result, in the latter, more parathyroidectomies were performed in the year previous to inclusion to COSMOS.

CONCLUSIONS

The COSMOS baseline results show important differences across Europe in the management of CKD-MBD.

Proximal tubular injury in Chinese herbs nephropathy: monitoring by neutral endopeptidase enzymuria

Neutral endopeptidase (NEP) is a 94 kDa ectoenzyme of the proximal tubule brush border, physiologically released into the urine with apical membrane fragments. As proximal tubular atrophy was a histological hallmark of Chinese herbs nephropathy (CHN), this study firstly determined renal excretion of NEP in healthy control subjects (N = 31), in patients with CHN (N = 26) and in women having consumed Chinese herbs and whose renal function was normal but running the risk of developing CHN (N = 27). Another patient group consisted of female patients with glomerular diseases (N = 12). At the same time, measurements of urinary microproteins (Clara cell protein, retinol binding protein, beta 2-microglobulin and alpha 1-microglobulin) were performed, as indicators of tubular dysfunction. Cell damage was estimated by the excretion of N-acetyl-beta-D-glucosaminidase (NAG). In the control group, the physiological NEP enzymuria was 43.1 micrograms/24 hr (geometric mean). In CHN patients, levels of urinary NEP were significantly decreased in those with moderate renal failure (26.7 micrograms/24 hr; N = 21; P < 0.05) and almost abolished in end-stage renal failure patients (4.35 micrograms/24 hr; N = 5; P < 0.05). In patients at risk as well as in patients with glomerular diseases, urinary NEP levels were not statistically different from those observed in control subjects (40.68 micrograms/24 hr and 48.5 micrograms/24 hr, respectively). Several degrees of tubular dysfunction and injury were noted in patients groups, as attested by increased urinary microproteins and NAG excretions. Considering the data from control and CHN patients, NEP enzymuria positively correlated with individual creatinine clearance values (r = 0.76; P = 0.0001) and negatively correlated with urinary microproteins levels (r = -0.55; P = 0.00001). Finally, NEP was regularly quantitated in the urine of 6 CHN patients for a period ranging from six months to two years and in 19 patients at risk during two years, respectively. In the first group, renal function progressively deteriorated in 3 patients, leading them to renal replacement therapy after 38 to 115 weeks. Stable parameters were observed in the remaining 3 patients. A direct correlation between creatinine clearance and NEP excretion was found longitudinally in each case. In the second group, no significant change of urinary NEP levels was observed (45.9 micrograms/24 hr), in parallel with stable renal function. Taken together, these results indicate that, in CHN patients, NEP enzymuria provides a rapid and noninvasive determination of the degree of structural impairment affecting the proximal tubular population and further reflecting the severity of the renal disease. The interest of this urinary marker in monitoring the progression of other tubulointerstitial diseases remains to be assessed.

Effects of ultrapure and non-sterile dialysate on the inflammatory response during in vitro hemodialysis

Several studies support the hypothesis that bacterial contamination of the dialysate stimulates the inflammatory response to hemodialysis (HD) and increases the long-term morbidity of HD patients; this phenomenon could also be modulated by the nature of the HD membrane. Therefore, this study was designed to compare the effects of non-sterile (NSBD, mean endotoxin content +/- SEM 97 +/- 22 EU/ml) and ultrapure bicarbonate dialysate (UPBD, sterile and pyrogen-free, obtained by ultrafiltration through polyamide) on several aspects of the inflammatory reaction during in vitro HD. The HD sessions (7 in each experimental group) were performed using miniaturized new cuprophane (CU) and polyacrylonitrile (PAN) hollow fiber dialyzers, and closed dialysate and blood circuits (the latter filled with heparinized blood from healthy donors). Plasma C3aDesarg levels were significantly increased after 15 minutes (t1) and increased further after three hours (t2) of CU HD, while during PAN dialysis they decreased from t0 to t1 and t2; however, no difference appeared between experiments with NSBD and UPBD. Granulocyte (PMN) and monocyte (MNC) expression of LFA-1, Mac-1, and CD45 at the start (t0), t1 and t2 was quantitated by flow cytometry analysis, after staining of the cells with specific fluorescinated monoclonal antibodies. In contrast with published data of in vivo HD, LFA-1 was overexpressed at t1 and peaked at t2, which suggests that the leukocytes expressing more LFA-1 leave the systemic circulation during in vivo HD. During CU HD, Mac-1 and CD45 on PMN and MNC were significantly increased at t1, and still more at t2. During PAN HD, Mac-1 and CD45 remained unchanged at t1, but increased significantly at t2 on PMN as on MNC. Again, no significant difference was found between NSBD and UPBD in LFA-1, Mac-1 and CD45 expression on PMN and MNC, during both CU and PAN HD. AFter three hours of dialysis, plasma levels of TNF-alpha, but not of IL-6, were significantly increased with CU and PAN. Again, no difference appeared when NSBD and UPBD were compared. Moreover, the lack of influence of bacterial contamination of the dialysate on TNF-alpha production was confirmed when MNC were cultured up to 24 hours after the end of the HD session. We conclude that complement activation products, either in plasma (CU) of those adsorbed on the HD membrane (CU and PAN) play the major role in the overexpression of beta 2-integrins and CD45 by PMN and MNC during HD. Also, bacterial products (at the levels that can be found in clinical conditions) do not influence either beta 2-integrin overexpression or TNF-alpha production induced by the dialysis membrane.

