Molecular profiling in IgA nephropathy and focal and segmental glomerulosclerosis

The aim of the study was to characterize by molecular profiling two glomerular diseases: IgA nephropathy (IgAN) and focal segmental glomerulosclerosis (FSGS) and to identify potential molecular markers of IgAN and FSGS progression. The expressions of 90 immune-related genes were compared in biopsies of patients with IgAN (n=33), FSGS (n=17) and in controls (n=11) using RT-qPCR. To identify markers of disease progression, gene expression was compared between progressors and non-progressors in 1 year follow-up. The results were verified on validation cohort of patients with IgAN (n=8) and in controls (n=6) using laser-capture microdissection, that enables to analyze gene expression separately for glomeruli and interstitium. In comparison to controls, patients with both IgAN and FSGS, had lower expression of BAX (apoptotic molecule BCL2-associated protein) and HMOX-1 (heme oxygenase 1) and higher expression of SELP (selectin P). Furthermore, in IgAN higher expression of PTPRC (protein-tyrosine phosphatase, receptor-type C) and in FSGS higher expression of BCL2L1 (regulator of apoptosis BCL2-like 1) and IL18 compared to control was observed. Validation of differentially expressed genes between IgAN and controls on another cohort using laser-capture microdissection confirmed higher expression of PTPRC in glomeruli of patients with IgAN. The risk of progression in IgAN was associated with higher expression EDN1 (endothelin 1) (AUC=0.77) and FASLG (Fas ligand) (AUC=0.82) and lower expression of VEGF (vascular endothelial growth factor) (AUC=0.8) and in FSGS with lower expression of CCL19 (chemokine (C-C motif) ligand 19) (AUC=0.86). Higher expression of EDN1 and FASLG along with lower expression of VEGF in IgAN and lower expression of CCL19 in FSGS at the time of biopsy can help to identify patients at risk of future disease progression.

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.

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 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.

Influence of VEGF polymorphism on progression of autosomal dominant polycystic kidney disease

BACKGROUND

Significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). Dysregulation of vascular endothelial growth factor (VEGF) expression in the kidney has been demonstrated in a wide range of renal diseases. The aim of the present study was to assess the influence of the -2578 C/A and the -1154 G/A polymorphisms in the regulatory region of the VEGF gene upon the progression of ADPKD toward end-stage renal disease (ESRD).

METHODS

The study was performed on 283 ADPKD patients (145 males, 138 females, mean age 51.7 +/- 10.3 years) who had reached ESRD. Patients were divided into three groups: (1) ESRD development later than in 63 years (slow progressors, n = 47), (2) ESRD development before 45 years (rapid progressors, n = 69), and (3) ESRD development between 45 and 63 years (intermediate progressors, n = 167). Genetically unrelated healthy Czech individuals were analyzed as a control group (n = 311, 153 males, 158 females, mean age 44.6 +/- 9.2 years). DNA samples were genotyped for the -2578 C/A and for the -1154 G/A polymorphisms of the VEGF gene promoter. The serum levels of VEGF were established in 111 healthy Czech individuals from the control group.

RESULTS

The VEGF -2578 C/A and -1154 G/A genotype distribution showed no differences among the groups of slow, rapid and intermediate progressors. The age of ESRD with regard to different genotypes was not significantly different in all ADPKD patients. However, the AA genotype of the -2578 C/A polymorphism was associated with a significantly higher age of ESRD than other genotypes in rapid progressors (42.7 vs. 40.5 years, p = 0.01). The CG haplotype was found significantly more frequent in ADPKD rapid progressors than in slow progressors (p = 0.047). Serum levels of VEGF did not significantly differ in the control group, according to different genotypes of both polymorphisms.

CONCLUSION

To conclude, AA genotype of the -2578 C/A polymorphism was related to better prognosis of the disease in a limited group of ADPKD patients. Classical genetic recessive and dominant model did not find significant influence of separate VEGF polymorphisms on the progression of ADPKD. Accordingly, CG haplotype was associated with earlier onset of ESRD in ADPKD patients.

T cells in the pathogenesis of ANCA-associated vasculitis: current knowledge

AAV are a group of systemic immune-mediated diseases with a strong and highly specific association with ANCA. In recent years, there has been increasing evidence that ANCA might play a direct pathogenic role in triggering AAV. Nevertheless, effectors of cell-mediated immunity prevail in the inflammation sites in patients with AAV. Numerous studies found increased markers of T-cell activation in AAV. Moreover, this activation persisted even in remission and despite treatment. Finally, successful therapeutic attempts using T cell-directed treatment were also reported. There has therefore been substantial evidence that T cells are involved in the pathogenesis of AAV, even though the exact mechanisms are yet to be elucidated. In this review, recent findings on the contribution of T cells to the pathogenic processes in AAV will be briefly summarized. Special emphasis will be placed on the Th1/Th2 concept, the role of T-regulatory cells, and the role of effector memory T cells in the pathogenesis of AAV.

The influence of two megsin polymorphisms on the progression of IgA nephropathy

The clinical course of chronic renal diseases and their progression to ESRD is highly variable. The strongest predictors of poor outcome of IgAN involve hypertension, severe proteinuria and elevated serum creatinine level. Different candidate gene polymorphisms have been advocated as possible modulators of the progression of IgAN. Megsin belongs to the serpin superfamily and was mapped to chromosome 18q21.3. Megsin plays a role in the regulation of a wide variety of processes in mesangial cells, such as matrix metabolism, cell proliferation, and apoptosis. Overexpression of Megsin might lead to mesangial dysfunction, and impair degradation of the mesangial matrix and disposal of immune complexes. The expression of Megsin is upregulated in a variety of glomerular diseases with mesangial injury in humans and in animal models. We investigated a possible association of two C2093T, C2180T polymorphisms of the megsin gene with the progression of IgAN towards ESRD, as well as the haplotype reconstruction of megsin gene polymorphisms and clinical manifestation of IgAN. We examined a group of 197 pts with histologically proven IGAN (84 pts with normal renal function, 113 pts with progressive renal insufficiency); as a control group we used 61 genetically unrelated healthy subjects. DNA samples from collected blood were genotyped for two singlenucleotide polymorphisms of megsin C2093T, C2180T by means of PCR with defined primers, electrophoresis on 2% agarose gel, UV light visualization and direct sequencing. The megsin genotype distribution showed no differences among the groups of IgAN with normal renal function, progressive renal insufficiency and the control group. According to haplotype analysis, the TT haplotype (defined as T-2093, T-2180 alleles) was substantially more frequent in pts with IgAN and normal renal function (Table 1, P = 0.025; Table 3, P = 0.062). Pts in the progressive group showed significantly higher levels of 24-h UP (3.53 +/- 2.80 vs 2.06 +/- 2.06, P = 0.042; Table 10), diastolic blood pressure (92.89 +/- 15.66 vs 84.93 +/- 10.43, P = 0.047; Table 10) and almost significantly systolic blood pressure (150.79 +/- 32.88 vs 135.21 +/- 14.88, P = 0.058; Table 10). We confirmed the negative prognostic influence of hypertension and proteinuria on the progression of IgAN in Czech pts. We found out that the TT haplotype (defined as T-2093, T-2180 alleles) could play a protective role in the progression of IgAN. In our Czech population, we excluded the negative influence of the 2093C-2180T haplotype, which was proposed by Chinese studies.

