Background: 

Reliable estimates of glomerular filtration rate (GFR) are important in the clinical management of HIV-positive patients. Data on the performance of widely used estimating equations (eGFR) relative to exogenously measured GFR are sparse in this population.

Methods: 

We evaluated cross-sectional and longitudinal accuracy and bias of eGFR, based on creatinine and cystatin C, relative to disappearance of infused iohexol from plasma (iGFR) in a cohort of participants followed annually for up to 7 years.

Results: 

A total of 222 HIV-positive and 139 HIV-negative participants contributed 1240 visits with valid iGFR and eGFR measures. Estimated GFR based on both creatinine and cystatin C performed the best. Estimated GFR based on creatinine alone overestimated iGFR by 9 mL·min·1.73 m⁻² on average and was significantly less accurate in HIV-positive than HIV-negative individuals. The performance of equations based on either creatinine alone or cystatin C alone were significantly affected by participant factors (eg, non-suppressed HIV RNA, nadir CD4 count, hepatitis C virus coinfection). The average iGFR slope was −4% per year in HIV-positive participants. In both HIV-positive and HIV-negative participants, eGFR slope measures were generally unbiased but inaccurate, with only 60%–74% of observations falling within ±5% points of iGFR slope.

Conclusions: 

Both creatinine and cystatin C have limitations as GFR indices in HIV-positive individuals. Estimated GFR based on both creatinine and cystatin C performed best in our study and may be preferred in HIV-positive persons with kidney disease or comorbidities that place them at high risk for kidney disease.

中文翻译：

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基于肌酐和胱抑素C的估计方程的横断面和纵向性能（相对于外源测量的HIV阳性和HIV阴性者的肾小球滤过率）

背景： 

可靠的肾小球滤过率估计值对HIV阳性患者的临床管理很重要。在此人群中，与外测GFR相关的广泛使用的估计方程（eGFR）的性能数据很少。

方法： 

我们基于一组肌酐和半胱氨酸蛋白酶抑制剂C评估了eGFR的横截面和纵向精度以及偏倚，相对于一组参与者中从血浆（iGFR）中注入的碘海醇消失的情况，每年随访长达7年。

结果： 

共有222名HIV阳性和139名HIV阴性参与者通过有效的iGFR和eGFR措施进行了1240次随访。基于肌酐和半胱氨酸蛋白酶抑制剂C估算的GFR表现最佳。仅基于肌酐的估计GFR平均高出iGFR 9 mL·min·1.73 m ^-2，在HIV阳性患者中的准确率明显低于在HIV阴性个体中。单独基于肌酐或半胱氨酸蛋白酶抑制剂C的方程式的性能受参与者因素（例如，未抑制的HIV RNA，最低点CD4计数，丙型肝炎病毒）显着影响共同感染）。HIV阳性参与者的平均iGFR斜率每年为−4％。在HIV阳性和HIV阴性参与者中，eGFR斜率测量通常无偏见但不准确，只有60％–74％的观察结果落在iGFR斜率的±5％以内。

结论： 

无论肌酐和胱抑素C具有局限性，因为HIV阳性患者GFR指标。在我们的研究中，基于肌酐和半胱氨酸蛋白酶抑制剂C估算的GFR表现最佳，可能更适合患有肾脏疾病或合并有肾脏疾病高风险的HIV阳性患者。