The clinical value of testing for antibodies to phosphatidylethanolamine (aPE) in patients with systemic lupus erythematosus (SLE)

Abstract

The value of testing for aPE in venous thrombosis and fetal death is in constant debate. We evaluated if testing for aPE has a diagnostic value in patients with SLE.

Patients and methods: We included 224 patients. aPE were tested by an in-house ELISA using FCS.

Results: aPE were found in 41% of the patients. IgG and IgM aPE were more frequently found along with other aPL than in those negative for aPL (p=0.003 and p=0.01). IgG aPE were more frequently found in patients with definite APS than in those without (p=0.003). aPE were more frequent in patients with thrombosis than in those without, particularly the IgG isotype (p=0.03). When subdividing between venous and arterial thrombosis, only an association between IgG aPE with venous thrombosis was retained (p=0.01). Titres of IgG aPE were significantly higher in patients with arterial or those with venous thrombosis, when compared to the patients without thrombosis (p=0.004 and p=0.001). Titres of IgM aPE were higher in patients with arterial thrombosis when compared to those without (p=0.014). No associations were found between the presence of aPE and/or pregnancy morbidity. The presence of aPE did not correlate with that of any other aPL. After multivariate analysis all clinical associations failed to retain significance.

Conclusions: aPE are frequently seen in SLE and do not correlate with other routinely tested aPL. Although more prevalent, aPE is not an independent risk factor for thrombosis or pregnancy morbidity in patients with SLE.