Skip to main content

Department

Biochemistry

Preferred Sample Type

Urine Protein:Creatinine ratio (Random urine)

Suitable Specimen Types

  • Plain Spot Urine
2 mL (minimum sample volume 0.5 mL)

Sample Processing in Laboratory

Usual

Sample Preparation

Usual

Turnaround Time

1 Day

Sample Stability

4 ºC

Urine Protein:Creatinine ratio (Random urine)

General Information

Diabetes is a very common cause of kidney failure. Studies have shown that identifying diabetics in the very early stages of kidney disease by demonstrating an abnormal albumin:creatinine ratio (ACR) helps patients and doctors adjust treatment. With better diabetic control and better control of other complications, such as high blood pressure, the progression of diabetic kidney disease can be slowed down or prevented.

Albumin is the principal component of proteinuria in glomerular disease. Reagent strips in current clinical practice predominantly detect albumin, not total protein, but are not reliably quantitative. ACR has far greater sensitivity than protein:creatinine ratio (PCR) for the detection of low levels of proteinuria and enhances early identification of CKD. However, there may be clinical reasons for a specialist to subsequently use PCR to quantify and monitor significant levels of proteinuria.

To detect and identify proteinuria, use urine albumin:creatinine ratio (ACR) in preference, as it has greater sensitivity than PCR for low levels of proteinuria.

Patient Preparation

Early morning urine sample preferable

Notes

The urine protein:creatinine ratio is calculated as follows:

(Urine protein(g/L) X 1000)/Urine creatinine(mmol/L)

Please note, from 22/7/19 analysis performed using Abbott Alinity analyser.   The test is awaiting UKAS accreditation.

Reference Range

  • <15 mg/mmol Creatinine = Normal
  • 15 – 49 mg/mmol Creatinine = Trace Proteinuria. Consider ACEI or ARB in diabetes.
  • 50 – 99 mg/mmol Creatinine = Significant proteinuria. Repeat using early am sample. Consider ACEI or ARB in hypertension.
  • 100 – 300 mg/mmol Creatinine = High proteinuria. If new finding, seek nephrology advice regardless of eGFR.
  • >300 mg/mmol Creatinine = “Nephrotic range” proteinuria. If new finding, seek nephrology advice regardless of eGFR.
                                      
Proteinuria is a risk factor for cardiovascular disease and for decline in GFR in CKD
UK CKD Guidelines suggest if PCR is >100 mg/mmol patient should be referred to Nephrologists irrespective of GFR.
 

Source of Reference Range: NICE guideline CG73 (2008) and UK eCKD guidelines 2009.)