Beta 2-microglobulin Serum Levels during Dialysis: Effect of Cuprophan and Serum Osmolality Changes

New cuprophan dialysers were used in twenty, re-used dialysers in twelve dialyses and new dialysers in ten sequential ultrafiltrations. Serum beta 2-microglobulin (β2m) concentration was measured before and after all these procedures. Serum osmolality changes were compared with changes in serum β2m concentrations. These concentrations rose in dialyses with new and re-used dialysers, but remained unchanged during sequential ultrafiltration. β2m increased with serum hypo-osmolality, decreased with serum hyperosmolality and did not change during iso-osmolar dialysis. These results indicate that cuprophan membrane does not raise β2m concentration during dialysis. It is hypo-osmolality that is responsible for the increment of β2m in serum.

Comparison of Different Techniques of Hemodialysis Vascular Access Flow Evaluation

Measurement of vascular access flow (QVA) has been suggested as a method of choice for vascular access quality (VAQ) monitoring. Besides traditional duplex Doppler, a number of bedside methods based mostly on the Krivitski principle of QVA evaluation from recirculation at reversed needles (RX), have been developed. This work compares ultrasonic dilution (UD), taken as a reference, HD01, Transonic Systems; duplex Doppler (DD); thermodilution (TD), BTM, Fresenius; optodilutional RX measurement (ORX), Critline III, R-mode, HemaMetrics; direct optodilutional QVA evaluation from jumpwise changes in ultrafiltration rate at both normal and reversed needles connection (OABF), Critline III, ABF-mode; and direct transcutaneous optodilutional QVA evaluation (TQA), Critline III TQA.

Firstly, reproducibility of each method was assessed by duplicate measurement at unchanged conditions. This was followed by paired measurement with each method performed at controlled change in relevant measurement condition (two different extracorporeal blood flows in UD and TD, changed sensor position in TQA). Finally paired measurements by each method and the reference method performed at identical conditions were evaluated to assess accuracy of each method. The simple Krivitski formula QVA= QB(1-RX)/RX was used wherever manual QVA calculation was needed.

Very high reproducibility was seen in UD, both for measurement at the same extra corporeal blood flow (QB) (correlation coefficient of duplicate measurement r= 0.9702, n= 58) and for measurement at two different QB (r= 0.9735, n= 24), justifying its current status of a reference method in QVA evaluation. Slightly lower reproducibility of TD measurement at the same QB (r= 0.9197, n= 40) and at two different QB (r= 0.8508, n= 168) can be easily overcome by duplicate measurement with averaging. High correlation of TD vs. UD (r= 0.9543, n= 54) makes TD a viable clinical alternative in QVA evaluation. Consistently different QVA obtained at two different QB should prompt closer investigation of anatomical conditions of the access. Use of the simple Krivitski formula in TD (which measures total recirculation, i.e. sum of access recirculation and cardiopulmonary recirculation) brings about underestimation of QVA, which progressively increases from QVA of about 600 ml/min up. Good correlation, although with significant scatter (r= 0.8691, n= 27) was found between the DD- and UD-based QVA. By far the worst reproducibility at the same QB from among the investigated methods was found in ORX (0.6430, n= 23). Also the correlation of ORX vs. UD was lower than in other methods (r= 0.702, n=33) and general overestimation of QVA by about 25% was noted. Correlation of OABF vs. UD (r= 0.6957, n= 26) was slightly better than that of ORX and it gave less overestimated values. The TQA method showed very high reproducibility (r= 0.9712, n= 85), however only for unchanged sensor position. Correlation of QVA measured at two different sensor positions was much worse (r= 0.7255, n= 22). Correspondence of TQA vs. UD was satisfactory (r= 0.8077, n= 36). Skilled and experienced operators are a must with this method.

CONTINUOUS BLOOD VOLUME MONITORING AND “DRY WEIGHT” ASSESSMENT

There are two distinct facets of adequate fluid balance control in haemodialysis patients--estimation of dry weight (DW) as the target and adequate ultrafiltration (UF) strategy, i.e. the way to reach the target in a possibly symptom-free way. The article reviews the continuous blood volume monitoring (CBVM) based procedures to deal with the former facet-DW determination. The existing approaches are divided in three groups--methods defining certain alert value of relative blood volume (RBV) reduction, methods working with RBV response to constant UF rate, and methods evaluating dynamics of RBV response to UF pulse or chain of UF pulses. While the first and the third approaches are relatively easy to automate, the second group of methods are suitable mainly for observational evaluations only. All the discussed methods, without exception, need large-scale verification, as they all were evaluated in the majority by their authors only and on small patient cohorts.

The correlation of serum prolactin level and psychic stress in women undergoing a chronic hemodialysis programme

Altogether eight women undergoing a chronic hemodialysis treatment were studied for five months. Four of them were in the premenopause and four in the postmenopause. Once a month levels of prolactin, FSH, LH, estradiol and progesterone were measured, Lüscher colour test was performed, from which the screamer index as an indicator of psychic stress was calculated and the levels of urea, creatinine and hematocrite were assessed to inform us of the adequacy of dialysis. We tested the hypothesis, whether there exists a correlation between psychic stress and the prolactin level in these women. For statistic evaluation we used linear regression under the use of dummy variables to intercept the interindividual differences in the Lüscher test. We found that the fluctuation of the prolactin level and of the value of the screamer index of the Lüscher test are parallel (p less than 0.05). These results bear witness of a participation of psychic stress in the onset and level of hyperprolactinemia in women being in a chronic hemodialysis treatment.

Increase of nocturnal melatonin levels in hemodialyzed patients after parathyroidectomy: a pilot study

In hemodialyzed patients hormonal disturbances are known to occur. However, melatonin levels have not been completely studied. The aim of the study was to find whether changes in calcaemia affect melatonin secretion. For this reason we followed the nocturnal serum concentrations of melatonin and parathyroid hormone (PTH) in 9 hemodialyzed patients (6 women and 3 men, aged 37-65 years) both before and 1-3 months after parathyroidectomy at 6 p.m., 9 p.m., 11 p.m., 2 a.m., 5 a.m. and 7 a.m. At 6 p.m. blood samples to evaluate the levels of calcium and phosphate were also collected. Parathyroidectomy resulted in an increase in nocturnal melatonin levels. As expected, the parathyroidectomy was followed by considerable PTH decrease. PTH showed no nocturnal variation before or after parathyroidectomy. Calcium levels significantly decreased after the operation while phosphate levels increased. In summary, in hemodialyzed patients with hyperparathyroidism, parathyroidectomy significantly increases the nocturnal secretion of melatonin. Relationships between the pineal gland and parathyroid glands have yet to be elucidated.

Plasma ghrelin levels in patients with end-stage renal disease

Ghrelin is an acylated peptide stimulating secretion of the growth hormone (GH). It was originally isolated from the rat stomach as an endogenous ligand for the growth hormone secretagogue receptor. Although being predominantly produced by endocrine cells of the gastric fundus, its secretion has been found in various tissues including the kidney. To study the influence of renal failure on plasma ghrelin levels we examined 16 patients with end-stage renal disease (ESRD) receiving hemodialysis (8 men and 8 women) and 19 controls (10 men and 9 women). Both groups were comparable in age and BMI. In all subjects we assessed plasma levels of ghrelin, leptin, soluble leptin receptor, insulin, IGF-I, IGFBP-1, IGFBP-3 and IGFBP-6. Ghrelin levels were significantly higher in the group of dialyzed patients (4.49+/-0.74 vs. 1.79+/-0.15 ng/ml; p<0.001). These patients had significantly higher levels of GH, IGFBP-1, IGFBP-6, leptin and percentage of body fat (p<0.05). In the group of patients with ESRD plasma ghrelin levels positively correlated with IGFBP-1 (p<0.01). In the control group, ghrelin positively correlated with GH concentrations (p<0.01) and negatively correlated with the levels of insulin and creatinine (p<0.05). In conclusion, patients with ESRD have higher ghrelin concentrations, which might be caused by a decreased excretion/metabolism of ghrelin in the kidney during renal failure.

Plasma ghrelin levels in patients with end-stage renal disease

Ghrelin is an acylated peptide stimulating secretion of the growth hormone (GH). It was originally isolated from the rat stomach as an endogenous ligand for the growth hormone secretagogue receptor. Although being predominantly produced by endocrine cells of the gastric fundus, its secretion has been found in various tissues including the kidney. To study the influence of renal failure on plasma ghrelin levels we examined 16 patients with end-stage renal disease (ESRD) receiving hemodialysis (8 men and 8 women) and 19 controls (10 men and 9 women). Both groups were comparable in age and BMI. In all subjects we assessed plasma levels of ghrelin, leptin, soluble leptin receptor, insulin, IGF-I, IGFBP-1, IGFBP-3 and IGFBP-6. Ghrelin levels were significantly higher in the group of dialyzed patients (4.49±0.74 vs. 1.79±0.15 ng/ml; p<0.001). These patients had significantly higher levels of GH, IGFBP-1, IGFBP-6, leptin and percentage of body fat (p<0.05). In the group of patients with ESRD plasma ghrelin levels positively correlated with IGFBP-1 (p<0.01). In the control group, ghrelin positively correlated with GH concentrations (p<0.01) and negatively correlated with the levels of insulin and creatinine (p<0.05). In conclusion, patients with ESRD have higher ghrelin concentrations, which might be caused by a decreased excretion/metabolism of ghrelin in the kidney during renal failure.

Increased Levels of Pregnancy-Associated Plasma Protein A Are Associated with Mortality in Hemodialysis Patients: Preliminary Results

Pregnancy-associated plasma protein A (PAPP-A) is a new prognostic indicator of acute coronary syndrome. This protein is elevated in hemodialysis (HD) patients and is closely related to inflammation and oxidative stress. The aim of our pilot study was to find out whether PAPP-A is related to mortality in HD patients. 40 HD patients in a stable clinical state (20 men and 20 women, mean age 69 +/- 12 years) were enrolled in the study and followed up for 20 months. PAPP-A was assessed immunochemically (TRACE method) in serum samples (before the HD session) at the beginning of the observation period. During the follow-up, 22 patients died, 15 of them due to cardiovascular events. PAPP-A levels were significantly higher in the patients who died, compared to living HD patients: 26.8 (21.6-36.8) vs. 20 (14.9-26.6) mU/l, p = 0.034. PAPP-A could also be a new prognostic marker in hemodialysis patients, probably due to its close association with cardiovascular risk. More extensive studies are required to confirm this hypothesis.

[An importance of vitamin D metabolites assessment in patients with impaired renal function]

The goal of this prospective multicentric study was to assess concentrations of vitamin D metabolites in patients with renal insufficiency and to monitor response of calcium phosphate metabolism parameters to a focused individualised therapy. The sample consisted of 184 patients, 66 of them were undergoing regular dialysis (Ccreat 0.11 +/- 0.05 ml/sec., age 57.6 +/- 16.6) and 118 patients were dispensed for renal insufficiency (Ccreat 0.42 +/- 0.23 ml/sec., age 60.8 +/- 11.0). After an assessment of basic parameters of bone metabolism (Ca, Pi, ALP) and parameters of acidobasic balance, calcidiol, calcitriol, and parathormon were assessed by radiation immunisation and than the used treatment was evaluated and adjusted according to results of the assessment. Two month later laboratory tests were done. Entry concentrations of calcidiol were in 73% of patients in reference area. However, according to clinical recommendations the bottom value of the reference area had to be reevaluated towards higher values. Such more strict criteria suited only 20% of patients. Calcitriol levels in reference area were found in 30% of patients, after treatment adjustment in 49% of patients. Treatment with vitamin D pharmaceuticals was often limited by hyperphosphataemia, low PTH or hypercalinemia. Input levels of calcitriol in nondialised patients significantly correlated with input calcidiol, 1alpha-hydroxylasis in kidneys could be stimulated in them via calcidiol administration. Attention deserve especially low calcidiol and calcitriol levels in patients with renal failure because timely, individualised and controllable supplementation of vitamin D metabolites in renal insufficiency serves as a prevention of later advanced forms of bone metabolism impairment in a period of dialysis treatment.

Comparison of different techniques of hemodialysis vascular access flow evaluation

Measurement of vascular access flow (QVA) has been suggested as a method of choice for vascular access quality (VAQ) monitoring. Besides traditional duplex Doppler, a number of bedside methods based mostly on the Krivitski principle of QVA evaluation from recirculation at reversed needles (RX), have been developed. This work compares ultrasonic dilution (UD), taken as a reference, HD01, Transonic Systems; duplex Doppler (DD); thermodilution (TD), BTM, Fresenius; optodilutional RX measurement (ORX), Critline III, R-mode, HemaMetrics; direct optodilutional QVA evaluation from jumpwise changes in ultrafiltration rate at both normal and reversed needles connection (OABF), Critline III, ABF-mode; and direct transcutaneous optodilutional QVA evaluation (TQA), Critline III TQA. Firstly, reproducibility of each method was assessed by duplicate measurement at unchanged conditions. This was followed by paired measurement with each method performed at controlled change in relevant measurement condition (two different extracorporeal blood flows in UD and TD, changed sensor position in TQA). Finally paired measurements by each method and the reference method performed at identical conditions were evaluated to assess accuracy of each method. The simple Krivitski formula QVA=QB(1-RX)/RX was used wherever manual QVA calculation was needed. Very high reproducibility was seen in UD, both for measurement at the same extra corporeal blood flow (QB) (correlation coefficient of duplicate measurement r=0.9702, n=58) and for measurement at two different QB (r=0.9735, n=24), justifying its current status of a reference method in QVA evaluation. Slightly lower reproducibility of TD measurement at the same QB (r=0.9197, n=40) and at two different QB (r=0.8508, n=168) can be easily overcome by duplicate measurement with averaging. High correlation of TD vs. UD (r=0.9543, n=54) makes TD a viable clinical alternative in QVA evaluation. Consistently different QVA obtained at two different QB should prompt closer investigation of anatomical conditions of the access. Use of the simple Krivitski formula in TD (which measures total recirculation, i.e. sum of access recirculation and cardiopulmonary recirculation) brings about underestimation of QVA, which progressively increases from QVA of about 600 mL/min up. Good correlation, although with significant scatter (r=0.8691, n=27) was found between the DD- and UD-based QVA. By far the worst reproducibility at the same QB from among the investigated methods was found in ORX (0.6430, n 23). Also the correlation of ORX vs. UD was lower than in other methods (r=0.702, n=33) and general overestimation of QVA by about 25% was noted. Correlation of OABF vs. UD (r=0.6957, n=26) was slightly better than that of ORX and it gave less overestimated values. The TQA method showed very high reproducibility (r=0.9712, n=85), however only for unchanged sensor position. Correlation of QVA measured at two different sensor positions was much worse (r=0.7255, n=22). Correspondence of TQA vs. UD was satisfactory (r=0.8077, n=36). Skilled and experienced operators are a must with this method.

Soluble leptin receptor levels in patients with chronic renal failure

Soluble leptin receptor (SLR) is the extracellular part of the leptin receptor. This protein is released into circulation and constitutes the main circulating leptin-binding protein. The aim of our study was to measure SLR concentrations in patients with chronic renal failure (CRF) and healthy subjects and to explore the relationship of SLR to other hormones and cytokines. The patients with CRF had significantly higher serum leptin, TNF-alpha and insulin levels than healthy subjects (25.1+/-23.5 vs. 9.4+/-7.6 ng.ml(-1) (S.D.); 14.2+/-4.2 vs. 4.55+/-2.5 ng.ml(-1); 39.8+/-36.1 vs. 20.3+/-11.1 mU.l(-1)). Serum soluble leptin receptor levels did not differ between these groups (19.1+/-11.3 vs. 19.6+/-6.1 U.ml(-1)). An inverse relationship between serum SLR and leptin levels was found in both groups. In patients with CRF the inverse relationship between SLR and insulin, body fat content and total protein levels were also found, while in healthy subjects only inverse relationship of SLR with insulin and albumin concentrations were detected. We conclude that soluble leptin receptor levels in patients with chronic renal failure do not differ from those of healthy subjects despite higher serum leptin levels in CRF patients. The physiological consequences of this finding require further investigation.

