Division of Nephrology, Department of Medicine, Mount Sinai School of Medicine, New York, New York, United States of America.
PLoS One. 2013 Aug 8;8(8):e69601. doi: 10.1371/journal.pone.0069601. eCollection 2013.
More than two-thirds of the world's HIV-positive individuals live in sub-Saharan Africa, where genetic susceptibility to kidney disease is high and resources for kidney disease screening and antiretroviral therapy (ART) toxicity monitoring are limited. Equations to estimate glomerular filtration rate (GFR) from serum creatinine were derived in Western populations and may be less accurate in this population.
We compared results from published GFR estimating equations with a direct measure of GFR by iohexol clearance in 99 HIV-infected, ART-naïve Kenyan adults. Iohexol concentration was measured from dried blood spots on filter paper. The bias ratio (mean of the ratio of estimated to measured GFR) and accuracy (percentage of estimates within 30% of the measured GFR) were calculated.
The median age was 35 years, and 60% were women. The majority had asymptomatic HIV, with median CD4+ cell count of 355 cells/mm(3). Median measured GFR was 115 mL/min/1.73 m(2). Overall accuracy was highest for the Chronic Kidney Disease Epidemiology Consortium (CKD-EPI) equation. Consistent with a prior report, bias and accuracy were improved by eliminating the coefficient for black race (85% of estimates within 30% of measured GFR). Accuracy of all equations was poor in participants with GFR 60-90 mL/min/1.73 m(2) (<65% of estimates within 30% of measured GFR), although this subgroup was too small to reach definitive conclusions.
Overall accuracy was highest for the CKD-EPI equation. Eliminating the coefficient for race further improved performance. Future studies are needed to determine the most accurate GFR estimate for use in individuals with GFR <90 mL/min/1.73 m(2), in whom accurate estimation of kidney function is important to guide drug dosing. Direct measurement of GFR by iohexol clearance using a filter paper based assay is feasible for research purposes in resource-limited settings, and could be used to develop more accurate GFR estimates in African populations.
全世界超过三分之二的 HIV 阳性个体生活在撒哈拉以南非洲地区，该地区对肾脏疾病的遗传易感性较高，而用于肾脏疾病筛查和抗逆转录病毒治疗 (ART) 毒性监测的资源有限。从血清肌酐推导肾小球滤过率 (GFR) 的方程是在西方人群中得出的，在该人群中可能不太准确。
我们比较了来自已发表的 GFR 估算方程的结果与通过 iohexol 清除率直接测量的 99 名 HIV 感染、未接受 ART 的肯尼亚成年人的 GFR。iohexol 浓度是从滤纸上的干血斑中测量的。计算了估算的与测量的 GFR 之比的平均值（比值的均值）和准确性（估计值在测量的 GFR 的 30%范围内的百分比）。
中位年龄为 35 岁，60%为女性。大多数人患有无症状 HIV，中位 CD4+细胞计数为 355 个细胞/mm3。中位测量的 GFR 为 115 mL/min/1.73 m2。总体而言，慢性肾脏病流行病学合作 (CKD-EPI) 方程的准确性最高。与之前的报告一致，通过消除黑人种族的系数（85%的估计值在测量的 GFR 的 30%范围内），可以提高偏差和准确性。所有方程在 GFR 60-90 mL/min/1.73 m2 的参与者中的准确性都较差（<65%的估计值在测量的 GFR 的 30%范围内），尽管该亚组太小，无法得出明确的结论。
总体而言，CKD-EPI 方程的准确性最高。消除种族系数进一步提高了性能。需要进一步的研究来确定最准确的 GFR 估计值，用于 GFR<90 mL/min/1.73 m2 的个体，在这些个体中，准确估计肾功能对于指导药物剂量很重要。使用基于滤纸的测定法通过 iohexol 清除直接测量 GFR 对于资源有限的环境中的研究是可行的，并且可以用于在非洲人群中开发更准确的 GFR 估计值。