The influence of endothelin-A receptor gene polymorphism on the progression of autosomal dominant polycystic kidney disease and IgA nephropathy

ADPKD is the most common hereditary renal disease. IGAN is a mesangial proliferative glomerulonephritis characterized by diffuse mesangial deposition of immunoglobulin A. ET-1 has been suggested to be a major disease-promoting factor in renal diseases. The vasoconstrictor effect of ET-1 is mediated by the ET-A receptor. We have investigated the influence of C/T polymorphism in exon 8 of the EDNRA gene. A total number of 193 patients (87 males, 106 females) with ADPKD entered into this study. Patients were divided into three groups: 1. 47 pts with ESRD later than in 63 years (slow progressors), 2. 49 pts with ESRD before 45 (rapid progressors) and 3. 97 pts with ESRD between 45-63 years. Moreover, we examined a group of 153 pts with histologically proven IGAN (116 males, 37 females). Pts were divided into two groups: 1. 79 pts with ERSD during 5 years of the study (IGAN rapid progressors) and 2. 74 patients with normal renal function (IGAN slow progressors). As a control group we used 100 genetically unrelated healthy subjects. The distribution of C/T polymorphism did not significantly differ between rapid and slow progressors of ADPKD and IGAN. The comparison of ESRD ages showed that CC females with ADPKD failed significantly later than CT heterozygotes: CC (57.4 +/- 8.1 years), CT (53.0 +/- 9.1 years) and TT (54.5 +/- 6.4years) (t-test, P = 0.018). To conclude, the CC genotype could be protective in ADPKD females. This genotype was described to be associated with lower pulse pressure.

The influence of three endothelin-1 polymorphisms on the progression of IgA nephropathy

The clinical course of chronic renal diseases and their progression to ESRF is highly variable. Different candidate gene polymorphisms have been advocated as possible modulators of ESRF progression. Moreover, ET-1 has been suggested as a major promoting factor in renal disease. However, limited data are available regarding an association of three ET-1 SNP K198N, T- 1370G and 3A/4A with the progression of IgAN to ESRF. We examined a group of 122 pts with histologically proved IgAN (91 pts with normal renal function, 31 pts with ESRF), as a control group we used 132 genetically unrelated healthy subjects. Patients' DNAs were genotyped for three ET-1 SNP: K198N, T-1370G and 3A/4A by means of PCR. The frequencies of different genotypes and ET-1 gene haplotypes were compared among control group, IgAN pts with normal renal function and IgAN pts with ESRF. The ET-1 genotype distribution showed no differences among the groups of IgAN with normal renal function (1. K198N - 63.74% KK, 32.97% KN, 3.3% NN; 2. TT - 68.13% TT, 28.57% TG, 3.3% GG; 3. 3A/4A - 42.22% 3A/3A, 50.0% 3A/4A, 7.69% 4A/4A ), IgAN with ESRF (1. K198N - 74.19% KK, 25.81% KN, 0% NN; 2. TT - 77.42% TT, 22.58% TG, 0% GG, 3. 3A/4A - 56.25% 3A/3A, 37.5% 3A/4A, 6.25% 4A/4A ) and the control group (1. K198N - 66.67% KK, 31.82% KN, 1.52% NN, 2. TT - 76.51% TT, 22.72% TG, 0.76% GG, 3. 3A/4A - 43.94% 3A/3A, 44.70% 3A/4A, 11.36% 4A/4A ). The analysis of haplotypes showed that the frequency of G-198, G-1370 and 4A allele combination was significantly higher in comparison with the control group (P=0.0056). We excluded the effect of K198N, T-1370G and 3A/4A polymorphisms of the ET-1 gene in single-gene analysis on the progression of IgAN to ESRF. A significant association of the GG4A haplotype with IgAN, demonstrated by haplotype reconstruction of the ET-1 gene, could suggest a role in the pathogenesis of IgAN.

Influence of endothelin-1 gene polymorphisms on the progression of autosomal dominant polycystic kidney disease

BACKGROUND/AIM

A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). The variability cannot be fully explained by the genetic heterogeneity of the disease. Endothelin-1 (ET-1) has been suggested to be a major promoting factor in renal diseases. The role of the ET-1 gene locus (EDN1) in the renal function in the general nondiabetic population was evaluated. We examined the influence of three single-nucleotide polymorphisms of the ET-1 gene (EDN1)--K198N, 3A/4A, and T-1370G--on the progression of ADPKD towards end-stage renal disease (ESRD).

METHODS

Two hundred and five ADPKD patients (113 males and 92 females) who had reached ESRD were analyzed. The patients were divided into three groups: (1) 48 patients (23 males and 25 females) with ESRD later than 63 years of age (slow progressors), (2) 74 patients (41 males and 33 females) with ESRD before 45 years of age (rapid progressors), and (3) 83 patients (49 males and 34 females) with ESRD between 45 and 63 years old. DNA samples from collected blood were genotyped for three single-nucleotide polymorphisms of EDN1: K198N, 3A/4A, and T-1370G. Haplotype analysis was also done in 200 healthy individuals. We compared the frequencies of the different genotypes between the groups of slow and rapid progressors and the ages at the time of ESRD regarding the EDN1 genotypes.

