Erythropoiesis-stimulating agent withdrawal and oxidative stress in hemodialysis.

AIMS: Variation of the action of erythropoiesis-stimulating agent (ESA) may modify oxidative stress in hemodialyzed (HD) patients. Our aim was to follow changes of oxidative stress during withdrawal and subsequent resumption of ESA therapy. PATIENTS AND METHODS: After a 14-day suspension of epoietin-beta treatment, 11 HD patients received epoietin-beta and 10 patients darbepoietin-alpha. The whole blood oxidized and reduced glutathione (GSSG, GSH) and erythrocyte malondialdehyde (E-MDA) concentrations and the erythrocyte superoxide dismutase (E-SOD) and catalase (E-CAT) activities were determined before the ESA-free interval (baseline) and at Weeks 2, 6, 10 and 14. RESULTS: In both groups, the ratios GSSG/ GSH were increased at Weeks 2 and 6 (p < 0.001). The E-MDA levels were elevated (p < 0.01) and the E-SOD activities were decreased (p < 0.001) at Week 6. By Week 14, these markers had returned to the baseline, whereas the GSH (p < 0.001) and E-CAT activity levels (p < 0.001) had increased. CONCLUSIONS: An increase in oxidative stress was revealed by the ratio GSSG/GSH directly after the short-term withdrawal of epoietin-b therapy in HD. This new finding may have implications in conditions involving transiently depressed ESA action. For both ESAs, the early phase of readministration was associated with similarly increased oxidative stress, with a subsequent return to the baseline level.

The roles of platelet function, thromboxane, blood lipids and nitric oxide in hypertension of children and adolescents.

The roles of platelet function, plasma lipids and nitric oxide (NO) were studied in adolescent patients with essential hypertension (JEHT group), with chronic renal failure (CRF) associated with hypertension (CRFH group), and CRF patients with normal blood pressure (CRF group), as compared with normal controls (cont. group). Platelet aggregation and the thromboxane B(2)(TxB(2)) level were significantly higher in the JEHT and CRFH groups as compared with the cont. group, whereas they were significantly lower in the CRF group. On the other hand, the platelet cAMP level was significantly lower in the JEHT and CRFH groups than in the cont. group. The plasma NO level was significantly higher only in the JEHT as compared with the cont. group (120 +/- 39 and 89 +/- 21 microM, respectively). The plasma total cholesterol, triglyceride and LDL cholesterol concentrations were normal in the JEHT group, but high in the CRF and CRFH group, the HDL cholesterol level was lower in the CRF and CRFH groups as compared with the cont. and JEHT groups. There was a positive correlation between the platelet aggregation and the TxB(2)level and between the BP and the platelet aggregation. In conclusion, hyperlipidaemia is commonly present in uraemia with haemodialysis, but is not specific for hypertension in children, while an increased platelet function is frequently associated with hypertension. The increased NO level might play a compensatory role in JEHT.

Vitamin E alleviates the oxidative stress of erythropoietin in uremic children on hemodialysis.

The efficacy of combined therapy with recombinant human erythropoietin (rhEPO) and vitamin E versus rhEPO alone in the treatment of anemia was examined in children (n = 10, aged 15.2 +/- 3.2 years) on chronic hemodialysis at the restart of rhEPO therapy after a 4-week interval. The results confirmed that rhEPO induced oxidative stress of the red blood cells as observed during the first rhEPO therapy. Vitamin E (15 mg/kg per day per os) was introduced after 2 weeks of rhEPO monotherapy, when the signs of acute oxidative stress appeared. The level of oxidized glutathione (GSSG) increased from 8.9 +/- 3.1 to 26.7 +/- 5.7 nmol/g hemoglobin (Hb) by that time. After 2 weeks of simultaneous vitamin E treatment, there was a significant difference in GSSG values compared with rhEPO monotherapy (10.1 +/- 3.9 vs. 56.7 +/- 15.8 nmol/g Hb, P < 0.001). A considerable decrease was observed in the previously high ratio of GSSG/reduced glutathione (GSH), an indicator of oxidative stress, and the level of carboxyhemoglobin, indicating hemolysis. A significant increase in Hb and hematocrit (P < 0.01) was achieved within 2 weeks of starting the combined therapy, while similar results occurred only at the 8th and 5th weeks without vitamin E. Antioxidant vitamin E supplementation improved the therapeutic effect of rhEPO in patients with chronic renal failure on hemodialysis.

Childhood membranous nephropathy, circulating antibodies to the 58-kD TIN antigen, and anti-tubular basement membrane nephritis: an 11-year follow-up.

