ImmunoDip: an improved screening method for microalbuminuria.
BACKGROUND
It is important to test for microalbuminuria in patients with diabetes, hypertension and possible insulin resistance syndrome. Current screening methods are suboptimal. This study evaluates a new office screening test for microalbuminuria that utilizes a monoclonal antibody against human serum albumin (ImmunoDip).


METHODS
182 urine samples were collected from patients attending diabetes, nephrology or hypertension clinics. The ImmunoDip screening test was carried out in the 182 samples after which albumin and creatinine concentrations were measured quantitatively in a reference laboratory.


RESULTS
Screening the 182 patient samples with ImmunoDip and designating an albumin:creatinine ratio of > or =30 microg/mg as positive yielded a sensitivity of 96%, a specificity of 80%, a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 98%. The reduced specificity and PPV were not due to an intrinsic inaccuracy with ImmunoDip screening of these samples, but rather was shown to be due to the discordance between the accepted upper limits of normal for the albumin:creatinine ratio (30 microg/mg) and the albumin concentration (20 mg/l), the latter corresponding to a ratio of 20 microg/mg. In 35 samples with albumin concentrations of 20-50 mg/l, ImmunoDip screening yielded only one false negative (FN) result.


CONCLUSIONS
ImmunoDip is an excellent screening tool for microalbuminuria.
Davidson
Mayer B
MB
Clinical Trials Unit, Charles R. Drew University, Los Angeles, Calif 90059, USA. mdavids@cdrewu.edu
Bazargan
Mohsen
M
Bakris
George
G
Peters Harmel
Anne
A
Campese
Vito
V
Basta
Emad
E
D000419:Albuminuria / Q000652:urine*; D006801:Humans; D011934:Reagent Strips / Q000592:standards
D011934:Reagent Strips