Management of apixaban anticoagulation in a patient requiring therapeutic plasma exchange: a case report and a literature review.

Therapeutic plasma exchange (TPE) is used as an effective treatment modality for a variety of autoimmune disorders. Apart from its desired effect of removing pathological blood components, it also can remove coagulation factors and drugs. Currently, there is an insufficient amount of information regarding the use of direct oral anticoagulants in this setting. In this article, we present a case report of a patient with myasthenia gravis and chronic anticoagulation with apixaban who underwent a series of TPE while continuing apixaban treatment. We observed that only 10% of daily dose was removed by the procedure and plasma levels of apixaban corresponded with expected range. TPE was not associated with shortened drug plasma half-life. We did not observe any significant alteration of apixaban pharmacokinetics during the period of TPE therapy, as well as no thrombotic or bleeding events. This case report supports the use of apixaban in patients treated by TPE, nevertheless, to firmly establish apixaban efficacy and safety profile in this clinical setting further research is needed.

Matrix Metalloproteinases and Their Tissue Inhibitors: an Evaluation of Novel Biomarkers in ANCA-Associated Vasculitis.

Matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) may play an important role in both inflammation with subsequent fibrosis and in repair and healing in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). We evaluated the circulating levels of MMPs, including pregnancy-associated plasma protein A (PAPP-A), and TIMPs in patients with AAV. PAPP-A, MMP-2, MMP-3, MMP-7, MMP-9, TIMP-1, TIMP-2 and selected parameters were measured in 100 AAV patients (36 patients with active disease and 64 patients in remission) and 34 healthy subjects. The levels of MMP-2, MMP-3, MMP-7, MMP-9, TIMP-1, TIMP-2, and PAPP-A in AAV were all found to be different to those of the controls. The MMP-7 and PAPP-A concentrations were increased in active disease in comparison to the controls (MMP-7: 13 ±.7 vs. 2 ± 0.6 ng/ml, PAPP-A: 14 ± 18 vs. 6.8 ± 2.6 ng/ml, both P < 0.005). The MMP-2 and TIMP-2 levels were increased in remission when compared to the controls (MMP-2: 242 ± 50 ng/ml vs. 212 ± 26 ng /ml, TIMP-2: 82 ± 14 ng/ml vs. 68 ± 93 ng/ml) and to the active AAV (MMP-2: 242 ± 50 vs. 219 ± 54 ng/ml, TIMP-2: 82 ± 14 ng/ml vs. 73 ± 15 ng/ml, all P < 0.005). MMP-3, MMP-7, TIMP-1, and PAPP-A correlated with serum creatinine. The serum levels of MMPs, TIMPs and PAPP-A are all altered in AAV. MMP-2, MMP-7 and TIMP-2 appear to be promising markers in distinguishing active AAV from remission. MMP-3, MMP-7, TIMP-1, and PAPP-A are associated with kidney function in AAV. Further studies are needed to delineate the exact roles of circulating MMPs, TIMPs and PAPP-A in patients with AAV.

EULAR/ERA-EDTA recommendations for the management of ANCA-associated vasculitis.

In this article, the 2009 European League Against Rheumatism (EULAR) recommendations for the management of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) have been updated. The 2009 recommendations were on the management of primary small and medium vessel vasculitis. The 2015 update has been developed by an international task force representing EULAR, the European Renal Association and the European Vasculitis Society (EUVAS). The recommendations are based upon evidence from systematic literature reviews, as well as expert opinion where appropriate. The evidence presented was discussed and summarised by the experts in the course of a consensus-finding and voting process. Levels of evidence and grades of recommendations were derived and levels of agreement (strengths of recommendations) determined. In addition to the voting by the task force members, the relevance of the recommendations was assessed by an online voting survey among members of EUVAS. Fifteen recommendations were developed, covering general aspects, such as attaining remission and the need for shared decision making between clinicians and patients. More specific items relate to starting immunosuppressive therapy in combination with glucocorticoids to induce remission, followed by a period of remission maintenance; for remission induction in life-threatening or organ-threatening AAV, cyclophosphamide and rituximab are considered to have similar efficacy; plasma exchange which is recommended, where licensed, in the setting of rapidly progressive renal failure or severe diffuse pulmonary haemorrhage. These recommendations are intended for use by healthcare professionals, doctors in specialist training, medical students, pharmaceutical industries and drug regulatory organisations.