RESULTS

The EDN1 genotype distribution showed no differences among the groups of slow progressors, rapid progressors, the ADPKD group with ESRD between 45 and 63 years old, and the control group. Comparing the ages of ESRD of all patients, we did not find significant differences with regard to the different genotypes. Furthermore, we compared the combinations of the different haplotypes and the ages at the time of ESRD. We found no differences in ages at the time of ESRD in patients with different haplotypes in the endothelin promoter (T-1370G) in combination with 3A/4A or K198N polymorphisms. Comparing the ages at the time of ESRD in patients with different 3A/4A and K198N haplotypes, we found a significantly lower age at the time of ESRD (47.1 +/- 8.7 years) in the carriers of the 4A allele in combination with the 198N allele (4A/4A, 3A/4A + 198KN,NN) than in the carriers of the 4A allele homozygous for the K198 allele (52.9 +/- 10.9 years; 4A/4A, 3A/4A + 198KK; t test: p < 0.01) and in the carriers of the 198N allele homozygous for the 3A allele (53 +/- 11.2 years; 3A/3A + 198KN,NN; t test: p < 0.05).

CONCLUSIONS

We excluded an effect of K198N, 3A/4A, and T-1370G polymorphisms of EDN1 on the progression of ADPKD. However, a deleterious effect of the combination of 4A and 198N alleles of EDN1 was observed in APKDK individuals.

The influence of the endothelin-converting enzyme-1 gene polymorphism on the progression of autosomal dominant polycystic kidney disease

BACKGROUND; A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD), the most common renal hereditary disease. Endothelin-1 (ET-1) has been suggested to be an important disease-promoting factor of the kidney. Endothelin-converting enzyme-1 (ECE-1) is the main protease responsible for ET-1 generation by cleavage of its functionally inactive precursor. We examined the influence of the ECE-1b C-338A polymorphism on the progression of ADPKD toward end-stage renal disease (ESRD). The A allele was suggested to be associated with higher plasma level of ET-1.

METHODS

200 ADPKD patients (107 males, 93 females) who had reached ESRD were analyzed. Patients were divided into three groups: (1) 47 patients (23 males, 24 females) with ESRD later than in 63 yr (slow progressors); (2) 71 patients (38 males, 33 females) with ESRD before 45 yr (rapid progressors); and (3) 82 patients (46 males, 36 females) with ESRD between 45-63 yr. Moreover, we analyzed 160 genetically unrelated healthy Czech subjects as the control group (82 males, 78 females, mean age 51.4 +/- 8.2 yr). DNA samples from collected blood were genotyped for ECE-1b C-338A polymorphism using described polymerase chain reaction (PCR) followed by restriction enzyme digestion. We compared the frequencies of different genotypes between the groups of slow and rapid progressors and the ages of ESRD with regard to different genotypes.

RESULTS

The ECE-1b C-338A genotype distribution showed no differences among the groups of slow progressors, rapid progressors, ADPKD group with ESRD between 45-63 yr and control group. Comparing the ages of ESRD of all patients, we did not find significant differences in the ages with regard to different genotypes: CC (51.5 +/- 10.1 yr), AC (51.6 +/- 11.4 yr), AA (48.2 +/- 5.9 yr). There was a tendency to lower age of ESRD in AA homozygotes in comparison with other genotypes (t-test, p = 0.12). We found no influence of gender.

CONCLUSION

We excluded the effect of ECE-1b C-338A polymorphism on the progression of ADPKD. We could observe a mild tendency toward faster decline of renal function in AA homozygous individuals.

[Urinary tract infection in patients with diabetes mellitus]

Urinary tract infection is an important infection in patients with diabetes mellitus. Asymptomatic and symptomatic infections of urinary tract, and also some rarer serious complications of urinary tract infections (papillary necrosis, renal and perirenal abscess, emphysematous and xantogranulomatous pyelonephritis and s.o.). Incidence, outcome and treatment in patients with diabetes, which deserve special clinical attention, are commonly viewed by prism of personal opinion, and should be based on clinical studies, focused on this topic.

Genetic basis of nephrotic syndrome--review

Nephrotic syndrome (NS) is one of the most frequent syndromes characterized namely by heavy proteinuria. Majority of NS occurs as a sporadic form, the incidence of familial cases is from 3 to 5%. Seven genes have been recognized till present, which mutations are responsible for severe forms of NS: NPHS1, NPHS2, ACTN4, CD2AP and WT1, TRPC6, LAMB2. Proteins encoded by these genes (nephrin, podocin, alpha-actinin-4, an adapter protein anchoring CD2 and others) influence the function of the podocytes. In cases of mutation in NPHS1 gene, causing congenital nephrotic syndrome of the Finnish type (CNF), resistance to steroid therapy occurs regularly and recurrence of proteinuria after renal transplantation is about 20-25%. Mutations in NPHS2 gene lead to autosomal recessive steroid resistant nephrotic syndrome (histologically focal segmental glomerulosclerosis). It was concluded that patients with steroid resistant nephrotic syndrome (SRNS) with homozygous or compound heterozygous mutations in NPHS2 have reduced risk for recurrence of focal segmental glomerulosclerosis (FSGS) in renal transplant (only 8% in comparison with 35% in patients without mutation in NPHS2). A functional polymorphism of NPHS2 gene--R229Q was associated with a late-onset nephrotic syndrome and also with an increased risk of microalbuminuria in the general population. The R229Q variant encodes a protein with lower affinity for binding nephrin. This polymorphism appears to enhance susceptibility to FSGS in association with a second mutant NPHS2 allele. There are also 3 genetic loci connected with autosomal dominant forms of FSGS: ACTN4, TRPC6 and CD2AP (found only in the mice models). These forms of FSGS differ from the recessive form by later-onset and more slowly progressive course of the disease; these mutations seem to be responsible for only a fraction of the autosomal dominant pattern of FSGS.

