A modification of the commercial radioimmunoassay (RIA) kit adapting to the assay
of β-thromboglobulin (β-TG) in the urine, is described. The urine was concentrated
by dialysis against dry Sepharose G 200. l31I-albumin was used as marker. Experiments in which l25I-β-TG and 131I-albumin were added simultaneously showed a parallel recovery of both markers in
the final sample. The sensitivity of the RIA was enhanced by incubation overnight
of the urine sample with the antiserum. Increased urinary pTG values were found in
20 patients with diabetes mellitus as compared to 20 young healthy normals. Increased
urinary β-TG values correlated with decreased creatinine clearance, but the difference
between diabetics and normals was still observed when patients with a creatinine clearance
of less than 100 ml/min were excluded. The urine βTG level was correlated with the
presence of neovascularization within the diabetic group.
Keywords
β-thromboglobulin - Diabetes - Microangiopathy - Radioimmunoassay
