Pediatric urolithiasis in Armenia: a study of 198 patients observed from 1991 to 1999

To study prospectively the risk factors and etiology of urolithiasis in all stone patients aged <15 years admitted from 1991 to 1999 to the Arabkir hospital in Yerevan. Stones were obtained by surgery (64%), extracorporeal shockwave lithotripsy (ESWL) (7%) or cystoscopic extraction (4%); 25% passed spontaneously. All were examined by infrared spectroscopy, and spot urines were analyzed chemically. 198 patients, 180 (68% males) with renal stones and 18 (83% males) with primary bladder stones, were studied. Calcium oxalate (CaOx) was the predominant constituent in 62% of the kidney stones, followed by struvite (17%), calcium phosphate (7%), uric acid (7%), ammonium acid urate (5%), and cystine (2%). Bladder stones contained CaOx in 72%, uric acid in 22% and ammonium acid urate in 6% of patients. Etiology was obviously metabolic in 5% and possibly metabolic in 26%. Twenty percent of stones were infectious, and 19% were endemic (9% bladder and 10% kidney stones); 4% were secondary to urinary stasis with malformation but no infection. Etiology in 26% remained unknown. Stone composition and metabolic etiology are similar to that in central Europe and North America. In contrast, infectious calculi and particularly endemic stones are still common, although becoming less so now. Urolithiasis in Armenia thus reflects the transition from a rural to an urban society.

Simultaneous occurrence of the haemolytic uraemic syndrome and acute post-infectious glomerulonephritis

We report on two children, a 12-year-old boy and a 6-year-old girl, with simultaneous occurrence of clinical and laboratory features consistent with both diarrhoea-negative haemolytic uraemic syndrome (D-HUS) and acute post-infectious glomerulonephritis (APGN). Both presented with acute renal insufficiency, hypertension and oedema. Laboratory evaluation revealed micro-angiopathic anaemia with burr cells, thrombocytopenia, elevated lactic dehydrogenase and low complement C3. Urinalysis showed marked proteinuria and haematuria. Renal biopsy was characteristic of APGN, but not of HUS. The outcome was good in both children. Conclusion. The simultaneous occurrence of diarrhoea-negative haemolytic uraemic syndrome and acute post-infectious glomerulonephritis is rare. The outcome is generally good as is expected in the latter condition in contrast to the former.

[Pediatric kidney transplantation and living donors--invaluable by virtue of necessity]

Renal transplantation is the treatment of choice for paediatric patients with end-stage renal failure. Living donor transplantation (LDT) has become an important therapeutic option due to the shortage of cadaver donors and increasingly long waiting times.

METHODS

Between 1992 and 1999, a total of 48 paediatric and adolescent patients underwent renal transplantation in Zurich. Of these, 21 patients (44%) received a kidney from a living related donor. 11 patients had been dialysed before LDT over a period of 0.2-5.7 years (median 0.6), and 10 were transplanted preemptively. Triple immunosuppression consisted of cyclosporine A, azathioprine or mycophenolate mofetil (MMF; since 1998), and prednisone. The observation period was 0.5-7.3 years (median 2).

RESULTS

Recipients were 2-18 (median 10.5) years old at transplantation. One third had either a congenital malformation, an inherited disease, or an acquired disorder. One patient died of an associated cardiac disease at 4 months with functioning graft, and one functional graft loss occurred after 2.8 years. 9 patients were switched from cyclosporine to tacrolimus, 7 for biopsy-proven rejection and 2 for cosmetic reasons (hypertrichosis). No antibody preparations were used. Median glomerular filtration rate (51Cr-EDTA), measured after one year in 11 donor/recipients, was 64 (55-95) and 54 (32-82) ml/min/1.73 m2, respectively. The most recent estimated renal function (Schwartz formula) of 19 functioning grafts was 37-79 ml/min/1.73 m2 (median 63). Median body height of 16 patients with no associated extrarenal disease was -0.9 SDS (standard deviation score); the remaining 3--with serious extra-renal disease--were considerably growth retarded. Main complications were reversible rejection episodes in 19 (90%), arterial hypertension (16), CMV disease (2) and asymptomatic CMV infection (3), pyelonephritis (3), and recurrence of the primary renal disease, seizures, diabetes mellitus and non-compliance (one each). Actuarial patient and graft survival (Kaplan-Meier) after 3 years was 95 and 83% respectively. This was not statistically different from the cadaveric donor group (n = 27) with 100 and 80% survival respectively. Overall rehabilitation was excellent. The donors were 12 mothers, 8 fathers and one grandmother aged 31 to 50 (median 39) years; none of them experienced serious postoperative problems.