Influence of body mass index on the association of weight changes with mortality in hemodialysis patients

BACKGROUND AND OBJECTIVES

A high body mass index (BMI) is associated with lower mortality in patients undergoing hemodialysis. Short-term weight gains and losses are also related to lower and higher mortality risk, respectively. The implications of weight gain or loss may, however, differ between obese individuals and their nonobese counterparts.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Current Management of Secondary Hyperparathyroidism: A Multicenter Observational Study (COSMOS) is an observational study including 6797 European hemodialysis patients recruited between February 2005 and July 2007, with prospective data collection every 6 months for 3 years. Time-dependent Cox proportional hazard regressions assessed the effect of BMI and weight changes on mortality. Analyses were performed after patient stratification according to their starting BMI.

RESULTS

Among 6296 patients with complete data, 1643 died. At study entry, 42% of patients had a normal weight (BMI, 20-25 kg/m(2)), 11% were underweight, 31% were overweight, and 16% were obese (BMI ≥ 30 kg/m(2)). Weight loss or gain (<1% or >1% of body weight) was strongly associated with higher rates of mortality or survival, respectively. After stratification by BMI categories, this was true in nonobese categories and especially in underweight patients. In obese patients, however, the association between weight loss and mortality was attenuated (hazard ratio, 1.28 [95% confidence interval (CI), 0.74 to 2.14]), and no survival benefit of gaining weight was seen (hazard ratio, 0.98 [95% CI, 0.59 to 1.62]).

CONCLUSIONS

Assuming that these weight changes were unintentional, our study brings attention to rapid weight variations as a clinical sign of health monitoring in hemodialysis patients. In addition, a patient's BMI modifies the strength of the association between weight changes with mortality.

Long-term results of subcutaneous parathyroid grafts in uremic patients

HYPOTHESIS

Parathyroid glands are normally surrounded (entirely or partially) by fatty tissue. Subcutaneous parathyroid grafts are thus located in a normal environment. Therefore, we postulated that the late results of subcutaneous implantation of parathyroid tissue in uremic patients should be at least as good as those reported for intramuscular grafting. We also challenged the idea that the recurrence rate of renal hyperparathyroidism after surgery depended solely on the type of hyperplasia (diffuse vs nodular) observed in the implanted tissue.

DESIGN

A retrospective study of a series of patients without loss to follow-up.

SETTING

A university hospital and 9 affiliated dialysis units.

PATIENTS AND INTERVENTIONS

Fifty-nine patients (33 women and 26 men) operated on for renal hyperparathyroidism underwent the resection of at least 4 parathyroid glands followed by presternal subcutaneous implantation of parathyroid tissue. They were followed up for 12 to 130 months (median, 38 months).

MAIN OUTCOME MEASURES

Failure of treatment, recurrence of disease, and hypoparathyroidism.

RESULTS

During the study period, 9 patients had to undergo another operation: 2 (3%) for persistent hyperparathyroidism due to a fifth ectopic gland and 7 (12%) for recurrence of hyperparathyroidism resulting from hypertrophy of the subcutaneous grafts. Four patients received a kidney transplant. The prevalence of hypoparathyroidism (intact parathyroid hormone serum level <1.6 pmol/L with a normal or low serum calcium concentration) was 14% (8 of 59 patients), and the curve representing the distribution of intact parathyroid hormone serum concentrations among operated on patients was shifted to the left when compared with the curve of patients who underwent hemodialysis and who had no indication for parathyroid surgery. In this latter group, the peak of the curve was situated between 1 and 2 times the upper normal limit, while it was in the normal range 12 to 130 months after total parathyroidectomy and subcutaneous parathyroid autotransplantation. No relation was observed between the recurrence rate of the disease and the histological characteristics of the parathyroid grafts. Also, their function was not influenced by the presence or absence of aluminum deposits in bone biopsy specimens that were obtained at the time of cervical exploration.

