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Idiopathic hypercalciuria (IHC) has been reported mainly in children with hematuria in the 1980s and early 1990s, when renal sonography was just becoming routine. The presence of microcalculi, i.e., of hyperechogenic spots < 3 mm in diameter in renal calyces, was not taken into account in those studies. We attempted to outline clinical presentation and natural course of IHC not only in children with hematuria, but also in those with dysuria and/or recurrent abdominal/flank pain and a family history of nephrolithiasis, taking into account the finding of microcalculi. We analyzed retrospectively the data at diagnosis from 74 consecutive children aged 2.4-18 years (mean 8.6) with IHC (calciuria 4.1-15.1 mg kg-1 24 h-1, mean 6.1) and the outcome of 30 of them who were followed > or = 1 years (mean 3.2) with no specific therapy. At diagnosis, 38 patients (51%) had no hematuria, 42 (57%) had microcalculi and four (5%) had calculi. Of the patients with normal urinalysis, 71% had microcalculi or stones. The subjects with microcalculi and those with stones were significantly older than those without microcalculi and stones (P = 0.004 and 0.007). A normal urinalysis at our evaluation and a history of abdominal/flank pain were significantly more frequent in patients with microcalculi than in those without (P = 0.02 and 0.0001, respectively). During the follow-up, four of 30 patients formed stones 1-3 years after first diagnosis of IHC. More than half of children with IHC have microcalculi. The risk of formation of microcalculi or stones increases with age. The lack of hematuria does not exclude the presence of microcalculi or calculi. Hypercalciuria has to be suspected in children with dysuria and/or recurrent abdominal flank pain and a family history of nephrolithiasis, even when they have no hematuria.

We studied the prevalence of a history of nephrolithiasis in first- and second-degree relatives of 74 children with hypercalciuria (HC), 61 with hyperuricosuria (HU), and 41 with HC plus HU, and in a control population of 261 children with different diseases. Family history of nephrolithiasis was found in 69% of HC, 75% of HU, 78% of HC plus HU, and 22% of control patients. The prevalence was not different among HC, HU, and HC plus HU groups, but was significantly higher in each study group than the control group (P=0.0001). Body mass index >95th percentile was found in only 4.7% of the patients with HC or HC plus HU. Calculi (>3 mm in diameter) were present in 8.9% of the patients with a family history of nephrolithiasis and in 9.4% of those with no family history (P=0.85). Microcalculi (<3 mm in diameter) were found by sonography in 56.6% of the patients with and in 53.3% of those without a family history of nephrolithiasis (P=0.83). Children with HC and/or HU have a strong familial prevalence of nephrolithiasis. Obesity does not seem to affect the association of familial nephrolithiasis and hypercalciuria in children. The presence of nephrolithiasis in families of children with HC and/or HU is not associated with a higher rate of formation of calculi or microcalculi.

We compared the accuracy of isotope cystography (IC) and fluoroscopic cystourethrography (FC) in detecting vesicoureteric reflux (VUR) in children. FC and IC were performed in 124 children, 56 boys and 68 girls, aged 1 month to 9.2 years (mean 2.1 years), admitted consecutively for suspected VUR over a 10-month period. VUR was diagnosed by one or both studies in 51 of 124 (41%) patients. The two methods were concordant for the detection of VUR in 84% of kidney-ureter units and in 93% for the detection or exclusion of severe VUR. IC detected VUR more accurately than FC, both when all grades of VUR were considered together (P=0.00001) and when only severe reflux was considered (P=0.004). VUR was missed by FC in 23 of 51 (45%) subjects. Of those 23, 12 had severe VUR detected on one side at least by IC. VUR was missed by IC in 3 subjects. IC is significantly more accurate than FC in the initial diagnosis of VUR, even of severe grade. IC is the method of choice for the first diagnosis of VUR. Boys with VUR diagnosed by IC also need FC to investigate for posterior urethral valves.

Cyclic voiding cystourethrography (CVC) enhances the detection of vesicoureteric reflux (VUR). We investigated whether more-severe VUR may be overlooked, and whether older children are at risk of having their VUR missed with the conventional single-cycle study. Three hundred and seventy patients, 168 boys and 202 girls aged 1 month to 16 years, consecutively admitted over 1 year for suspicion of VUR, underwent two complete cycles of filling and voiding CVC. One hundred and four subjects, 33 boys and 71 girls, were older than 3 years (mean age 5.7 years, range 3.2-16 years). Sixty-six refluxing ureters from 51 patients were identified in the first cycle and 61 refluxing ureters from 45 patients were identified only with the second cycle. Four instances of grade IV VUR in 4 patients and three of grade V VUR in 3 patients were overlooked completely in the first cycle. Seven episodes of VUR < or = grade III from 5 patients diagnosed in the first cycle were upgraded to > or = grade IV at the second cycle. The presence of VUR was identified only in the second cycle in 35 of 74 subjects aged < or = 3 years and in 10 of 22 aged > 3 years (not significant). Of the 10 children aged > 3 years, 2, who had diagnosis only at the second cycle, had > or = grade IV VUR. More-severe VUR may be overlooked or down-graded in a single-cycle study. Two-cycle CVC is also useful in children older than 3 years.

Body growth was studied in 32 subjects with vesicoureteric reflux (VUR), diagnosed following the prenatal finding of urinary tract dilatation, who had normal renal filtration function and who received antibacterial prophylaxis by the first few days of life. They were followed for 1-5 years (mean 2.3 years). Most had persistent VUR during the 1st year of life. Body growth performance was compared with that of 94 subjects with VUR diagnosed and treated by us after the neonatal period. During the follow-up period, none of the patients with prenatally detected VUR had a height Z score below -2, nor a weight-for-height index below 90%, and 1 had variations in height Z score >/=1. The difference in the percentage of patients with prenatally detected VUR (1/32) and those with VUR diagnosed and treated after the neonatal period (20/94) who had variations in height Z score >/=1 was significant (P=0.035). Patients with prenatally detected VUR and normal renal filtration function, given antibacterial prophylaxis by the first few days of life, have normal body growth, although VUR still persists.