CONCLUSIONS

The paediatric transplantation programme would no longer be feasible in Switzerland without LDT. The results are very encouraging; preemptive transplantation makes it possible to avoid dialysis in half of the patients. The risk for the donor is small, and careful evaluation without putting pressure on the family is essential.

Heparin-induced thrombocytopenia type II on hemodialysis: switch to danaparoid

We report two pediatric patients with end-stage renal failure who developed heparin-induced thrombocytopenia type II (HIT II) on hemodialysis (HD). Both developed acute respiratory distress and chest pain within 30 min of initiating the 5th HD session. The platelets dropped during HD from 168 to 38x10(9)/l and from 248 to 109x10(9)/l, respectively. Marked clots were observed in the dialyzers. Substitution of heparin with the low molecular weight heparin dalteparin had no effect. Switching from anticoagulation to the heparinoid danaparoid resulted in immediate disappearance of all adverse effects, and further long-term HD was uneventful. HIT II was diagnosed clinically; heparin-induced platelet activation test (HIPA) and serum IgG, IgA, and IgM to heparin-platelet factor 4 complexes (HPF4) were both negative. We conclude that HIT II may occur in children on HD. HIT II is essentially a clinical diagnosis, as HIPA and antibodies to HPF4 are not always positive. Once HIT II is suspected, heparin (and low-molecular-weight heparins) should be stopped immediately. Long-term anticoagulation with danaparoid is a valuable option for patients on HD.

Urinary oxalate excretion in urolithiasis and nephrocalcinosis

AIMS

To investigate urinary oxalate excretion in children with urolithiasis and/or nephrocalcinosis and to classify hyperoxaluria (HyOx).

METHODS

A total of 106 patients were screened. In those in whom the oxalate: creatinine ratio was increased, 24 hour urinary oxalate excretion was measured. Liver biopsy and/or genomic analysis was performed if primary hyperoxaluria (PH) was suspected. Stool specimens were examined for Oxalobacter formigenes in HyOx not related to PH type 1 or 2 (PH1, PH2) and in controls.

RESULTS

A total of 21 patients screened had HyOx (>0.5 mmol/24 h per 1.73 m(2)); they were classified into five groups. Eleven had PH (PH1 in nine and neither PH1 nor PH2 in two). Six had secondary HyOx: two enteric and four dietary. Four could not be classified. Seven patients had concomitant hypercalciuria. Only one of 12 patients was colonised with O formigenes compared to six of 13 controls.

CONCLUSIONS

HyOx is an important risk factor for urolithiasis and nephrocalcinosis in children, and can coexist with hypercalciuria. A novel type of PH is proposed. Absence of O formigenes may contribute to HyOx not related to PH1.

Renal chloride channel, CLCN5, mutations in Dent's disease

Dent's disease is an X-linked renal tubular disorder characterized by low-molecular-weight proteinuria, hypercalciuria, nephrocalcinosis, nephrolithiasis, and renal failure. Patients with Dent's disease may also suffer from rickets and other features of the renal Fanconi Syndrome. Patients may have mutations in the X-linked renal chloride channel gene, CLCN5, which encodes a 746-amino-acid protein with 12-13 transmembrane domains. We have investigated the 11 coding exons of CLCN5 for mutations in eight unrelated patients with Dent's disease. Leukocyte DNA was used for the polymerase chain reaction amplification of CLCN5 and the products analyzed for single-stranded conformational polymorphisms (SSCPs). Abnormal SSCPs were sequenced and revealed eight mutations. These consisted of three nonsense mutations (Arg34Stop, Arg648Stop, Arg704Stop), four deletions involving codons 40, 86, 157, and 241, and one acceptor splice consensus sequence mutation tgcag --> tgaag. The mutations were confirmed either by restriction endonuclease or sequence-specific oligonucleotide hybridization analysis. In addition, an analysis of 110 alleles from 74 unrelated normal individuals demonstrated that the DNA sequence changes were not common polymorphisms. All of the mutations predict truncated chloride channels that are likely to result in a functional loss. Thus, our findings expand the spectrum of CLCN5 mutations associated with Dent's disease and the results will help to elucidate further the functional domains of this novel chloride channel.

