Abstract

Objective: To study the prevalence of IgA antiphospholipid antibodies, particularly anticardiolipin antibodies (aCL) and anti-β₂-glycoprotein I (aβ₂GPI), in a cohort of patients with pregnancy morbidity.

Patients and methods: Serum samples from four groups of patients were studied by an in house enzyme linked immunosorbent assay (ELISA). Group I: 28 patients with primary antiphospholipid syndrome (PAPS) (median age 32.5 years, range 25–34). Twelve patients had a history of thrombosis. All were positive for IgG/M aCL or lupus anticoagulant (LA), or both. Group II: 28 patients with unexplained pregnancy morbidity (median age 35 years, range 23–48). Seven had history of thrombosis. Nine patients were positive for IgG/M aCL. None from this group fulfilled Sapporo criteria for APS. Group III: 28 patients with systemic lupus erythematosus (SLE) (median age 34 years, range 25–52). Eleven had a history of thrombosis. