Associations with thrombosis are stronger for antiphosphatidylserine/prothrombin antibodies than for the Sydney criteria antiphospholipid antibody tests in SLE. (July 2021)

• Record Type: Journal Article
• Authors: Elbagir, Sahwa; Grosso, Giorgia; Mohammed, NasrEldeen A; Elshafie, Amir I; Elagib, Elnour M; Zickert, Agneta; Manivel, Vivek Anand; Pertsinidou, Eleftheria; Nur, Musa A. M; Gunnarsson, Iva; Rönnelid, Johan; Svenungsson, Elisabet
• Is Part Of: Lupus. Volume 30:Number 8(2021)
• Page Start: 1289
• Page End: 1299
• Publication Date: 2021-07
• Subjects: Antiphosphatidylserine/prothrombin -- carotid plaques -- lupus anticoagulant -- systemic lupus erythematosus -- thrombosis; Systemic lupus erythematosus -- Periodicals; 616.772005
• DOI: 10.1177/09612033211014570
• Languages: English
• ISSNs: 0961-2033

Abstract

Objectives: Antiphosphatidylserine/prothrombin complex antibodies (aPS/PT) are risk factors for thrombosis, yet further validation of their clinical relevance in different ethnic groups is required. We investigated the performance of aPS/PT of IgA/G/M isotypes among Sudanese and Swedish systemic lupus erythematosus (SLE) patients. Methods: Consecutive SLE patients/matched controls from Sudan (n = 91/102) and Sweden (n = 332/163) were included. All patients fulfilled the 1982 ACR SLE classification criteria. IgA/G/M of aPS/PT, anti-cardiolipin and anti-β2 glycoprotein I (anti-β2 GPI) were tested in both cohorts, and lupus anticoagulant (LA) also in the Swedish cohort. Clinical antiphospholipid syndrome-related events and atherosclerosis, measured as carotid plaques were assessed for associations. Univariate and multivariate analyses adjusting for cardiovascular risk factors were performed. Results: Sudanese SLE patients had higher levels of IgM aPS/PT, but using national cut-offs, the frequency of positivity was similar to Swedish patients for all isotypes. Among Swedish patients, all isotypes of aPS/PT associated with venous thromboembolism (VTE), while only IgA aPS/PT associated with arterial thrombosis (AT). aPS/PT antibodies associated strongly with LA and they were, independently, the best predictor for VTE. Double positivity for aPS/PT and anti-β2 GPI associated with higher VTE risk than the conventional triple positivity. Carotid plaques did not associate with any antiphospholipid antibody. Conclusions: IgA aPS/PT associated with AT, and the association of IgG/M aPS/PT with VTE outperforms LA and criteria antiphospholipid antibodies in Swedish SLE patients. Furthermore, double positivity for aPS/PT and anti-β2 GPI performed better than conventional triple positivity. Future studies need to address if aPS/PT can replace LA, as this would simplify clinical procedures.