Urinary tract infection’s etiopathogenic role in nephrolithiasis formation

J.L. Bauza, E.C. Pieras, F. Grases, V. Tubau, J. Guimerà, X.A. Sabaté, P. Pizà

Urolithiasis has a high prevalence and recurrence rate, especially in developed countries, and is a major public health issue with a high socioeconomic cost. There are multiple causes of urolithiasis, including urinary tract infection (UTI). Infection stones (mainly composed of struvite) are associated with renal infections by urease-producing bacteria. However, there is limited knowledge about the role of UTIs in the formation of stones that are apparently not related with infection. We hypothesize that UTIs promote the formation of certain urolithiasis that appear to be non-infection stones. Some recent studies have reported the presence of bacterial growth in cultures of stones removed by endourological procedures. These findings have led to the hypothesis that UTIs have a role in the formation of stones that are apparently non-infection stones. It is unknown whether these UTIs promoted stone formation, or if the stones became infected after formation. Several in vitro studies and ultrastructural microscopic analyses of urolithiasis are consistent with our hypothesis. If our hypothesis is correct, it could have a great impact on the treatment of urolithiasis. Especially, early identification and treatment of renal infections could help to prevent septic events, which are frequently life-threatening. It could also help to reduce the recurrence of urolithiasis, and thereby reduce health care costs. In conclusion, some evidence suggests that UTIs have a role in the formation of some apparently non-infection urolithiasis. If this is so, it could have a great impact on the treatment and prevention of this disease.