Long-term outcome of patients with idiopathic membranous nephropathy

Although idiopathic membranous nephropathy (iMN) is a common glomerular disease, its therapy still remains controversial. The aim of our study was to analyse the outcome of patients with iMN diagnosed and treated in our center. We retrospectively studied 82 patients with iMN that were diagnosed between January 1991 and June 2002. The group consisted of 57 males (69.5%) and 25 females (30.5%) with a mean age of 53 years. The mean follow-up was 56 +/- 38 months. Remission was achieved in 59.2% of patients treated with chlorambucil, 71.4% treated with cyclophosphamide, 85.7% treated with cyclosporine and in 71.4% of those who were left untreated intentionally. However, the proportion of patients in the different treatment subgroups differed significantly (60% vs. 8.5% vs. 8.5% vs. 23%, respectively). The relapse rate was 31.3%. The second-line treatment was effective in a majority of the patients. At the end of follow-up, almost 70% of the patients were in remission with the parameters of nephrotic syndrome significantly improved and renal function unchanged. The renal survival was 100%. Immunosuppressive therapy is effective in iMN, but spontaneous remissions occur as well. Although relapses are frequent, almost 70% of the patients were in remission at the end of follow-up. The renal survival in our group of iMN patients was very good, probably due to preserved renal function at diagnosis.

The pathogenetic aspects and gene polymorphisms of IgA nephropathy

Immunoglobulin A nephropathy is an immune-complex-mediated glomerulonephritis characterized by diffuse mesangial deposition of immunoglobulin A or IgA--containing immune complexes. Although its most common clinical presentation is macroscopic hematuria provoked by upper respiratory tract infection, this is neither universal nor necessary for the diagnosis. The patients with IgA nephropathy manifest with variable clinical symptoms (e.g., microhematuria with preserved renal function or progressive deterioration of renal functions resulting in end-stage renal disease). The pathogenetic mechanisms include the abnormality of O-glycosylation of the IgA1 molecule, genetic factors, environmental factors and various inflammatory mediators. The source of mesangial IgA deposits is total circulating serum IgA but the response of the mesangium and the mesangial cells to the deposited IgA is critical to the development of IgAN. Without a genetic predisposition to IgAN, IgA deposition can cause no risk for triggering glomerulonephritis. If generic progression risk factors of an unfavourable outcome coincide (e.g. hypertension, severe proteinuria, elevated serum creatinine level), this will increase the likelihood of progressive renal impairment. Further studies are needed to disclose the precise pathogenetic mechanisms involved in primary IgA nephropathy and to facilitate the development of newer therapeutic possibilities.

Optimizing the therapeutic strategies in ANCA-associated vasculitis--single centre experience with international randomized trials

ANCA-associated vasculitides, including Wegener's granulomatosis and microscopic polyangiitis, are systemic autoimmune diseases with poor prognosis in untreated patients, which can be dramatically improved by current therapeutic modalities. The aim of multi-centre randomized trials of the European Vasculitis Study Group is to optimise and standardise treatment of these diseases. From 1995-2001 our department contributed a total of 40 patients to the trials CYCAZAREM (cyclophosphamide versus azathioprine during remission for generalised vasculitis), MEPEX (plasma exchange versus methylprednisolone for severe renal vasculitis) and CYCLOPS (daily oral versus pulse cyclophosphamide during induction phase for generalised vasculitis). In this paper, we report on the preliminary results of long-term follow up of our patients included in international trials. The mean time of follow-up of the patients was 55.7 months with the patient survival rate of 72% and renal survival rate of 65%. Remission was achieved in 82% of patients, out of which 42% suffered a relapse. In generalised forms of vasculitides, treatment with cyclophosphamide is nowadays established as the standard therapy. The aim, however, is to further minimise its toxic effects by choosing the optimal therapeutic strategies. Complete results of all trials have not yet been published; nevertheless, the preliminary available data have already revealed new potential therapeutic approaches.

Ethylene glycol poisoning in the Czech Republic (2000-2002)

BACKGROUND

The objective of the study was to evaluate the severity of kidney damage retrospectively and to analyze prognostic factors following ethylene glycol (EG) poisonings.

METHODS

Data concerning the clinical course of patients with EG poisoning between 2000 and 2002 were analyzed. The chi2 test, Student's t test, Fisher's test and the calculation of linear correlation coefficients were used for statistical analysis.

RESULTS

Thirty-three discharge records were obtained. Three patients died, and 11 patients developed acute renal failure (mean maximum serum creatinine level 618 micromol/l). Upon discharge, serum creatinine levels were still elevated in 10 patients. In all but 1 patient, renal function completely normalized within 20 months after intoxication.

CONCLUSION

Adult men are the most endangered segment of the population. The most important prognostic factors are the ingested dose and early antidotal treatment. EG toxic kidney damage is reversible.

Does electron microscopy change the view of the diagnosis of IgA nephropathy?

Our study is aimed to reveal the frequency and clinical significance of the coincidence of two widely spread entities, e.g. minimal change disease (MCD) and IgA nephropathy (IgAN), claimed to be found in an overwhelming number in some Asian regions. We retrospectively analyzed clinical and histological data from 627 renal biopsies, performed in our department from January 2002 to January 2005 and completed electron microscopy in 112 specimens diagnosed as IgAN. The coincidence of IgAN and MCD was found in 8 patients (7.1%). The coincidence of IgAN and minimal change nephrotic syndrome (MCNS) clinically--especially presence of nephrotic syndrome and the response to drug therapy (with corticosteroids)--behaves as "pure" MCN. Our data from Czech Republic seem to suggest that the combination of IgAN with MCNS can be found relatively frequently not only in Asian patients (as stressed by some authors of Asian origin) but also in European inhabitants. The pathogenesis of the coincidence of IgAN and MCD needs to be elucidated by further studies.

Role of endothelin and nitric oxide in the pathogenesis of arterial hypertension in autosomal dominant polycystic kidney disease

The pathogenesis of arterial hypertension in autosomal dominant polycystic kidney disease (ADPKD) is complex and likely dependent on interaction of hemodynamic, endocrine and neurogenic factors. We decided to evaluate the role of endothelin (ET1) and nitric oxide (NO) in the regulation of arterial blood pressure (BP) and to determine plasma levels of ET1 and NO in the group of patients with ADPKD. The ADPKD group (18 patients, 6 men + 12 women, mean age 44.6+/-11.7 years, with creatinine clearancecorrig > 1.1 ml/s) was compared with a control group of 27 healthy volunteers of comparable age. Plasma levels of ET1 assessed by direct RIA determination in the group of ADPKD patients (11.03+/-1.8 fmol/ml) were significantly increased (p<0.001) in comparison with the control group (2.66+/-0.58 fmol/ml), while no significant differences were observed between normotensive and hypertensive patients in the ADPKD group. Serum levels of NO were evaluated according to the determination of serum levels of their metabolites - nitrites/nitrates. Serum levels of NO in the group of ADPKD patients (39.85+/-.38 micro mol/l) were significantly higher (p<0.05) in comparison with the control group (22.7+/-1.20 micro mol/l), whereas in the ADPKD group no significant differences were observed between normotensive and hypertensive patients. Thus, our study supports the concept of complex alteration of both vasoconstrictor and vasodilator systems in the pathogenesis of arterial hypertension in ADPKD.

