Sponge kidney and renal lithiasis

Abstract

Introduction: Sponge kidney is a renal malformation of the collecting tubules, which is usually associated with nephrocalcinosis or distal tubular acidosis. The association with renal lithiasis is observed between 4-20%. Objective: The aim of our work was to describe the biochemical risk factors of renal lithiasis in patients with sponge kidney. Methods: A retrospective, observational, cross-sectional study was conducted between 2000 and 2017, in which 37 patients with sponge kidney and renal lithiasis (26 women and 11 men), aged 37.3 ± 13.2 years, were studied. The diagnosis of sponge kidney was made by excretory urography. Results: Nephrocalcinosis was observed in 95% of patients. The most frequent biochemical diagnosis was idiopathic hypercalciuria, which was observed, as a single and associated alteration, in 59.4% of cases. Hyperuricosuria was the second diagnosis found in 32.4% (single and associated) followed by hypocitraturia, hypomagnesuria and persistently acid pHu. Surprisingly, 46.2% of men presented no biochemical alteration. Conclusions: Our findings highlight the relatively frequent association of sponge kidney and renal lithiasis. Idiopathic hypercalciuria was the most common metabolic alteration as the cause of lithogenesis, followed by hyperuricosuria, similar to that described in the literature, but to a lesser extent. Other alterations, such as hypocitraturia, hypomagnesuria and persistently acid pHu, should also be considered in the study of these patients.

Keywords

• riñón en esponja
• litiasis renal
• alteraciones bioquímicas
• malformaciones renales