Sorted By Test Name - Mayo Medical Laboratories

BETA2
80351
patients with APS.(4) Anticardiolipin and beta 2 GP1 antibodies of the IgA isotype are not part of the
laboratory criteria for APS due to lack of specificity.
Useful For: Evaluation of suspected cases of antiphospholipid syndrome
Interpretation: Strongly positive results for beta 2 glycoprotein 1 (beta 2 GPI) antibodies (>40 U/mL
for IgG and/or IgM) are diagnostic criterion for antiphospholipid syndrome (APS). Lesser levels of beta 2
GP1 antibodies and antibodies of the IgA isotype may occur in patients with clinical signs of APS but the
results are not considered diagnostic. Beta 2 GP1 antibodies must be detected on 2 or more occasions at
least 12 weeks apart to fulfill the laboratory diagnostic criteria for APS. Detection of beta 2 GP1
antibodies is not affected by anticoagulant treatment.
Reference Values:
or =15.0 U/mL (positive)
Results are expressed in arbitrary units.
Reference values apply to all ages.
Clinical References: 1. Caronti B, Calderaro C, Alessandri C, et al: Beta 2 glycoprotein 1 (beta 2
GP1) mRNA is expressed by several cell types involved in anti-phospholipid syndrome-related tissue
damage. Clin Exp Immunol 1999;115:214-219 2. Lozier J, Takahashi N, Putnam F: Complete amino acid
sequence of human plasma beta 2 glycoprotein 1. Proc Natl Acad Sci USA 1984;81:3640-3644 3. Kra-Oz
Z, Lorber M, Shoenfeld Y, et al: Inhibitor(s) of natural anti-cardiolipin autoantibodies. Clin Exp Immunol
1993;93:265-268 4. Audrain Ma, El-Kouri D, Hamidou MA, et al: Value of autoantibodies to
beta(2)-glycoprotein 1 in the diagnosis of antiphospholipid syndrome. Rheumatology (Oxford)
2002;41:550-553 5. Wong RCW, Flavaloro EJ, Adelstein S, et al: Consensus guidelines on anti-beta 2
glycoprotein I testing and reporting. Pathology 2008 Jan;40(1):58-63
Beta-2 Transferrin: Detection of Spinal Fluid in Other Body
Fluid
Clinical Information: The diagnosis of cerebrospinal fluid (CSF) rhinorrhea or otorrhea (leakage of
CSF into the nose or ear canal, usually as a result of head trauma, tumor, congenital malformation, or
surgery) is often difficult to confirm. Traditional chemical analyses (eg, glucose, protein, specific gravity)
are unreliable. Radiographic studies, especially those involving the injection of dyes or radiographic
compounds, are costly and may introduce additional risks to the patient. Transferrin that migrates in the
beta-1 electrophoretic fraction (beta-1 transferrin) is found in most body fluids. Beta-2 transferrin is a
CSF-specific variant of transferrin and is used as an endogenous marker of CSF leakage. Beta-2
transferrin is formed by loss of sialic acid due to the presence of neuraminidase in the central nervous
system. Beta-2 transferrin has also been called CSF-specific transferrin and tau protein. Prompt diagnosis
and localization facilitates appropriate decisions and decreases the risk of meningitis.
Useful For: Detection of spinal fluid in body fluids, such as ear or nasal fluid
Interpretation: The cerebrospinal fluid (CSF) variant of transferrin is identified by its unique
electrophoretic migration. If beta-1 and beta-2 transferrin are detected in drainage fluids, the specimen is
presumed to be contaminated with CSF. The presence of beta-2 transferrin band is detectable with as little
as 2.5% spinal fluid contamination of body fluids.
Reference Values:
Negative, no beta-2 transferrin (spinal fluid) detected
Clinical References: 1. Oberascher G: Cerebrospinal fluid otorrhea--new trends in diagnosis. Am J
Otol 1988;9:102-108 2. Normansell DE, Stacy EK, Booker CF, et al: Detection of beta-2 transferrin in
otorrhea and rhinorrhea in a routine clinical laboratory setting. Clin Diag Lab Immunol 1994;1:68-70
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