Diagnostic value of a test-strip in detecting increased urinary excretion of albumin, IgG and β₂-microglobulin in patients with suspected proteinuria

Abstract

Hemmingsen, L. & Skaarup, P. Diagnostic value of a test-strip in detecting increased urinary excretion of albumin, IgG and β₂-microglobulin in patients with suspected proteinuria. Scand. J. clin. Lab. Invest. 41, 785—789, 1981.

Test-strip screening for increased urinary protein excretion was performed in 482 patients with suspected proteinuria. The test-strip readings were compared with the urinary concentration and 24-h excretion of albumin, IgG and β₂-micro-globulin (β₂m), determined by an immunoprecipitin reaction, using the upper limit of the reference interval for these proteins for descriminating between normal and increased protein excretion. Increased concentration and 24-h excretion of albumin and IgG showed about 25 and 40 % false negative text-strip reactions, respectively, whereas only few false positive reactions were observed. Thus the predictive value of a negative test was low and that of a positive test high. The overall predictive value in detecting increased urinary excretion of β₂m was low. Consequently, test-strip results should be interpreted with caution, and specific protein determinations should be preferred in patients with suspected proteinuria.

Key Words:

• automated immunonephelometry
• dip-stick
• precision
• predictive value
• protein testing
• proteinuria
• sensitivity
• specific proteins