Metabolic Evaluation of Infected Renal Lithiasis: Clinical Relevance

Abstract

Complete metabolic evaluation was performed in 21 patients with infected renal lithiasis. Patients with pure struvite stones (struvite +/- carbonate apatite) were significantly less likely to have metabolic abnormalities than patients who had struvite +/- carbonate apatite+calcium oxalate (2 of 14 v 7 of 7, P = 0.0003). Urine calcium excretion was markedly higher in the mixed stone group than the pure struvite group (342 +/- 98 mg/24 h v 136 +/- 82 mg/24 h; P < 0.0001). The differing opinions among researchers regarding the likelihood of finding metabolic abnormalities in patients with urolithiasis and infection probably reflect differences in the definitions of the populations studied. If patients with calculi containing only struvite +/- carbonate apatite are evaluated, we believe that few significant metabolic abnormalities will be identified.

Contemporary Management of Struvite Stones Using Combined Endourologic and Medical Treatment: Predictors of Unfavorable Clinical Outcome

“…22 Lingeman and associates 25 reported that only 14.2% of their pure struvite stone formers had a metabolic abnormality (hypercalciuria) whereas 100% of mixed struvite stones had abnormalities on 24-hour urine studies. In comparison, we found metabolic abnormalities (hypercalciuria, 2;…”

Associations between interventions for urolithiasis and urinary tract cancer among patients in Taiwan

“…This may be caused by the fact that a shortened urethra in females is associated with an increased risk of infection by certain pathogens, which can induce struvite (infection-related) stone formation. [25,26] Nevertheless, when we directly compared men and women with UTC, regardless of whether or not they had a history of urolithiasis, we found that men had a higher risk of developing UTC. This implied that men were exposed to more risk factors for UTC formation than women were.…”

Infection-Related Kidney Stones

“…This reaction neutralizes the normal negative charge of the urothelium, thereby favoring adhesion of nascent struvite crystals, and perhaps helping to accelerate crystal retention and growth of large struvite stones Clinic Rev Bone Miner Metab (2011) 9:218-228 221 treatment of the infection stone. In one series, persons with stones composed of struvite ± carbonate apatite rarely had contributing metabolic urinary abnormalities (2/14), while seven out of seven patients with stones containing calcium oxalate did [42]. In particular, urinary calcium excretion was markedly higher in the mixed stone group (349 vs. 136 mg/day) [42].…”

“…In one series, persons with stones composed of struvite ± carbonate apatite rarely had contributing metabolic urinary abnormalities (2/14), while seven out of seven patients with stones containing calcium oxalate did [42]. In particular, urinary calcium excretion was markedly higher in the mixed stone group (349 vs. 136 mg/day) [42]. The most common urease-producing bacteria implicated as causes for infection stones are Proteus, Klebsiella, Pseudomonas, and Staphylococcus species (Table 2) [43].…”