Advanced Glycation End Products in Clinical Nephrology

As a result of oxidative and carbonyl stress, advanced glycation end products (AGEs) are involved in the pathogenesis of severe and frequent diseases and their fatal vascular/cardiovascular complications, i.e. diabetes mellitus and its complications (nephropathy, angiopathy, neuropathy and retinopathy, renal failure and uremic and dialysis-associated complications), atherosclerosis and dialysis-related amyloidosis, neurodegenerative diseases, and rheumatoid arthritis. They are formed via non-enzymatic glycation which is specifically enhanced through the presence of oxidative and carbonyl stress, and their ability to form glycoxidation products in peptide and protein structures finally modulating or inducing biological reactivity. Food can be another source of AGEs; however, high serum AGEs in hemodialysis patients might reflect nutritional status better. Several methods of renal replacement therapy have been studied in connection with the AGE removal, but unfortunately the possibilities are still unsatisfactory even if high flux dialysis, hemofiltration, or hemodiafiltration give better results than conventional low flux dialysis. AGEs are currently being studied in the patients on peritoneal dialysis as their precursors can be formed in the dialysis fluid. AGEs can cause damage to the peritoneum and so a loss of ultrafiltration capacity. Many compounds give promising results in AGE inhibition (inhibition of formation of AGEs, inhibition of their action or degradation of AGEs), are tested for these properties, and eventually undergo clinical studies (e.g. aminoguanidine, OPB-9195, pyridoxamine, antioxidants, N-phenacylthiazolium bromide, antihypertensive drugs, angiotensin-converting enzyme inhibitors and angiotensin II receptor-1 antagonists).

Relationship of pregnancy-associated plasma protein-a to renal function and dialysis modalities

BACKGROUND

The aim of the study was to determine pregnancy-associated plasma protein-A (PAPP-A), which was recently described as a new marker of cardiovascular events, in patients with chronic renal insufficiency/failure and to find out its relationship to renal function and to prominent markers of oxidative stress (advanced oxidation protein products--AOPP) and inflammation (C-reactive protein--CRP).

METHODS

The studied group consisted of 36 chronic hemodialysis patients (HD), 10 patients treated with continuous ambulatory peritoneal dialysis (CAPD) and 38 patients with chronic renal insufficiency (CHRI) not yet dialyzed. PAPP-A was measured by Time Resolved Amplified Cryptate Emission technology. Determination of AOPP is based on a spectrophotometric method.

RESULTS

PAPP-A levels are statistically significantly elevated in the both groups of dialyzed patients in comparison with healthy subjects (27.0 +/- 16.5 mIU/l in HD and 14.07 +/- 6.73 mIU/l in CAPD vs. 8.22 +/- 2.7 mIU/l in the control group, p < 0.0001 and p < 0.001, respectively, p < 0.05 HD vs. CAPD). The mean serum PAPP-A levels in the CHRI patients not yet dialyzed were not significantly higher in comparison with the control group (9.72 +/-4.44 vs. 8.22 +/- 2.7 mIU/l, n.s.). In the CHRI not dialyzed patients, we found a significant positive correlation between serum creatinine and PAPP-A levels (r = 0.68, p < 0.05). In comparison with controls, AOPP and CRP levels were significantly higher in HD patients [AOPP 155.0 +/- 37.9 micromol/l, p < 0.0001 vs. controls, CRP 10.0 (4.6- 26.9) mg/l (median, interquartile range), p < 0.0001 vs. controls], CAPD patients [AOPP 118.5 +/- 25.8 micromol/l, p < 0.0001 vs. controls, CRP 7.7 (2.0-18.8) mg/l, p < 0.01 vs. controls] and AOPP levels in chronic renal failure patients not yet dialyzed (98.5 +/- 43.24 micromol/l, p < 0.01 vs. controls). The correlations between PAPP-A and AOPP (r = 0.49, p < 0.05) and PAPP-A and CRP (r = 0.48, p < 0.05) serum concentration were statistically significant in HD patients. In CAPD patients, neither a correlation between PAPP-A and AOPP nor a correlation between PAPP-A and CRP were found.

CONCLUSION

We can conclude that serum PAPP-A levels sensitively reflect the changes in renal function, depend on dialysis modality, and may represent a novel marker associated with inflammation and oxidative stress in chronic renal failure patients.

[Junctions of hepatology and nephrology]

The liver and the kidney jointly or in a complementary manner play an important role in maintaining homeostasis of the internal environment, mainly regarding detoxification, excretion and regulation. Hepatorenal syndrome can develop under pathological circumstances due to severe hepatic impairment, when the metabolism of both organs is affected by various xenobiotics, when they are damaged by genetic defects as in renal polycystosis, glycogenoses, alpha-1 antitrypsin deficiency or in hereditary amyloidosis. In primary hyperoxaluria or familiar thrombotic microangiopathy renal impairment develops due to the metabolic defect in the liver. Both organs may be impaired also in some hemolytic anemias, viral hepatitis, AIDS, leptospirosis, in circulatory failure, intoxications, and after the bone marrow or solid organ transplantation. In the dialysis units, prevention of viral hepatitis and HIV infection is of the basic importance; its principles are discussed in more detail.

[Tuberculosis in patients with chronic kidney failure]

BACKGROUND

In a retrospective study we analysed the incidence of tuberculosis (tb) in end-stage renal disease patients undergoing dialysis treatment at the Department of Medicine Strahov, General University Hospital, 1st Medical Faculty, Charles University, Prague. Study included patients who died and were autopsied from 1991 till 2000.

METHODS AND RESULTS

Active tb was found in 11 cases (4 men and 7 women, age 56 to 84 years) from the total of 275 patients, i.e. in 4%. The results confirmed the increased risk of tb in our group as compared to general population. Tuberculosis was diagnosed of in 2 patients before they died and in 3 patients there was a suspicion of tb before the death. In 6 cases tb was found during autopsy. Unlike the non-dialysed population, where pulmonary tb has the highest incidence (in Czech republic 75%), in the studied group extrapulmonary forms of tb were predominant (9 patients, i.e. 81.8% had some form of extrapulmonary tb). Miliary tb was found in 8 cases (72.7%). Because the symptoms of tb are unspecific and they are not pathognomonic, they were masked by other, already known diseases in patients with multiple co-morbidities. The low number of cases of tb diagnosed before death represents a serious problem. Obviously, it is difficult to prove tb unambiguously, even when such possibility is taken into account.

CONCLUSIONS

In differential diagnosis, we always have to bear in mind the possibility of the patient having tb. In examination algorithm we have to concentrate on both pulmonary and extra-pulmonary forms of tb.

[Diabetes mellitus and chronic renal insufficiency]

In the nineties of the 20th century diabetic nephropathy has become the leading cause of regular dialysis treatment (RDT) in developed countries. In particular type 2 diabetics are involved. A similar trend can be observed also in the Czech Republic which holds in this respect the first place among countries of the former eastern block (33% patients with RDT) suffer from diabetes. The cause of the increase of patients with diabetic nephropathy and renal failure caused by diabetes is not only the rising prevalence and incidence of type 2 diabetes in the population but in particular the better care provided to patients with type 2 diabetes which enables them to survive macro- and microvascular complications incl. diabetic nephropathy. It is estimated that diabetic nephropathy affects 4-8% patients attending diabetic clinics. With regard to the increasing number of diabetics in RDT, moreover associated with their high polymorbidity, this is a serious medical and economic problem. The main factors which influence in the diabetic patients the risk of development of diabetic nephropathy are long-term control of glycaemia, genetic (ethnic) factors, age and sex. The decisive factor influencing in patients with diabetic nephropathy the progression of chronic renal insufficiency is control of the blood pressure. Including diabetics in RDT is not associated only with medical problems but also with socio-economic issues. The quality of life of diabetics is much lower and the survival of diabetics treated within the framework of RDT is still almost half as compared with the survival of non-diabetic patients. Decision on the selection of the dialysis method is not easy. Medical differences are well defined but should not be considered absolute. It is important to consider also which method is preferred by the patient. Optimally the decision is taken during the period of dispensarization. Both dialyzation methods have comparable results and survival although for diabetics under 50 years of age a more favourable prognosis of peritoneal dialysis is reported. However, the risk of "failure of the method" is in general higher in peritoneal dialysis.

