Objective:To analyze and compare the practical value of serum cystatin C(Scys C)and serum creatinine(SCr)in the assessment of kidney function in older adults.Methods:A retrospective, cross-sectional study was performed in 2 450 participants who were divided into a non-elderly group(<65 years)and an elderly group(≥65 years).Glomerular filtration rate(GFR), Scys C and SCr were measured by 99mTc-DTPA clearance, particle-enhanced immunoturbidimetry and an oxidase method, respectively.The χ2 test was used to compare increases in percentage of Scys C and SCr at the same GFR level.The screening value of Scys C and SCr for GFR<60 ml·min -1·1.73m -2was evaluated by the area under curve(AUC)of the receiver operating characteristic(ROC)curve.Values of 95% reference ranges were established for Scys C and SCr at different GFR levels. Results:The proportions of the general population with increased Scys C were 82.74%(556/672)and 94.74%(90/95), respectively, for GFR levels between 30~59 ml·min -1·1.73m -2and <30 ml·min -1·1.73m -2, while only 38.24%(257/672)and 75.79%(72/95)had elevated SCr levels( χ2=278.328, 13.571, both P<0.001).For the above GFR intervals, the proportions of older adults with increased Scys C were 84.81%(240/283)and 100.00%(43/43)respectively, and the proportions for non-elderly adults with increased Scys C were 81.23%(316/389)and 90.38%(47/52)( χ2=1.463, 4.364, P=0.226, 0.037), respectively.The screening value of Scys C for GFR<60 ml·min -1·1.73m -2was slightly better than SCr in terms of sensitivity, specificity and the Youden index.However, the sensitivity and specificity of Scys C in older adults were 76.4% and 75.7%, respectively, both lower than 78.7% and 84.0% in non-older adults.The variability of Scys C increased progressively with age.The reference range for Scys C was higher in older adults than in non-older adults at the same GFR level. Conclusions:When screening for GFR<60 ml·min -1·1.73m -2, the sensitivity and specificity of Scys C are slightly better than those of SCr, but are lower in older adults than in non-older adults.Scys C levels are higher and more variable in older adults.Using Scys C to assess GFR may lead to over-diagnosis of chronic kidney disease in older adults.

Background and purpose:Chimeric antigen receptor T(CAR-T)cell therapy has shown remarkable efficacy in treating hematological and lymphatic system tumors,but its effectiveness in solid tumors is relatively poor,which is partly attributed to target selection.For Ewing sarcoma(ES),CD99 can be a potential target for CAR-T cells.However,due to T cells'endogenous expression of CD99 protein,CAR-T cells targeting CD99 face limitations in their expansion capacity in vitro.This study aimed to identify the optimal conditions for preparing CD99 CAR-T cells by incorporating CD99 knockdown short hairpin RNA(shRNA),optimizing the multiplicity of infection(MOI)for lentiviral transduction,and screening for the best culture medium and container for CAR-T cell expansion.Methods:shRNA sequences were screened to enhance the expansion capacity of CD99 CAR-T cells.Different MOI,culture media,and containers were used to assess CAR-T cell transduction efficiency,cell viability,proliferation capacity,specific killing ability,and interferon-γ(IFN-γ)release levels under various conditions,in order to identify the optimal cell preparation conditions.Results:The expansion level of KO-CD99 CAR-T cells obtained through shRNA knockdown was significantly higher than that of CD99 CAR-T cells[(16.40±0.40)vs(6.33±1.53),P<0.01].The optimal expansion effect was observed when the transduction MOI was between 0.25 and 1.0,and OptiVitro was used as the culture medium.CAR-T cells cultured in ventilated flasks exhibited significantly higher expansion rates compared to cells cultured in bags[MOI=0.25:(50.23±3.32)vs(13.02±4.82);MOI=0.50:(49.96±0.83)vs(18.25±2.88);MOI=1.00:(48.27±5.08)vs(13.16±6.26);P<0.01],with better cell phenotype and higher specific killing ability.Conclusion:KO-CD99 CAR-T cells obtained through shRNA technology can achieve stable expansion.Based on the optimization of expansion conditions,KO-CD99 CAR-T cells exhibit superior expansion capacity and a higher proportion of memory T cells when the MOI is between 0.25 and 1.00,OptiVitro is used as the culture medium,and ventilated flasks are used as the culture container.These findings lay a solid foundation for further clinical trials of CD99 CAR-T cell therapy for ES.