[Small patients--big costs: the economic aspects of treating young children with renal failure]

Since 1985, 20 children have been followed with early onset of chronic renal failure (plasma creatinine > 120 mumol/l in first year of life). So far, 10 and 7 patients underwent peritoneal dialysis and renal transplantation, respectively. The aim of this study was to assess the overall costs. The recorded costs comprised both the direct costs of dialysis and transplantation, and the costs of all medical and psychosocial measures. The annual median costs of conservative treatment, peritoneal dialysis, the year of transplantation, and follow-up after transplantation amounted to 30,000, 93,000, 130,000 and 28,000 Swiss francs, respectively. The youngest patients caused the highest expenses. The active treatment permitted not only survival, but--in most patients--also a normal cognitive and psychosocial development.

Influence of nutrition on urinary oxalate and calcium in preterm and term infants

Few data for normal urinary oxalate (Ox) and calcium (Ca) excretion related both to gestational age and nutritional factors have been reported in preterm or term infants. We therefore determined the molar Ox and Ca to creatinine (Cr) ratios in spot urines from 64 preterm and 37 term infants aged 1-60 days, either fed formula or human milk (HM). Only vitamin D was supplemented; renal or metabolic diseases were excluded. Urinary Ox/Cr ratio was higher in preterm than in term infants, both when formula fed (1st month 253 vs. 180 mmol/mol and 2nd month 306 vs. 212 mmol/mol; P<0.05) or HM fed (206 vs. 169 mmol/ mol and 283* vs. 232 mmol/mol; *P<0.05). Ox/Cr was also higher in formula- than HM-fed preterm infants. The ratio increased during the first 2 months of life irrespective of nutrition. Urinary Ca/Cr ratio was comparable in all groups during the 1st month of life, except for a lower (P < 0.05) value in term infants fed HM (0.10 mol/mol). It increased in all groups during the 2nd month of life, being highest in HM-fed preterm infants (1.86 mol/mol). In conclusion, urinary Ox and Ca excretion is influenced by both gestational age and nutrient intake in preterm and term infants.

An epidemic of acute postinfectious glomerulonephritis in Armenia

AIM

To evaluate the presentation and course of acute postinfectious glomerulonephritis (APGN), which has increased dramatically in Armenia after serious deterioration in the living conditions.

STUDY DESIGN

Observational study, based on case notes, of a large homogeneous group of patients hospitalised for APGN at one centre over a five year period (1992-6).

PATIENTS

474 patients aged < 16 years with a diagnosis of APGN.

RESULTS

The annual number of patients increased tenfold from 19 (average 1992/3) to 196 in 1995. Sixty two per cent were in the age group 4-9 years and 65% were boys. Upper respiratory infections, scarlet fever, and skin infections preceded APGN in 51%, 23%, and 13%, respectively. All patients had haematuria (93% gross), 84% had oedema, and 72% had hypertension. C3 was initially decreased in 95% of the patients examined. Renal function was impaired (serum creatinine > 100 mumol/l) in 29%. Four patients with renal failure had crescentic glomerulonephritis at biopsy; of these, three required temporary haemodialysis. Main extrarenal complications were heart failure (10%) and convulsions (3%). One patient died and five (3%) did not recover completely.

CONCLUSIONS

APGN in children is associated with considerable initial morbidity, and long term outcome is not uniformly benign. Outbreaks of APGN may occur anytime in countries such as Armenia that are suffering from a sudden decline in socioeconomic conditions.

Familial progressive tubulo-interstitial nephropathy and cholestatic liver disease -- a newly recognized entity?

We describe two siblings (female and male) with progressive tubulo-interstitial nephropathy and cholestatic liver disease. The main characteristics were progressive renal failure and elevated liver enzymes (AST, ALT and gamma-GT). Dialysis was started at the age of 1.9 and 6.5 years, respectively. Renal histology disclosed sclerosed glomeruli and atrophic tubules; the interstitium was fibrotic and infiltrated by lymphocytes. Endoscopic retrograde cholangiopancreatography revealed segmental irregularities and narrowing of the intrahepatic bile ducts, consistent with early primary sclerosing cholangitis. Liver histology showed enlarged portal triads, mild proliferation and inflammation of bile ducts, and fibrosis. At 5.9 years the girl underwent a successful renal transplantation whereas the boy is still on dialysis.

CONCLUSION

The association of progressive tubulointerstitial nephropathy and cholestatic liver disease, consistent with early primary sclerosing cholangitis, constitutes a distinct autosomal recessive entity.

