Prevention and treatment of renal osteodystrophy in children on chronic renal failure: European guidelines

Childhood renal osteodystrophy (ROD) is the consequence of disturbances of the calcium-regulating hormones vitamin D and parathyroid hormone (PTH) as well as of the somatotroph hormone axis associated with local modulation of bone and growth cartilage function. The resulting growth retardation and the potentially rapid onset of ROD in children are different from ROD in adults. The biochemical changes of ROD as well as its prevention and treatment affect calcium and phosphorus homeostasis and are directly associated with the development of cardiovascular disease in pediatric renal patients. The aims of the clinical and biochemical surveillance of pediatric patients with CRF or on dialysis are prevention of hyperphosphatemia, avoidance of hypercalcemia and keeping the calcium phosphorus product below 5 mmol(2)/l(2). The PTH levels should be within the normal range in chronic renal failure (CRF) and up to 2-3 times the upper limit of normal levels in dialysed children. Prevention of ROD is expected to result in improved growth and less vascular calcification.

[Results of treatment with recombinant human growth hormone in children with growth retardation in end-stage renal disease]

The aim of the study was to estimate the results of recombinant human growth hormone (rhGH) treatment in children with end-stage renal disease (ESRD). 60 growth retarded children with ESRD (mean age 11.2 +/- 7.2 years) were treated with rhGH at a dose of 1-1.1 IU/kg/week. The time of observation was 24 months. Thirty children completed first year, 18--second year of treatment. The mean growth velocity prior to the treatment was 3.03 +/- 1.9, during first year of the study--7.52 +/- 2.42, during second year 6.68 +/- 2.87 cm/year. The negative correlation between growth velocity and patient's age (r = -0.39; p < 0.05) suggest the better growth results in younger children during rhGH treatment. The rhGH therapy is effective method of treatment in growth retarded children with ESRD. Side effects are rare.

[Efficacy and safety of renal biopsy in children performed with an automatic biopsy device under control of ultrasonographic imaging]

The efficacy and safety of kidney biopsy in children performed with an automatic Biopty Gun device under real time ultrasound was analysed. The procedure was performed under sedation during short hospitalisation with ultrasound assessment of complications performed after 24 hours. 98% of 131 biopsies yielded representative material with an average 16 glomeruli obtained per biopsy. Symptomatic perirenal haematomas were observed in 80%, subcapsular haematomas in 3.8% and arteriovenous fistulas in 4.6% of children on post biopsy ultrasound. They resolved spontaneously in all patients.

CONCLUSIONS

Real time ultrasound guidance with the use of automatic biopsy devices should become the standard practice for kidney biopsy in children due to its efficacy and safety. The procedure should be performed during short hospitalization to enable ultrasound monitoring of early complications.

[Epidemiology of HBV infections and possibilities for therapeutic actions in children and adolescents with end-stage renal failure treated with dialysis]

Wide spreading of prophylaxis principles of HBV infections in dialysis centers decreased the HBV infection rate in general population of dialyzed patients in Poland last years. There is neither data concerned with HBV infection epidemiology in children and adolescents, nor data about anti-viral treatment possibilities and effects in this group of dialyzed patients. The aim of the study was evaluating of HBV infection rate in patients of pediatric dialysis centers and analysis of causes of infection and efficacy of treatment. Study was based on data sent in a query-answer by 8 biggest pediatric dialysis centers, all of them treating 210 patients. HBV infection was found much more often (16.6%) than in population of all hemodialyzed patients in Poland. More than 75% non-vaccinated patients was infected before dialysis therapy, remaining were infected during vaccination, before the protecting level of antibodies was gained. Big differences in HBV infection rate among centers are observed. Nowadays HCV infections (more than 40% patients infected) are a bigger issue. Only 10 patients in 5 centers had anti-viral treatment (5 with isolated HBV infection, 5 with mixed HBV/HCV infection). In 9 patients interferon-alpha and in 1 patient lamivudine was administered. Efficacy of interferon-alpha treatment was similar to the population of non-uremic children (33.3% vs. 50% of HBeAg elimination). Majority of patients quite well tolerated the drug. Only in 1 case interferon-alpha treatment had to be ceased because of side effects. In a boy treated with lamivudine, after 3 months elimination of viremia and decrease of ALAT activity was observed. HBV infection in patients of pediatric dialysis centers is still a serious matter. More strict applying of vaccination against hepatitis B before dialysis treatment is needed. The possibility of HBV infections therapy is limited, mostly for economical reasons.