[An unusual cause of acute anuric renal failure]

We present a case of a 79-years old woman with acute anuric renal failure due to biopsy confirmed immunotactoid glomerulonephritis. Despite biclonal gammopathy IgG lambda, no hematologic or any other underlying malignancy was found. A possible association with viral hepatitis, cryoglobulinemia or autoimmune disease was also excluded. The patient was treated with pulse i.v. dexamethasone with very good results. Diuresis resumed and renal function gradually normalized. Our patient is one of the oldest patients with immunotactoid glomerulonephritis described. The presentation by acute renal failure with an improvement of renal function after therapy has not been previously published.

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.

Daily oral versus pulse intravenous cyclophosphamide in the therapy of ANCA-associated vasculitis--preliminary single center experience

The aim of the multicentric randomized trial CYCLOPS is to optimize the treatment of induction of remission in patients with generalized, but not immediately life-threatening ANCA (antineutrophil cytoplasmic antibodies) -associated vasculitis. This will be achieved by reducing the dose of cyclophosphamide by administering it as intermittent pulses. The lower cumulative dose will be very probably accompanied with lower toxicity, whereas the effectivity should be comparable. We have enrolled 28 patients to the study. At present, 18 of them are suitable for evaluation. Our preliminary results show that pulse intermittent administration of cyclophosphamide is safer from the point of morbidity and mortality due to infectious complications. In our hands, this treatment modality does not seem to be less effective than the conventional daily oral cyclophosphamide. However, unambiguous results and treatment recommendations will not be available until the final evaluation of all patients enrolled in the trial.

Focal segmental glomerulosclerosis in solitary kidney in WAGR syndrome

WAGR syndrome consists of Wilms' tumour, aniridia, genitourinary malformations and mental retardation, and is associated with chromosomal microdeletion of 11p13. We report a case of young male, exhibiting several typical features of WAGR syndrome (e.g. WT, aniridia and genitourinary abnormalities), but missing some other (mental retardation and chromosomal abnormality absent). Renal biopsy performed in our patient for unexplained proteinuria showed focal segmental glomerulosclerosis, presumably of secondary origin; the decrease of proteinuria was achieved by the firm control of BP in conjunction with the reduction of body weight.

ANCA-associated renal vasculitis--epidemiology, diagnostics and treatment

The pauciimmune small-vessel vasculitides are multisystem diseases with frequent renal involvement. They are strongly associated with the presence of anti-neutrophil cytoplasmic antibodies (ANCA). In this review we have focused on the ethiopathogenesis and the role of ANCA, clinical presentation and histopathologic findings of different ANCA - associated vasculitides (AAV). Current treatment strategies and the overall and renal outcome of patients with AAV are also discussed.

Influence of the alpha-adducin and ACE gene polymorphism on the progression of autosomal-dominant polycystic kidney disease

BACKGROUND

A significant phenotypical variability is observed in autosomal dominant polycystic kidney disease (ADPKD). The variability can not be fully explained by the genetic heterogeneity of the disease. We examined the influence of the ACE I/D polymorphism, adducin Trp460Gly polymorphism and the association of both polymorphisms on the progression of ADPKD towards end-stage renal failure (ESRF).

METHODS

320 ADPKD patients (pts) were analyzed, 220 pts (113 males, 107 females) with ESRF before 63 years of age, with a subgroup (rapid progressors) of 20 pts (12 males, 8 females) with ESRF before 40 years of age, 52 pts (23 males, 29 females) with ESRF later than 63 years of age (slow progressors), 48 ADPKD pts (18 males, 30 females) with mean age +/-50 years with serum creatinine <110 micromol/l (slow progressors) and 200 genetically unrelated healthy Czech subjects. DNA samples from collected blood were genotyped for the ACE I/D polymorphism and the Trp460Gly of alpha-adducin gene polymorphism.

RESULTS

The alpha-adducin genotypes showed no differences among the groups of slow progressors (74% Gly/Gly, 22.9% Gly/Trp and 3.1% Trp/Trp), pts with ESRF before 63 years of age (67.7% Gly/Gly, 30.5% Gly/Trp and 1.8% Trp/Trp) and rapid progressors (75% Gly/Gly, 25% Gly/Trp). The ACE genotypes did not differ among the groups of slow progressors (27.1% I/I, 44.8% I/D and 28.1% D/D), pts with ESRF before 63 years of age (23.6% I/I, 51.4% I/D and 25% D/D) and rapid progressors (20% I/I, 55% I/D and 25% D/D). The distribution did not differ from the control group. The ages of ESRF according to different genotypes did not significantly differ. We observed a significant tendency to better prognosis in Trp allele carriers for I/I genotype in comparison with Gly/Gly homozygous subjects.

CONCLUSION

The ACE and alpha-adducin polymorphisms do not play a significant role in the progression of ADPKD to ESRF.

[Is the current treatment of primary and secondary amyloidosis effective?]

BACKGROUND

Retrospective study about results of treatment of patients (pts) with primary (AL) and secondary (AA) amyloidosis is given. 31 pts with systemic forms of amyloidosis have been treated and followed-up in our department since 1993.

