Outcome of Henoch-Schoenlein nephritis with nephrotic-range proteinuria.

PATIENTS AND METHODS: All children with Henoch-Schoenlein glomerulonephritis (HSP-GN) and nephrotic-range proteinuria (> 40 mg/h/m2), treated at 5 university hospitals and in 1 central hospital in Finland during in 1990-1997, were analyzed retrospectively. The mean age of these 19 patients (8 girls, 11 boys) at the time of diagnosis was 9.9 years (range 4.6-15.1 years). A renal biopsy had been performed in all cases, giving findings according to the classification used in the International Study of Kidney Diseases in Children (ISKDC) of grade II (4 patients), grade III (10), grade IV (4) and grade V (1). Six patients underwent a second biopsy. RESULTS: The yearly incidence of nephrotic-range HSP-GN in Finland was 2 per 1 million children under 15 years of age. After a mean follow-up of 4.6 years (range 9 months-9.1 years), 3 patients (15.7%) had no signs of nephritis, 11 (57.9%) had proteinuria < 1 g/day or microscopic hematuria, 2 (10.5%) had proteinuria > 1 g/day, and 3 (15.7%) had developed ESRD or uremia. 47% of the patients needed medication for proteinuria at the time of the latest follow-up. The first kidney biopsy did not predict the outcome of HSP-GN, since all the patients with the poorest outcome had only ISKDC II-III findings in their first biopsy. CONCLUSION: According to our series, the morbidity in cases of HSP-GN with nephrotic-range proteinuria is high and a close clinical follow-up is needed. The treatment of HSP-GN patients should be based on the clinical presentation rather than on the biopsy findings.

Predictive factors associated with significant urinary tract abnormalities in infants with pyelonephritis.

BACKGROUND: Major urinary tract abnormalities are detected in 20 to 40% of infants with acute pyelonephritis (APN). Early detection of structural defects is essential for protecting the kidneys from reinfection and subsequent scarring. The purpose of this study was to investigate whether any factors present during the acute phase of infection could predict the presence of existing significant urinary tract abnormalities in infants. METHODS: A prospective study of 180 infants, aged 1 to 24 months, with APN was conducted. Blood and urine samples were collected. Renal ultrasound (US) was performed within 0 to 6 days from admission. Final diagnosis of the urinary tract anatomy was elucidated using the results of two or more radiologic imaging studies. RESULTS: Risk factors for the presence of significant urinary tract abnormalities in infants were pathogens other than Escherichia coli in urine [relative risk (RR) 3.4, 95% confidence interval (CI) 2.2 to 5.3; P = 0.001], positive blood culture (RR 2.3, 95% CI 1.3 to 4.0; P = 0.039), young age (1 to 6 months) (RR 2.2, 95% CI 1.3 to 3.9; P = 0.004), lack of papG adhesin genes of E. coli in urine (RR 2.1, 95% CI 1.2 to 3.9; P = 0.016) and abnormal renal US (RR 2.0, 95% CI 1.2 to 3.4; P = 0.008). CONCLUSIONS: Infants 1 to 6 months of age with APN caused by bacteria other than E. coli or by papG-negative E. coli strain, positive blood culture and abnormal renal US carry an increased risk for significant urinary tract abnormalities and need enforced follow-up.

Nephronophthisis and ulcerative colitis in siblings: a new association.

Nephronophthisis (NPH) is a chronic tubulointerstitial nephritis leading to terminal renal insufficiency. The disease is heterogeneous, but usually the inheritance pattern is autosomal recessive. In 80% of cases, the disease is caused by a homozygous deletion in NPHP1 gene in chromosome 2q13. Ulcerative colitis is an inflammatory bowel disease with chronic diarrhea, rectal bleeding and characteristic histological findings. Its etiology is suggested to be multifactorial, consisting of genetic susceptibility and unknown exogenous factors. We present two siblings with NPH and ulcerative colitis. As NPH in this family is not linked to 2q13, this association may represent a new, syndromic form of NPH.