Genome-wide methylation analysis of tubulocystic and papillary renal cell carcinomas.

Tubulocystic renal cell carcinoma (TRCC) represents a rare tumor with incidence lower than 1 % of all renal carcinomas. This study was undertaken to contribute to characterization of molecular signatures associated with TRCC and to compare them with the features of papillary renal cell carcinoma (PRCC) at the level of genome wide methylation analysis.We performed methylated DNA immunoprecipitation (MeDIP) coupled with microarray analysis (Roche NimbleGen). Using the CHARM package, we compared the levels of gene methylation between paired samples of tumors and control renal tissues of each examined individual. We found significant global demethylation in all tumor samples in comparison with adjacent kidney tissues of normal histological appearance but no significant differences in gene methylation between the both compared tumor entities. Therefore we focused on characterization of differentially methylated regions between both tumors and control tissues. We found 42 differentially methylated genes.Hypermethylated genes for protocadherins (PCDHG) and genes coding for products associated with functions of plasma membrane were evaluated as significantly overrepresented among hypermethylated genes detected in both types of renal cell carcinomas.In our pilot study, we provide the first evidence that identical features in the process of carcinogenesis leading to TRCC and/or to PRCC may be found at the gene methylation level.

Comparability of patients with ANCA-associated vasculitis enrolled in clinical trials or in observational cohorts.

OBJECTIVES: To analyse the differences between patients with granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) entered into randomised clinical trials (RCTs) and those followed in large observational cohorts. METHODS: The main characteristics and outcomes of patients with generalised and/or severe GPA or MPA with a five-factor score ≥ 1 enrolled in the French Vasculitis Study Group (FVSG) or the US-Canadian-based Vasculitis Clinical Research Consortium cohorts were compared to those enrolled in one of 2 FVSG clinical RCTs (WEG91, WEGENT) or 3 European Vasculitis Society clinical trials (CYCLOPS, CYCAZAREM, IMPROVE). RESULTS: 657 patients (65.3% with GPA) in RCTs were compared to 437 in cohorts (90.6% with GPA). RCT patients were older at diagnosis than the cohort patients (56.6 ± 13.9 vs. 46.8 ± 17.3 years), had higher Birmingham vasculitis activity score (19.5 ± 9.1 vs. 16.9 ± 7.4), and more frequent kidney disease (84.0% vs. 54.9%) but fewer ear, nose, and throat symptoms (56.8% vs. 72.2%). At 56 months post-diagnosis, mortality and relapse rates, adjusted for age and renal function, were higher for patients with GPA in RCTs vs. cohorts (10.7% vs. 2.5% [p=0.001] and 22.5% vs. 15.6% [p=0.03], respectively) but similar for patients with MPA (6.2% vs. 6.6% [p=0.92] and 16.6% vs. 10.1% [p=0.39], respectively). CONCLUSIONS: Patients with GPA or MPA in RCTs and those in observational cohorts show important differences that should be remembered when interpreting results based on these study populations.

Increased levels of soluble ST2 in patients with active newly diagnosed ANCA-associated vasculitis.

