Session Information
Title: Antiphospholipid Syndrome: Clinical Manifestations and New Biomarkers in Antiphospholipid Syndrome
Session Type: Abstract Submissions (ACR)
Background/Purpose:
Criteria laboratory tests for antiphospholipid syndrome (APS) include lupus anticoagulant (LAC) as well as IgG and IgM antibodies for cardiolipin and beta2 glycoprotein. Of these tests, only the LAC strongly predicts thrombosis. A recent study (PROMISSE) also showed that LAC was the primary predictor of adverse pregnancy outcome after 12 weeks gestation in aPL(antiphospholipid antibody)-associated pregnancies. Antibodies to phosphatidylserine-prothrombin complex (aPS/PT) have been suggested to strongly correlate with the presence of LAC. Anti-PS/PT antibodies are detected with immunoassay, which is more likely to be amenable to standardization than LAC testing, and can be performed on patients during anticoagulation therapy. Using the PROMISSE cohort we investigated if aPS/PT, similarly to LAC, can predict pregnancy outcomes.
Methods: A total of 97 samples from the PROMISSE study were analyzed at the APLS Laboratory using QUANTA Lite® PS/PT IgG and IgM ELISA kits (INOVA Diagnostics). LAC test results were obtained from PROMISSE investigators. Qualitative agreements, kappa scores, and univariate and multivariable logistic regression analyses were done with SPSS software.
Results:
The prevalence of LAC positivity was 53/97 (54.6%), aPS/PT IgG was 35/97 (36.1%), aPS/PT IgM was 51/97 (52.6%) and any aPS/PT was 64/97 (66.0%). The inter-assay agreement between the aPS/PT and LAC is shown in Table 1. Both aPS/PT IgG and IgM showed significant correlation to LAC (p<0.001 and p=0.015). Anti-PS/PT IgG was significantly associated with any pregnancy morbidity (p=0.002; OR=6.2, 95% CI 1.7-22.8) and any pregnancy losses (p=0.006; OR=4.3, 95% CI 1.5-12.7). The correlation with preeclampsia did not reach significance (p=0.061; OR=3.4, 95% CI 1.0-11.3). Anti-PS/PT IgM was not correlated with adverse pregnancy outcomes. In a multivariable model, anti-PS/PT IgG remained a significant predictor of pregnancy morbidity and pregnancy losses.
Conclusion:
Anti-PS/PT IgG antibodies show good correlation to LAC and association with pregnancy complications in APS patients. This suggests that aPS/PT may be a promising biomarker for obstetric risk assessment in APS given its advantages with respect to clinical applicability and standardization.
Table 1. Inter-assay agreement and association of aPS/PT with LAC
|
|
Total/Positive/Negative agreement (Kappa) |
Chi squareP value OR (95% CI) |
|
PS/PT IgG |
67.0/63.6/69.8 (0.357) |
P=0.000 5.920 (2.241-15.637) |
|
PS/PT IgM |
62.9/65.4/60.0 (0.254) |
P=0.015 2.842 (1.243-6.496) |
|
ANY PS/PT |
68.0/73.5/56.7 (0.341) |
P=0.001 4.710(1.901-11.670) |
Disclosure:
R. Willis,
None;
A. E. Tebo,
None;
G. Lakos,
Inova Diagnostics, Inc.,
3;
M. Mahler,
Inova Diagnostics, Inc.,
3;
G. L. Norman,
Inova Diagnostics, Inc.,
3;
W. D. Branch,
UCB,
5;
J. Salmon,
None;
M. M. Guerra,
None;
S. S. Pierangeli,
None.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/phosphatidiyserine-prothrombin-complex-apspt-igg-antibodies-correlate-with-lupus-anticoagulant-and-specific-pregnancy-complications-in-patients-with-antiphospholipid-syndrome/