As the prevalence of chronic kidney disease continues to increase dramatically so does the burden on healthcare resources worldwide. The early detection of kidney disease is crucial in order to reduce healthcare costs, avoid disease progression and the need for dialysis or transplantation.
Traditionally creatinine was the most widely used marker of GFR and kidney function however several recent studies have documented cystatin C as a far superior and sensitive marker. Cystatin C is produced at a constant rate throughout the body and is removed and broken down by the kidneys, levels will therefore remain steady if the kidneys are working efficiently and the GFR is normal.
Unlike creatinine, cystatin C is virtually unaffected by non renal factors including muscle mass, weight, height, age, gender, diet and drugs. This makes it particularly useful in cases where creatinine measurement is not appropriate e.g. in individuals who are obese, malnourished or who have liver disease. Cystatin C is also sensitive to changes in the ‘creatinine blind’ range enabling detection of early reductions in GFR and subsequent early treatment of kidney disease. In addition to this cystatin C shows several other advantages over creatinine; the ability of cystatin C to detect even small changes in GFR makes it the ideal marker for dosing medication eliminated by the kidneys. Cystatin C is also the preferred marker for estimating GFR in infants, the elderly, diabetics and those with reduced muscle mass.
The Randox cystatin C assay is based on an immunoturbidimetric method and is suitable for use on a wide range of chemistry analysers. All reagents are supplied liquid ready to use for added convenience, furthermore reagents are stable for 28 days at +10 C onboard the analyser minimising the possibility of reagent waste. The assay has a wide measuring range of 0.4 to 10 mg/l allowing both normal and abnormal values to be measured accurately and reliably without the need for additional dilutions. Further benefits include excellent precision (CVs under 5%) and limited interference from bilirubin, haemoglobin, triglycerides, and intralipids. A full range of supporting quality controls and calibrators are also available.