ALB and diabetic kidney disease: Though albuminuria has classically been considered the sine qua non of diabetic kidney disease, there is increasing recognition that many persons with diabetes and CKD do not have persistent or extreme elevations in urine albumin, even in cases of biopsy-diagnosed diabetic kidney disease.35, 36, 37, 38 These findings underscore the importance of identifying additional biomarkers, especially those that can reveal the accrual of tubulointerstitial damage.