[Bilateral hydrothorax in a 13-year old girl treated with continuous ambulatory peritoneal dialysis renal replacement therapy]

Bilateral hydrothorax is a very rare complication of ambulatory peritoneal dialysis in children. We present a case of a 13-year-old girl who developed bilateral acute hydrothorax during after seven months of CCPD. Peritoneal dialysis was temporarily discontinued and the child was transferred to haemodialysis. Six weeks later the patient was successfully resumed CCPD.

[Peritonitis in children treated with automated peritoneal dialysis]

The rate of peritonitis, its etiology and efficacy of treatment was compared between 28 children treated with APD for a total of 439 dialysis months and 24 children on CAPD treated for 328 dialysis months. The peritonitis rate was significantly lower in children on APD (1 episode per 27 months) than in children on CAPD (1 episode per 17 months) (p = 0.005). The etiology of peritonitis (68% v. 62% Gram + organisms), efficacy of treatment (100% v. 100%) and relapse rate did not differ between the machine operated and manual methods of peritoneal dialysis.

[Changing clinical course of hemolytic uremic syndrome in children]

An incidence of hemolytic-uraemic syndrome as a cause of the acute renal failure in childhood, its early survival rate and long-term sequela quences were compared in the 1970s, 1980s, and 1990s in the same geographical area. 196 children with HUS were treated between 1972-1999. 94% had a typical D+ HUS. The majority were of patients severely ill with 87% requiring peritoneal dialysis of an average 14 days duration. The children were grouped into three 9-year periods for comparison (1972-1980, 1981-1989, 1990-1999). 105 patients were followed for 2-27 years (mean 1 years). An incidence of HUS as a cause of ARF in childhood ranged from 58% and 50% in the 1970s and 1980s to 30% in the past decade. With time survival rate has improved dramatically over the years from 80% and 75% to 97% in the 1990s. Deo spite better short term outcome the late consequences of HUS are serious. The longer the follow-up, the greater percentage of patients with severe outcome. At last follow-up only 32% children showed full recovery. 33% are on renal replacement therapy or have impaired renal function. The severity of the initial lesions to the kidney measured by the duration of anuria is a marker of poor late prognosis. With improving early outcome the clinical significance of HUS is focusing on its severe long-term consequences.

[Bilateral renal obstruction caused by cystine stones in a child with Henoch-Schönlein syndrome]

Haematuria is a typical symptom of glomerular involvement in Henoch-Schoenlein syndrome in children. The authors present an unusual case of haematuria and deterioration of renal function caused by cystine stones in a child with anaphylactic purpura. This 6 year old girl was hospitalized because of severe gastrointestinal symptoms in the course of a typical Henoch-Schoenlein syndrome. After 4 weeks of illness--the child demonstrated haematuria and oliguria with severe loin pain and a rise in serum creatinine to 5.8 mg%. Urine findings of mainly non-glomerular erythrocytes and slight proteinuria were suggestive of a non-glomerular cause of renal failure. Ultrasound examination revealed the unexpected finding of bilateral kidney obstruction caused by multiple renal stones. Cystine crystals observed under microscopic examination of the urinary sediment and a positive cyanide-nitroprusside test suggested cystinuria as the cause of nephrolithiasis. High water intake and alkalization of urine and captopril for cystine excretion reduction resulted in fast improvement of renal function and and with time complete dissolution of calculi. The symptoms of Henoch-Schoenlein syndrome resolved over several weeks, and the child did not develop any signs of glomerular involvement.