Postrenal anuria after appendectomy in childhood

An 11-year-old boy suffered from macroscopic haematuria and bilateral flank pain a few days after uneventful appendectomy for retrocaecal appendicitis phlegmonosa. Ultrasonography revealed a complete bilateral distal obstruction of the ureters. Renal failure due to postrenal anuria resolved completely after intravenous antibiotics.

[Kidney transplantation in the child]

The goal of treatment of end-stage renal failure in pediatric patients is a functioning transplant. Due to the serious shortage of cadaver kidneys, we have to consider living related donor transplantation (tpl) more frequently. Certain features are characteristic of pediatric patients before transplantation: underlying disease (over 2/3 are congenital or hereditary), the form of dialysis (automated peritoneal dialysis at home in young children) and the frequent need for tube feeding and treatment with growth hormone. Patients weighing 10 kg or more can be given an adult kidney. Young recipients are at risk for vascular thrombosis and hence the CVP should be kept high to allow good circulation, and continuous heparinization (10 units per kg and hour) is advocated. Minor rejection episodes may be overlooked in the presence of a large graft in a small child. Bladder dysfunction is a problem in many children with obstructive uropathy. Later on, viral infections (CMV, EBV) may pose serious problems since most children have not previously been exposed to them. Further problems are pyelonephritis in the graft and recurrence of the underlying disease. Long-term results are very satisfactory in terms of survival and quality of life including later social integration.

Pyelonephritis and vesicoureteral reflux after renal transplantation in young children

PURPOSE

We assessed morbidity and risk factors of pyelonephritis in children after renal transplantation.

MATERIALS AND METHODS

Between 1986 and 1995, 41 children underwent transplantation and all who had documented pyelonephritis were evaluated.

RESULTS

Six children who underwent transplantation before age 7 years had 1 to 3 episodes of pyelonephritis with significant renal dysfunction and vesicoureteral reflux into the grafted system. An antireflux reimplantation procedure in 5 children was complicated by temporary functional obstruction in 3. No further infection occurred after correction of vesicoureteral reflux. After a median of 4.5 years post-transplantation all patients have a functioning graft.

CONCLUSIONS

After renal transplantation vesicoureteral reflux and young recipient age are major risk factors for pyelonephritis with subsequent graft dysfunction.

New mutations in the AQP2 gene in nephrogenic diabetes insipidus resulting in functional but misrouted water channels

Nephrogenic diabetes insipidus (NDI) is characterized by the inability of the kidney to concentrate urine in response to vasopressin. The autosomal recessive form of NDI is caused by mutations in the AQP2 gene, encoding the vasopressin-regulated water channel of the kidney collecting duct. This report presents three new mutations in the AQP2 gene that cause NDI, resulting in A147T-, T126M-, or N68S-substituted AQP2 proteins. Expression of the A147T and T126M mutant AQP2 proteins in Xenopus oocytes revealed a relatively small, but significant increase in water permeability, whereas the water permeability of N68S expressing oocytes was not increased. cRNA encoding missense and wild-type AQP2 were equally stable in oocytes. Immunoblots of oocyte lysates showed that only the A147T mutant protein was less stable than wild-type AQP2. The mutant AQP2 proteins showed, in addition to the wild-type 29-kd band, an endoplasmic reticulum-retarded form of AQP2 of approximately 32 kd. Immunoblotting and immunocytochemistry demonstrated only intense labeling of the plasma membranes of oocytes expressing wild-type AQP2. In summary, two mutant AQP2 proteins encoded in NDI are functional water channels. Therefore, the major cause underlying autosomal recessive NDI is the misrouting of AQP2 mutant proteins.

A vertical (pseudodominant) pattern of inheritance in the autosomal recessive disease primary hyperoxaluria type 1: lack of relationship between genotype, enzymic phenotype, and disease severity

