High carbonate level of apatite in kidney stones implies infection, but is it predictive?
High carbonate level of apatite in kidney stones implies infection, but is it predictive?
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DOI：
10.1007/s00240-013-0591-6
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发表时间：
2013-10-01
期刊：
影响因子：
3.1
通讯作者：
Williams, James C., Jr.
中科院分区：
文献类型：
--
作者：
Englert, Kate M.;McAteer, James A.;Williams, James C., Jr.
泌尿系结石中感染性微生物的存在通常是从结石的组成，特别是通过结石中鸟粪石的存在来推断的。高度碳酸化的磷灰石的存在也被认为是结石中细菌存在的标志。我们回顾性研究了368例接受经皮肾镜取石术（PCNL）的患者，他们也有结石和尿液培养结果。尿培养与结石矿物含量无关，但含鸟粪石结石（73%）和大多数磷灰石结石（65%）的结石培养阳性率明显高于其他类型结石（54%），P < 0.02。在51例可测量磷灰石碳酸盐含量的患者中，磷灰石中的碳酸盐对阳性结石培养的预测能力较弱，最佳临界值为13.5%碳酸盐（灵敏度0.61，特异性0.80）。在结石的阳性培养物中（所有矿物类型组合），71%的病例中存在特征性产生尿素酶的生物体，不同类型结石的比例没有差异。总之，石头中的矿物类型是阳性结石文化的预测，但这种相关性是不完善的，因为超过一半的非鸟粪石，非磷灰石石头被发现窝藏可培养的生物体。我们的结论是，矿物类型是一个不充分的预测结石是否含有感染性微生物，结石文化更有可能提供有用的信息，接受PCNL的患者的管理。
The presence of infectious microorganisms in urinary stones is commonly inferred from stone composition, especially by the presence of struvite in a stone. The presence of highly carbonated apatite has also been proposed as a marker of the presence of bacteria within a stone. We retrospectively studied 368 patients who had undergone percutaneous nephrolithotomy (PCNL), and who also had culture results for both stone and urine. Urine culture showed no association with stone mineral content, but stone culture was more often positive in struvite-containing stones (73 % positive) and majority apatite stones (65 %) than in other stone types (54 %, lower than the others, P < 0.02). In 51 patients in whom the carbonate content of apatite could be measured, carbonate in the apatite was weakly predictive of positive stone culture with an optimal cutoff value of 13.5 % carbonate (sensitivity 0.61, specificity 0.80). In positive cultures of stones (all mineral types combined), organisms that characteristically produce urease were present in 71 % of the cases, with no difference in this proportion among different types of stone. In summary, the type of mineral in the stone was predictive of positive stone culture, but this correlation is imperfect, as over half of non-struvite, non-apatite stones were found to harbor culturable organisms. We conclude that mineral type is an inadequate predictor of whether a stone contains infectious organisms, and that stone culture is more likely to provide information useful to the management of patients undergoing PCNL.