albumin in body fluid
Reference interval
- Adults: 3350-4765 mg/dL (serum)
- < 1.9 mg/dL (urine) (see albumin/creatinine in urine)
Clinical significance
Plasma levels of albumin, because they depend on protein intake, are frequently used to assess nutritional status. Moderate to large changes in plasma concentration of albumin have significant effects on the relative amounts of the bound & free concentrations of the ligands it carries; since free ligands are those which interact with tissue receptor sites & which can be excreted, plasma albumin levels have important influences on the metabolism of endogenous substances such as calcium, bilirubin, and fatty acids, & on the effects of drugs & hormones.
Albumin levels, although important for management & follow-up, have very little value in diagnosis. Hypoalbuminemia, however, is very common in many illnesses.
The most severe hypoalbuminemia is caused by protein loss by way of urine or feces. When plasma albumin levels are below 2.0 g/L, edema is usually present.
Decreases
- also see hypoalbuminemia
- impaired synthesis, of albumin, either primary as in liver disease or secondary to diminished protein intake
- increased catabolism as a result of tissue damage & inflammation
- reduced absorption of amino acids caused by malabsorption syndromes or malnutrition
- protein loss: in urine, due to nephrotic syndrome, chronic glomerulonephritis, diabetes, or systemic lupus erythematosus; in feces, due to protein-losing enteropathy arising from inflammatory or neoplastic disease; or from the skin through burns.
- altered distribution that may sequester large amounts of albumin in an extravascular compartment, as for instance in ascites where high pressure in the portal circulation drives albumin into the peritoneal fluid.
Methods
The Beckman Array Protein System in conjunction with the Albumin Regent Test Kit, is intended for in vitro diagnostic quantitation of albumin in biological fluids by rate nephelometry.
Specimen
No special patient preparation is required. 200 uls of serum, CSF or urine. Store sample in freezer until ready for assay. Highly lipemic samples may result in inaccurate determination & should be redrawn on a fasting patient.
Antigen Excess
When running IgG, IgA, IgM, Kappa, Lambda, Haptoglobin or CSF Albumin it is sometimes possible to encounter specimens (for example, monoclonal proteins) which contain protein concentrations high enough to be in excess of the antibody in the reaction cell. In these cases, an antigen excess situation would lead to falsely low results if not detected. For this reason the Array antigen excess check monitors the kinetic reactions of these samples to ascertain if the potential for this condition of antigen excess exists. If the monitoring detects this potential situation, the system will make a third injection of antigen excess solution to verify whether free antibody remains in the reaction cell or not. If this third injection causes further reaction, free antibody is avalable & the result is reported. However, if the third injection does not trigger further reaction, the sample will be reassayed at a higher dilution.
More general terms
More specific terms
- albumin in amniotic fluid
- albumin in CSF
- albumin in pericardial fluid
- albumin in peritoneal fluid
- albumin in pleural fluid
- albumin in semen
- albumin in serum/plasma
- albumin in serum/plasma/blood
- albumin in stool
- albumin in synovial fluid
- albumin in urine
- microalbumin in body fluid
Additional terms
Component of
References
- ↑ Beckman Array Protein System Operating Manual.
- ↑ Tietz, Norbert, W.: Textbook of Clinical Chemistry, 1986; p. 587-590.
- ↑ Albumin Level Body Fluid Laboratory Test Directory ARUP: http://www.aruplab.com/guides/ug/tests/0050024.jsp