Clinical presentation and natural course of idiopathic hypercalciuria in children

Abstract

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.

Molecular Mechanisms of Primary Hypercalciuria

“…In pediatric patients with nephrolithiasis, 73% had a family history of kidney stones in at least one first-order or second-order relative, as opposed to a prevalence of 22% in a control population of pediatric renal and urologic patients (18). Of the patients with hypercalciuria, the prevalence of nephrolithiasis in the family history was 69% (18).…”

Descriptive study of clinical profile and benefit of therapy in childhood hypercalciuria

“…1,3,4 However, according to a study done by Safaei et al in Rasht, Iran, the prevalence of idiopathic hypercalciuria in males and females was the same. 5 Kalia et al reported a 10-week-old infant with hypercalciuria, 6 whereas the youngest baby in our study was 39 days old.…”

“…1 Hypercalciuria in children can lead to tubulointerstitial damage resulting in chronic kidney disease. We studied the clinical profile and benefit of therapy for children with hypercalciuria from a southern region in India.…”

“…Polito et al reported 42 children with microcalculi and four with calculi on ultrasonography 1 and we identified 16 children with renal stones in this way.…”

Investigação de nefrolitíase no Oeste do Paraná

“…Hypercalciuria may be associated with hypophosphatemia due to mutations in phosphorus /sodium cotransporter proteins, encoded by the NPT2a gene [23][24][25] . In children with hypercalciuria, the prevalence of renal lithiasis in the family ranges from 46 to 49% [26][27][28] .…”