Contribution of Serum Globulins to Total Fructosamine in Patients Treated by Haemodialysis

Assays of protein glycation are well established in the monitoring of long-term control of diabetes mellitus. Measures of haemoglobin glycation are widely accepted; but until recently the methods available were labour intensive, time consuming and difficult to automate. The same drawbacks have applied to methods assessing glycation of specific serum proteins. The fructosamine assay was described as a simple, automatable measure of serum protein glycation, I measuring the ability of glycated proteins to reduce nitro-blue tetrazolium (NBT) under alkaline conditions. It is prone to interference from other reducing agents in serum, and up to 60010 of NBT-reducing activity in serum may be unrelated to protein glycation.? Some specificity is provided by the reaction conditions chosen, but the assay is sensitive to changes in these.! About 80% of protein-bound activity reflects albumin glycation, the remainder reflecting glycation of globulins. Most workers have found the assay not to be sensitive to variation in serum proteins within the reference range, although correction for changes in albumin concentration during pregnancy has been suggested. Chronic renal failure (CRF) is a major complication of diabetes. Elevated fructosamine concentrations and fructosamine/albumin ratios (FAR) have been reported in non-diabetic patients with CRF, 4,5 but recent changes in the formulation and standardization of commercial