Special Precautions/Comments:

On first detection of proteinuria (ACR 3-70 mg/mmol) repeat on early morning sample. NICE/regional guidelines recommend referral if ACR >30 mg/mmol with haematuria or any patient with ACR >70 mg/mmol unless known diabetes mellitus and already treated.  

Additional Information:

Only small amounts of protein are usually found in the urine because proteins are too large to pass through the glomerulus of the kidney. Increased amounts of protein in the urine (proteinuria) indicate inappropriate loss and possible kidney damage. The most abundant protein seen in both urine and serum is albumin. Microalbumin refers to the small amounts of albumin seen in urine, rather than a smaller form of albumin itself. Urine microalbumin is reported as an albumin creatinine ratio (ACR). Although a urine dipstick is useful for screening, laboratory measurement of urine microalbumin is much more sensitive.  

Proteinuria is screened for in pregnancy and in diabetes to check renal function. Urine ACR is used to investigate and stage chronic kidney disease (CKD). Urine ACR may also be elevated in nephrotic syndrome. Total urine protein, reported as a urine protein creatinine ratio (PCR), can also be measured and can be elevated in multiple myeloma (Bence Jones protein). Urine PCR is automatically reflexed if microalbumin >400 mg.