Lymphocytopenia is associated with anti-Beta-2 glycoprotein-1 in patients with systemic lupus erythematosus

Background: Anti B2-Glicoprotein 1 (B2-GPI) is an antiphospholipid antibody that may be present in primary or secondary antiphospholipid syndrome (APS). Systemic Lupus erythematosus (SLE) is the main disease associated with secondary APS. Objective: To study the prevalence of anti B2-GPI in SLE patients. Methods: Anti B2-GPI (IgM/IgG) was studied by ELISA in 88 patients with SLE of both genders; 18.6% of which with secondary APS. Charts were reviewed for clinical and serological profile. Results: Anti B2-GPI was present in 18.6% of the whole sample and in 29.4% of those with secondary APS. At univariated analysis, the presence of anti B2-GPI was more common in patients with serositis (p=0.04), lymphocytopenia (p=0.003) and anti cardiolipin (aCl) IgM antibodies (p=0.04). In a logistic regression study, only the associations with lymphocytopenia (OR=8.2; 95% CI=2.1-39.3) and aCl IgM (p=0.04; OR=3.4; 95% CI=1.05-11.1) remained significant. Conclusion: There is a 18.6% prevalence of positive anti B2-GPI in SLE population that is associated with the presence of aCl IgM and lymphocytopenia.