proteinuria

proteinuria /pro·tein·uria/ (-ūr´e-ah) an excess of serum proteins in the urine, as in renal disease or after strenuous exercise.proteinu´ric

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pro·tein·u·ri·a (prtn-r-, prt-nr-)

n.

1. Excessive amounts of protein in the urine.

2. See albuminuria.

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Proteinuria

The presence of protein in the urine exceeding normal levels.

Mentioned in: Proteinuric Syndrome, Nail-Patella Syndrome

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proteinuria

[prō′tēnyoo͡r′ē·ə]

Etymology: Gk, proteios + ouron, urine

the presence in the urine of abnormally large quantities of protein, usually albumin. Healthy adults excrete less than 250 mg of protein per day. Persistent proteinuria is usually a sign of renal disease or renal complications of another disease, such as hypertension or heart failure. However, proteinuria can result from heavy exercise or fever. Also called albuminuria.

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proteinuria (prō´tēnyoo´rē),

n the presence of protein in the urine. It is an indication of kidney disease.

proteinuria, orthostatic,

n (postural proteinuria) a type that occurs during daily activities but does not occur when the individual is recumbent.

proteinuria, physiologic,

n See proteinuria, transient.

proteinuria, postural,

n See proteinuria, orthostatic.

proteinuria, transient,

n (physiologic proteinuria) a type that occurs in normal persons after a high-protein meal, violent exercise, severe emotional stress, or syncope. It may occur after an epileptic seizure or during pregnancy. It disappears after the cause subsides.

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proteinuria

an excess of serum proteins in the urine; an important indicator of renal disease. It is a constant finding in glomerulonephritis, renal infarction, amyloidosis and nephrosis, but is also common in congestive heart failure and renal ischemia of all kinds. The significance of proteinuria as an indicator of renal disease is greatly enhanced by the presence of renal casts in the urine.

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Bence Jones proteinuria

see bence jones protein.

neonatal proteinuria

occurs transiently during the period of intestinal absorption of proteins, some of which are small enough to pass the glomerular membrane.

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proteinuria

Nephrology The excretion of excessive (> 5 mg/dL) protein in the urine; normally, about 150 mg/day of protein is lost in the urine,¹⁄₃ is albumin,¹⁄₃ is Tamm-Horsfall glycoprotein; the rest is divided among actively secreted proteins–eg, retinol binding proteins, β₂-microglobulin, Ig light chains and lysozyme; in absence of disease, large proteins are retained due to their size, while the smaller proteins are actively resorbed; proteinuria is most often caused by kidney disease, due to glomerular defects, and defective renal tubular resorption, and most often detected by screening with reagent strip–dipstick. See Functional proteinuria, Overflow proteinuria.

Proteinuria, severity

Severe ≥ 1.0 g/dL, due to glomerulonephritis, nephrotic syndrome, lupus nephritis, amyloidosis

Moderate ≥ 0.2 g/dL, ≤ 1.0 g/dL, due to CHF, drugs, acute infections, myeloma, chemical toxins

Mild 0.05-0.2 g/dL, due to polycystic kidneys, pyelonephritis, renal tubular defects

Proteinuria, patterns

Glomerular pattern Due to a loss of fixed negative charge on the glomerular capillary wall, allowing albumin and other large (≥ 68 kD) molecules to leak into Bowman's space–eg, in glomerulonephritis and nephrotic syndrome Lab ↓ albumin, antithrombin, transferrin, prealbumin, α₁-acid glycoprotein, α₁-antitrypsin

Hemodynamic pattern Due to rheostatic changes in the body, causing a loss of 20 to 68 kD molecules, seen in transient proteinuria, CHF, fever, seizures, excess exercise

Overflow pattern Due to tissue/cell destruction that overwhelms renal capacity to excrete certain proteins–eg, Bence-Jones proteinuria and myoglobinuria

Tubular pattern Due to renal tubular dysfunction with loss of normally filtered low molecular weight (≤ 40 kD) molecules Lab ↓ β₂-microglobulin and lysozyme–eg, Fanconi syndrome, Wilson's disease, interstitial nephritis, antibiotic-induced injury and heavy metal intoxication