Alpha 1-microglobulin: clinical laboratory aspects and applications.
BACKGROUND
Urinary microproteins are becoming increasingly important in clinical diagnostics. They can contribute in the non-invasive early detection of renal abnormalities and the differentiation of various nephrological and urological pathologies. Alpha 1-microglobulin (A1M) is an immunomodulatory protein with a broad spectrum of possible clinical applications and seems a promising marker for evaluation of tubular function.


METHODS
We performed a systematic review of the peer-reviewed literature (until end of November 2003) on A1M with emphasis on clinical diagnostic utility and laboratory aspects.


CONCLUSIONS
A1M is a 27-kDa glycoprotein, present in various body fluids, with unknown exact biological function. The protein acts as a mediator of bacterial adhesion to polymer surfaces and is involved in inhibiting renal lithogenesis. Because A1M is not an acute phase protein, is stable in a broad range of physiological conditions and sensitive immunoassays have been developed, its measurement can be used for clinical purposes. Unfortunately, international standardisation is still lacking. Altered plasma/serum levels are usually due to impaired liver or kidney functions but are also observed in clinical conditions such as HIV and mood disorders. Urinary A1M provides a non-invasive, inexpensive diagnostic alternative for the diagnosis and monitoring of urinary tract disorders (early detection of tubular disorders such as heavy metal intoxications, diabetic nephropathy, urinary outflow disorders and pyelonephritis).
Penders
Joris
J
Department of Clinical Chemistry, University Hospital Ghent-2P8, De Pintelaan 185, B-9000 Ghent, Belgium.
Delanghe
Joris R
JR
D000510:Alpha-Globulins / Q000652:urine*; D015415:Biomarkers; D019411:Clinical Laboratory Techniques / Q000379:methods* / Q000639:trends; D007118:Immunoassay; D007674:Kidney Diseases / Q000175:diagnosis; D007677:Kidney Function Tests; D007687:Kidney Tubules, Proximal / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D011480:Protease Inhibitors / Q000652:urine; D014552:Urinary Tract Infections / Q000175:diagnosis
D000510:Alpha-Globulins; D015415:Biomarkers; D011480:Protease Inhibitors; C016001:alpha-1-microglobulin