METHODS AND RESULTS

6 men and 11 women were in the AL group with the mean age of 59 years. Multiple myeloma was diagnosed in 9 pts, monoclonal gammapathy of undetermined significance (MGUS) was found in 8 pts. The kidneys were affected in all pts, heart in 59% of pts, liver, joints and skin in 26% of pts and polyneuropathy was detected only in 1 pt. Progression of renal insufficiency with decrease of glomerular filtration rate (GFR) was detected in the AL group at the end of follow-up period compared with the initial level (p < 0.05) despite the intensive treatment. The difference did not reach statistical significance in other investigated parameters. Median of survival was 13 months from the assessment of diagnosis. Partial remission of amyloidosis was achieved in 9 pts, stable disease was in 5 pts and in 3 pts the disease progressed. 4 men and 10 women were in the AA group with mean age of 58 years. Underlying disease was rheumatoid arthritis in 7 pts, ankylosing spondylitis in 2 pts, juvenile chronic arthritis in 1 pt, Crohn's disease in 2 pts, eosinophilic fasciitis in 1 pt and chronic abscesses in NK cell deficiency in 1 pt. The kidneys were affected in all pts, bowels and heart in 36% of pts. GFR (p < 0.05) and plasma creatinine (p < 0.01) significantly decreased at the end of follow-up period compared with initial levels. Median of survival was 30 months. Partial remission was achieved in 2 pts, stable disease was in 3 pts and progression was detected in 9 pts despite the use of various treatment regimens.

CONCLUSIONS

Both forms of systemic amyloidosis represent severe disease with limited response to treatment. The use of new drugs is promising and could lead to better response to treatment.

Current treatment strategies in ANCA-positive renal vasculitis-lessons from European randomized trials

Antineutrophil cytoplasmic antibody (ANCA)-positive renal vasculitis is the most common cause of rapidly progressive (crescentic) glomerulonephritis. Its life-threatening natural course may be modified substantially by current treatment modalities. The European Vasculitis Study Group (EUVAS) developed a subclassification of ANCA-positive vasculitides based on the disease severity at presentation, and have organized (so far) two waves of clinical trials. The first wave of randomized clinical trials had the aim of optimizing the existing therapeutic regimens; the second wave concentrated on testing some newer therapeutic approaches. Here, the design and available results of the first wave and the design of some second wave trials are reviewed briefly. The potential of the new targeted approaches (e.g. anti-tumour necrosis factor therapy) is also briefly mentioned.

Genetics of diabetic nephropathy

Diabetic nephropathy (DN) develops in approximately 40% of type 1 diabetic patients and is a leading cause of end-stage renal failure. Its rate of progression varies greatly among individuals. Several factors, including genetic predisposition, metabolic and haemodynamic alterations and various growth factors, may contribute to the initiation and progression of DN. The genetic background of DN is believed to be polygenic. Polymorphisms of different genes, mainly from the renin-angiotensin system, have been studied extensively, and some of them have been suggested to contribute to the development of DN. A search for genes and combinations of genes which could influence the development and progression of DN is in progress.

Current therapeutic possibilities in primary and secondary amyloidosis and our experience with 31 patients

Primary (AL) and secondary (AA) amyloidosis are systemic diseases characterized by a process of amyloid deposition in many organs with unsatisfactory survival of patients. Apart from surgical intervention in those patients with bronchiectasias or osteomyelitis, the possibilities of influencing the development of AA amyloidosis are limited. The milestone therapy in patients with rheumatic diseases includes early treatment with DMARDs (disease-modifying antirheumatic drugs). A new promising therapeutic alternative is represented by anti-tumour necrosis factor-alpha (TNF-alpha) drugs such as infliximab and etanercept. The last class of agents used in the treatment of AA interferes with fibril formation: iododoxorubicin and low molecular weight sulfates (fibrilex). In the group of patients with AL, in addition to the standard combination of melphalan and prednisone, other therapeutic approaches such as ASCT (autologous stem cell transplantation) and new drugs with different mechanisms of action have been added recently. For the future, we can expect the development of immunotherapy (both active vaccination and passive immunization). In our department, we have treated 17 patients with AL and 14 patients with AA amyloidosis since 1995. We used various treatment regimens in both groups of patients. The treatment stabilized the disease or achieved partial remission in only 36% of patients with AA amyloidosis despite the use of intensive therapeutic modalities, while in the AL group a response was achieved in 82% of patients. ASCT improves patients survival in AL amyloidosis, but strict selection criteria are necessary (less than two affected organs and no signs of myocardial dysfunction).

[Molecular genetic diagnosis of autosomal dominant polycystic kidney disease]

Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary disease of kidney. The renal function is impaired by the development of the cysts. Patients with ADPKD have often affected other organs. Nowadays there is established linkage analysis of ADPKD using microsatellites in Czech Republic. Molecular analysis allows presymptomatic diagnosis in risk-individuals and prenatal diagnosis in affected families. The detection of mutations is performed supporting by the grant in Czech Republic. The detection of mutation will contribute to more precise diagnosis in controversial cases.

[Renal infiltration in lymphoma--diagnosis in renal biopsy (case report)]

A case story of a patient with renal biopsy (RB) proven infiltration with lymphoma is given. RB in patient with known malignancy and onset of renal failure was indicated with regard to an atypical picture of kidney involvement (non-enlarged kidneys, without any structural changes typical for tumour mass presence). Though spread of the primary tumour to the kidney is not uncommon, involvement severe enough to impair renal function is unusual and occurs primarily with rapidly growing haematologic malignancies; diagnosis is being established by renal biopsy only rarely.

[Bartter syndrome or renal tubular acidosis?]

In normotensive patients (pts) with apparently inherited electrolyte disorder characterized by hypokalemia and with metabolic alkalosis the suspicion is usually pronounced on the diagnosis of Bartter syndrome or Gitelman syndrome. During the last two years three pts were admitted to our nephrologic unit of the 1st Internal Department of the 1st Medical School who presented with hypokalemia, metabolic alkalosis and alkalic urine and were followed previously under working diagnosis of (incomplete) renal tubular acidosis. In the article we give the description of the clinical picture in the three pts diagnosed as Bartter/Gitelman syndrome. In conclusion--the problems of differential diagnosis in pts with such a complex disorder of acidobase balance are discussed and new diagnostic approach with mutational studies is suggested.

[Fibrillary glomerulonephritis]

An overview of fibrillary glomerulonephritis (GN) is given as well as the description of clinical course in four patients diagnosed and treated in our department. Fibrillary GN and immunotactoid glomerulopathy are entities, characterized by fibrillar and microtubular deposits in mesangium and the glomerular capillary loops. Decisive for diagnosis of fibrillary GN (resp. immunotactoid GN) remains the electron microscopy (EM) of the renal biopsy (RB) specimen. At the nephrologic division of 1st Internal Department of 1st Medical School of Charles University four cases of patients with fibrillary GN were diagnosed from the mid seventies (when both entities were newly described) by the end of the year 2001. In all patients the diagnosis was proven by EM. RB was indicated mainly for proteinuria, hematuria and decrease of renal function. On conclusion: though fibrillary GN/immunotactoid GN are relatively rare disorders, they represent entities, which should not be omitted in the differential diagnosis of nephrotic syndrome/renal insufficiency and which deserve further study.