OBJECTIVE: ST2, a member of the interleukin-1 receptor family, is selectively expressed on Th2 cells and mediates important Th2 functions. IL-33 is a specific ligand of ST2. The aim of the study was to determine whether serum levels of soluble ST2 (sST2) or IL-33 predict activity of the disease in patients with ANCA-associated vasculitides (AAV). METHODS: 139 AAV patients and 62 controls were studied. IL-33 and sST2 in the blood were measured with a commercially available ELISA. RESULTS: Newly diagnosed AAV patients had higher sST2 levels than controls (P < 0.01). Levels of sST2 were significantly higher in active newly diagnosed AAV patients than in patients with remission (P < 0.001). IL-33 levels were higher in AAV patients than in the control groups (P = 0.002). However, serum IL-33 levels were not increased in patients with active AAV compared to patients in remission. IL-33 levels were higher in patients with granulomatosis with polyangiitis than in patients with microscopic polyangiitis (P = 0.012). CONCLUSIONS: Serum sST2, but not serum IL-33, may be a marker of activity in AAV patients.

Extended follow-up of the CYCLOFA-LUNE trial comparing two sequential induction and maintenance treatment regimens for proliferative lupus nephritis based either on cyclophosphamide or on cyclosporine A.

Objective To evaluate the extended follow-up of the CYCLOFA-LUNE trial, a randomized prospective trial comparing two sequential induction and maintenance treatment regimens for proliferative lupus nephritis based either on cyclophosphamide (CPH) or cyclosporine A (CyA). Patients and methods Data for kidney function and adverse events were collected by a cross-sectional survey for 38 of 40 patients initially randomized in the CYCLOFA-LUNE trial. Results The median follow-up time was 7.7 years (range 5.0-10.3). Rates of renal impairment and end-stage renal disease, adverse events (death, cardiovascular event, tumor, premature menopause) did not differ between the CPH and CyA group, nor did mean serum creatinine, 24 h proteinuria and SLICC damage score at last follow-up. Most patients in both groups were still treated with glucocorticoids, other immunosuppressant agents and blood pressure lowering drugs. Conclusion An immunosuppressive regimen based on CyA achieved similar clinical results to that based on CPH in the very long term.

Long-term outcome of severe alveolar haemorrhage in ANCA-associated vasculitis: a retrospective cohort study.

OBJECTIVES: Alveolar haemorrhage (AH) is a major cause of early death in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). There is a paucity of information regarding the outcomes of AAV patients presenting with severe AH. METHOD: A retrospective cohort study. Patients with severe AH were identified from a case review of 824 AAV patients. Demography, presenting features, treatment, and outcomes are described. RESULTS: Fifty-three patients (33 males, 20 females; median age 59 years) with severe AH were identified: 37 (69.8%) with granulomatosis with polyangiitis (Wegener's) and 16 with microscopic polyangiitis [36 proteinase 3 (PR3)-ANCA positive and 17 myeloperoxidase (MPO)-ANCA positive]. AH was the first disease manifestation in 46 (86.8%) patients. Assisted ventilation was required in 36 (67.9%), renal involvement was present in 52 (98.1%), and 28 (52.8%) required dialysis. Forty (75.5%) received plasma exchange. At 3 months, 44/53 (83.0%) were alive. The mean follow-up was 49 months when 31 (58.5%) were alive and 24 (45.3%) dialysis independent. Mortality was higher in those requiring dialysis at entry (57.1% vs. 24%, p = 0.02) and in patients aged > 65 years (71.4% vs. 30.8%, p = 0.01), and tended to be higher in those requiring intubation (54.5% vs. 32.2%, p = 0.1). CONCLUSIONS: Severe AH was more commonly associated with PR3-ANCA (vs. MPO-ANCA) and strongly correlated with renal vasculitis. Current treatment of severe AH leads to remission but long-term mortality remains high. Concurrent renal failure and older age were associated with higher mortality.

Endotelial activation and flow-mediated vasodilation in young patients with breast cancer.

