Sakhaee K, Poindexter J R, Pak C Y
Center in Mineral Metabolism and Clinical Research, University of Texas Southwestern Medical Center, Dallas 75235.
J Urol. 1989 Apr;141(4):819-21. doi: 10.1016/s0022-5347(17)41019-6.
To elucidate the pathophysiology of mixed stone formation in cystinuria, 27 patients with documented cystine nephrolithiasis underwent an inpatient evaluation under a constant dietary regimen. All patients had homozygous cystinuria, since the daily urinary cystine excretion exceeded 250 mg. per gm. creatinine. Hypercalciuria was noted in 5 patients (18.5 per cent), 4 of whom had fasting hypercalciuria. Hyperuricosuria was found in 6 patients (22.2 per cent) and it was not caused by a consumption of a diet rich in animal proteins, since urinary pH was higher and urinary sulfate lower than in control subjects. Serum uric acid was slightly lower and uric acid clearance was higher in hyperuricosuric patients than in control subjects. Hypocitraturia was found in 12 patients (44.4 per cent) and it was associated with defective renal acidification in 4 of 5 patients in whom it was tested. Thus, hypercalciuria, hyperuricosuria and hypocitraturia frequently accompany cystinuria in patients with cystine nephrolithiasis. These conditions might be renal in origin, rather than a result of dietary or environmental aberrations. They may contribute to the formation of calcium and uric acid stones, which sometimes complicate cystine nephrolithiasis.
为阐明胱氨酸尿症中混合结石形成的病理生理学，27例有记录的胱氨酸肾结石患者在恒定饮食方案下接受了住院评估。所有患者均为纯合子胱氨酸尿症，因为每日尿胱氨酸排泄量超过每克肌酐250毫克。5例患者（18.5%）出现高钙尿症，其中4例有空腹高钙尿症。6例患者（22.2%）发现高尿酸尿症，且其并非由富含动物蛋白的饮食所致，因为与对照受试者相比，其尿pH值更高，尿硫酸盐更低。高尿酸尿症患者的血清尿酸略低，尿酸清除率高于对照受试者。12例患者（44.4%）发现低枸橼酸尿症，在接受检测的5例患者中，有4例与肾酸化缺陷有关。因此，高钙尿症、高尿酸尿症和低枸橼酸尿症在胱氨酸肾结石患者的胱氨酸尿症中经常出现。这些情况可能源于肾脏，而非饮食或环境异常的结果。它们可能促成钙和尿酸结石的形成，而这些结石有时会使胱氨酸肾结石复杂化。
