Nephrology Section MC 5100, University of Chicago Medicine, 5841 S. Maryland Avenue, Chicago, Illinois, 60637 USA.
Department of Anatomy and Cell Biology, Indiana University School of Medicine, 635 Barnhill Drive, MS 5055, Indianapolis, IN 46220, Indiana, USA.
Nat Rev Nephrol. 2016 Sep;12(9):519-33. doi: 10.1038/nrneph.2016.101. Epub 2016 Jul 25.
The most common presentation of nephrolithiasis is idiopathic calcium stones in patients without systemic disease. Most stones are primarily composed of calcium oxalate and form on a base of interstitial apatite deposits, known as Randall's plaque. By contrast some stones are composed largely of calcium phosphate, as either hydroxyapatite or brushite (calcium monohydrogen phosphate), and are usually accompanied by deposits of calcium phosphate in the Bellini ducts. These deposits result in local tissue damage and might serve as a site of mineral overgrowth. Stone formation is driven by supersaturation of urine with calcium oxalate and brushite. The level of supersaturation is related to fluid intake as well as to the levels of urinary citrate and calcium. Risk of stone formation is increased when urine citrate excretion is <400 mg per day, and treatment with potassium citrate has been used to prevent stones. Urine calcium levels >200 mg per day also increase stone risk and often result in negative calcium balance. Reduced renal calcium reabsorption has a role in idiopathic hypercalciuria. Low sodium diets and thiazide-type diuretics lower urine calcium levels and potentially reduce the risk of stone recurrence and bone disease.
肾结石最常见的表现是特发性钙结石，发生于无系统性疾病的患者中。大多数结石主要由草酸钙组成，在间质磷灰石沉积的基础上形成，即 Randall 斑。相比之下，一些结石主要由磷酸钙组成，可为羟磷灰石或二水草酸钙（磷酸氢钙），通常伴有 Bellini 管内的磷酸钙沉积。这些沉积物导致局部组织损伤，并可能成为矿物质过度生长的部位。结石形成是由尿液中草酸钙和二水草酸钙过饱和度驱动的。过饱和度水平与液体摄入以及尿枸橼酸盐和钙的水平有关。当尿枸橼酸盐排泄 <400mg/天时，结石形成的风险增加，并且已经使用枸橼酸钾治疗来预防结石。每日尿钙水平 >200mg 也会增加结石风险，并且经常导致负钙平衡。肾脏钙重吸收减少在特发性高钙尿症中起作用。低钠饮食和噻嗪类利尿剂降低尿钙水平，并可能降低结石复发和骨病的风险。
