Hematuria due to hyperuricosuria in children: 36-month follow-up.

Hyperuricosuria (HU), defined as a urinary acid excretion higher than 95 percent of normal values, is an important lithogenic factor, accounting for about 5-20% of recurrent hematuria in childhood. We prospectively studied 30 children (15 male, 15 female; aged 3 to 13 years old) with previously undiagnosed isolated hematuria and HU for 6 to 36 months. The family history of nephrolithiasis was positive in 40%. Idiopathic hypercalciuria (IH), UCa > 4 mg/kg/day, was not found initially, but was diagnosed after 6 to 24 months in 20% of the patients. The following treatments were utilized: restricted purine diet (13%), allopurinol (4%) and potassium citrate (1%). No specific treatment was given to 82% of the patients. Therapy normalized uricosuria with resolution of hematuria over 6-12 months. Thirteen percent and 6% of untreated patients developed urolithiasis after 6 and 12 months respectively. The data suggest that HU, like IH, is associated with hematuria. Furthermore, recognition of this association may prevent unnecessary, and in some cases, invasive diagnostic manoeuvres.

Urinary inhibitors of crystallization in hypercalciuric children with hematuria and nephrolithiasis.

Urinary inhibitors are suggested to play a significant role in reducing crystallization in calcium (Ca) stone former and idiopathic hypercalciuria (IH). Urinary inhibitors such as magnesium (Mg), citrate, and glycosaminoglycans (GAGs) were evaluated, as well as urinary Ca and creatinine (Cr), in IH children with nephrolithiasis (LIT) or with hematuria plus IH (HEM) and were compared with a control group. The mean 24-h urinary excretion of Mg was similar in all groups. However, the urine Ca/Mg ratio was significantly increased (P < 0.005) in LIT and HEM groups. A higher mean value for GAGs and citrate was found in the HEM group, but a very low level of GAGs (less than 60% of the normal value) and citrate (less than 30% of the normal value) was found in the LIT group. These data suggest that, despite a high urinary Ca excretion (3.6 +/- 0.1 mg/kg per day) in the HEM group, elevated urinary GAGs (32.0 +/- 1.0 mg/g Cr) and a normal urinary citrate (428.7 +/- 62.3 mg/24 h) excretion may prevent Ca crystallization and thus renal stones. In contrast, in the LIT group low urinary GAG (10.3 +/- 0.9 mg/g Cr) and citrate (235.2 +/- 52.3 mg/24 h) excretion may precipitate stone formation in the presence of a high urinary Ca excretion. Thus, it is reasonable to suggest that patients with hematuria and IH may not develop overt renal stone due to the presence of normal levels of renal stone inhibitors.

Estudo metabolico da nefrolitiase na infancia: avaliacao em cinquenta criancas litiasicas / Metabolic study of the nephrolitiasis in the childhood: evaluation in fifty lithyasic children

Para avaliar os fatores litogenicos, estudamos retrospectivamente, com relacao a idade, ao sexo, a manifestacao clinicas e antecedentes, cinquenta criancas com nefrolitiase. Todas elas foram submetidas a protocolo prospectivo que constou dos seguintes exames: urina I, urocultura, urinas de 24 horas para dosagem de calcio, acido urico e creatinina, urografia excretora, uretrocistografia miccional, ultra-som renal e prova de sobrecarga oral de calcio. As criancas foram classificadas quanto ao disturbio metabolico conforme criteiros ja estabelecidos. Das cinquenta criancas estudadas apenas 7 (14//) nao apresentaram anormalidade metabolica. Encontramos hipercalciuria renal (HCaR) em 17 (34//); absorvida (HAInt) em 16 (32//); hiperuricosuria (HEAcUr) em 7 (14//) e infeccao dotrato urinario (ITU) em 4 (8//). Observamos um caso de cistinuria. Atraves deste estudo pudemos verificar a importancia da avaliacao metabolica para proposicao de terapeutica especifica para cada caso, principalmente se considerarmos que em 86// das criancas estudadas houve deteccao de alguma, alteracao metabolica

Urolithiasis in childhood: metabolic evaluation.

In order to determine metabolic disorders in children with urolithiasis, 50 patients with urinary calculi were studied. Abdominal pain and/or haematuria were the most predominant symptoms. Surgical procedures were required in 22% of these children and urinary tract infection was observed in 34% of this group. Only 2 children had anatomical malformations of the urinary tract. Absorptive hypercalciuria (32%), renal hypercalciuria (34%) and uric acid hyperexcretion (24%) were the most common metabolic abnormalities in these children. We were unable to find an underlying metabolic abnormality in only 14% of the patients. These data suggest that appropriate metabolic study will allow rational management of children with urinary stones.

Metabolic disturbance as a cause of recurrent hematuria in children.

Metabolic disturbance as a cause of recurrent hematuria in children. To evaluate metabolic disturbance as a cause of hematuria, 250 children, aged eight months to fourteen years, with recurrent hematuria were studied. In the present series, metabolic disturbance was mainly due to idiopathic hypercalciuria (IH), the most common etiology of hematuria without proteinuria in childhood. Sixty-seven (27%) of the children had IH, ten children (4%) had hyperuricosuria, and 27 (11%) had nephrolithiasis. To better characterize the IH into renal (RH) or absorptive hypercalciuria (AH) subtypes, 45 of the 67 children (ranging age from six to twelve years) were further submitted to an oral calcium load test. Eighteen patients (40%) had AH, 7 (15.5%) RH and 20 (44.4%) could not be classified as having AH or RH [indeterminant (ID) idiopathic hypercalciuria group]. Intravenous pyelography or ultrasound were normal in all children. The oral calcium load test may be useful in characterizing the subtype of IH in some children; however, a great number of the IH children were characterized as indeterminant. Also hyperuricosuria, recently described as another metabolic disturbance associated with hematuria, may be an important cause of recurrent hematuria in children.

[Recurrent hematuria in children: study of 250 cases]. / Hematúria recorrente na infância: estudo de 250 casos.

In order to analyse the etiology of recurrent hematuria in childhood, we studied 250 children, referred to our Service (age: 6 mo-17 ys; 102 female and 148 male). They were submitted to the following protocol: urine analyses, uroculture, serum total and fraction complement, electrophoresis of hemoglobin, serum creatinine, BUN, 24h urinary calcium, uric acid and protein, oral calcium load test in children with hypercalciuria (UCa greater than 4mg/kg/day). Radiological evaluation and renal percutaneous biopsy was performed when necessary. The following diagnostic distribution was obtained: Alport syndrome, 19; Berger disease, 15; other glomerulopathies, 45; hypercalciuria, 67; uric acid hyperexcretion, 10; nephrolithiasis, 27; urinary tract infection, 14; renal malformation, 8; no diagnosis, 43. Based in these results, we conclude that appropriate investigation on recurrent hematuria, leads to determination of etiology in over 80% of cases.

Hydrocarbon aerosol pneumonitis in an adult.

A 20-year-old woman was exposed to a kerosene mist for five days at an insecticide manufacturing facility. She had shortness of breath, fever, severe hypoxemia, bilateral pulmonary infiltrates, and a notable reduction of diffusion capacity/total lung capacity ratio. Her symptoms and roentgenographic findings resolved rapidly after cessation of exposure and corticosteroid therapy. Whether her roentgenographic findings resulted from a pulmonary injury similar to that seen with aspirate hydrocarbons is unclear. Industrial exposure to hydrocarbon aerosols is a potential health hazard that may result in short-term and long-term pulmonary disability.