[Epidemiology of functional disorders of the kidneys]

The new classification K/DOQI of chronic renal disease differentiates five stages according to the grade of glomerular filtration. In the fifth, most severe grade (= renal failure) dialyzation/transplantation treatment is indicated. For dialyzation/transplantation activities in developed countries relatively accurate epidemiological data exist (national and supranational registers of dialyzation and transplantation programmes). The number of patients increases year by year, in particular in the more advanced age groups. The predominating diagnosis is renal failure is diabetes. Although treatment by one of the methods substituting renal function involves less than 0.1% of the population the economic costs amount to as much as 6 = of the total expenditure on health services (Medicare data, USA). On the other hand the prevalence of chronic renal disease in less advanced stages is not exactly known. It is estimated that chronic kidney disease may be present in some 10% of the population. If the disease were detected in time and the patient was given professional care which can retard the disease, it would be not only of medical but also of socio-economic benefit.

[Renal bone disease]

Renal bone disease is a serious complication associated with chronic renal failure. The pathogenetic mechanisms are very complicated. The disorder develops as a result of hypophosphataemia, hypocalcaemia and calcitrol deficiency already during the period when renal functions decline below 50%. Formerly the form with an excessive bone turnover predominated, nowadays we encounter ever more frequently so-called a dynamic bone disease. A serious manifestation are extraosseous calcifications. In treatment phosphate binding substances in the gastrointestinal tract are involved (along with other provisions, correcting hypophosphataemia), supplementation of calcium in case of hypocalcaemia correction of metabolic acidosis and administration of the active vitamin D metabolite (continuously as supplementation in deficient endogenous production, in a pulsatile pattern with the aim to suppress the activity of parathyroid bodies). In case of "resistant" hyperparathyroidism surgery is indicated (parathyroidectomy). Treatment of the dynamic form is not known, prevention of suppression of excessive parathyroid activity is important. New trends in the treatment of renal bone disease are non-calcium phosphate binding substances in the gastrointestinal tract, vitamin D analogues (with a lower hypercalcaemic potential) and calcium mimetics.

Age-related extracellular to total body water volume ratio (Ecv/TBW)--can it be used for "dry weight" determination in dialysis patients? Application of multifrequency bioimpedance measurement

The article suggests a novel method for quantitative determination of optimal dry weight in dialysis patient based on their extracellular volume (ECV) to total body water (TBW) ratio and its relation to age. Values of ECV and TBW are evaluated by means of whole body multifrequency bioimpedometry. In an effort to find a suitable marker of hydration status in an individual from bioimpedance data, significant correlation has been found between ECV/TBW ratio and age in health. Assuming that all excess fluid in dialysis patients is stored exclusively in ECV and that distribution of their TBW at the state of optimal dry weight corresponds to that of a healthy person of the same age, the pre-dialysis ECV/TBW could be used for quantitative determination of optimal dry weight and/or of the ultrafiltration to reach this weight. Practical bioimpedance measurement of ECV/TBW in a group of dialysis patients both pre- and post-dialysis confirmed both above assumptions, i.e. nearly exclusively extracellular origin of ultrafiltration as well as normalisation of the ECV/TBW ratio towards the end of dialysis. Supporting evidence of increasing ECV/TBW value with age was also found in literature. Although the suggested method needs detailed analysis of possible disturbing factors (ethnic "specificity" of the reference ECV/TBW vs. age characteristics in health, possible difference in "biological" and "physical" age of dialysis patient and others), the article is published at this early stage to enable wider testing of the proposed novel method by different investigators.

[Parameters of bone metabolism in patients with various degrees of kidney function damage]

BACKGROUND

Patients with renal failure frequently have their calcium and phosphate metabolism seriously disrupted. It may result in a skeletal malady--the renal osteopathy. Late forms of this syndrome are difficult to cure. The aim of this comparative study is to follow the relation between parameters of the bone metabolism (calcitriol, calcidiol, parathormone, calcitonin, osteocalcin, Pi, Ca--total or ionised, and others) and the degree of deterioration of the kidney function.

METHODS AND RESULTS

Three groups of patients were included into the study: A-hemodialyzed patients with chronic renal failure (Ccreat = 0.07 +/- 0.02 ml/s, n = 21, age 71.0 +/- 10.6 years); B--not dialyzed patients with decreased renal function (Ccreat = 0.33 +/- 0.05 ml/s, n = 19, age 65.0 +/- 9.6 years); C--patients with normal renal function (Ccreat = 1.45 +/- 0.12 ml/s, n = 16, age 85.2 +/- 4.7 years). Calcidiol concentration [microgram/l] did not differ in individual groups (A: 11.3 +/- 4.7, B: 10.7 +/- 8.2, C: 11.7 +/- 5.7, reference limits RM: 8.9-46.7). In contrast, calcitriol concentration [ng/l] was statistically different in all studied groups (A: 1.7 +/- 2.8, B: 17.6 +/- 12.4, C: 30.6 +/- 9.1, p < 0.001, RM: 19.9-67.0) and it correlated with the degree of renal function deterioration (calcitriol vs. creatinine, r = -0.76, p < 0.001). In PTH levels (pmol/l) the group C differed significantly from groups A and B (A: 27.4 +/- 32.0, B: 23.7 +/- 16.5, C: 6.2 +/- 2.4, C vs. A, p < 0.01, C vs. B, p < 0.001, RM: 1.0-6.8). PTH concentrations correlated with osteocalcine and HCO3 (r = 0.74, r = -0.56, p < 0.001).

CONCLUSIONS

Results of the tested parameters have shown that abnormalities in the bone metabolism significantly correlate with the degree of renal deterioration. It demonstrates the requirements for vitamin D metabolites supplementation for patients is needed already in the pre-dialysis stage.

[Evaluation of the severity of vascular impairment in the lower extremities in patients with chronic kidney failure]

BACKGROUND

Arterial ischemic disease represents highly serious complication for patients undergoing chronic haemodialysis. The aim of the study was to examine peripheral arteries in the group of haemodialysed patients and to estimate the incidence and seriousness of pathological findings.

METHODS AND RESULTS

Total 82 sonographic examinations of arteries in lower extremities using Multi Dopplex II set with graphic registration of dopplex curves was done in 53 dialysed patients. Blood pressure values of four peripheral arteries at legs together with blood pressure values at the brachial artery were evaluated as the ankle-arm index (API). Character of changes of dopplex curves was classified as SO index (obliteration index). Also with normal API, changes in SO were identified. SO index was significantly higher (p = 0.034) in patients of the peritoneal dialysis program in comparison with haemodialysed patients, in persons with diabetes the value was only marginally higher. Patients who died later (of the cardiovascular complications), the SO index was significantly higher then in others (p < 0.0001), though the API values were not different. Repeated testing in 29 patients after 6 months brought about worsening of the SO index (p < 0.00001) in those patients where no changes of API were seen. No relation with any of the followed biochemical parameters was found.

CONCLUSIONS

To estimate most accurately the conditions of the peripheral arteries in dialysed patients ankle-arm index was used together with evaluation of the shape of dopplex curves (index SO). Such detailed Doppler examination has proved identifiable changes of arteries in 73 out of 82 cases.

[Gastrointestinal hemorrhage and endoscopic findings in patients with chronic kidney failure]

Case-control study comparing 81 patients with chronic renal failure (CRF) with 58 patients without renal disease who were evaluated by endoscopy of upper and/or lower gastrointestinal tract (GIT) for gastrointestinal bleeding or dyspepsia. The success of endoscopic examinations was the same in both groups. Patients with CRF more often underwent endoscopic examination because of gastrointestinal bleeding and they presented more often by hematochezia. Patients with CRF were more often found to have hemorrhagic gastropathy or duodenopathy and angiodysplasia of upper and lower GIT. However, duodenal ulcer was significantly more common in the control group without renal disease. Incidence of Helicobacter Pylori infection was low in both groups.