[Ultrasound of exit-site and tunnel infections in children on peritoneal dialysis]

Ultrasound diagnosis of catheter related infections in patients on peritoneal dialysis is easy to perform diagnostic procedure which enables more precise diagnosis and better follow-up of therapy. The authors present three cases of exit site and tunnel infections in children, illustrating the value of ultrasound evaluation in their diagnosis and in decisions on conservative treatment or catheter removal.

[Hypertension in children with chronic renal failure]

Hypertension is one of the main risk factors of mortality for children on renal replacement therapy. It has also been recognised as one of the major risk factors for progression of renal failure. The aim of the study was to define the prevalence of hypertension in children with chronic renal failure, treated in a single centre, and to assess the efficacy of its diagnosis and management. Hypertension was present in 27% of 40 children before the onset of chronic renal failure, increasing to 57% with the development of CRF, and reaching 86% at onset of dialysis. Reflux nephropathy, hemolytic-uraemic syndrome and glomerular disease were most frequently associated with severe hypertension. ACE inhibitors (70%), diuretics (52%), and calcium channel blockers were the most frequently used antihypertensives with 49% of the children being on monotherapy. Despite therapy 43% of children had elevated blood pressure levels and 16% had echocardiographic signs of LVH. A 24 hour ambulatory blood pressure measurements were more sensitive in diagnosing hypertension and assessing adequacy of blood pressure control. Early and intensified treatment should prevent end organ damage though optimal blood pressure values to aim obtain are still to be defined.

[Bone metabolism markers and bone histomorphometry in children with chronic renal failure in predialysis period during growth hormone treatment]

The aim of the study was to estimate biochemical bone metabolism markers and bone histomorphometric parameters in children with chronic renal failure (CRF) treated with recombinant human growth hormone (rhGH). Twelve children with CRF aged 2-13.4 years were treated with rhGH 1-1.1 IU/kg per week and alfacalcidol. Bone biopsies were performed before and after 12 months of therapy. An increase in the biochemical markers of bone formation and bone resorption were noted. A statistically significant increase in mineral apposition rate (MAR) was observed in bone histomorphometry. The administration of active vitamin D metabolites enable proper bone mineralization in fast growing children with CRF during rhGH treatment.

HLA-DRB and -DQB1 alleles in Polish patients with hepatitis B associated membranous nephropathy

We have studied the HLA-DRB and -DQB1 alleles of 42 paediatric patients who have suffered from membranous nephropathy associated with a hepatitis B infection (HBVMN). These patients were all from the Gdansk area of Northern Poland and the disease was diagnosed by light and electron microscopy. The control population consisted of 55 healthy children, approximately age matched, from schools in Gdansk. In addition we have also analysed 40 patients chronically infected with hepatitis B, without any renal involvement, as hepatitis B disease controls. The HLA alleles were defined using PCR/SSP. As idiopathic membranous nephropathy and low responsiveness to hepatitis B vaccine have been found to be associated with DR3 in Caucasoids, our hypothesis was that the HBVMN patients would show an increase in DR3. Our results indicate that, although there is a small increase in the frequency of DRBl*0301 in the HBVMN patients (16/42 38%) when compared to the healthy controls (15/55 31%), this does not approach significance. There is a significant increase in the frequency of DQB1*0303 in the HBVMN patients vs the healthy controls, after correction for the number of antigens detected (Pc)(13/42 vs 2/55, RR=11.6, P=0.0007, Pc=0.02). A similar increase in DQB1*0303 is seen in the HBVMN patients when compared to the hepatitis controls (13/42 vs 4/40) but this is only significant before correction (RR=4.3, P=0.04).