Renal growth in children with severe vesicoureteral reflux: 10-year prospective study of medical and surgical treatment: the International Reflux Study in Children (European branch).

PURPOSE: To determine whether medical or surgical treatment better promotes renal growth in children with severe vesicoureteric reflux (VUR) and to examine factors influencing renal growth. MATERIALS AND METHODS: Three hundred two children younger than 11 years with urinary tract infection and grade III or IV VUR were randomly assigned to surgical (n = 149) or medical (n = 153) treatment and were followed up at serial intravenous urography for up to 5 years; 223, for up to 10 years (surgical, n = 110; medical, n = 113). Renal size was measured planimetrically on serial intravenous urograms and was related to the virtual height of L1 through L3 by expressing it as an SD score. RESULTS: There was no significant difference in mean renal growth between patients treated surgically or those treated medically after 5- or 10-year follow-up. Bilateral renal size of 80 surgical and 75 medical patients remained within 1 SD score. In patients entering the study at 2 years of age or younger and in those with grade IV VUR, bilateral VUR, or renal scars, there was a trend toward improved renal growth in those treated medically, but this finding was not statistically significant. When renal scarring or thin parenchyma was unilateral, the affected kidney grew less well, irrespective of treatment. Bilateral renal scarring was usually asymmetrical, with a corresponding effect on renal growth. CONCLUSION: There was no significant difference in renal growth during 10 years between surgical and medical treatment in patients with severe reflux.

Spectrum of COL4A5 mutations in Finnish Alport syndrome patients.

Alport syndrome (AS) is a hereditary kidney disorder, mainly caused by mutations in the X-chromosomal gene (COL4A5) encoding the type IV collagen a5 chain. In this study, detection of COL4A5 mutations was performed in 17 Finnish Alport syndrome families. Regions around the 51 previously known exons, as well as the two recently characterized exons 41A and 41B in COL4A5, were PCR-amplified from the patient DNA. Direct sequencing of the amplified products was performed and mutations were found in 12 families. None of the mutations involved exons 41A or 41B. Three of the mutations were potential splicing mutations, two of which were studied at the mRNA level. Seven of the mutations were single base substitutions, and two were deletions. In five families, no mutations were found.

Predominance of class II papG allele of Escherichia coli in pyelonephritis in infants with normal urinary tract anatomy.

P-fimbrial genotypes of Escherichia coli strains and their possible association with urinary tract abnormalities were studied in infants with pyelonephritis. A total of 153 urinary E. coli strains were analyzed by polymerase chain reaction for class I, II, and III alleles of the pyelonephritis-associated adhesin gene papG. Strains with any class II papG alleles were found significantly more often in infants with normal anatomy and function or in infants with clinically insignificant abnormalities than they were in infants with significant abnormalities (90 of 119 vs. 14 of 34 infants; P<. 001). On the other hand, strains without any papG alleles were found significantly more often in infants with major urinary tract abnormalities (11 of 34 vs. 17 of 119 infants; P=.016). Our genotypic findings indicate that, especially in infants with a normal urinary tract, infection is caused by more-virulent E. coli than is present in infants without a normal urinary tract. This virulence could be due to expression of pyelonephritogenic P fimbriae by an infecting E. coli strain.

The burden of genetic disease and attitudes towards gene testing in Alport syndrome.

We evaluated the burden of Alport syndrome (AS) and the attitudes towards gene testing in patients with AS and their healthy family members from 37 families using a multiple-choice questionnaire. We also evaluated how the disease affected the decision to have children and the information received about the syndrome. A total of 53 individuals responded to this questionnaire. The risk of renal insufficiency and the uncertainty of the prognosis were considered the worst components of AS. Many of the respondents felt that children should be informed about AS as soon as they start asking (45%), preferably by a parent (74%). Almost all of the respondents (96%) had a positive attitude towards genetic research, which in the opinion of the majority should be aimed at better treatment and diagnosis of the disease rather than developing methods for prenatal diagnosis (89% and 75% versus 43%). AS seems to be well tolerated; 28% and 19% of the respondents found abortion acceptable in cases of an affected male and female fetus, respectively. Our study indicates a desire for prenatal tests in order to predict the health of a future child rather than for selective abortion.