[Sleep disorders in patients treated with continuous ambulatory peritoneal dialysis]

BACKGROUND

A lot of patients with end stage renal disease with the necessity of renal replacement therapy have some sleep problems. The aim of this study was to get basic information about the sleep of patients treated with continuous ambulatory peritoneal dialysis (CAPD), mainly their subjective view on their sleep, including comparison with hemodialyzed patients (HD).

METHODS

All patients treated with continuous ambulatory peritoneal dialysis in two dialysis centres were given a simple questionnary containing 20 questions concerning sleep. It was filled in by all these patients--25 patients (mean age 58.1 years)--12 men and 13 women. Data obtained from 103 hemodialyzed patients from the same two-dialysis centres were used for comparison (mean age 60.4 years)--61 men and 42 women (the same questionnary).

RESULTS

40% of CAPD patients regard their sleep as bad. Thirty six percent of patients have problems with falling asleep, 32% awake three times or more during the night and 28% snore or have some breath problems. CAPD patients feel more frequently tired after the night (32% vs. 18.4% HD), more patients sleep during the day (64% vs. 5.15% HD) and fewer patients feel restlessness of legs (36% vs. 45.6% HD). These differences are not statistically significant.

CONCLUSION

Occurrence of sleep disorders and their characteristics in patients on CAPD is similar to that in hemodialyzed patients.

[The calciphylaxis syndrome as a complication of chronic kidney failure. 6 case reports and literature review]

Calciphylaxis is a rate complication of unknown pathogenesis in patients with end stage renal disease. It is characterized by calcification of tunica media of small arteries associated with intimal fibrosis and thrombus formation which leads to the development of skin and subcutaneous tissue necrosis. Superinfection of skin lesions is a common consequence of this syndrome which may lead to the sepsis. The prognosis of this condition in serious. We performed a retrospective study of 6 subjects (4 men and 2 women) in the age of 35 to 59 years. We followed the parameters of calcium-phosphate metabolism, presence of calciphylaxis risk factors and the effect of parathyreoidectomy. Five patients were on hemodialysis, one had a kidney transplant. Skin and subcutaneous tissue necrosis were present in all subjects. The serum levels of parathormone were either high, normal or low, levels of calcium were normal or slightly elevated and phosphate levels were high or normal. Calcium was substituted before calciphylaxis development in 5 patients, calcitriole in 3 of therm. Five patients underwent parathyroidectomy. Three patients died (all of sepsis), one patient had the lower into amputation for infected lesions and the remaining two achieved regression. Our findings do support the hypothesis that calcium and calcitriole administration participates in development of calciphylaxis. Fatal prognosis of the once infections skin lesions was also proved.

[Mediators of amyloidogenesis and cytokines in dialysis-related amyloidosis]

BACKGROUND

Dialysis related amyloidosis (DRA) is a severe complication of the long-term dialysis treatment. beta 2 microglobulin and probably other factors influence the development of amyloid deposits. We investigated some of these factors during hemodialysis session.

METHODS AND RESULTS

We investigated 20 patients undergoing regular hemodialysis treatment. Patients were divided into AMYL group (with histologically proven DRA) and NE-AMYL group (without signs of DRA). Plasma levels of following factors were investigated using standard ELISA kits: serum amyloid A (SAA), interleukin-6 (IL-6), macrophage-colony stimulating factor (M-CSF). In addition plasma concentrations of C-reactive protein (CRP) and beta 2 microglobulin (beta 2M) were investigated in the AMYL group. All these parameters were studied during different time periods of the hemodialysis session. Plasma levels of SAA and IL-6 did not increase during hemodialysis session and we did not find any difference in plasma levels of these factors between the group of patients with AMYLand NE-AMYL. Plasma levels of M-CSF increased during hemodialysis and its levels in AMYL group were significantly higher in comparison with NE-AMYL group at the end of hemodialysis session (5345.10 +/- 340.42 vs. 3458.45 +/- 332.15 pg/ml, p = 0.0011). A linear correlation was found between plasma levels of SAA and CRP during hemodialysis whereas no correlation was found between plasma levels of beta 2M and other factors.

CONCLUSIONS

Our study suggests that plasma levels of M-CSF are increased in patients with chronic renal failure. Significant increase of M-CSF levels in the AMYL group could lead to greater activation of monocyte-macrophage system and could serve as factor supporting amyloid deposition process.

[Sonographic study of the diameter of the inferior vena cava for optimal ultrafiltration in hemodialysis]

The objective of the work was to evaluate the results of sonographic examination of the diameter of the vena cava inferior (VCI) as a parameter of hydratation of haemodialyzed patients. In a group of 84 haemodialyzed patients, mean age 66.32 years, the collapsibility index of the IVC was measure. The collapsibility index (CI) was calculated according to the formula: [formula: see text] where IVCexp = the maximum diameter of the IVC in maximum inspiration. Values of the index within the range from 40-75% corresponded to normal hydratation. The results were compared with ultrafiltration (total and expressed as % of body weight after haemodialyzation), "dry" body weight and with changes of BP during haemodialysis. The mean value of CI was 63.24 +/- 18.54. In 54 instances it was within the normal range (62.26 +/- 11.4), in 10 it was lower (27.7 +/- 6.02; possible sign of inadequate ultrafiltration during dialysis) and in 20 instances it was higher (84.9 +/- 7.53; risk of excessive ultrafiltration). Clinically assessed "dry" weight was adequate in 64% cases. In 24% UF was excessive. With this corresponded also the incidence of hypotension (40%) and in these patients the "dry" weight was subsequently elevated. The predictive importance of low values of CI for inadequate UF is however not unequivocal. Some of these patients were hypotensive even in case of low UF and did not tolerate its increase.

[Evaluation of vascular access for hemodialysis using combined measurement of recirculation in normal and inverted needle placement and determination of blood flow through the access]

The article describes novel method of vascular access quality assessment by means of combined measurement of recirculation with normal and inverse needles placement and calculation of vascular access blood flow from the recirculation data. Blood flow values seen in a large group of patients ranged from as low as 200 ml/min up to as high as 2 l/min. Females and diabetics exhibited lower values as compared to males and non-diabetics. The method enables to detect a number of anomalous sates which cannot be detected by conventional means based on monitoring of pressures or recirculation measurement at normal needles placement only (stenosis between both needles, uintentionally erroneous placement of needles in accesses with a loop). Assessment of access blood flow is suitable also for evaluation of interventions on the access, such as percutaneous transluminal angioplasty or surgical narrowing of anastomosis in case of too high blood flow.

[Relation between serum leptin levels and selected nutritional parameters in hemodialyzed patients]

Leptin is a protein hormone produced predominantly by adipocytes. Its serum concentrations positively correlate with body fat content and body mass index (BMI) i.e. they are lower in lean than obese subjects. The aim of our study was to compare serum levels of leptin, selected nutritional parameters and serum lipids in hemodialysed patients (n = 46) and healthy subjects (n = 24) and to explore the relationship between serum leptin levels and the rest of nutritional parameters in both groups. The tendency towards higher serum leptin levels in hemodialysed patients compared to control group was found, but the difference did not reach the statistical significance (24.31 +/- 24.06 ng/ml vs. 7.97 +/- 4.4 ng/ml). The leptin/body fat content ratio was significantly higher in hemodialysed patients compared to control subjects (0.85 +/- 0.74 vs. 0.27 +/- 0.11, p plain 0.01). The serum total protein, transpherine, albumin and cholesterol levels were significantly lower in hemodialysed patients compared to control group (68.14 +/- 5.56 g/l vs. 75.53 +/- 3.43 g/l; 2.04 +/- 0.49 g/l vs. 2.5 +/- 0.23 g/l; 33.65 +/- 2.86 g/l vs. 48.38 +/- 3.5 g/l; 4.56 +/- 1.19 mmol/l vs. 5.82 +/- 0.98 mmol/l; p = 0.001). Serum triglyceride levels were significantly lower in hemodialysed patients compared to controls (1.29 +/- 0.5 mmol/l vs. 2.31 +/- 1.23 mmol/l, p < 0.0001). Serum leptin levels in hemodialysed patients correlated positively with body fat content, serum cholesterol and triglyceride levels. In the control group only the significant positive correlation with body fat content was found. In conclusion, this study demonstrated relatively higher serum leptin levels in hemodialysed patients compared to healthy subjects, although their nutritional status expressed by serum protein nutritional parameters and body fat content is significantly impaired. Except of the positive correlation with serum lipids levels no statistically significant relationships between serum leptin levels and biochemical nutritional parameters were found in our study.