Childhood membranous nephropathy (MNP) with anti-tubular basement membrane (anti-TBM) nephritis is a rare disorder that may have extrarenal manifestations. This article describes a new case to be added to the 10 previously reported. A renal biopsy specimen from a 1-year-old white boy with nephrotic syndrome, microhematuria, and hypertension showed MNP (granular global IgG, IgA and C3, and segmental IgM and C1q) associated with hypercellularity and granular deposits of IgM and C1q in the mesangium, arteriolar IgA, and linear TBM IgG, IgA, and C3. A biopsy at age 4 years showed MNP (IgG and C3) and linear IgG and C3 along the TBM. Six months later, temporary glucosuria suggested a mild tubular dysfunction. Biopsy at age 8 years showed sclerosing MNP (IgG and C3), linear TBM IgG and C3, and chronic active tubulointerstitial nephritis (TIN). Indirect immunofluorescence showed circulating anti-TBM antibodies, and the enzyme-linked immunosorbent assay (ELISA) approach verified strong reactivity with the 58-kd TIN antigen. Despite trials with steroids, chlorambucil, azathioprine, and cyclosporine, end-stage renal disease developed by the age of 9 years. At age 10 years, the patient received a cadaveric kidney transplant. With the patient now aged 12 years, the graft is still functioning well, without any clinical evidence of disease recurrence. Neurological, ocular, and abdominal symptoms, including nonbacterial diarrhea, were observed during the follow-up period. The pathophysiology of these extrarenal symptoms remains unclear. Serotyping and genotyping of HLA antigens (A2, A10, B12, B41, DR5 [1101, 1103-4, 1106 or 1108-1113], DR6 [1303, 1312, or 1413], DRB3 [*0101 and 0201-2 or 0301], DQA1 [*0501 homozygous], and DQB1 [*0301 homozygous]) did not indicate any HLA association similar to those described previously in childhood MNP with anti-TBM nephritis (HLA-B7 in four patients, HLA-DR8 in two patients). The presented case is the fifth in the literature that displays reactivity with the 58-kd TIN antigen, and for which data on HLA antigens are reported.

Synergistic effect of promethazine with gentamycin in frequently recurring pyelonephritis.

The effects of promethazine were studied in children with frequently recurring pyelonephritis which was not associated with urological abnormalities. The results of three methods of treatment were compared: 10 children were given a combination of gentamycin and promethazine for 7 days (Group 1), 11 received gentamycin treatment alone for 10 days (Group 2), and 19 (Group 3) were on long-term oral antibiotic prophylaxis (5.6 +/- 2.1 years) with episodes of intensive treatment of recurrences. In a 3-year follow-up period, the number of pyelonephritis recurrences was significantly lower in Group 1 than in Groups 2 and 3. Six out of 19 children in Group 3 had renal scarring. The authors suggest a synergistic effect between gentamycin and promethazine therapy. Promethazine increases antibiotic sensitivity, which could contribute to the elimination of recurring urinary tract infections.

Long-term follow-up of patients with persistent/recurrent, isolated haematuria: a Hungarian multicentre study.

A retrospective multicentre study of 341 children with persistent/recurrent, isolated haematuria is described. The haematuria was isolated for at least 6 months at the beginning of observation. The duration of follow-up was 2-5 years in 201, 5-10 years in 119, 10-15 years in 19, and over 15 years in 2 cases. Of these patients 47.8% became symptom-free. In 18.4% the haematuria remained isolated; in 13.8% it was combined with proteinuria over 250 mg/day more than 2 years later. The occurrence of associated proteinuria increased progressively with time. It was 8.6% between the 3rd and 5th years, and 37.0% after the 5th year. Renal biopsy was performed because of the symptoms of glomerular disease in 47 cases at an average time of 12 months following the appearance of proteinuria. Proteinuria appeared after a 2-5, 5-10, 10-15 and more than 15 years follow-up period in 16, 23, 6, and 2 patients respectively; 14 of them had Alport's nephropathy. The percentage of more serious azotaemia was 1.7 (creatinine clearance: 10-50 ml/min per 1.73 m2) and 0.3 (creatinine clearance: less than 10 ml/min per 1.73 m2). Mortality was 0.58%. Most of the patients who developed severe azotaemia had persistent microscopic haematuria at the beginning. The prevalence of hypertension was only 1.2%. The time of its appearance was above 5 years in 2 and below 5 years in 2 cases. All these patients had chronic glomerulonephritis. The haematuria was associated with hypercalciuria in 19.9%. In 14.3% of the overall group of patients urolithiasis developed 2-15 years after onset. All of these had hypercalciuria.(ABSTRACT TRUNCATED AT 250 WORDS)

[Long-term follow up of chronic recurrent isolated hematuria]. / A folyamatos, ill. gyakran ismétlödö, izolált haematuria tartós gondozásának tapasztalatai.

