INCREASED URINARY-EXCRETION OF NON-ALBUMIN ANTIGEN DETECTED WITH YO-2, A NOVEL MONOCLONAL-ANTIBODY, IN DIABETIC-PATIENTS

Monoclonal antibodies were raised against urine proteins from diabetic patients. An antibody, YO-2, stained three protein bands with apparen t molecular weights of 66, 49, and 36 kDa. These bands were not reacti ve with an anti-human albumin antibody, The urine levels of YO-2-react ive antigen in the normal control were 0.97 +/- 0.37 U/g-Cr (units per gram of urine creatinine) (mean +/- SD). Those of the normo-, micro-, and macroalbuminuric diabetic patients, respectively, were 1.38 +/- 1 .36, 2.87 +/- 2.07, and 3.92 +/- 3.33 U/g-Cr. They were significantly higher in the micro- and macroalbuminuric patients. The urine levels o f YO-2-reactive antigen had no significant correlation with the urine albumin levels and hemoglobin A(1c). We concluded that; a) monoclonal antibody YO-2 recognized a non-albumin urine antigen increasingly excr eted in diabetic patients with nephropathy, b) recent glycemic control of diabetes would not significantly affect the urinary excretion rate of YO-2-reactive antigen, and c) the excretion rate and probably the mechanism of YO-2-reactive protein differed from those of albumin. The urine levels of YO-2-reactive antigen could be a clinical marker of d iabetic nephropathy.