Ocular findings in 34 patients with Alport syndrome: correlation of the findings to mutations in COL4A5 gene.

PURPOSE: To describe the incidence and type of ocular findings of 34 patients with Alport syndrome and to analyze the association of gene defect in COL4A5 gene to ocular abnormalities found. METHODS: A nationwide search of Alport syndrome patients was performed in Finland, and patients were invited to take part in a thorough ophthalmologic investigation. RESULTS: A total of 34 Alport syndrome patients from 14 different pedigrees were examined, and ocular abnormalities were found in 32% of them. The visual acuities were normal except in 4 of the 34 patients. Six individuals had retinal flecks and 4 men had anterior lenticonus. In 57% of the pedigrees the defect in COL4A5 gene was known. CONCLUSION: Ocular abnormalities were rare in childhood and increased with age. There was no correlation between the type of mutation and the type of ocular changes. In addition, the penetrance of the ocular findings varied considerably within most families.

Nephronophthisis in Finland: epidemiology and comparison of genetically classified subgroups.

Nephronophthisis--medullary cystic kidney disease is a progressive chronic tubulointerstitial nephritis leading to terminal renal failure. About two thirds of the patients with familial juvenile nephronophthisis, an autosomal recessive disease, have a homozygous deletion at the gene locus on 2q13. Through a nationwide search, 59 patients were ascertained in Finland. The incidence was 1:61,800 live births when calculated over a 20-year period. Of the patients, 17 came from four families showing dominant inheritance and 37 patients from 28 apparently recessive families when classified by family history, clinical features or presence of a deletion on 2q13. Two were considered as new dominant mutations; three sporadic patients could not be classified. The most significant difference between the patients with deletions, patients without deletions but having recessive family history, and patients belonging to families with dominant inheritance was the age at first symptoms, at the start of dialysis and at transplantation. These facts will be of help in determining the mode of inheritance of a sporadic patient without a deletion.

Growth and weight gain in children with vesicoureteral reflux receiving medical versus surgical treatment: 10-year results of a prospective, randomized study. International Reflux Study in Children (European Branch).

In children with vesicoureteral reflux (VUR) and urinary tract infection, retardation of growth and weight gain at the time of diagnosis and catch-up growth during follow-up, mostly after operating for VUR, have been reported. A controlled trial comparing the effect on growth of surgical treatment and long-term prophylactic antibiotic treatment has not been reported previously. Between 1980 and 1985, 306 children younger than 11 y with non-obstructive grade III or IV VUR, with a history of symptomatic urinary tract infection, were randomly allocated to surgical or medical treatment. Of these, 236 were followed for 10 y, 118 randomized to surgical treatment (mean age at entry 3.5 +/- 2.3 y) and 118 to medical treatment (mean age at entry 3.8 +/- 2.5 y). All children had renal function and blood pressure in the normal range. Body height, measured at start and after 1, 5 and 10 y, was transformed to standard deviation score of height for chronological age (SDSH-CA) and body weight to percentage of ideal body weight for height (%IBW). The evolution of SDSH-CA and %IBW was similar in both treatment groups (SDSH-CA: surgical: start, 0.23 +/- 1.4; 10 y, 0.40 +/- 1.0; medical: start, 0.14 +/- 1.2; 10 y, 0.44 +/- 1.2; %IBW: surgical: start, 99 +/- 9%; 10 y, 107 +/- 14%; medical: start, 98 +/- 10%; 10 y, 105 +/- 16%). While children starting the study below the age of 3 y (SDSH-CA 0.55 +/- 1.34) started significantly taller than those older than 3 y (SDSH-CA -0.1 +/- 1.39), the young ones demonstrated a significant drop in SDSH-CA during the 1st year (SDSH-CA 0.19 +/- 1.23), which was regained up to the 10th year (SDSH-CA 0.6 +/- 1.13), and the older ones steadily gained height up to an SDSH-CA of 0.28 +/- 1.05 at 10 y. During all of the study period, treatment protocol, grade of VUR, renal parenchymal scars at entrance and urinary tract infections did not influence growth and weight gain. Age at entry and gender were the only significant correlates with growth and weight gain.

