[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.