Clinical value of cystatin C determination

It has been reported that cystatin C (cys-C) is elevated in patients with m alignant disease. In order to investigate whether this phenomenon is linked to or independent of renal function, and at the same time examine the role of this marker in other pathological situations, cys-C concentrations were compared with 24-h creatinine clearance values in three groups of patients ; the first group were undergoing treatment for malignant disease, the seco nd group were renal transplant patients and the third randomly taken from p atients for whom a routine creatinine clearance had been requested. Several patients with malignant disease had high cys-C levels without any correspo ndence to creatinine clearance values. Additionally, although cys-C shows a high sensitivity for detecting: impaired glomerular function in renal tran splant patients, the specificity was very low, with little discrimination b eing observed between patients with normal and pathological creatinine clea rance levels. in other patients both the sensitivity and specificity of cys -C could be shown to be very good. Thus although cys-C can generally be rec ommended as a marker of the glomerular filtration rate, there are some pati ents for whom the clinical relevance is unclear. (C) 2000 Elsevier Science B.V. All rights reserved.