Albumin and beta 2-microglobulin radioimmunoassays applied to monitoring of renal-allograft function and in differentiating glomerular and tubular diseases.

Blood and urine were samples daily from 11 renal-allograft recipients from one to six weeks after the transplant. Clearances of both albumin (Calb) and beta2-microglobulin (C beta 2 mu) were significantly increased in all 11 patients. Five patients (Group I) with acute allograft rejection showed markedly increased Calb and moderately increased C beta 2 mu, concurrent with decreased creatinine clearance (CCr). Five other patients (Group II) with no evidence of rejection demonstrated episodes of grossly increased C beta 2 mu with minimally increased but stable Calb and normal CCr. One patient had no evidence of rejection nor indications of glomerular or tubular proteinuria. While changes in serum beta 2-microglobulin concentration closely paralleled those of serum creatinine in the Group II patients, the results diverged in the Group I patients because the increase in serum beta 2-microglobulin exceeded that of serum creatinine and preceded the increased in creatinine by one to five days, suggesting that measurement of serum beta 2-microglobulin might afford earlier indication of the nature and extent of renal damage in the allograft recipients.