Primary hyperoxaluria type 1 (PH1) is a rare autosomal recessive disease caused by a deficiency of alanine:glyoxylate aminotransferase (encoded by the AGXT gene). Primary hyperoxaluria type 1 is characterized by the elevated urinary excretion of oxalate and glycolate, and the deposition of insoluble calcium oxalate in the renal parenchyma and urinary tract. In the present study, we investigated an unusual family containing four affected individuals in two different generations. Based on our genetic, enzymic, metabolic, and clinical analyses, we have come to the following conclusions. First, although the pattern of inheritance of PH1 is usually horizontal (ie, all patients in the same generation), as expected for an autosomal recessive disease, it can sometimes show a vertical (pseudodominant) pattern of inheritance (ie, patients in more than one generation) due to the segregation within a family of three, rather than two, mutant AGXT alleles. Second, affected members of such a family can manifest very different clinical phenotypes both within and between generations. Although the clinical differences between generations might be at least partly due to differences in AGXT genotype, differences can equally occur within the same generation in individuals who possess the same AGXT genotype. Finally, individuals with PH1 at the level of the AGXT genotype might remain asymptomatic and undiagnosed for many years. The consequences of these findings for the clinical management and genetic counseling of families with PH1 are profound and wide-ranging.

[25 years of dialysis and kidney transplantation in children and adolescents]

Between 1970 and 1994 84 children and adolescents with end stage renal failure (ESRF) were started on renal replacement therapy (RRT). Renal transplantation was the main goal from the beginning. The long term results were evaluated with emphasis on survival, development and social integration. RRT was started in nearly half of the children (45%) between the age of 10 and 15 years and in 14% before 5 years. 52 patients were first treated by hemodialysis (HD) and 27 by peritoneal dialysis (PD, since 1979). 5 patients underwent preemptive transplantation. By December 1994, 75 patients had received 99 grafts, i.e. 75 1st, 21 2nd and 3 3rd grafts; 3 kidneys were from living related donors and 8 patients were transplanted elsewhere. 7 patients were still on dialysis and 2 had died before transplantation. Actuarial patient survival (Kaplan-Meier) after start of RRT is 88% at 10 years and 75% at 17-25 years. Actuarial patient survival after first transplantation increased from 91% (1970-1984) at 5 years to 97% (1985-1994). 7 of the first 10 patients transplanted from 1970-1974 are alive, all with functioning grafts (4 with their first graft). 9 patients died after transplantation: 4 of recurrent disease, 2 of viral (CMV, EBV) infections and 1 each of spinalioma, allergic shock and traffic accident. First graft survival was 37% at 10 years. It increased from 53% (1970-1984) to 72% (1985-1994) at 5 years. The main causes of first graft loss (n = 33) were irreversible rejection (21) and recurrent disease (7). All patients aged > 22 years were further evaluated: patients with start of RRT 1970-1979 (group A, n = 18) were compared with those starting RRT from 1980-1987 (B, n = 19). Mean adult height in A was less than in B (163.9 cm vs 168.5 cm in men; 146.3 cm vs 156.5 cm in women). 50% in A vs 32% in B had a disability. Fewer patients in A (39%) than in B (62%) were fully employed. Considerably more patients in A (61%) than in B (37%) lived with their parents or siblings although the mean age in A was 31 years vs 25 years in B. 3 women were married (all in B), 2 of them gave birth to 3 healthy children and the third was pregnant. Long term patient and graft survival, somatic development and social integration have improved over the years due to a variety of factors. A comprehensive approach is necessary in treating children with ESRF.

Changing pattern of primary hyperoxaluria in Switzerland

BACKGROUND

The clinical course of primary hyperoxaluria (PH) is greatly variable and diagnosis is often delayed. Little is known about the overall occurrence and current prognosis.

METHODS

We evaluated all known patients with PH residing and observed in Switzerland during the last 15 years with the help of a survey among Swiss nephrologists.

RESULTS

Of the 25 patients observed between 7/79 and 6/94 in Switzerland, 18 were alive in 1994-14 on conservative therapy and four on renal replacement therapy (RRT). Twenty-two patients had PH type 1; the exact type was not determined in three. The estimated prevalence of PH (type 1) is 2 per million population; the minimal incidence is 1 per 100,000 live births. Diagnosis was delayed by 8 years (median) except in infants. Five patients were pyridoxine sensitive. According to life table analysis, 20% of patients were in end-stage renal failure (ESRF) and 10% had died by the age of 15 years, and 50% were in ESRF and 20% dead at 25 years. Prognosis has improved: Five of 13 patients died during the first half of the observation period as opposed to two of 20 in the second part.

CONCLUSIONS

Overall prognosis appears better than hitherto believed considering the large clinical spectrum of PH. Greater awareness of PH is needed to improve further long-term prognosis.