Molecular studies in Finnish patients with familial juvenile nephronophthisis exclude a founder effect and support a common mutation causing mechanism.

Familial juvenile nephronophthisis (NPH) is an autosomal recessive tubulointerstitial kidney disease associated with formation of medullary and corticomedullary cysts. It progresses to end stage renal failure and its biochemical defect is unknown. An NPH locus has been assigned to a 2 cM interval on chromosome 2q13 by linkage studies. Homozygous deletions of approximately 250 kb have been detected in 80% of familial cases and 65% of sporadic cases and a common mutation mechanism has been suggested. We examined 14 Finnish families for the presence or absence of a deletion. After detecting a deletion in 12 patients belonging to nine families, we studied a possible founder effect by haplotype analysis using markers D2S340, D2S1889, and D2S1893. No common ancestral disease associated haplotype was found suggesting no founder effect. Results of pairwise linkage analyses were suggestive of linkage in the nine families with a deletion (lod scores of 1.39-3.89 at a recombination fraction of 0). Negative lod scores were obtained in the five families without a deletion suggesting that the disease locus in these families lies elsewhere. The end stage renal disease occurred at a more advanced age in patients without a deletion compared to patients with a deletion, indicating a phenotypic difference between these two groups.

Familial juvenile nephronophthisis. An ultrasonographic follow-up of seven patients.

PURPOSE: To evaluate progressive US changes in the kidneys of patients with familial juvenile nephronophthisis (NPH), an autosomal recessive progressive kidney disease with polyuria, polydipsia, anemia and growth retardation. MATERIAL AND METHODS: The data from 29 US investigations of 5 boys and 2 girls comprised findings relating to kidney size, echogenicity of the kidney parenchyma, visualization of the corticomedullary junction, and the parameters of renal cysts. RESULTS: In the early stages of NPH, when the serum creatinine values were between 134 and 370 micromol/l, the corticomedullary differentiation was weak in 6 patients, the echogenicity of the kidney parenchyma was equal to or greater than that of the liver in 5 patients, and 6 patients had developed renal cysts. The findings became more intensive with the progression of NPH. The size of the kidneys remained normal in 4 patients. CONCLUSION: Renal US reveals characteristic changes already in the early stages of NPH and should therefore be an important part of the diagnostics of NPH because no specific diagnostic test is as yet available.

Alport's syndrome in 78 patients: epidemiological and clinical study.

In a nationwide study in Finland, 78 patients, 38 male and 40 female in 25 families, were found to have Alport's syndrome, corresponding to 1 in 53,000 live births. This frequency of clinically manifest Alport's syndrome was much lower than expected from earlier reports. This first sign of the disease was most often haematuria, but was sometimes proteinuria or hearing loss. These signs were detected at a similar median age in both boys and girls, namely 6.2 and 6.0 years, respectively. The patients were followed up over a median period of 12.1 years (range 0.1 - 34.0 years). The clinical course of the disease was more severe in the male subjects than in the female subjects: 53% of the males and 13% of the females developed terminal renal failure at median ages of 24.9 and 31.1 years, respectively. At the last observation, 34% males and 78% females were free of renal insufficiency at median ages of 10.3 and 26.8 years. Hearing loss was detected in 74% of the males and 5% of the females. Regarding the rate of deterioration of renal function, no statistically significant difference was noticed between males and females. The routine use of dialysis and transplantations has dramatically changed the life expectancy of the patients.

