Session Title: Antiphospholipid Syndrome
Session Type: Abstract Submissions (ACR)
Background/Purpose: The clinical accuracy of testing for antiphospholipid antibody (aPL) both, as individual tests and/or in combination, is still being investigated. We aimed to identify a panel of tests that may provide the best accuracy for diagnosing the antiphospholipid syndrome (APS) in a wide cohort of patients with Systemic Lupus Erythematosus
This study included 230 patients (218 women, mean age 42.7±11.9 years, mean disease duration 12.2±8.7years), all fulfilling the 1982 criteria for Systemic Lupus Erythematosus . Lupus anticoagulant (LA), anti-cardiolipin (aCL), anti-β2glycoprotein I (anti-b2GPI), solid phase anti-prothrombin (aPT), anti-phosphatidylserine/prothrombin (aPS/PT), and anti-phosphatidylethanolamine (aPE) antibodies were tested in all. Sensitivity, specificity and predictive values were calculated. The diagnostic accuracy for each combination of tests was assessed by ROC and their area under the curve analysis (AUC) as well as by the Youden’s index (YI).
Results: Testing for 6 aPL derived in 23 possible combinations of results. Among them, LA+ anti-β2GPI+aPS/PT had the best diagnostic accuracy for APS as a whole, and individually for both thrombosis and pregnancy loss (AUC 0.712, OR3.73 [95% CI 1.82-5.38], p=0.0001, YI= 0.32; AUC 0.709, OR3.75 [95% CI 2.13-6.62], p=0.0001, YI=0.37 and AUC 0.677, OR4.82 [95%CI 2.17-10.72], p=0.0007, YI= 0.38; respectively) and the best specificity when compared to all the other obtainable combination of tests. Triple positivity for LA+anti-β2GPI+aPS/PT was more strongly associated with clinical events (thrombosis and/or Pregnacy Loss) than double or single positivity (OR23.2 [95%CI 2.57-46.2] vs. OR7.3 [95%CI 2.21-25.97], OR5.7 [95%CI 2.12-17.01] or OR3.11 [95%CI 1.56-7.8] for single positivity for LA, aPS/PT and anti-β2GPI, respectively).
Combining LA, anti-β2GPI and aPS/PT improves the diagnostic power and helps in stratifying the risk for each patient, according to their aPL profile.
M. A. Khamashta,
M. L. Bertolaccini,
« Back to 2012 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/clinical-accuracy-for-diagnosis-of-antiphospholipid-syndrome-in-systemic-lupus-erythematosus-evaluation-of-23-possible-combinations-of-antiphospholipid-antibody-specificities/