Endothelial activation and dysfunction may play a significant role in the progression of breast cancer. In our study we examined markers of endothelial activation (soluble ICAM-1, P-selectin, E-selectin) in 98 young patients with breast cancer (< 40 years). In 50 of them (and 20 age-matched controls) we also measured flow mediated vasodilation. Patients with breast cancer had significantly higher serum levels of soluble E-selectin, P-selectin and ICAM-1, P-selectin was higher in patients with larger tumors, node involvement and seemed to be apredictor of poor outcome. We were unable to find significant difference in the parameters of flow mediated vasodilation between patients with breast cancer and healthy subjects, although both peak blood flow (PBF) and flow mediated vasodilation (FMD) seemed to be skewed compared to healthy subjects toward mean and lower levels. Cluster analysis enabled us to distinguish several larger groups of patients with different degree of endothelial activation and function and different outcome. Group of patients with high E-selectin, high ICAM-1 (higher endothelial activation) and low VEGF (putative endothelial damage) had more frequently negative estrogen receptors and had worse outcome compared to the group of patients with lower E-selectin, lower ICAM-1 and mostly positive estrogen receptors. Further studies of larger groups of patients should help to identify the panel of endothelial markers which could help in predicting the outcome of young patients with breast cancer.

Proteinuria and hypertension in patients treated with inhibitors of the VEGF signalling pathway--incidence, mechanisms and management.

Anti-VEGF therapy dramatically improved the outcome of patients with renal cancer and other advanced malignancies, but may be complicated by proteinuria and hypertension. VEGF is indispensable for the normal development of glomerulus and preservation of glomerular filtration barrier. Interference with its action may result in damage to glomerular endothelial cells and (in severe cases) in renal thrombotic microangiopathy. Blood pressure and proteinuria (using dipstick) should be assessed in all patients before starting anti-VEGF therapy and regularly monitored during the treatment. Patients with severe proteinuria and/or impaired renal function should be referred to the nephrologist for further work-up. Hypertension caused by anti-VEGF therapy can be effectively treated; progression of proteinuria and/or renal dysfunction may require tapering, or even withdrawal of anti-VEGF treatment.

Mutational analysis of ACTN4, encoding α-actinin 4, in patients with focal segmental glomerulosclerosis using HRM method.

α-Actinin 4, encoded by ACTN4, is an F-actin crosslinking protein which belongs to the spectrin gene superfamily. It has a head-to-tail homodimer structure with three main domains. Mutations in ACTN4 are associated with idiopathic nephrotic syndrome (NS). However, until today only a few mutations have been described in this gene. We used genomic DNA of 48 patients with focal segmental glomerulosclerosis (FSGS) and minimal change disease (MCD) to screen for ACTN4 mutations by high-resolution melting analysis (HRM). Suspect samples were sequenced and compared with healthy controls. To investigate the prevalence and possible effect of some substitutions found in FSGS/MCD patients we also looked for these changes in patients with IgA nephropathy (IgAN) and membranous glomerulonephritis (MGN). We found 20 exonic and intronic substitutions in the group of 48 Czech patients. The substitution 2242A>G (p.Asn748Asp) is a candidate mutation which was identified in one patient but not in any of the 200 healthy controls. Exon 19 seems to be a variable region due to the amount of revealed polymorphisms. In this region we also found three unreported substitutions in IgAN patients, c.2351C>T (p.Ala784Val), c.2378G>A (p.Cys793Tyr) and c.2393G>A (p.Gly798Asp). These substitutions were not found in any tested healthy controls. To conclude, the ACTN4 mutations are not a frequent cause of FSGS/MCD in Czech adult patients. One new ACTN4 mutation has been identified.

Recent insights into the pathogenesis of nephrotic syndrome.

Nephrotic syndrome is characterized by heavy proteinuria followed by hypoproteinemia, hypercholestrolemia, lipiduria, and edema. The glomerular filtration barrier (GFB) consists of glomerular endothelial cells covered with glycocalyx, the basement membrane, subpodocyte space and podocytes with foot processes and slit membranes between them. The coordinated function of GFB has been considered to be the major barrier against filtration of plasma proteins to urine. However, new hypothesis suggesting more permeable GFB has emerged. According to this, proteinuria might be prevented by tubular protein reabsorbtion. Experiments and human studies have revealed numerous putative permeability factors in idiopathic nephrotic syndrome (minimal change disease/focal segmental glomerulosclerosis). New antigens and antibodies have been suggested in "idiopathic" membranous nephropathy as well. Formation of nephrotic edema, the role of oncotic pressure and of different sodium and water retaining hormones have been subject of intensive study. These findings should pave the way to new therapeutic modalities targeted more precisely to the pathogenic mechanisms.