Mechanism underlying early anaemia in children with familial juvenile nephronophthisis.

Familial juvenile nephronophthisis (NPH) is a hereditary form of chronic tubulointerstitial nephritis with onset in childhood. About one-third of patients develop anaemia before renal insufficiency. We investigated the pathogenetic mechanisms leading to anaemia by comparing 6 patients with NPH and 12 reference patients with other renal diseases. We studied their iron metabolism and measured transferrin receptor-ferritin ratios. There was no evidence for iron deficiency or haemolysis. The serum erythropoietin concentrations of the patients with NPH (12 +/- 2.3 U/I) were low compared with the 12 reference patients (25 +/- 18.9 U/I). In the 2 patients with NPH who were fully investigated, the pharmacokinetics of recombinant human erythropoietin appeared normal. Thus, anaemia in patients with NPH does not result from iron deficiency or correlate with impaired iron status. The mechanism underlying the anaemia of NPH appears to affect the function or regulation of the cells producing erythropoietin.

Alphacalcidol oral pulses are effective in secondary hyperparathyroidism prior to dialysis.

Secondary hyperparathyroidism in chronic renal failure (CRF) is due to the increased activity of parathyroid gland. The negative feedback control exerted by the vitamin D metabolite 1,25 (OH)2 D3 is lacking due to the deficiency of this metabolite in CRF. We have studied whether alphacalcidol given orally as thrice weekly evening pulses lowers parathyroid hormone (PTH) levels of children with CRF. Alphacalcidol 0.5-3.0 micrograms was given thrice weekly orally to a total of 22 children (mean age 5.6 years) with CRF; the dosis was adjusted according to PTH, ionized calcium and phosphate concentration. Serum PTH decreased significantly from a pretreatment level of 393 +/- 81 to 122 +/- 34 ng/l after 12 months, and stabilized at this level. Mean vitamin D metabolite concentrations were within normal range. 1,25 dihydroxyvitamin D did not increase during therapy while PTH decreased. The estimated creatinine clearance remained nearly the same (20 +/- 3 and 21 +/- 6 ml/min/ 1.73 m2). Growth remained low normal and bone mineral density did not decrease. Oral alphacalcidol pulse therapy for hyperparathyroidism in uremic children seemed to be easy and effective. The response is even better in inhibiting potential autonomous parathyroid hyperplasia if this treatment was started early. We conclude that feedback regulation of PTH with oral alphacalcidol pulse therapy is efficient in the treatment of hyperparathyroidism in children with CRF prior to dialysis.

Alphacalcidol oral pulses normalize uremic hyperparathyroidism prior to dialysis.

Alphacalcidol oral pulse therapy was given for secondary hyperparathyroidism to 22 children (mean age of 5.6 years) with renal insufficiency. At the beginning of the study, the glomerular filtration rate was < 50% of normal, serum intact parathyroid hormone (PTH) was > 100 ng/l and the serum phosphate and calcium concentrations were within the normal range. Alphacalcidol (0.5-3.0 micrograms) was given orally thrice weekly in the evening and adjusted according to PTH, ionized calcium and phosphate concentrations. Serum PTH (mean +/- SEM) decreased significantly from a pre-treatment level of 393 +/- 81 ng/l to 122 +/- 34 ng/l after 12 months, and stabilized at this level. Mean vitamin D metabolite concentrations were within the normal range. 1,25-Dihydroxyvitamin D did not increase during therapy, while PTH decreased. The estimated creatinine clearance remained almost unchanged (20 +/- 3 and 21 +/- 6 ml/min per 1.73 m2). Growth remained low normal (height standard deviation score -1.8 +/- 0.3 initially and -1.7 +/- 0.4 12 months later) and bone mineral density did not decrease. We concluded that feedback regulation of PTH with oral alphacalcidol pulse therapy is effective in the treatment of hyperparathyroidism in children with renal failure prior to dialysis.