Prenatal sonographic diagnosis of autosomal recessive polycystic kidney disease (ARPKD) during the early second trimester

Autosomal recessive polycystic kidney disease (ARPKD) is a rare hereditary disease with a high neonatal mortality. Currently, prenatal diagnosis is possible only during the second half of pregnancy, when bilaterally enlarged, echogenic kidneys are visible by ultrasound. We describe a case in which a diagnosis of ARPKD was sought in the first half of pregnancy. High-resolution ultrasonography revealed echogenic, normal-sized kidneys at 15 + 4 weeks. Microsatellite DNA analysis of a chorionic villus sample, parental blood, and blood of an affected sibling showed that the fetus had the maternal haplotype and a recombination of the paternal haplotype. Thus, no distinction between homo- and heterozygosity for the ARPKD mutation in the fetus was possible. A further ultrasound examination at 19 + 4 weeks confirmed the previous results, indicating that the fetus was likely to be affected. After termination of the pregnancy, the diagnosis was confirmed on microscopic examination.

Efficacy of oral citrate administration in primary hyperoxaluria

Urinary citrate is a potent inhibitor of calcium oxalate (CaOx) crystallization, but oral citrate has rarely been used in patients with primary hyperoxaluria (PH). We studied the effect of sodium citrate administration (0.1-0.15 g/kg/day) on urinary citrate excretion and CaOx saturation in seven paediatric patients and the clinical response to long-term treatment (average 4 years) in five patients. Urinary citrate increased from 0.73 to 2.54 mmol/24 h/1.73 m2 and urinary saturation for CaOx (calculated by equil 2) decreased from 11.41 to 6.79 (for both, p < 0.02). Long-term administration of alkali citrate [0.15 g (0.5 mmol)/kg/day] resulted in stable or improved renal function in three and slow deterioration in two partially non-compliant patients. Alkali citrate is effective in patients with PH.

[Therapy with growth hormone in pediatric patients with chronic kidney insufficiency]

Statural growth in children with chronic renal failure (CRF) is often delayed. Several studies have shown that one of the main causes is partial resistance to growth hormone (GH), which can be overcome by supraphysiologic doses of recombinant human (rh) GH. Since August 1990 we have been treating 8 boys and 1 girl (ages 1.7-12.7, mean 5.3 yrs) with rhGH (4 IU/m2 s.c. daily). All patients were prepubertal and were 2.4-4.5 (mean 3.2) SDS below the mean normal height for age and sex. 5 patients were on dialysis. Mean growth velocity was -2.0 SDS (5.4 cm/yr) before and +2.6 SDS (9.5 cm/yr) during the first year of therapy with rhGH. Mean height increased from -3.2 to -2.5 SDS at 1 year. Height in the 4 boys treated > 2 yrs with rhGH improved from -3.3 SDS (before rhGH) to -2.4 (1st yr) and to -2.0 SDS (2nd yr); their height increased by 9.6 cm (1st yr) and 7.8 cm (2nd yr) as compared to 4.6 cm in the year before treatment. The response to rhGH was better in the 4 patients treated conservatively than in those on dialysis. Side effects did not occur. Plasma insulin increased but the oral glucose tolerance test remained normal. We conclude that treatment with rhGH represents an important step forward in selected pediatric patients with CRF. The excellent acceptance reflects the high expectations of the patients and their families.

Paediatric nephrology in countries with limited resources

This paper summarises a symposium concerned with the provision of care for children with kidney disease in developing countries. Better organisation of services is required to prevent waste of resources, with the emphasis on team work between professionals, shared care with local health care personnel remote from the paediatric nephrology unit and good communications. Families need to be educated and provided with appropriate information so that they can care for their child at home. Technology should be simple and robust and the staff using it should be fully trained to maintain it in use. Therapies should be definitive where possible, because long-term supervision of treatment is often difficult. Effective but inexpensive medications should be used where possible. Twinning of developing and richer countries is valuable to transfer technology, help with training and assist in care through the development of personal contacts.

The role of surgery and lithotripsy in childhood urolithiasis

From 1982 through 1993 36 interventions in 32 infants and children with urolithiasis have been performed in our department. There were 22 boys and 10 girls. The main cause for the interventions have been congenital malformations in 9, followed by recurrent urinary tract infections in 6, previous operations in 5 and hypercalciuria in 5 patients. In 7 children the cause of the urolithiasis remained unknown. As a therapeutic option extracorporeal shock-wave lithotripsy (ESWL) was available after 1988. The malformations as well as the postoperative conditions have been corrected surgically and the calculi were removed at the same time. For post-infectious, idiopathic or hypercalciuric calculi ESWL was used in the majority of patients after 1988. Therefore a total of 26 calculi were removed by operation and 13 by ESWL. Only 1 calculus was extracted endoscopically. There were no complications either after ESWL or after open surgery. Our results show that ESWL gains more and more importance in infants and children. Calculi in congenital malformations or as result of operations are still removed by open surgery. In the other cases ESWL is the method of choice.