CONCLUSIONS

The late results of total parathyroidectomy and presternal subcutaneous grafting compare favorably with the published data on other surgical techniques proposed for the treatment of renal hyperparathyroidism. The ease with which the hypertrophied grafts are removed when the disease recurs warrants further use of this procedure.

Twenty-four-hour blood pressure and heart rate patterns in chronic hemodialysis patients

To test the assumption that the previously reported abnormal 24-hour blood pressure (BP) variations in hemodialysis (HD) patients might be due to associated complications of chronic renal failure, we recorded the 24-hour noninvasive BP and heart rate (HR) patterns in 14 carefully selected chronic HD patients. No of the patients suffered from orthostatic hypotension, and all were free of any previously reported associated condition known to affect the 24-hour BP profiles. The BP and HR profiles were quantitatively analyzed using the periodogram method. The results were compared those from 14 controls matched for age, sex, and casual BP. No difference could be found between the HD patients and the controls, either in the absolute and relative amplitudes of the 24-hour systolic BP and diastolic BP variations or in the timings and levels of their respective acrophases and nadirs (except for the timings of the second systolic BP and diastolic BP acrophases; P < 0.05). The absolute levels of the HR acrophases and nadirs were higher in the HD patients than in the controls (P < 0.05 and P < 0.01, respectively), while both the absolute and relative amplitudes of the 24-hour HR profiles and the relative values and timings of the HR acrophases and nadirs were similar in both groups. Consequently, the 24-hour HR pattern was similar in the HD patients than in the controls, except that the entire profile was shifted upward.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of regional citrate anticoagulation on leukopenia, complement activation, and expression of leukocyte surface molecules during hemodialysis with unmodified cellulose membranes

BACKGROUND

Dialysis with complement-activating membranes is associated with leukopenia, which is related to an increased expression of adhesion molecules on leukocytes. Citrate chelates calcium and has been claimed to attenuate leukopenia.

METHODS

In this study, the effects of citrate anticoagulation on leukocyte and granulocyte counts, complement activation, and the expression of CD11b, CD11c, and CD45 on the surface of granulocytes were evaluated during hemodialysis with unmodified cellulose membranes. Standard heparin was compared to citrate in three different schedules: citrate was infused to obtain a concentration of either 7 or 10 mmol/l blood. CaCl(2) was administered into the dialyzer outlet at 8. 25 mmol Ca(2+)/h (citrate 10 mmol/l) or at 11 mmol Ca(2+)/h (citrate 7 and 10 mmol/l) to reconstitute the calcium levels in the blood returning to the patient.

RESULTS

The use of citrate at a high concentration (10 mmol/l) was associated with a blunted upregulation of CD11b, both at the inlet and at the outlet bloodline; for CD11c a reduced upregulation was observed on granulocytes harvested from the inlet bloodline. No effects of citrate were observed on leukopenia, granulocytopenia, or complement activation. A positive correlation between the decrease in systemic ionized Ca(2+) concentration and the increase in CD11b and CD11c expression was found.

CONCLUSION

Citrate/CaCl(2) administration affects leukocyte adhesion molecule expression in a dose-dependent way; however, no significant effect could be demonstrated on leukopenia and complement activation.

Lipid and apoprotein changes during atorvastatin up-titration in hemodialysis patients with hypercholesterolemia: a placebo-controlled study

BACKGROUND

Patients with end-stage renal disease commonly present with an atherogenic lipid profile characterized by the accumulation of triglyceride-rich, apoprotein B-containing "remnant" lipoproteins, small dense low-density lipoprotein, and low levels of high-density lipoprotein. They are at increased cardiovascular risk and may benefit from drastic lipid-lowering treatment with atorvastatin, a potent, broadacting lipid regulator. This study aims to assess the effects of atorvastatin on the lipid profile in hemodialysis patients, to determine wether atorvastatin is also effective at lowering lipid levels in this particular high-risk subgroup.

METHODS

In this randomized, placebo-controlled, double-blind study in hemodialysis patients with hypercholesterolemia (n = 42, mean total cholesterol 243 +/- 33 mg/dl (6.3 +/- 0.8 mmol/l)), the efficacy of 4-weekly increasing doses of atorvastatin (10 - 40 mg daily) was investigated. Lipids and apoproteins were measured in plasma and isolated lipoprotein fractions.

