Electrophoresis refers to a laboratory test in which electrically charged particles of blood migrate in an electric field.The speed of this migration depends, among other things, on the ionic charge of the particles, the field strength, and the radius of the particles. One can distinguish the different forms of electrophoresis:
- Protein electrophoresis in blood serum (synonym: serum electrophoresis), urine or cerebrospinal fluid.
- Hemoglobin electrophoresis (synonym: Hb electrophoresis).
- Immunofixation electrophoresis
- Lipid electrophoresis
Urine protein electrophoresis (synonyms: urine electrophoresis; urine protein electrophoresis) involves splitting the following fractions:
- Total protein
- Albumin
- Alpha-1 fraction
- Alpha-2 fraction
- Beta fraction
- Gamma faction
The procedure
Material needed
- Spontaneous urine (midstream urine)
- 24 h urine
Preparation of the patient
- For 24 h urine, please specify the collection amount
- The 2nd morning urine is equivalent to the collection urine
Interfering factors
- Strong physical stress
- Polyuric renal dysfunction – renal dysfunction in which there is excessive urine output.
Normal values
Standard values depending on the method/laboratory
Indications
Diagnosis of proteinuria (excretion of protein in urine).
- Acute/chronic glomerulonephritis (inflammation of the renal corpuscles).
- Chronic renal failure
- Diabetes mellitus (diabetes)
- Hemodialysis (blood washing)
- HELLP syndrome (H = hemolysis/dissolution of erythrocytes (red blood cells) in the blood), EL = elevated liver enzymes (elevation of liver enzymes), LP = low platelets (thrombocytopenia / reduction of platelets) – special form of preeclampsia, which can take life-threatening courses.
- IgA nephritis – special form of inflammation of the kidneys.
- Interstitial nephritis – special form of kidney inflammation.
- Collagenoses (group of connective tissue diseases caused by autoimmune processes) – systemic lupus erythematosus (SLE), polymyositis (PM) or dermatomyositis (DM), Sjögren’s syndrome (Sj), scleroderma (SSc) and Sharp syndrome (“mixed connective tissue disease”, MCTD).
- Microhematuria – blood in the urine, which is not visible to the naked eye, however.
- Monoclonal gammopathy – form of multiple myeloma (plasmacytoma).
- Nephrotic syndrome – collective term for symptoms that occur in various diseases of the glomerulus (renal corpuscles); symptoms include: Proteinuria (excretion of protein in the urine) with a protein loss of more than 1 g/m²/body surface per day; Hypoproteinemia, peripheral edema (water retention) due to hypalbuminemia of < 2.5 g/dl in serum, hyperlipoproteinemia (lipid metabolism disorder).
- Pyelonephritis (inflammation of the renal pelvis).
- Rapid progressive glomerulonephritis (rapid progressive glomerulonephritis, RPGN) – relatively rare disease associated with rapidly progressive deterioration of kidney function.
- Condition after kidney transplantation
Interpretation
Urinary protein electrophoresis is orientationally useful for differentiating primary glomerular, primary tubular, and mixed disorders. Further notes
- Quantitative measurement of lead proteins is more appropriate for differential diagnosis of proteinuria:
- Albumin in urine (site of damage: glomerular, selective), determination for eg:
- Diabetes mellitus
- Hypertension
- Glomerulonephritides
- Orthostatic proteinuria
- Also increased in: Fever and physical exertion
- Alpha-1 microglobulin (site of injury: tubular), determination in eg:
- Bacterial pyelonephritis
- Fanconi syndrome
- Interstitial nephritis
- Also increased in: physical stress
- Albumin in urine (site of damage: glomerular, selective), determination for eg:
- If Bence-Jones proteinuria or paraproteinuria (in monoclonal gammopathy, e.g., plasmocytoma) is suspected, “immunofixation electrophoresis in urine” is indicated (indicated/appropriate).