[Cyclosporin in autoimmune diseases]

At a symposium held in Zurich in November 1993, a series of presentations covered the optimal use of cyclosporin A (CsA) in autoimmune diseases. Besides its immunosuppressive effects in organ transplantation, CsA appears to be active in a variety of autoimmune disorders. Its most pronounced and beneficial clinical effects are seen in patients with severe rheumatoid arthritis. New clinical studies include the nephrotic syndrome in children and patients with systemic lupus erythematodes. The main concern remains CsA induced nephrotoxicity. For the treatment of autoimmune disorders CsA can be used at lower doses (< or = 5 mg/kg per day) than in transplantation medicine. Thus, monitoring of CsA blood concentrations is not usually necessary. The galenics of CsA has been optimized recently, an achievement which will further improve the clinical use of CsA. Due to increased knowledge of intracellular CsA binding proteins and of effects of CsA on T-lymphocytes and cytokine production, it can be expected that novel immunosuppressive compounds will be developed.

From dialysis to basic paediatric nephrology: an unorthodox project applied in Yerevan, Armenia

Following the earthquake in December 1988, a long-term project was developed: starting from haemodialysis, it was extended to basic nephrology and urology, with a programme for schooling and psychosocial care. Medical training had first priority. The programme relied on robust and often second-hand equipment and voluntary work. The approach chosen (an inverse help programme, from sophisticated to basic medicine) strongly stimulated motivation and proved to be practicable.

Urinary saturation and nephrocalcinosis in preterm infants: effect of parenteral nutrition

Urinary lithogenic and inhibitory factors were studied in 27 preterm infants; 16 had total parenteral nutrition (TPN) and 11 had breastmilk with an additional glucose-sodium chloride infusion. Urines were collected for 24 hours on day 2 (period A), day 3 (B), and once between days 4 and 10 (C). Urinary calcium oxalate saturation was calculated by the computer program EQUIL 2. Renal ultrasonography was performed every second week until discharge. The calcium/creatinine ratio increased in infants on TPN (A 0.91; C 1.68 mol/mol) and was significantly higher at period C than that in infants on breastmilk/infusion (A 0.52; C 0.36). The oxalate/creatinine ratio was persistently higher with TPN (203 mmol/mol) than with breastmilk/infusion (98; 137). The citrate/creatinine remained constant with TPN (0.44 mol/mol), whereas it increased significantly with breastmilk/infusion (0.26; 0.49). Calcium/citrate rose considerably with TPN, but decreased with breastmilk/infusion to a significantly lower level than with TPN. The urinary calcium oxalate saturation increased with TPN (2.4; 4.5) and decreased with breastmilk/infusion (2.1; 1.5) to a significantly lower value than with TPN. Nephrocalcinosis developed in two infants on TPN. Mean daily calcium intake was similar in both groups, whereas protein, sodium, and phosphorus intake were significantly higher on TPN. It is concluded that the increase in urinary calcium oxalate saturation observed with TPN is due to the combined effect of an increased urinary calcium excretion and higher urinary oxalate/creatinine and calcium/citrate ratios. The changes observed are likely to be caused by TPN itself, which differs in several respects from breastmilk feeding.

Management of primary hyperoxaluria: efficacy of oral citrate administration

The prognosis of primary hyperoxaluria (PH) is not only related to endogenous oxalate production and the response (if any) to pyridoxine (in type I), but is greatly influenced by extrarenal factors like dehydration. The earlier the diagnosis of PH, the better the chances of improving the prognosis in individual patients. Measures to enhance the solubility of calcium oxalate are important. Besides ensuring at all times a generous fluid intake (> 2 l/m2), administration of alkali citrate (0.15 g/kg), which has not been advocated so far in PH, appears very promising. We studied the effect of sodium citrate in six patients with PH. Mean urinary citrate excretion (mmol/day per 1.73 m2) without oral citrate was very low (0.57) and rose to 2.49 with citrate administration. This was accompanied by a significant decrease in the calcium oxalate saturation (calculated by equil 2) from 11.7 to 6.9 (P < 0.05). Treatment in five patients over 10-36 months resulted in improved (1) or stabilized (4) renal function and reduced passage of stones. Additional measures include restriction of salt and of oxalate-rich food. We conclude that long-term administration of alkali citrate is beneficial in patients with PH.