[Hypertension in patients with polycystic kidney disease -  incidence, pathogenesis, prognosis, therapy]. / Hypertenze u pacientu s polycystickými ledvinami -  incidence, patogeneze, prognóza, terapie.

Hypertension is common in patients with autosomal dominant polycystic kidney disease (ADPKD) very early usually already in adolescence and its occurrence precedes the decrease of glomerular filtration rate. Expansion of renal cysts causing local renal ischemia and activation of the reninangiotensin system is believed to play a decisive role in its pathogenesis. Hypertension in ADPKD leads to early development of left ventricle hypertrophy and definitely contributes to the progression of chronic renal insufficiency. In ADPKD optimal control of blood pressure dramatically decreases the risk of left ventricle hypertrophy and contributes to its regression, but the beneficial effect of optimal compared to standard blood pressure control on the progression of chronic renal insufficiency has yet to be unequivocally demonstrated. Angiotensin converting enzyme inhibitors and/ or angiotensin receptor blockers are the drugs of choice in the treatment of hypertension in ADPKD. New drugs blocking the growth of renal cysts (e. g. inhibitors of V2 vasopressin antagonists) may have in ADPKD positive impact not only of the growth of the cysts and kidney volume, but also on the rate of loss of glomerular filtration rate. The influence of these drugs on the control of blood pressure, if any, remains uncertain.

Novel flow cytometric method for the detection of podocalyxin-positive elements in urine of patients with glomerulonephritides - first promising results.

Glomerulonephritides together create a heterogenic group of supposedly immunologically mediated diseases of glomeruli. They still belong among the most frequent causes of chronic renal failure. Detection of podocytes in urine might serve as an important marker of glomerulonephritides activity. The aim of this study was to develop a novel flow cytometric method for the detection of podocyte fragments and podocytes in urine and assess its possible use in clinical practice. We placed emphasis on the improvement of pre-analytic phase. To suppress the autofluorescence of the background, blocking solutions and magnetic separation were used. An additional surface marker CD10 (nephrilysin) was used together with routinely used podocalyxin (PCX) in order to achieve better identification of podocytes. Based on the surface marker expression, three different element types were identified in the urine samples: PCX+/CD10+ elements (EL) (supposedly podocytes), PCX-/CD10+ EL (supposedly parietal epithelial cells) and PCX+ EL. We examined a total of 36 patients who underwent renal biopsy (non-glomerular nephropathy, MGN, FSGS, IgAN, AAV and MPGN) and 27 healthy controls. Negative results were found in non-glomerular nephropathy and in MGN. In patients with FSGS and IgAN, the levels of urine elements were slightly increased. The highest levels of all elements were found in AAV and MPGN. Our first results suggest that flow cytometric detection may distinguish between glomerular and nonglomerular diseases and that the levels of urine elements might correlate with the degree of glomerular destruction.

Mutational analysis of the NPHS2 gene in Czech patients with idiopathic nephrotic syndrome.

