Development and Evaluation of a Quantitative Fluorescent Lateral Flow Immunoassay for Cystatin-C, a Renal Dysfunction Biomarker

Abstract

The diagnosis, prognosis, and control of chronic kidney disease rely on an understanding of the glomerular filtration rate (GFR). The renal clearance of the cystatin-C is closely associated with the GFR. Cystatin-C is a more suitable GFR marker than the commonly used creatinine. General techniques for cystatin-C calculation, such as particle-enhanced turbidimetric and nephelometric assay, are time-consuming and tedious. Here, we propose a rapid, quantitative immunoassay for the detection of cystatin-C. A fluorescence-based lateral-flow kit was developed in a sandwich format by using a monoclonal antibody. A Linear calibration was obtained over the clinical diagnostic range of 0.023–32 µg/mL and the limit of detection (LOD) was 0.023 µg/mL and the limit of quantification (LOQ) was 0.029 µg/mL. Average recoveries from spiked urine samples ranged from 96–100% and the coefficient of variation was less than 4% for both intra and inter-day assays with excellent repeatability. With the comparison with an ELISA kit, the developed kit is highly sensitive, performs well over the detection range, provides repeatable results in a short time, and can easily be used at point-of-care (POC), making it an ideal candidate for rapid testing in early detection, community screening for renal function disorders.

Nucleic Acid Nanotechnology for Diagnostics and Therapeutics in Acute Kidney Injury

“…The LOD was 216.077 pg/mL. Natarajan et al [ 27 ] designed a quantitative fluorescence kit for cysC based on an aptamer-antibody pair-based lateral flow assay (LFA), in which the target protein formed a sandwich-like structure together with 5’-dye-modified aptamer and cysC-specific capturing antibodies. The LOD of this aptamer-based kit was 0.023 µg/mL, which was comparable to commercially available cysC kit.…”

Design and Engineering of a Palm-Sized Optical Immunosensing Device for the Detection of a Kidney Dysfunction Biomarker

“…Thus, we attempted to incorporate the anti-CR antibody onto a paper surface to make the reaction more selective and sensitive. Although a few attempts were made to develop a lateral flow assay-based kit for creatinine detection, especially for kidney patients, in such a system, there is a chance of an interruption in the flow of the target analyte due to the profusion of pores [ 34 , 37 ]. This issue has been examined and resolved by using a paper disc, which does not require any sample movement, thus having an edge on other systems [ 34 , 38 ].…”

A Non-Immunized and BSA-Template Aggregation-Induced Emission Sensor for Noninvasive Detection of Cystatin C in the Clinical Diagnosis of Diabetes Nephropathy

“…Besides, Cys C can be filtered through glomerulus, reabsorbed, and degraded by renal tubular epithelial cells. , When renal tubular function is damaged, Cys C can not be reabsorbed or degraded in renal tubules, resulting in the Cys C concentration having a notable increase in urine. Meanwhile, the increase of serum Cys C level is an index that could effectively reflect glomerular injury. , Therefore, Cys C could not only be used as an important indicator of glomerular filtration rate but also reflect the degree of renal tubular injury. , Accumulative evidence had proved that tubulointerstitial lesion is the main feature of DN. − The inflammatory reaction caused by renal tubular injury could lead to tubulointerstitial fibrosis. − In the process of DN, the kidney is the only organ that clears serum Cys C. Indeed, Cys C expression is usually abnormal when renal damage has occurred. What’s more, Cys C concentration is not affected by gender, weight, age, and other factors.…”

“…Meanwhile, the increase of serum Cys C level is an index that could effectively reflect glomerular injury. 15,16 Therefore, Cys C could not only be used as an important indicator of glomerular filtration rate but also reflect the degree of renal tubular injury. 15,16 Accumulative evidence had proved that tubulointerstitial lesion is the main feature of DN.…”

“…15,16 Therefore, Cys C could not only be used as an important indicator of glomerular filtration rate but also reflect the degree of renal tubular injury. 15,16 Accumulative evidence had proved that tubulointerstitial lesion is the main feature of DN. 17−19 The inflammatory reaction caused by renal tubular injury could lead to tubulointerstitial fibrosis.…”