Measurement of urinary albumin excretion (UAE) in diabetic patients: immunonephelometry versus radioimmunoassay.
We have compared the chemico-clinical characteristics of an immuno-nephelometric technique (INA) with those of a solid-phase radioimmunoassay (RIA) method for the measurement of urinary albumin excretion (UAE) in diabetic patients. The UAE was evaluated in 227 diabetics; all, except 9, were Albustix-negative. The calibration of the nephelometer apparatus every time before the assay did significantly improve the accuracy and precision of the INA method. Similar values were obtained with the two methods (INA = 2.1 + 0.95 RIA, n = 227, r = 0.969) through all the ranges of albumin concentration explored. INA seems as suitable as RIA for the assay of UAE in diabetics. The two methods are comparably accurate and precise. However, RIA appears more sensitive than INA, while immunonephelometric system is easier and faster to perform (up to 200 samples can be assayed in about 1 hour, while 2-4 hours are necessary with RIA), with fewer handling steps. The INA instrumentation is automated and the reagents are more stable and less hazardous than those used in RIA. However, due to the cost of the nephelometer apparatus, the INA technique may be employed by those laboratories which have already this instrumentation or by those which will use it in the next future for the assay of other analytes in addition to albumin.
Giampietro
O
O
Lucchetti
A
A
Cruschelli
L
L
Clerico
A
A
Berni
R
R
Penno
G
G
Gregori
G
G
Bertoli
S
S
Giordani
R
R
Navalesi
R
R
D000419:Albuminuria / Q000175:diagnosis*; D002138:Calibration; D003365:Costs and Cost Analysis; D003928:Diabetic Nephropathies / Q000652:urine*; D006801:Humans; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation / Q000379:methods*; D011863:Radioimmunoassay; D011933:Reagent Kits, Diagnostic
D011933:Reagent Kits, Diagnostic