Focal segmental glomerulosclerosis and minimal change disease represent frequent histological patterns of renal injury in patients with nephrotic syndrome. Few cases carrying NPHS2 gene variants have been described to date. Mutational analysis of the NPHS2 gene was performed in 50 Czech adult patients with histologically proved FSGS/MCD. The common p.P20L and p.R229Q polymorphisms of the NPHS2 gene were tested in 169 patients with IgA nephropathy and in 300 individuals of the control group. No mutation in the NPHS2 gene in patients with adult onset was identified. One homozygous mutation p.V290M in a patient with onset in early childhood was found. One new heterozygous variant in the non-conservative area of the NPHS2 gene, p.G97S, was identified in a patient with childhood-onset FSGS. In one adult patient, there were two polymorphisms, p.P20L and p.R229Q, in trans-heterozygous state, which could contribute to steroid-resistant nephrotic syndrome. The most common polymorphism p.R229Q was identified in 12 % of FSGS/ MCD patients, in 11.8 % of IGAN patients and in 10% of controls. The heterozygosity of p.R229Q polymorphism was similar in the IGAN group, with non-significantly higher prevalence in IGAN patients with progressive form of the disease (15.9 % versus 9.4 %). The prevalence of p.P20L polymorphism was not significantly different among the groups (6 % in FSGS patients, 1.8 % in IGAN patients, 1 % in the control group). To conclude, NPHS2 mutations are rare in patients with adult onset of FSGS/MCD. The R229Q polymorphism is frequent in the Czech population and probably could have some influence on IGAN.

TRPC6 gene variants in Czech adult patients with focal segmental glomerulosclerosis and minimal change disease.

Blood filtration and formation of primary urine in the kidney glomerulus is provided by a specialized membrane called slit diaphragm located between well-branched pedicels of podocytes. Actually, the slit diaphragm is a protein supercomplex, whose disruption can cause failure of renal filtration, and patients usually manifest nephrotic syndrome. Recently, familial forms of nephrotic syndrome have been described which arise from malfunction of mutated proteins making up the slit diaphragm. In 2005 it was found that one of the proteins present in this complex was non-selective cation channel TRPC6. The aim of this work was to screen mutations and polymorphisms of the TRPC6 gene in a group of 64 Czech patients with nephrotic syndrome and subsequently, on the basis of these data, evaluate the role of mutations in the TRPC6 gene in Czech population. The analysis was performed by the PCR method followed by direct sequencing and high-resolution melting method. We have not identified any mutations in our group of patients. Two additional single nucleotide polymorphisms - p.P15S and p.A404V - were detected along with nucleotide changes that did not result in amino acid changes and with a few intronic changes. P.P15S heterozygotes were more frequent in patients with steroid-resistant FSGS than in steroid- sensitive patients (29 % versus 12.1 %). To conclude, we did not find any probable disease-causing mutation in the TRPC6 gene in the cohort of 64 Czech patients. The p.P15S polymorphism might have some influence on the therapeutic response of FSGS patients.

Recent news in the treatment of lupus nephritis.

Patient survival and renal survival of patients with lupus nephritis improved, but still in a significant proportion of patients the disease progresses to end-stage renal failure, possibly at least partly due to slow and incomplete response to induction treatment and high relapse rate on the maintenance treatment. Mycophenolate mofetil was recently demonstrated to be a comparably effective and safe induction treatment of lupus nephritis as high-dose cyclophosphamide pulses, in Caucasian patients it has become a reasonable alternative to low-dose cyclophosphamide pulses according to the EUROLUPUS protocol. Mycophenolate was shown to be more effective than azathioprine in the maintenance treatment and is currently the treatment of choice for this phase of the disease. Rituximab should be reserved for patients refractory (or intolerant) to cyclophosphamide and/or mycophenolate. Therapy of lupus nephritis should be individually tailored; more aggressive therapy should be reserved for patients at high risk for renal dysfunction and its progression.

The influence of vascular endothelial growth factor (VEGF) polymorphism on the progression of chronic glomerulonephritides.

Vascular endothelial growth factor is an important mediator in maintaining normal kidney functions. In addition, several lines of evidence show that up-regulation of this mediator in glomeruli may be associated with or may directly cause renal dysfunction. We tried to assess the influence of the -2578 C/A and -1154 G/A polymorphisms in the regulatory region of the vascular endothelial growth factor gene upon progression of three primary chronic glomerulonephritides (minimal change disease/focal and segmental glomerulosclerosis, membranous nephropathy, immunoglobulin A nephropathy). We studied a cohort of 213 patients compared to 311 unrelated healthy controls. Analysis of the C/A polymorphism of vascular endothelial growth factor revealed an increased prevalence of CC genotype in the minimal change disease/focal and segmental glomerulosclerosis group in comparison with the other groups. A balanced distribution of G and A alleles among the respective types of chronic glomerulonephritides was shown in the analysis of -1154 G/A polymorphism. Finally, we have not proved any significant influence of the polymorphisms at positions -2578 C/A and -1154 G/A of the vascular endothelial growth factor gene promoter on the progression of chronic glomerulonephritides even though our study suggests a negative effect of CC genotype of -2578 C/A polymorphism on the clinical course of minimal change disease/focal segmental glomerulosclerosis.