RESULTS

Mean total cholesterol and low-density lipoprotein cholesterol progressively decreased with increasing doses of atorvastatin (total cholesterol -33%, low-density lipoprotein cholesterol -43% after 12 weeks), while high-density lipoprotein cholesterol remained unchanged. Plasma levels of apoprotein B and apoprotein E were also significantly reduced by atorvastatin 10 mg, while up-titration to 20 and 40 mg daily provided additional benefits by lowering triglycerides and apoprotein C-III. At week 12, the fraction of small dense low-density lipoprotein was significantly reduced from 23% - 18%, and apoprotein B-containing intermediate-density lipoproteins were no longer detectable.

CONCLUSION

In conclusion, atorvastatin not only treated hypercholesterolemia but also favorably affected the uremic lipid profile in patients on hemodialysis. Atorvastatin 4-weekly dose escalation up to 40 mg daily was well-tolerated. Further prospective studies are needed to evaluate the impact of this improved lipid profile on morbidity and mortality.

Pseudomonas paucimobilis peritonitis in patients treated by peritoneal dialysis

Pseudomonas paucimobilis has rarely been reported as an opportunistic human pathogen. We report the isolation of this organism in two patients who developed peritonitis during the course of intermittent or continuous ambulatory peritoneal dialysis. The origin of the infection was related to contamination of the dialysate in the first patient but could not be determined in the second case.

Immunogenicity and safety of an investigational AS02(v)-adjuvanted hepatitis B vaccine in patients with renal insufficiency who failed to respond or to maintain antibody levels after prior vaccination: results of two open, randomized, comparative trials

An investigational AS02(v)-adjuvanted hepatitis B (HB-AS02) was compared with a licensed conventional recombinant hepatitis B vaccine (HBVAXPRO™; Sanofi Pasteur MSD, Lyon, France) in pre-dialysis, peritoneal dialysis and hemodialysis patients aged ≥18 years who had failed either to respond to prior vaccination with a conventional hepatitis B vaccine (Study A; n=251) or to maintain protective antibody concentrations after prior hepatitis B vaccination (Study B; n=181). These were open, randomized, comparative trials. Mean (range) age was 65.9 (31-92) and 64.6 (29-92) years in the two studies, respectively. In Study A, two doses of HB-AS02 given one month apart were found to be superior to two doses of the licensed vaccine in terms of seroprotection rate (76.9% versus 37.6%) and anti-HBs geometric mean antibody concentration (GMC; 139.3 versus 6.9mIU/ml), with antibody concentrations ≥100mIU/ml in 61.1% and 15.4% of subjects in the two groups, respectively. In Study B, one month after administration of a single booster dose, seroprotection rates were 89.0% in the HB-AS02 group and 90.8% in the licensed vaccine group, 81.3% and 60.9% of subjects had antibody concentrations ≥100mIU/ml, and anti-HBs GMCs were 1726.8 and 189.5mIU/ml. HB-AS02 was found to be more reactogenic than the licensed vaccine. In summary, the investigational HB-AS02 vaccine induced higher seroprotection rates and anti-HBs GMCs than a licensed conventional hepatitis B vaccine in uremic patients who had failed to respond or to maintain protective antibody titers after prior hepatitis B vaccination.

Effect of aluminum on porphyrin metabolism in hemodialyzed patients

In patients with renal failure and on chronic hemodialysis, serum aluminum, serum delta-aminolevulinic acid, serum porphobilinogen and erythrocyte zinc protoporphyrin (ZPP) are significantly elevated, whereas erythrocyte delta-aminolevulinic acid dehydratase activity (ALAD, values in percent) is significantly reduced. The last two parameters (ZPP and ALAD) are statistically related to serum aluminum concentration (Al-S), but only the correlation between Al-S and ALAD remains statistically significant after standardization for the degree of renal insufficiency (expressed in terms of urea level). This study does not support the hypothesis that the retention of aluminum is responsible for the increase of ZPP in uremic patients on dialysis. The disturbances of porphyrin metabolism found in patients with renal failure and on chronic dialysis are not similar to those observed in porphyria cutanea tarda.

Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study

BACKGROUND

Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH.

METHODS

Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH.

RESULTS

Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 ± 3 versus 31 ± 4% of sessions, respectively, P l= l0.03), as was the per cent of clinical interventions (17 ± 3% of sessions with almost one intervention on HFR-Aeq versus 22 ± 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 ± 3% of sessions with hypotension on HFR-Aeq versus 71 ± 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq.