[Leptin in patients wit nephrotic syndrome]

Nephrotic syndrome (NS) remains a serious clinical setting characterized by marked proteinuria, hypoproteinemia and hypercholesterolemia, usually accompanied by the presence of oedemas. It could be presumed, that the newly discovered hormone leptin plays an important role in the complex metabolic processes occurring in patients with NS, in which apart from the changes in the hydratation, and the protein and lipid spectre profile changes, the alteration of the metabolism of glycides elicited by the treatment with corticosteroids (CS) is often observed. The aim of the study was to investigate the plasma levels of leptin and its plasma soluble receptor (sLe-R) before and after the treatment with CS and to evaluate their relationship with albuminemia and/or proteinuria. The study group consisted of 15 men and 15 women (mean age 49 +/- 13.7 years) with newly diagnosed NS, verified by renal biopsy, in which subsequently CS treatment was started. Before the treatment (period 1) and further one month (period 2) and six months (period 3) after the start of the treatment the following parameters were measured: body mass index (BMI), serum levels of creatinine, albumin, cholesterol, triglyceride, cholinesterase, proteinuria/24 hour and plasma levels of leptin and sLe-R. In comparison to the relatively high values of BMI in the period 1 a decrease of BMI towards the physiologic range was observed during the treatment periods. Statistically significant changes were also observed in proteinuria (decrease) and in serum cholesterol and albumin levels of whereas in other biochemical parameters, including plasma leptin and sLe-R levels, statistically significant changes were not found. A trend to negative correlation with borderline statistical significance could be observed between leptin and sLe-R. The results of our relatively unique study on leptin--dealing with long-term follow-up of the patients with NS suggest that regardless prominent metabolic alterations present in NS the plasma levels of leptin and sLe-R remain relatively stable, and that of regulation of leptin in this setting is probably complex and multifactorial.

[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.

Four novel mutations of the PKD2 gene in Czech families with autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a genetically heterogeneous disease caused by mutations in at least three different loci. Mutations in the PKD2 gene are responsible for approximately 15% of the cases of the disease. We have screened 14 Czech families for mutation in the PKD2 gene. Clear evidence against linkage to the PKD1 gene was established by CA-repeat markers in five families. The disease could be linked to both genes according to linkage analysis in nine families but we have chosen these families because of the mild clinical course. An affected member from each family was analyzed by heteroduplex analysis (HA) and single strand conformation polymorphism (SSCP) for all 15 coding regions. Samples exhibiting shifted bands on HA or SSCP gels were sequenced. We detected five mutations (four new, and one which was previously described) and two polymorphisms. The four new mutations include one insertion, one deletion, one substitution (leading to premature translation stop), one amino acid substitution. Our results confirm that different point or small changes distributed throughout the PKD2 gene without clustering are responsible for the disease.

[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.

[Optimal therapy with erythropoietin (EPO) in patients with renal anemia on hemodialysis therapy]

Treatment of anaemia of renal origin by recombinant erythropoietin (EPO) is well established and is considered to be an integral part of therapy in patients with chronic renal failure. An open, non-controlled and multicenter study was designed with aim to verify the dosage of EPO, necessary to reach and maintain rational correction of renal anaemia in a representative group of patients in chronic haemodialysis (HD) treatment. Target range of haemoglobin (Hb) was defined to be 100-120 g/l in adult patient, length of maintenance phase of follow-up 6 months. 183 patients from z 8 HD centres were included to the study, in this number 83 (45.4%) men and 100 (54.6%) women, aged 59.8 +/- 14.4 years (min. 20 and max. 87 years). During the next 6 months haemoglobin levels raised from baseline value Hb0 100 g/l to Hb1 102.9, resp. Hb2-104.9, Hb3 106.1, Hb4 107.5, Hb5 108.2 and Hb6 108.1 g/l; while mean total weekly doses of EPO/kg (TWD/kg) in the respective period corresponded to TWD/kg0 62 IU, resp. TWD/kg1 66 IU, TWD/kg2 67 IU, TWD/kg3 62 IU, TWD/kg4 64 IU, TWD/kg5 60 IU, TWD/kg6 56 IU. Clinical complications (inflammatory state, bleeding...) that could in different extent reduce the effectivity of EPO treatment were observed in 50 cases. No serious clinical complications that could be attributed to EPO treatment were found. On basis of results of our study, it is justified to assume that target range of Hb between 100-120 g/l can be reached with relatively modest increase of EPO dosage in comparison to current praxis in HD centres in CR, and that following cautious dosing of EPO (comparable to the dosing schema in our study) the treatment should not be connected with the development of major clinical complications.

[Kidney involvement in light-chain deposition disease]

An overview concerning different types of kidney involvement associated with monoclonal gammapathy (MG) is given, focused on light-chain deposition disease (LCDD). Pathophysiologic basis of LCDD remains in the light-chain tissue deposition (resp. in tissue deposition of immunoglobulin's stable domain). This mechanism is typical for monoclonal immunoglobulin's overproduction as found in MG. Clinical picture of LCDD reflects multiorgan character of disorder, while renal lesions rank among the most frequent, serious and best documented ones. Clinical data referring to a group of six patients, treated in our nephrologic department are presented. Diagnosis of LCDD was established on basis of the renal biopsy finding. Renal functions were decreased at the time of diagnosis in all patients, whereas haemodialysis treatment was started in one patient. On conclusion therapeutic possibilities of LCDD are discussed, in which number symptomatic therapy of renal failure is combined with corticosteroids therapy and cytostatic therapy; prognosis of most patients remains serious.