[Sleep disorders in hemodialysis patients]

BACKGROUND

Many hemodialyzed patients complain about bad sleep. The aim of this study was to learn the subjective view of patients on their sleep and its influence by hemodialysis treatment.

METHODS AND RESULTS

A simple questionnary containing 20 questions concerning sleep was prepared and given to regularly hemodialyzed patients in two hemodialysis centres. Uncorperating as well as severely ill patients were excluded. The questionnary was responded by 103 patients (mean age 60.4 years)--61 men (mean age 56.7 years) and 42 women (mean age 65.7 years). 34% of patient regard their sleep as bad. 45.6% of dialyzed patients feel restlessness of legs during the night and 32% snore or have some breath problems. 38% of patients considered their sleep as better before starting the hemodialysis treatment, in 14.6% the sleep became better after starting the dialysis treatment.

CONCLUSIONS

Sleep disorders in hemodialysed patients worsen the quality of life of these patients. Moreover, sleep disorders represent a serious problem as they can increase the mortality.

[Evaluation of stress in dialyzed patients]

BACKGROUND

Patients with chronic renal failure treated with hemodialysis are subjected to a high degree of stress. The aim of the study was to determine which components of stress become the most critical for the dialysed persons and how the degree of subjective stress depends on sex, age, and continuance of dialysis.

METHODS AND RESULTS

66 patients (40 females and 26 males) with chronic renal failure regularly treated with hemodialysis were included into the studied group. Average age was 57 years (26 to 75 years). Serial hemodialysis program lasted in average 51 months (4 to 144 months). Patients filled in the Scale of Hemodialysing Stressors, which contained 31 items, 6 of them physiological and 25 psychosocial. Each stressor was ranked in four-point Likert's scale. Results were given in average values with standard deviation. To compare differences in subgroups, non-paired t-test was employed. Results showed that among the most serious stressors belongs the limitation of physical activity (average 1.91), limited possibilities for recreation (average 1.76), loss of body functions (average 1.68), fatigue (average 1.67), restriction of drinking (average 1.61). Average stress score for the whole scale was 32 +/- 11 with theoretically highest value of 93. Global stress score did not differ in males and females, in elderly patients (over 50 years) it was statistically higher than in younger ones (p < 0.05) and in patients treated over one year it was higher than in those cured less long (p < 0.05).

CONCLUSIONS

Dialysed patients are stressed namely by psychosocial factors. Most influenced are the older and for longer time dialysed patients. The short and long-lasting dialysis brings about similar level of stress. Stress can reach the highest level during the last year of the patient's life.

[Results of laparoscopic implantation of peritoneal catheters]]

The advantages of miniinvasive surgical techniques were proved in a number of surgical operations. In the submitted article the authors evaluate five years' experience with laparoscopic implantation of Tenckhoff's catheter for peritoneal dialysis. The authors implanted in 1995-1999 catheters by the laparoscopic route in 34 patients. The most frequent complication was early leak of the dialysate along the catheter (41%). After modification of the surgical technique early leak was observed in 11% of the patients. Escape of the catheter from the lesser pelvis was observed in 14.8% patients. The authors did not observe early infection of the tunnel along the catheter. It may be concluded that the laparoscopic technique of implantation of a peritoneal catheter was not associated with a higher incidence of complications than the laparotomy. The advantage of laparoscopic operation is earlier mobilisation and shorter hospitalization of the patient. Another advantage of this technique, tested by the authors, is the possibility of exact diagnosis possibly with an immediate single-stage plastic operation of hernias in the abdominal region.

[Viral hepatitis of patients in a regular haemodialysis programme]

After cardiovascular diseases and bacterial infections viral hepatitis is the most frequent disease which complicates haemodialyzation treatment of patients with chronic renal failure. Substitution of renal function is for these patients a life saving procedure. It is, however, complicated treatment associated with various risks of acute and chronic complications. The prevalence of parenterally transmitted viral hepatitis in the population of haemodialyzed patients is by far higher than the prevalence of these diseases in the general population. There are several reasons for this condition. In addition to the character of this treatment there is also the fact that for reasons of immunodeficiency the course proper of infetious hepatitis in haemodialyzed patients is markedly more often terminated by development of the chronic state of the disease with permanent viraemia. These patients become a possible source of infection of the other patients and possibly also the staff of haemodialyzation centres. Vaccination against viral hepatitis B reduces the risk of transmission of the disease. However a large proportion of patients is enlisted in the haemodialyzation programme acutely without the possibility of previous vaccination. Some patients who are vaccinated during the predialyzation period do not respond by antibody formation. Viral hepatitis complicates or makes it impossible in some cases to include the patient in the transplantation programme. The prevalence of viral hepatitis in patients in the haemodialyzation programme was significantly reduced despite all mentioned facts. During the last three years a certain stagnation of this positive trend was recorded. New therapeutic possibilities (the use of interferon and new antiviral properations--analogues of nucleoside bases) offer a chance of a further decrease of the number of these serious diseases.

Vascular access monitoring evaluated from automated recirculation measurement

Vascular access quality monitoring by means of vascular access blood flow (QVA) evaluated from automated thermodilutional measurement of recirculation with reverse needle position is described. This method provides significant advantages over conventional methods based on simple monitoring of pressures in the extracorporeal circuit and/or measurement of recirculation with normal needle position. AQVA evaluation protocol was developed and introduced into the system of primary nursing. The QVA values were found independent of the extracorporeal blood flow used during the recirculation measurement. QVA values from below 200 ml/min to over 2 l/min were seen. In general, lower values were found in diabetics compared to non-diabetics and in females compared to males. While blood flow below 600 ml/min is considered risky for synthetic vascular grafts, native AV-fistulae seem to remain stable and patent at a flow of 400 ml/min or even below. The method is able to detect erroneous needle placement in looped grafts, stenosis between needles, and is also well suited for effective evaluation of success/failure of interventions on access.

[Relation between serum leptin levels, blood parameters and erythropoietin levels in hemodialyzed patients]

BACKGROUND

Serum leptin levels are significantly increased in hemodialysed patients compared to healthy subjects. There are some data suggesting the possible relationship of leptin and the regulation of haematopoiesis. The aim of our study was to compare serum leptin levels in two groups of hemodialysed patients: the group treated by recombinant human erythropoietin (n = 40) (HD + EPO), the group without erythropoietin treatment (HD) and the control group of healthy subjects (n = 20) to explore the influence of erythropoietin treatment on serum leptin levels.

METHODS AND RESULTS

The tendency towards lower body fat content and higher serum leptin levels was found in both groups of HD patients compared to control group, but the differences did not reach statistical significance due to high variability of those parameters (leptinu levels: HD 19.5 +/- 18.5, HD + EPO 24.9 +/- 23.3, K 10.4 +/- 8.8 ng.ml-1). The erythrocyte count and haemoglobin levels in both groups of HD patients were significantly lower than in control group. The erythrocyte count and haemoglobin levels were significantly lower in HD patients treated by erythropoietin compared to untreated HD group. The leptin/body fat content ratio was significantly higher in HD patients compared to healthy subjects (HD 0.86 +/- 0.72, HD + EPO 0.92 +/- 0.78, K 0.35 +/- 0.21, p < 0.05). Serum leptin levels in all studied groups correlated positively with body fat content and negatively with erythrocyte count. No significant relationships of serum leptin levels to erythropoietin levels or other parameters studied were found in any of groups.

CONCLUSIONS

Our study further supported the fact that serum leptin levels in HD patients are relatively higher than in healthy subjects. Serum leptin levels in HD patients treated by recombinant human erythropoietin did not significantly differ from HD patients without this treatment. Except of the negative correlation between serum leptin levels and the erythrocyte count no statistically significant relationships of serum leptin levels and the blood count parameters were found.