CONCLUSIONS

HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na(+) measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.

Avoidance of systemic anticoagulation during intermittent haemodialysis with heparin-grafted polyacrilonitrile membrane and citrate-enriched dialysate: a retrospective cohort study

Background

Since October 2010, the combination of a heparin-grafted polyacrilonitrile (AN69ST) membrane with a 0.80 mmol/L citric acid-containing dialysate is routinely used in our centre for intermittent haemodialysis, without systemic anticoagulation, in critically ill patients with increased bleeding risk. The primary outcome of this retrospective cohort study was to assess the development of circuit clotting during these dialysis procedures. Secondly, we assessed the impact of clotting on treatment duration, the incidence rate of coagulation-induced retransfusion failure and the association of patient and dialysis characteristics with the occurrence of clotting.

Methods

Dialysis and patient data on consecutive intermittent haemodialysis procedures, performed at the Intensive Care Unit of Universitair Ziekenhuis Brussel between October 2010 and March 2012, were retrospectively reviewed. We used descriptive statistics as well as a random effects logit model with patient identity as a panel variable to assess associations.

Results

Of a total of 309 treatments combining a heparin-grafted AN69ST membrane and a 0.8 mmol/L citric acid-enriched dialysate in 94 patients, circuit clotting was reported in 17.5% (95% CI 13.2% to 21.7%; N = 54), and in 19% (95% CI 13.6% to 24.4%; N = 40) of sessions with prescribed treatment time ≥ 4 hours (N = 210). Clotting shortened treatment time in 15.2% (95% CI 11.4% to 19.7%; N = 47) of sessions by a median of 55 (IQR 20 to 80) minutes. Complete clotting of the circuit with inability for retransfusion occurred in 4.2% (95% CI 2.2% to 7.0%; N = 13) of sessions. Circuit coagulation was not associated with APACHE II score, patient age, gender, number of treatments, type of vascular access or ultrafiltration rate.

Conclusion

Intermittent haemodialysis without systemic anticoagulation combining a heparin-grafted AN69ST dialyzer with a citrate-enriched dialysate favourably compares as to clotting complications with the published outcomes of anticoagulation-free intermittent haemodialysis strategies using saline flushes, heparin-coated dialyzer in combination with regular dialysate or regional citrate anticoagulation with calcium supplemented dialysate. The incidence of circuit clotting in our cohort appears to be higher than previously reported for regional citrate anticoagulation with a calcium-free dialysate.

Flavobacterium multivorum septicemia in a hemodialyzed patient

A case of Flavobacterium multivorum septicemia in a hemodialyzed patient is reported. Two blood cultures were positive at 48 h, and the patient became afebrile only after antimicrobial therapy. The origin of the septicemia could not be determined.

Role of complement and platelet-activating factor in the stimulation of phagocytosis and reactive oxygen species production during haemodialysis

BACKGROUND

Neutrophil phagocytic functions have been studied extensively in haemodialysis (HD) patients; however, results are contradictory and the mechanisms that modulate phagocytosis and oxidative burst during dialysis are not completely understood.

METHODS

The present study investigated neutrophil functions in a selected population of patients before and during clinical dialysis with cuprophane, and polyacrylonitrile (AN69) membranes. We measured phagocytosis of Escherichia coli and intracellular hydrogen peroxide (H2O2) production by flow cytometry in whole blood.

RESULTS

Before dialysis, neutrophils from HD patients showed normal phagocytic capability and H2O2 formation. Phagocytosis of FITC-E. coli was significantly stimulated in cuprophane but not AN69-treated patients. Spontaneous and stimulated H2O2 production was enhanced with both cuprophane and AN69 membranes. We then investigated in vitro the role of complement and platelet-activating factor (PAF) in the activation of neutrophils. Incubation of whole blood with C5a increased phagocytosis but not H2O2 production. On the contrary, the addition of synthetic PAF showed a markedly stimulated H2O2 production without increase in phagocytosis. Moreover, during dialysis with formaldehyde-reused cuprophane, complement activation was abolished and phagocytosis was no longer enhanced, while the stimulation of H2O2 production persisted. In addition, we also excluded a particular role of the membrane itself in the activation of neutrophils.

CONCLUSION

We demonstrated that in a selected population of HD patients, neutrophils exhibit normal phagocytic capability and normal intracellular H2O2 production. During dialysis, the stimulation of phagocytosis observed with cuprophane is complement dependent, whereas the enhanced H2O2 production observed with both cuprophane and AN69 membranes might be related to PAF production.