A retrospective multicentre study of 341 children with persistent/recurrent, isolated haematuria is described. The haematuria was isolated for at least half a year in the beginning of observation. 47.8% of the patients became symptom-free. In 18.4% the haematuria remained isolated, in 13.8% it was combined with greater than 250 mg/day proteinuria greater than 2 years later. The occurrence of associated proteinuria was 8.6% between the 3rd to fifth years, and 37.0% after the 5th years. 14 cases had Alport's nephropathy. The percentage of more serious azotaemia was 1.7 (Ccreat: 10-50 ml/min/1.73 m2) and 0.3 (Ccreat: less than 10 ml/min/1.73 m2). Mortality was 0.58%, rate of hypertension 1.2%. Most of the patients who developed severe azotaemia, had persistent microscopic haematuria in the beginning. The haematuria was associated with hypercalciuria in 19.9%. In 14.3% of the overall group of patients urolithiasis developed 2-15 years after onset. All of them had hypercalciuria. Our findings suggest that symptoms of isolated haematuria may last for a long-term period and need systematic control. When proteinuria and/or hypertension associates to haematuria a worse prognosis can be expected.

Connective tissue metabolism in children with chronic renal failure.

To assess the characteristics of connective tissue metabolism in chronic renal failure (CRF), urinary excretion of glycosaminoglycan (GAG) fractions and hydroxyproline (HYP) was determined in ten patients with CRF and in ten age-matched healthy children. CRF was found to be associated with elevated free HYP (19.9 +/- 6.1 vs 9.8 +/- 3.6 mumol/day, P less than 0.05) and depressed peptide HYP excretion (33.1 +/- 13.5 vs 225.2 +/- 17.7 mumol/day, P less than 0.01), a low rate of total GAG excretion (7.0 +/- 2.4 vs 16.1 +/- 1.9 mumol uronic acid/day, P less than 0.05) with low chondroitin 4 -sulphate + chondroitin 6 -sulphate (Ch-Ss) (14.0 +/- 9.9 vs 65.0 +/- 22.1%) and a high proportion of non-sulphated or under-sulphated fractions, i.e. hyaluronic acid + chondroitin + heparan sulphate (HA + Ch + HS) (75.3 +/- 11.4 vs 31.5 +/- 5.7%). Urinary 3-methyl-histidine (3-met-HIS) excretion and plasma essential free amino acids did not differ in the two groups. In response to haemodialysis no consistent change occurred in urinary excretion of 3-met-HIS, peptide-bound HYP, total GAG or percentage distribution of individual GAG fractions. After haemodialysis all plasma amino acids decreased significantly, and there was a significant increase in urinary excretion of free HYP (P less than 0.05). We conclude that the alterations in urinary excretion of total and individual GAGs observed in CRF may reflect disturbed connective tissue metabolism which does not appear to be accounted for by protein malnutrition or enhanced protein breakdown and remains uninfluenced by haemodialysis therapy.

Plasma factors influencing PGI2-like activity in patients with IgA nephropathy and Henoch-Schönlein purpura.

Plasma factors influencing vascular PGI2-like activity (PSA) were studied in 45 patients with IgA nephropathy, 18 with Henoch-Schönlein purpura, including 8 children with nephrotic syndrome, and 41 controls. The results were compared with the levels of plasma high-density lipoprotein (HDL), low-density lipoprotein (LDL) and fatty acid components of plasma phospholipids. The plasma of 38 of 45 patients with IgA nephropathy and 14 with Henoch-Schönlein purpura showed a diminished ability or no ability to support PSA. Twenty-three patients with IgA nephropathy and 10 with Henoch-Schönlein purpura exhibited an inhibitory activity against PGI2 production. The plasma HDL level was lower, while the LDL level and the LDL/HDL ratio were significantly higher in IgA nephropathy and Henoch-Schönlein purpura cases than in the controls. A high LDL/HDL ratio was associated with a low plasma PSA. The levels of arachidonic acid and its precursor were not lower in the plasma of patients than in the controls. The decreased PGI2 synthesis may play an important role in the pathogenesis of IgA nephropathy and Henoch-Schönlein purpura, but it can not be explained by reduced PG precursors. LDL may have an inhibitory, and HDL a protective effect on PGI2 synthesis.

Plasma exchange and immunosuppressive therapy in a paediatric patient with systemic lupus erythematosus.

A case is reported of systemic lupus erythematosus (SLE) associated with steroid-resistant nephrotic syndrome. Serial plasma exchanges (PE) combined with prednisolone treatment induced complete normalization of the immunological findings: the anti-DNA antibody, antinuclear antibody, LE cell phenomenon and circulatory immune complexes became negative. The prostacyclin (PGI2) production-supporting activity in the plasma increased to the control range; inhibitors of PGI2 production were eliminated. The creatinine clearance normalized, the urinary protein excretion decreased significantly, and the facial erythema disappeared. Continued treatment with chlorambucil + low-dose prednisolone led to a complete and stable remission of the nephrotic syndrome, and the C3 complement normalized. The low level of PGI2 production-supporting activity in the plasma may be explained by the inhibitor of PGI2 production. PE + immunosuppressive therapy might have beneficial effects on the immunological changes and PGI2 metabolism, and also on the remission of SLE-nephrotic syndrome.