Serum leptin levels in diabetic patients on hemodialysis: the relationship to parameters of diabetes metabolic control

Leptin is a protein hormone produced predominantly by adipocytes that affects food intake and energy expenditure. Its serum levels are significantly higher in patients with chronic renal failure compared to healthy subjects. The aim of this study was to compare serum leptin levels in hemodialyzed patients with type II diabetes mellitus (n=26) with body content-matched hemodialyzed patients without diabetes (n=26) and to explore the relationship between parameters of the long term diabetes metabolic control and serum leptin levels. Serum leptin levels in diabetic patients did not significantly differ from those of non-diabetic patients (25.3+/-8.8 vs 25.7+/-8.7 ng/ml). Serum leptin levels in diabetic patients positively correlated with body fat content, body mass index and predialysis serum insulin levels. No significant relationship were observed between serum leptin levels and blood glucose, glycated hemoglobin, glycated protein, serum urea, creatinine, leukocyte count and total hemoglobin respectively. The multiple stepwise regression analysis revealed that body fat content together with body mass index accounted for 77.8% of variations in predialysis serum leptin levels, while insulin levels and the parameters of diabetes metabolic control had only slight prediction value for leptin concentrations. We conclude that serum leptin levels in hemodialysed patients with type III diabetes mellitus do not significantly differ from those of hemodialysed non-diabetic patients. The body fat content and body mass index are the strongest predictors of serum leptin levels, while parameters of long term diabetes metabolic control play probably only minor direct role in its regulation.

[Mushroom poisoning by Cortinarius orellanus]

The authors present the case-records of three patients who became intoxicated with the mushroom Cortinarius orellanus. This mushroom is very rare in this country and is not well known. The toxin orellanin is solely nephrotoxic and renal affection can lead to acute renal failure. A specific feature of this intoxication is the symptom-free period from 2 to 21 days, gastrointestinal complaints associated with back pain. The diagnosis can be established from a mycological analysis or by estimation of toxin in serum or tissue obtained by renal biopsy. The basis of treatment is disposal of the toxin by extracorporeal elimination methods: haemodialysis and haemoperfusion. As with the length of the interval between intoxication and onset of treatment the probability of irreversible renal affection increases, the medical community should take into consideration possible intoxication with this mushroom in the differential diagnosis of acute renal failure.

Erythropoietin, an update, and where to in the future?

Recombinant human erythropoietin has been produced by genetic technology since 1985 and since then many clinical trials have repeatedly demonstrated its success in the correction of anaemia associated with renal failure. This paper discusses basic principles for its administration, potential side effects and strategies for non response to erythropoietin (Epo) therapy.

[Effect of treatment with recombinant erythropoietin in patients with multiple myeloma and kidney failure]

The efficacy of recombinant human erythropoietin (r-HuEPO) in patients with multiple myeloma (MM) has been confirmed in several clinical trials. We report our experience of r-HuEPO treatment in 5 myeloma patients with renal failure. The therapy with r-HuEPO (Eprex, Janssen-Cilag or Recormon, Boehringer, Mannheim) was started after 4-8 months from diagnosis, the drug was administered intravenously (in one patient subcutaneously after cessation of hemodialysis treatment), two or three times weekly. The initial doses were 4-12,000 units/week (mean 8,400). In all patients good response during the first month of therapy was observed. Median Hb and hematocrit increased from 70 g/l and 20.8% to 87 g/l and 26% after 1 month and to 105 g/l and 30.3% after 4-6 months, respectively. The need for blood transfusion decreased significantly--from 2.72 TU/month to 0.13 TU/month. WHO performance status and patients self-assessment of quality of live improved substantially after r-HuEPO. No serious adverse events, including hypertension and/or thromboembolic events were observed. In accordance with some previous reports we conclude r-HuEPO is effective and safe treatment in patients with MM and renal failure. Moreover, lower doses of growth factor could be effective in this particular group of patients.

[The method of calculating the numeric value of the KT/V index in the evaluation of effectiveness of peritoneal dialysis]

BACKGROUND

For evaluation of the adequacy of peritoneal and haemodialyzation treatment the BP/V index is used. In the literature there is so far no uniform view on the procedure of calculation. The objective was to test whether and to what extent the results of different procedures differ.

METHODS AND RESULTS

The authors demonstrated that the method of calculation of this index has a marked impact on the result. The greatest discrepancy was due to differences in the distribution volume of urea (or total body water) where the mean difference was 10% of the absolute value. Also the procedure used to assess the residual renal function can influence the result. Differences due to the method of collection of the dialysate for assessment of the urea concentration are insignificant. The mean difference between the maximal and minimal BP/V index, when different methods of calculation are used, was in the same patient 0.45, which is cca 25% of the total value.

CONCLUSIONS

The BP/V index must be assessed always by the same method with maximum accuracy. When presenting results or comparing results of different departments, the method of calculation must be stated.

[Iron supplementation during erythropoietin therapy in patients on hemodialysis]

The development of secondary anaemia is a constant associated phenomenon of chronic renal failure. During its treatment by recombinant human erythropoietin (rHuEPO) erythropoiesis is accelerated and this increases demands on the supply of dietary erythropoietic precursors (Fe, pyridoxine, folic acid, vitamin B12). In particular as regards iron, frequently the dietary amount is not sufficient and supplementation is necessary. The objective of the present work is to compare oral and intravenous iron supplementation in the treatment of secondary anaemia by rHuEPO in patients with chronic renal failure treated by haemodialysis. A group of haemodialyzed patients (n = 61) treated with erythropoietin, where the serum ferritin concentration had dropped beneath 300 ng/ml, or the transferrin concentration below 0.20 was divided at random into two sub-groups. To group "A" Actiferrin was administered 3 x 1 cps/d (Ferrosi sulfas heptahydricus, corresponding to 34.5 mg elemental Fe and serine 129 mg per capsule, i.e. a total of 724.5 mg elemental Fe per week). To group "A" Ferrum-Lek was administered 1 vial per week by the i.v. route (Ferri oxidum saccharatum, corresponding to 100 mg elemental iron per week). The two groups were comparable as to the mean erythropoietin dose (50 U/kg per week) and the patients' mean age (61 years), the male/female ratio and the spectrum of basic diseases. After six weeks of treatment a comparable increase of the haematocrit and serum iron concentration was observed in both groups. As to transferrin saturation, there was a more marked increment in the intravenously supplemented group. The serum ferritin values in group "A" declined, while in group "F" they increased. After both types of iron supplementation a comparable increase of the haematocrit and serum iron concentration occurred, the iron reserves represented by serum ferritin differed however and from the long-term aspect they are in favour of intravenous iron supplementation in haemodialyzed patients treated with erythropoietin.

[Treatment of chronic kidney failure in diabetics with peritoneal dialysis]

The number of dialyzed diabetics in this country is increasing (14.5% of all dialyzed patients in 1993). Haemodialyzation treatment of diabetics has, however, some pitfalls: it is difficult to create a permanent vascular approach, the risk of intraocular haemorrhage during heparinization etc. Therefore some authors prefer peritoneal dialysis in the case of renal failure in diabetics. The technique of insertion of an intraperitoneal catheter and treatment proper are in principle the same as in non-diabetic subjects; the method does not require a vascular approach and heparin is not administered. Other advantages of peritoneal dialysis are the stability of the milieu intérieur, the preserved residual renal function and the possibility of intraperitoneal insulin administration which imitates the physiological release from the pancreas. Peritoneal dialysis has, however, also some disadvantages: the main risk is peritonitis. It can hasten atherosclerosis, malnutrition is relatively frequent etc. The main value of peritoneal dialysis is extension of therapeutic possibilities for diabetics with renal failure.

Erythropoietin and its use in renal failure

Causative treatment of anaemia associated with renal failure with human recombinant erythropoietin (rHuEPO) represents undoubtedly one of the most exciting benefits in the complex therapeutic care of patients on maintenance dialysis. Ten years have passed since the first clinical experience with rHuEPO. At present, the number of patients on rHuEPO therapy has increased to more than 300,000 worldwide. All of us being involved in renal and dialysis care should have knowledge on how to deal with this drug, what its benefits are as well as its potential untoward effects and limits.

