Session Type: Abstract Submissions (ACR)
Background/Purpose: Antibodies directed to APhL (a mixture of phospholipids) have been reported to predict APS more reliably than aCL tests. We designed this study to evaluate the performance characteristics of the IgG and IgM APhL ELISA, in an attempt to establish the diagnostic utility of these new aPL antibody tests in a wide cohort of SLE patients.
Methods: This study included 158 patients (152 women, mean age 41.8±11.6 years, mean disease duration 11.7±7.8years), all fulfilling the 1982 criteria for SLE. All the patients were tested for the routinely used aPL, including LA, aCL and ab2GPI. Data were compared with that obtained by the APhL ELISA (Louisville APL Diagnostic, Inc, Louisville, KY, USA). The diagnostic accuracy for each test was assessed by ROC and their area under the curve (AUC) analysis.
Results: APhL were found in 77% of the patients. IgG and IgM APhL were more frequently found along with routine aPL than in isolation (p=0.007 and p=0.04, respectively). APhL were more frequently found in patients with definite APS than in those without (p=0.001). aPhL were not only more frequent in patients with thrombosis than in those without (p=0.02) but their titres were also significantly higher in thrombosis, when compared to those without (p=0.02). APhL showed an OR for thrombosis of 1.46 [95%CI1.08-3.19] (AUC 0.533). Twenty-seven patients (17.09%) were positive for isolated APhL. Of those 8 (29.6%) had a thrombotic event (6 arterial, 1 venous, 1 both). No associations were found between the presence of APhL and pregnancy loss. The presence of aPhL did not correlate with that of any of the other aPL tested. Multivariate analysis confirmed the associations with APS, particularly with thrombosis.
Conclusion: APhL are frequent in patients with SLE. Their presence is associated with thrombosis, making these antibodies a novel marker for APS. The finding of isolated APhL in thrombosis (particularly arterial) deserves further investigation.
M. A. Khamashta,
M. L. Bertolaccini,
« Back to 2013 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-clinical-value-of-testing-for-aphl-a-new-elisa-kit-with-a-unique-phospholipid-mixture-in-patients-with-systemic-lupus-erythematosus-sle/