The Modification of Diet in Renal Disease (MDRD) equations provide a rapid method of assessing GFR in patients with chronic kidney disease (CKD). However, previous research indicated that modification of these equations is necessary for application in Chinese patients with CKD. The objective of this study was to modify MDRD equations on the basis of the data from the Chinese CKD population and compare the diagnostic performance of the modified MDRD equations with that of the original MDRD equations across CKD stages in a multicenter, cross-sectional study of GFR estimation from plasma creatinine, demographic data, and clinical characteristics. A total of 684 adult patients with CKD, from nine geographic regions of China were selected. A random sample of 454 of these patients were included in the training sample set, and the remaining 230 patients were included in the testing sample set. With the use of the dual plasma sampling 99m Tc-DTPA plasma clearance method as a reference for GFR measurement, the original MDRD equations were modified by two methods: First, by adding a racial factor for Chinese in the original MDRD equations, and, second, by applying multiple linear regression to the training sample and modifying the coefficient that is associated with each variable in the original MDRD equations and then validating in the testing sample and comparing it with the original MDRD equations. All modified MDRD equations showed significant performance improvement in bias, precision, and accuracy compared with the original MDRD equations, and the percentage of estimated GFR that did not deviate >30% from the reference GFR was >75%. The modified MDRD equations that were based on the Chinese patients with CKD offered significant advantages in different CKD stages and could be applied in clinical practice, at least in Chinese patients with CKD.

The CKD-EPI two-level race equation and the Chinese equation performed similarly in the Chinese population, and both performed better than the MDRD Study equation and the CKD-EPI four-level race equation.

Plasma creatinine may not reflect glomerular filtration rate (GFR) especially in the early stages of chronic kidney disease (CKD). Plasma cystatin C (cysC), however, has the potential to more accurately determine early GFR reduction. We sought to improve the creatinine-based GFR estimation by including cysC measurements. We derived a reference GFR from standard dual plasma sampling (99m)Tc-DTPA clearance in a training cohort of 376 randomly selected adult Chinese patients with CKD. We compared reference values to estimated GFR and applied multiple regression models to one equation based solely on cysC, and to another combining plasma creatinine (Pcr) and cysC measurements of the training cohort. The results were validated by testing an additional 191 patients. The difference, precision, and accuracy of the two estimates were compared with the modified Modification of Diet in Renal Disease (MDRD) equation for Chinese patients, and another estimate combining cysC and modified MDRD calculations. The estimated GFR combining Pcr and cysC measurements more accurately matched the reference GFR at all stages of CKD than the other equations, particularly in patients with near-normal kidney function.

Lipoprotein glomerulopathy is a rare inherited renal disease, caused by mutation of the APOE gene, characterized by proteinuria and nephrotic syndrome with elevated serum apoE. Since its treatment and outcome are unknown, we retrospectively studied 35 patients within 31 unrelated Han families with biopsy-proven lipoprotein glomerulopathy residing in the same county in southwest China. DNA sequencing detected the APOE Kyoto mutation (p. Arg25Cys) in all patients and 28 asymptomatic relatives. All shared the same ɛ3 allele. The patients presented with proteinuria, higher total triglyceride, and serum apoE levels relative to non-carriers. The serum apoE and triglyceride levels of asymptomatic carriers were between those of the patients and non-carriers. Sixteen patients received fenofibrate treatment for over 12 months. Six reached complete remission (proteinuria under 0.3 g/day with stable serum creatinine) with intensive control of their lipid profile (normalized serum apoE and triglycerides under 100 mg/dl). Eight reached partial remission. At 3 years of follow-up, patients treated with fenofibrate had superior survival and stable renal function. Thus, fenofibrate can induce lipoprotein glomerulopathy remission and the fibrate effects depend on the degree of lipid control and baseline proteinuria. Moreover, normalization of serum apoE and triglycerides can be used to judge the efficacy of lipid-lowering treatment.

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