A Diagnostic approach to Proteinuria
Proteinuria on initial dipstick urinalysis testing is found in as much as 17 percent of selected populations. Although a wide variety of conditions , ranging from benign to lethal, can cause proteinuria, fewer than 2 percent of patients whose urine dipstick test is positive for protein have serious and treatable urinary tract disorders.
|Common Causes of Benign Proteinuria |
||Most acute illnesses |
||(postural) disorder |
Definition of Proteinuria
Proteinuria is defined as urinary protein excretion of greater than 150 mg per day. Urinary protein
excretion in healthy persons varies considerably and may reach proteinuric levels under several circumstances. Most dipstick tests that are positive for protein are a result of benign proteinuria, which has no associated morbidity or mortality (Table 1). About 20 percent of normally excreted protein is a low-molecular-weight type such as immunoglobulins (molecular weight about 20,000 Daltons), 40 percent is high-molecular-weight albumin (about 65,000 Daltons) and 40 percent is made up of Tamm-Horsfall mucoproteins secreted by the distal tubule