[The effect of recombinant erythropoietin on candidicidal activity of polymorphonuclear leukocytes in hemodialyzed patients]

BACKGROUND

Some investigations, incl. ours, provided evidence that recombinant erythropoietin (rHU-EPO) used in the treatment of anaemia in dialyzed patients has an impact also on some immunological parameters. The objective of the present work was to study mechanisms of the effect of rHU-EPO on neutrophil leukocytes.

METHODS AND RESULTS

The candicidal activity (CI) of polymorphonuclear leukocytes in whole blood (CI-WB), after isolation of cells in the presence of pooled serum (CI-PMN) was assessed and parallel tests were performed in the presence of rHU-EPO in vitro in a concentration of 2 U/ml (CI-WB/E, CI-PMN/E) in anaemic patients before treatment with EHU-EPO (group A, n = 16), after achieving the target haematocrit (0.30-0.35) (group T, n = 14) and in healthy controls (group C, n = 8). The candicidal activity in group A was lower than in controls in whole blood; after removal of uraemic serum it reached normal values. Addition of rHU-EPO in vitro had a marked stimulating effect (CI-WB = 0.16 +/- 0.06, WB/E = 0.22 +/- 0.06*, PMN = 0.23 +/- 0.11*, PMN/E 0.34 +/- 0.1**). After achievement of the desirable Ht the candidacidal activity became normal and isolation of the cells did not change it. In this group a stimulating effect of rHU-EPO in vitro was apparent, contrary to the control group (group T: CI-WB = 0.22 +/- 0.05, WB/E = 0.29 +/- 0.05*, PMN = 0.21 +/- 0.04, PMN/E = 0.27 +/- 0.06*, group C: CI-WB = 0.21 +/- 0.06, WB/E = 0.21 +/- 0.06, PMN = 0.22 +/- 0.06 PMN/E = 0.21 +/- 0.05) (*/**p < 0.01/0.001).

CONCLUSIONS

The results of the investigation indicate that during treatment with rHU-EPO phagocytic functions in dialyzed patients attain normal levels. This effect may be also due to the direct effect of rHU-EPO on neutrophil leukocytes of dialyzed patients.

[Measurement of water content and distribution using whole-body multifrequency impedance in a healthy population in diseases of the kidney]

BACKGROUND

The whole-body multifrequency impedometry (MFI) is a new noninvasive method suggested for assessment of hydration status and distribution of the total body water into extra- and intracellular compartment. However, due to its as yet limited use reference values are still lacking. The aim of this work was to evaluate total body water (TBW) and its intra- (VIC) and extracellular compartment (VEC) from electrical resistances of intra- and extracellular fluid and to measure cell membrane capacity by means of MFI in healthy population and in renal patients.

METHODS AND RESULTS

MFI investigation was performed in 21 healthy individuals (group A), 19 patients followed for renal insufficiency but not yet dialysed (group B) and in 15 haemodialysis patients (group C). The bioimpedance analyzer BIS 4000B (Xitron Technologies, San Diego, USA) was used throughout the study. TBW values established by means of MFI corresponded very closely to those ones calculated from Watson's formulae. The ratio VEC/TBW was found to be related to age with regression analysis parameters being very similar both in group A and groups B, C: group A: VEC/TBW = 0.4696 + 0.0011. Age (r = 0.512) groups B, C: VEC/TBW = 0.4574 + 0.0016. Age (r = 0.420). (For group C the post-dialysis values were used). Close correlation of VEC changes with ultrafiltered volume during haemodialysis session (r = 0.87 pri n = 87) indicates mostly extracellular origin of ultrafiltrate. The highest capacity of the cellular wall was found in healthy individuals, the lowest values were seen in the dialysed group. During dialysis the capacity rose to values seen in the non-dialysed group of renal patients. Interindividual scater over 40% in CIC value is caused by differences in body size. Normalized capacity CIC/VIC in healthy group is 0.104 nF/L +/- 10% on average. In renal patients values from 0.73 to 0.9 nF/L were seen. With regard to low variation of CIC/VIC in health, this parameter can be considered a possible candidate for screening assessment of the renal patients' hydration status.

CONCLUSIONS

MFI was found suitable for monitoring of water content and distribution in the body both in out-patient department as well as during haemodialysis.

Hemocompatibility in hemodialysis and erythropoietin therapy

Two studies designed to investigate the effect of recombinant human erythropoietin (rHuEPO) treatment of anemia in chronic dialysis patients on hemocompatibility were conducted. Study 1, whose main aim was to establish whether treatment with rHuEPO enhances coagulation activation during dialysis, included 15 patients before rHuEPO therapy at a mean hematocrit (HCT) of 22.3% and then during therapy at a HCT of 29.3%. The plasma concentrations of the thrombin-antithrombin III complex were not higher during rHuEPO therapy than before it when performing hemodialysis with a Cuprophan membrane. No significant difference was demonstrated either in the values of activated clotting times (Hemochron), thrombocyte or white blood cell counts (Coulter S+II), or in plasma C5a concentrations (ELISA) established during dialysis sessions before and during rHuEPO therapy. In Study 2, which focused primarily on the question of whether or not rHuEPO therapy increases thrombocyte activation during hemodialysis, 8 patients on chronic dialysis were examined both before therapy at a mean HCT value of 22.1% and during rHuEPO therapy at a HCT of 31.5%, invariably during dialysis with either a Cuprophan or polyacrylonitrile (AN69HF) membrane. The plasma concentrations of beta-thromboglobulin (ELISA) did not differ between the examinations made during rHuEPO and before rHuEPO therapy; however, statistically significant differences were found between dialysis sessions involving Cuprophan and AN69HF membranes. No significant difference between examination before and during rHuEPO was demonstrated in activated clotting time nor thrombocyte and white blood cell counts in this study either. The authors conclude that rHuEPO therapy does not enhance coagulation activation during hemodialysis, does not have an effect on thrombocyte activation, and does not influence complement activation and changes in white blood cell counts.

[The effect of erythropoietin on fibrinolysis in hemodialyzed patients]

BACKGROUND

According to some data treatment with human recombinant erythropoietin (EPO) in dialyzed patients leads to a more frequent occurrence of thromboses. One of the possible causes could be reduced fibrinolysis. The objective of the present study was to assess the effect of EPO in dialyzed patients on two key enzymes of fibrinolysis, i.e. the tissue activator of plasminogen (t-PA) and the inhibitor of the plasminogen activator (PAI-1).

METHODS AND RESULTS

In eight patients dialyzed for prolonged periods examined under otherwise equal conditions before EPO treatment (haematocrit 22.9%--median value) and after 9.5 weeks of EPO treatment (Recormon, s.c.) when a haematocrit of 30% was achieved, activities (chromogenic substrates) and antigens (ELISA of t-PA and PAI) were assessed. All examinations were made before and after venous occlusion. Between examinations made before treatment and during EPO treatment no significant difference was found in the t-Pa activities assessed before venous occlusion (before EPO 0.9 IU/ml--during EPO 0.6, not significant Wilcoxon's paired test) nor after venous occlusion (3.2-3.8, n.s.). PAI activities before venous occlusion (10.9 U/ml-18.3, n.s.) and after venous occlusion (9.7-11.5, n.s.) did not differ significantly either, when comparing values before and in the course of EPO treatment. Similarly as in the case of activities in antigens t-PA and PAI no difference was found before and during EPO.

CONCLUSIONS

No effect of EPO on the investigated indicators of fibrinolysis was found. The results of the presented investigation are at variance with the idea that EPO reduces fibrinolysis in dialyzed patients and thus contributes to the development of thrombotic complications.

Antineutrophil cytoplasmic antibody-positive sera inhibit candidacidal activity of granulocytes

Antineutrophil cytoplasmic antibodies (ANCA) are suspected of being involved in the pathogenesis of tissue injury in systemic vasculitis. We have investigated the effect of 10 sera from 8 patients with ANCA-associated diseases on the capacity of neutrophils derived from healthy persons to kill ingested Candida albicans. ANCA-containing sera inhibited candidacidal activity by 55-80% in comparison to control sera. This phenomenon could lead to the depression of antimicrobial resistance of patients with ANCA and could be involved in the pathogenesis of granuloma formation.