24-Hour Urine Protein

What do Abnormal Results Mean?

Increased urinary protein can occur as a result of dehydration and relative renal ischemia (a deficient blood supply), for example, as a result of hemorrhage or salt depletion, and in illnesses involving fevers.

However, increased urinary protein is usually measured when glomerular disease is suspected. The deterioration in the integrity of the glomerulus allows albumin to permeate in large quantities. Glomerular disease, such as nephrotic syndrome may result in urine protein (mostly urine albumin) of greater than 3.5 gm/day. So-called microalbuminuria with urine albumin levels of 30 to 200 mg/day is considered an early sign of diabetic nephropathy.

Renal tubular diseases usually have urine protein levels in the range of 1 to 2 gm/day. In this case, most of the protein is represented by low-molecular weight globulins that would be reabsorbed by normal tubules. Diseases that fall into this category include: pyelonephritis, Fanconi's syndrome, cystinosis, and Wilson's disease.

Overflow protein in the urine results from the presence of greater than normal levels of protein in the plasma, (e.g., Bence-Jones proteinuria, which is in multiple myeloma, Waldenstrom's macroglobulinemia, and some lymphomas). The Bence-Jones protein (quantitative) test detects proteins that are light chains of immunoglobulins.

Additional conditions under which the test may be performed:

• Complicated UTI (pyelonephritis)