Can adequate treatment influence the postembolization syndrome and cytokine release in patients undergoing iatrogenic renal artery embolization?

The complete renal artery embolization is an alternative to surgical nephrectomy in seriously ill patients. Iatrogenic embolization can be used in many different conditions. Refractory nephrotic syndrome represents a very rare indication for embolization. Complete renal artery embolization has usually been complicated by postembolization syndrome (PES) which is characterized by flank pain and fever. Possible immunologic contribution to the PES leads some authors to the administration of corticosteroids to the patients undergoing embolization. We report here a cohort of 13 patients undergoing complete embolization of total 21 kidneys due to refractory nephrotic syndrome non-responding to the various specific treatment regimes. We treated our patients undergoing renal artery embolization according to special protocol containing combination of antibiotic drugs and corticosteroids (CS) to diminish PES and evaluated its influence to the cytokine production. The incidence of PES was less frequent and milder in comparison with the historical group of patients. Significant decrease in plasma levels of tumor necrosis factor α during first post-embolization day (8.37 pre- vs. 5.74 pg/ml post-embolization, P=0.0002) could partially explain the reduction of PES symptoms. The procedure was not complicated by severe complications and represents an elegant alternative to surgical procedure. The accurate timing of the embolization remains a controversial point in this intervention.

[The past, the present and the future of renal replacement therapy]. / Minulost, soucasnost a budoucnost náhrady funkce ledvin.

The observation that renal failure leads to 'uraemia' through retention of solutes that would otherwise be excreted by healthy kidneys, has been formulated as early as the first half of 19th century. The discovery of osmosis and a colloid membrane facilitated the first testing ofdialysis, originally in animals and in the first quarter of 20th century also in humans. In the mid 1940s, dialysis became the method of choice for the treatment of acute renal failure. At the beginning of 1960s, the development of long-term venous access made programmes of chronic haemodialysis possible in many countries. These achievements, together with kidney transplantation, saved or significantly extended life of millions of patients with chronic renal failure. The last 50 years saw a dramatic increase in the number of chronically dialyzed patients; the safety and efficacy of haemodialysis methods improved and effective treatments have been introduced of a number of complications associated with chronic renal failure (e.g. hypertension, anaemia or bone disease). Despite this, mortality of, particularly older chronically dialyzed patients, is very high and their quality of life sometimes low. High cardiovascular mortality, frequently due to chronic heart failure and sudden death (unlike ischemic heart disease in healthy population), is a dominating problem. However, it is difficult to reduce the high cardiovascular morbidity and mortality of haemodialyzed patients. Patient prognosis might probably be improved by more frequent use of convective methods of blood purification and frequent haemodialysis as well as effective management ofdyslipidemia. Nevertheless, early diagnosis of patients with chronic renal insufficiency and early management of all general as well as renal failure-specific risk factors in patients with mild to moderate chronic renal insufficiency is essential if the prognosis ofhaemodialyzed patients is to be improved. Future developments of renal replacement therapies are difficult to predict. The treatment should be individualized; early transplantation, peritoneal or home (frequent) haemodialysis should be performed in younger patients and conservative treatment, in addition to chronic haemodialysis, should be used in older patients. Miniaturization as one of the potential future trends could facilitate the use of portable artificial kidney. Artificial membranes coated with proximal tubule cells and ex vivo kidney cultivation represent another interesting perspective.