ACR Meeting Abstracts

ACR Meeting Abstracts

Abstract Number: 0081

Thrombin Generation Assay and Lupus Anticoagulant Identify Different Populations of Patients with Antiphospholipid Antibodies

Massimo Radin1, Alice Barinotti1, Irene Cecchi2, Silvia Grazietta Foddai1, Elena Rubini1, Dario Roccatello1, Elisa Menegatti1 and Savino Sciascia1, 1University of Turin, Turin, Italy, 2University of Turin, Torino, Italy

Meeting: ACR Convergence 2021

Keywords: , ,

Session Information

Date: Saturday, November 6, 2021

Title: Antiphospholipid Syndrome Poster (0069–0083)

Session Type: Poster Session A

Session Time: 8:30AM-10:30AM

Background/Purpose: Risk stratification in patients with antiphospholipid antibodies (aPL) remains a clinical challenge. We aim to evaluate the role of Thrombin Generation Assay (TGA) in distinguishing various populations of aPL positive patients (with and without lupus anticoagulant – LA) and its association with β2GPI-dependent and anti-phosphatidyl-serine/prothrombin (aPS/PT) antibodies.

Methods: One-hundred-and-eight patients were tested with TGA and divided as follows: 21 patients with aPS/PT IgG/IgM, 29 with aβ2GPI IgG/IgM, 31 with aPS/PT and aβ2GPI IgG/IgM, 27 with aPS/PT and/or aβ2GPI IgM low-titers. Table 1 resumes the clinical characteristics of the APS patients (excluding aPL asymptomatic). Thirty-one healthy donors (HDs) and 24 controls treated with VKA were also included.

Results: The most deranged TGA and LA profile was observed in patients with both aPS/PT and aβ2GPI when compared to those with an isolated positivity for aPS/PT or aβ2GPI and patients with aPS/PT and/or aβ2GPI IgM at low titres (Figure 1). Similarly, patients with aPS/PT and/or aβ2GPI at medium/high titres presented with the higher rate of clinical manifestations.

When comparing the TGA curves of APS patients, asymptomatic aPL positive (aPL+) subjects, HDs and controls treated with VKA, we observed that aPL+ patients (particularly those with a confirmed diagnosis of APS) showed a characteristic profile (Figure 2). Moreover, both in aPL+ subjects and in the control groups we observed a correlation between TGA and LA parameters.

Conclusion: TGA seems a valuable approach to stratify aPL+ patients according to their risk profile. The differences among groups and different populations of autoantibodies specificities obtained from this test can be considered a translational validation of the increased thrombotic risk of patients with triple or tetra aPL positivity.

“Classical” and “Extra-criteria” APS clinical manifestations of each group (considering solely patients with a confirmed diagnosis of APS).

Graphical representation of the differences between TGA and LA profiles between groups.
The differences between groups that reached statistical significance (p<0,05) are indicated in the graph.
(aPS/PT – Anti-phosphatidylserine/prothrombin antibodies; aβ2GPI – Anti-β2-glycoprotein-I antibodies; Ig – Immunoglobulin; tLag – Lag time; tPeak – Time to peak; AUC – Area under the curve; sctScreen – Silica Clotting Time screening; sctMix – Silica Clotting Time mix; sctConf – Silica Clotting Time confirmation; dRVVTscreen – Dilute Russell’s viper venom time screening; dRVVTmix – Dilute Russell’s viper venom time mix; dRVVTconf – Dilute Russell’s viper venom time confirmation)

Representative Thrombin Generation Assay profile of APS patients, asymptomatic aPL+ patients, healthy controls and controls treated with Vitamin K antagonists.
(TGA – Thrombin generation assay; APS – Antiphospholipid Syndrome; aPL – Antiphospholipid antibodies; HC – healthy controls)

Disclosures: M. Radin, None; A. Barinotti, None; I. Cecchi, None; S. Foddai, None; E. Rubini, None; D. Roccatello, None; E. Menegatti, None; S. Sciascia, None.

To cite this abstract in AMA style:

Radin M, Barinotti A, Cecchi I, Foddai S, Rubini E, Roccatello D, Menegatti E, Sciascia S. Thrombin Generation Assay and Lupus Anticoagulant Identify Different Populations of Patients with Antiphospholipid Antibodies [abstract]. Arthritis Rheumatol. 2021; 73 (suppl 9). https://acrabstracts.org/abstract/thrombin-generation-assay-and-lupus-anticoagulant-identify-different-populations-of-patients-with-antiphospholipid-antibodies/. Accessed .

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/thrombin-generation-assay-and-lupus-anticoagulant-identify-different-populations-of-patients-with-antiphospholipid-antibodies/