[Multiple extrarenal complications in Wegener granulomatosis]

This is a case report of a patient with Wegener's granulomatosis (WG), who initially presented with a corneal perforation. In addition to the eye involvement, the pauciimmune necrotizing glomerulonephritis with crescent formation, E.N.T. and pulmonary involvement were diagnosed. The patient also suffered from the acute myocardial infarction, most likely due to coronal arteritis. In addition to the coronal ischaemia she also had vasculitis of the aortic valve due to the WG. Another rare complication was the massive intestinal bleeding. The patient had also a skin vasculitis and non-specific symptoms such as artralgias and fever. The correct diagnosis was supported by positive cANCA. A clinical and laboratory remission of the disease was achieved by combined immunosuppressive therapy. Subsequently, she developed a subglotic stenosis possibly due to reparative changes.

[Effect of angiotensin-converting enzyme insertion-deletion polymorphism on progression of renal and cardiovascular diseases]

Many controversial studies concerning relation between angiotensin converting enzyme polymorphism and renal and cardiovascular disease have been published during the last years. Most of the papers have suggested that the DD genotype plays an important negative role in the progression of some renal diseases (e.g. IgA nephropathy, diabetic nepropathy). The D allele may be an independent risk factor for development of the target organ damage in essential hypertension. The therapeutic response on inhibitors of angiotensin converting enzyme depends on insertion-deletion polymorphism. It probably also depends on the gender. The pathological mechanisms of insertion-deletion polymorphism have not yet been clearly identified.

[Perspectives in gene therapy of polycystic kidney disease]

An overview concerning principles and development of gene therapy from experimental models to first trials of application gene therapy in clinical medicine is provided. Increased attention is focused on specific methods of gene transfer into kidneys. Renal hereditary diseases represent an important subgroup of the diseases of the kidney, leading non rarely to chronic renal failure; (autosomal dominant) polycystic kidney disease remains to be one of the most frequent and clinically important. Preliminary conditions, including technical tools and pathophysiological insights to be fulfilled, as prerequisites for an application of gene therapy in polycystic kidney disease, are discussed.

Determination of copper, selenium and zinc in human blood by inductively coupled mass spectrometry: the sources of uncertainty and variability of results

The concentration of Cu, Se and Zn in whole human blood and plasma was analysed by inductively coupled plasma mass spectrometry. Method involved dilution of sample by diluted nitric acid and Triton X-100 and measurement of 65Cu, 77Se and 66Zn intensities. Calibration solutions were spiked by main interferents. In order to evaluate suitability of the method for recognition of alternation of trace elements concentration, the uncertainty of results was estimated. The major part of uncertainty was due to repeatability, the other source (calibration and interferences) were found to be of lesser importance. The resulting uncertainty of concentration of mentioned trace elements is low as compared to between individual variability. Short-term (within day) and long-term (between day) variability of trace elements concentration was investigated and compared with between individual variability too. The time variability was negligible except for Zn concentration. The alternations of trace elements concentration in patients with several renal diseases were investigated. Only in case of patients in end-stage renal disease: hemodialyzed patients and patient treated by continuous ambulatory peritoneal dialysis the significant alternations were proved.

[Disorders of urinary acidification in patients with monoclonal gammapathies]

BACKGROUND

In patients with monoclonal gammapathy (MG), renal impairment becomes the frequent complication. At the same time, its exact pathogenetic mechanism remains to be identified. We tried to detect urinary acidification defect that may become the first sign of the kidney parenchymal injury. The goal of our work was to estimate the incidence of the acidification impairment, the contribution of proximal and distal types of renal tubular acidosis and the dependency of the defect on the type of light chain paraprotein.

METHODS AND RESULTS

In the group of 21 patients aged 38 to 82 years (14 females and 7 males) with monoclonal gammapathy accompanied with creatinemia lower than 180 micromol/l, the short acidification test was performed (calcium chloride was administrated and the urinary acidity was monitored). Renal tubular acidosis was diagnosed in those patients whose urinary acidity after the CaCl2 administration did not reach pH 5.25 or less. The control group consisted of 19 volunteers (6 males and 13 females) with normal renal functions. Results of the tests in MG patients and in control persons were compared using the unpaired Student's t-test. In 11 patients (52.4%) the urinary acidification defect of the incomplete type was detected. Eight of these patients (38.1%) had the distal and three (14.3%) had the proximal type of impairment. Eight patients with the acidification defect had the paraproteinuria kappa and four of them had that of lambda type. In persons without the acidification impairment kappa chains were found in 5 persons, lambda chains in 4 of them.

CONCLUSIONS

In our group of MG patients acidification defect occurred in more than half of them. Contrary to the assumed higher nephrotoxicity of the lambda chains, the disturbance was more frequently found in patients with paraproteinemia of the kappa type.

Long term treatment of IgA nephropathy with cyclosporine A

20-50% of patients with IgA nephropathy (IgAN) reach end-stage renal failure. Yet a standard treatment for those with progressive course and/or great proteinuria is lacking. We treated 6 patients with biopsy proven IgAN, proteinuria over 3.5 g/24 h and S-creatinine less than 200 micromol/L non-responding to corticosteroids administered for 3 months. They were given cyclosporine A (CsA) 5 mg/kg bw/day then titrated aiming at a serum concentration of 70-150 ng/mL for one year tapered to discontinuation in 9 months. Prednisone 5-10 mg on alternate days was given with CsA. Proteinuria (g/day) decreased from 4.66 +/- 0.43 to 1.38 +/- 0.29 (p < 0.01) after 1 month and to 0.59 +/- 0.14 (p < 0.001) after 1 year of treatment and remained lower than baseline 2 years from the beginning (1.44 +/- 0.27, p < 0.001). GFR (creatinine clearance) did not change during the first month (1.25 +/- 0.21 mL/s vs 1.38 +/- 0.29 mL/s), but decreased after 1 year (1.05 +/- 0.14 mL/s, p < 0.05). After two years it increased to 1.17 +/- 0.16, NS from baseline. We also calculated the ratio of proteinuria to the GFR (mg/L) to assess the role of hemodynamic changes in the decrease of proteinuria. This ratio was 53.80 + 6.47 before therapy, it decreased after 1 month (11.56 +/- 1.7, p < 0.05) and further after 1 year (6.78 + 1.45, p < 0.01). Three months after discontinuation it was still 14.32 +/- 1.00, p < 0.05 from baseline. In conclusion, CsA significantly lowered moderate to high proteinuria in 6 patients with IgAN. Significant decrease of the proteinuria/GFR ratio suggests some non-hemodynamic mechanism of CsA action. The therapy was well tolerated and side-effects were not so severe as to require CsA withdrawal.