[Acute renal insufficiency during Candida albicans candidiasis in a 2-month old infant]

In this paper has been described the case of 2-month old infant with acute renal insufficiency caused by mechanical obstacle of fungal bezoars. Bilateral pyelostomy has been performed and fungal masses have been washed out from kidney pelvis. The applied treatment including administration of Fluconazole intravenously caused disappearance of acute renal insufficiency. In this paper authors described pathogenesis, clinical symptoms, and treatment of urinary tract fungal infection.

A specific glomerular lesion of the graft: allograft glomerulopathy

During the period from January 1973 to December 1970, 774 renal transplantations in 698 children have been performed in our Renal Unit. A total of 540 grafts have been examined both by light and immunofluorescence microscopy at least once. Recurrent glomerulonephritis was diagnosed in 62 grafts, de novo glomerulonephritis in 68 and allograft glomerulopathy (AGP) in 38. AGP was defined as a lesion affecting all glomeruli and characterized by widespread reduplication of the GBM with widening of the subendothelial space and interposition of mesangial matrix and without significant deposits by immunofluorescence. The aim of the current study is to describe the natural history of AGP and to delinate its clinical significance. At time of biopsy, an increase in serum creatinine was present in 30 patients associated with a proteinuria > or = 1 g/day in 21. During the post-transplantation course, proteinuria was present in 29 patients and associated with a nephrotic syndrome in 10 of them. With a mean follow-up of eight years seven months, two patients died, 23 lost their grafts and 13 have a functioning graft. The lesions of AGP recurred in three of the nine children who received a second graft. Thirteen of the 33 patients in whom earlier biopsies were performed showed a different pattern of involvement characterized by a prominent swelling of active endothelial and mesangial cells and a hypercellularity related to the presence of mononuclear cells both in the lumens and in the mesangial areas.(ABSTRACT TRUNCATED AT 250 WORDS)

Hepatitis B virus-associated glomerulonephritis: electron microscopic studies in 98 children

Ninety-eight children with glomerulonephritis concomitant with hepatitis B surface HBs antigenemia were studied, the antigenemia being first documented at the clinical onset of glomerulopathy. Initial diagnoses, based on examination of the paraffin sections, varied, membrano-proliferative, mesangial, and membranous glomerulonephritis being most frequently considered. However, electron microscopic examination showed that 77 children had a uniform type of glomerulopathy, irrespective of the light microscopic appearance. This type was diagnosed as secondary membranous glomerulonephritis. The clinical course of this nephropathy was relatively indolent and short. Moreover, in many children, elimination of some hepatitis B virus (HBV) antigens from the circulation was also associated with clinical remission of glomerulopathy. The remaining 21 children with HBs antigenemia had various morphological forms of glomerulonephritis, these being similar to their idiopathic counterparts in both morphology and clinical course. The distinct clinical and morphological picture of secondary membranous glomerulonephritis with HBs antigenemia occurring in 77 of 98 children supports the hypothesis that HBsV-associated glomerulonephritis is of the secondary membranous type. Thus, we conclude that in children HBV antigenemia associated with glomerulonephritis other than secondary membranous is coincidental.

Mesangial proliferative glomerulonephritis in children

Over a ten year period 105 children with a histological diagnosis of a mesangial proliferative glomerulonephritis were diagnosed. Patients were divided into two groups according to their clinical presentation at the time of diagnosis. Ninety two children presented with nephrotic syndrome (NS) of whom 82 received steroid therapy. No response was observed in 26 children and in 56 remissions were short in duration and subsequent relapses were frequent. Eighty nine children with the nephrotic syndrome were treated with cyclophosphamide (CP) of whom 26 had a steroid resistant NS, 53 were steroid dependent and 10 were previously untreated. Eighty four entered remission with a mean duration of 46 months. Only 5 children did not respond to treatment with CP. No correlation could be found between the results of therapy and the degree of morphological changes on examination of renal biopsy. The second group consisted of 13 children presenting with a persistent nephritic syndrome and or proteinuria. These children were untreated and no progression of renal disease was observed after several years follow up.