TRANSFERRIN URINE

Transferrin is the iron-transport protein in plasma with a molecular weight (~80 kDa) very similar to albumin. The glomerular filter normally holds it back. When the filter is damaged, transferrin and albumin both leak into urine. Because transferrin is less negatively charged than albumin, it can sometimes leak earlier — making urinary transferrin a candidate "early-warning" marker of glomerular dysfunction in diabetes and hypertension.

The lab measures transferrin in a spot or 24-hour urine sample using immunoturbidimetry or immunonephelometry, usually reported as a transferrin-to-creatinine ratio. It is most often ordered alongside urine microalbumin in patients with diabetes, where the two together give a more complete picture of early kidney damage.

In India, the explosion of type 2 diabetes makes early detection of diabetic kidney disease (DKD) one of the most important goals in chronic-disease care. Urinary albumin (microalbuminuria) has been the standard early DKD marker for decades, but research suggests that transferrinuria may appear earlier in some patients — particularly those with type 2 diabetes and good glycaemic control where albumin remains negative. Earlier detection allows earlier intervention (RAAS blockade, SGLT2 inhibitors, BP control, glycaemic optimisation), which can slow or even reverse early damage.

Urinary transferrin is not yet a guideline-recommended routine screen but is offered by many large Indian labs as part of advanced kidney panels.

Either a clean mid-stream spot urine or a 24-hour urine collection, depending on what your doctor orders. For spot samples: first-morning urine is preferred. Avoid testing during menstruation, active UTI, fever, or after vigorous exercise — these transiently raise urinary protein excretion of all kinds. No fasting required. Mention any current medications, especially ACE inhibitors / ARBs and SGLT2 inhibitors.