| A B C D E F G H I J K L M N O P Q R S T U V W X Y Z # |
Beta-2-Glycoprotein I-Domain 1 Antibody (IgG)
Test Code12164
Preferred Specimen
0.5 mL Plasma.
Collection Instructions:
__Serum:
__Allow blood to clot (10-15 minutes) at room temperature.
__Centrifuge to separate serum. Pour off serum and
__refrigerate as soon as possible.
__
__Platelet Poor Plasma:
__Centrifuge light blue-top tube 15 minutes at approx. 1500
__x g within 60 minutes of collection. Using a plastic
__pipette, remove plasma, taking care to avoid the
__WBC/platelet buffy layer and place into a plastic vial.
__Centrifuge a second time and transfer platelet-poor plasma
__into a new plastic vial. Plasma must be free of platelets
__(< 10,000/mcL).
Collection Instructions:
__Serum:
__Allow blood to clot (10-15 minutes) at room temperature.
__Centrifuge to separate serum. Pour off serum and
__refrigerate as soon as possible.
__
__Platelet Poor Plasma:
__Centrifuge light blue-top tube 15 minutes at approx. 1500
__x g within 60 minutes of collection. Using a plastic
__pipette, remove plasma, taking care to avoid the
__WBC/platelet buffy layer and place into a plastic vial.
__Centrifuge a second time and transfer platelet-poor plasma
__into a new plastic vial. Plasma must be free of platelets
__(< 10,000/mcL).
Minimum Volume
0.3 mL Plasma
Other Acceptable Specimens
0.5 mL Serum
Transport Container
Plasma: 3.2% Sodium Citrate (lt. blue-top)
Serum
__Red-top (no gel)
__SST (red-top)
Serum
__Red-top (no gel)
__SST (red-top)
Transport Temperature
Plasma and Serum: Refrigerated preferred; Room temperature
_unacceptable; Frozen acceptable
_unacceptable; Frozen acceptable
Specimen Stability
Plasma
__Room temperature: 48 Hours
__Refrigerated: 14 Days
__Frozen: 30 Days
Serum
__Room temperature: 48 Hours
__Refrigerated: 7 Days
__Frozen: 30 Days
__Room temperature: 48 Hours
__Refrigerated: 14 Days
__Frozen: 30 Days
Serum
__Room temperature: 48 Hours
__Refrigerated: 7 Days
__Frozen: 30 Days
Methodology
Chemiluminescent Immunoassay (CIA)
Setup Schedule
Night Sets up 1 day a week.
Report Available
Reports in 3 to 8 days.
Clinical Significance
Antiphospholipid syndrome (APS) is a systemic autoimmune
disorder, characterized by recurrent arterial or venous
thrombosis, and/or early and late miscarriages.
Autoantibodies to phospholipids and to beta-2-glycoprotein
1 (B2GP1) play an important role in the pathogenesis of
APS, and the measurement of these antibodies aids the
diagnosis and management of the syndrome.
Beta-2-glycoprotein 1, also called apolipoprotein H, is a
54 kDa glycoprotein with five domains that is present in
plasma. The fifth domain contains a cluster of positively
charged amino acids which is responsible for the binding to
anionic phospholipids. APS patients can produce antibodies
against several epitopes of the molecule. Antibodies to
B2GPI are directed to one of the five domains of B2GPI, but
only IgG antibodies directed to epitopes on one domain
(called Domain 1 or D1) have been shown to be associated
with increased risk of venous thrombosis. Even greater risk
of venous thrombosis has been shown when
phosphatidylserine/prothrombin antibodies are also present.
This test should be used when B2GP1 IgG antibodies are
present to determine whether the antibodies are directed to
Domain 1. The presence of B2GPI Domain 1 antibodies should
be confirmed by repeat testing at least 12 weeks apart.
disorder, characterized by recurrent arterial or venous
thrombosis, and/or early and late miscarriages.
Autoantibodies to phospholipids and to beta-2-glycoprotein
1 (B2GP1) play an important role in the pathogenesis of
APS, and the measurement of these antibodies aids the
diagnosis and management of the syndrome.
Beta-2-glycoprotein 1, also called apolipoprotein H, is a
54 kDa glycoprotein with five domains that is present in
plasma. The fifth domain contains a cluster of positively
charged amino acids which is responsible for the binding to
anionic phospholipids. APS patients can produce antibodies
against several epitopes of the molecule. Antibodies to
B2GPI are directed to one of the five domains of B2GPI, but
only IgG antibodies directed to epitopes on one domain
(called Domain 1 or D1) have been shown to be associated
with increased risk of venous thrombosis. Even greater risk
of venous thrombosis has been shown when
phosphatidylserine/prothrombin antibodies are also present.
This test should be used when B2GP1 IgG antibodies are
present to determine whether the antibodies are directed to
Domain 1. The presence of B2GPI Domain 1 antibodies should
be confirmed by repeat testing at least 12 weeks apart.
