Urinalysis and chronic kidney disease

(Aotea News, December 2010)

John McCafferty
Anatomic & General Pathologist

Urinalysis is an important test for screening and investigating chronic kidney disease (CKD).

  • Recent bpac guidelines (July 2009) recommend the testing, where appropriate, of mid-stream urine (MSU) for red blood cell casts or dysmorphic red cells.
  • Please write “casts/dysmorphic RBC” on the request form to ensure that we know to carry out this test.

We are also changing the ranges for RBC in urine:

  • The most important change is to the lowest reported value (currently < 25 x 10 6 /L) to < 10 x 10 6 /L, a value currently accepted as normal.
  • Further groupings of abnormal resultswill be similarwith values of 11-100, 101-500 and >500

Urinalysis for CKD also involves detection of proteinuria:

The recommended testing for proteinuria is albumin creatinine ratio (i.e. urine microalbumin) or protein creatinine ratio.

  • Protein creatinine ratio is more appropriate for non-diabetic patients at risk of CKD.
  • To ensure the correct test is performed please note on the request form:

Urine microalbumin or

Prot-creat ratio