Hypercalciuria and nephrocalcinosis, a feature of Wilson's disease

Hypercalciuria and nephrocalcinosis are not uncommon in patients with Wilson's disease but have only once been reported as the presenting sign. We diagnosed Wilson's disease in a 17-year-old male patient 6 years after his first episode of gross hematuria and 2 years after detection of hypercalciuria and nephrocalcinosis. Therapy with penicillamine resulted only in a moderate reduction of urinary calcium excretion but oxalate excretion increased.

[Vitamin D poisoning in infants: a preventable cause of hypercalciuria and nephrocalcinosis]

The established prophylaxis for vitamin D-deficient rickets today is 400 IU vitamin D3 given daily during the first year of life. With this regimen, vitamin D intoxication is a rare event. Nevertheless, we have recently seen 4 infants with vitamin D intoxication after a so called "stoss" prophylaxis, i.e. twice 300,000 units (7.5 mg) vitamin D3 orally within 4 weeks. One patient presented with failure to thrive due to marked hypercalcemia (3.9 mmol/l) and nephrocalcinosis, 2 patients showed medullary nephrocalcinosis on ultrasonography and one patient had gross hematuria and spontaneous passage of a calculus. Three patients had massive hypercalciuria (calcium/creatinine ratio 1.8-4.8 mol/mol, normal less than 1). The 25 (OH) vitamin D3 plasma levels, measured only in 2 patients, were strikingly increased (270 and 158 nmol/l, respectively, normal 25-80). Urinary calcium excretion slowly decreased to normal values on a low calcium diet and high fluid intake. Nephrocalcinosis, however, persisted in 2 patients and showed a slight progression ultrasonographically in one patient. The short time interval between vitamin D administration and onset of symptoms and the subsequent clinical course provide strong evidence that hypercalciuria and nephrocalcinosis were due to vitamin D "stoss" prophylaxis in all four cases. In conclusion, there is no indication for vitamin D "stoss" prophylaxis for vitamin D-deficient rickets in infants. Vitamin D intoxication still has to be considered as a possible cause of hypercalciuria.

Unknown syndrome: ischiadic hypoplasia, renal dysfunction, immunodeficiency, and a pattern of minor congenital anomalies

We report a 6 year old male with a pattern of malformations and anomalies including intrauterine growth retardation, microcephaly, psychomotor retardation, a pattern of craniofacial anomalies (flat face, hypertelorism, epicanthic folds, strabismus, short nose, low set ears), hypospadias and cryptorchidism, bilateral partial cutaneous syndactyly between fingers 2 to 5 and toes 2 to 4, postaxial polydactyly of the fingers and toes, severe conductive hearing loss, hypoplasia of the ischiadic bones, complex renal dysfunction, hypogammaglobulinaemia with proneness to bacterial infections of the upper and lower respiratory tract, and recurrent pseudomembranous enterocolitis. The parents are cousins of Turkish origin.

[Elevation of unsaturated transcobalamin II in autoimmune diseases: study of the process in lupus erythematosis and dermatomyositis]

In an earlier study concerning patients with autoimmune diseases, a more reliable correlation of clinical disease activity was found with raised concentrations of the serum protein transcobalamin II than with several tests now in common use (complement factor C3, antinuclear antibody titer and antinative DNA binding capacity). These findings were subsequently confirmed in long-term observations over 1 to 3 years: the present paper discusses 5 of 7 investigated cases (2 with SLE, 2 with dermatomyositis of changing activity, and 1 with an erroneous diagnosis of SLE) in detail.

Hemolytic-uremic syndrome associated with neuraminidase-producing microorganisms: treatment by exchange transfusion

In two infants with pneumonia, Coombs test positive hemolytic anemia and hemolytic uremic syndrome (HUS), exposure of the Thomsen cryptantigen, probably due to the action of circulating neuraminidase, was demonstrated. Reaction between the exposed T-antigen and anti-T agglutinin, normally present in human blood, can lead to difficulties in serological testing and during blood transfusion. The place of exchange transfusions using washed RBC or heparinized whole blood in the management of this subgroup of HUS is discussed.