Morpho-Constitutional Classification of Urinary Stones as Prospective Approach for the Management of Human Pathological Biomineralization: New Insights from Southern Italy

The present investigation exposes the main results raised from an active collaboration started in 2018 with the San Pio Hospital (Benevento, Southern Italy), aiming at a detailed mineralogical investigation of urinary stones of patients from the Campania region. Forty-nine uroliths (both bladder and kidney stones) have been surgically collected from patients admitted between 2018 and 2020 at the Department of Urology of the San Pio Hospital and characterized for clinical purposes and environmental biomonitoring from a mineralogical point of view. Possible causes and environmental implications were inferred according to the morpho-constitutional classification of the uroliths carried out by means of a conventional analytical approach. The mineralogical frequency distribution of uroliths from the Campanian region can be discussed as a function of dietary, socio-demographic, and environmental risk factors. Whewellite [CaC2O4 center dot H2O] and weddellite [CaC2O4 center dot(2+x)H2O], along with anhydrous calcium oxalate, represent the main mineralogical phases forming the biominerals examined here. Worth to note is that the percentage of oxalates in the Campanian region (ca. 51%) is quite comparable to those of other Mediterranean areas. Frequent uricite [C5H4N4O3] (ca. 33%), mainly observed in bladder stones of older male patients, could be related to an incorrect lifestyle and dietary habits. Occurrence of lower percentages of phosphate (i.e., brushite [CaHPO4 center dot 2(H2O)] and carbonated apatite [Ca-10(PO4CO3)(6)(OH)(8)]) and mixed stones (such as, for example, a mixture of ammonium urate [NH4C5H3N4O3] and calcium oxalates) indicates specific etiopathogenetic mechanisms, suggesting proper therapeutical approaches.

Automated summary

This study conducted a detailed mineralogical investigation of urinary stones from patients in the Campania region, finding that hydrated and anhydrous calcium oxalate were the main mineral phases. Higher percentages of oxalates and uricites were observed, possibly related to dietary and lifestyle factors. Lower percentages of phosphates and mixed stones suggest specific etiopathogenetic mechanisms, requiring proper therapeutic approaches.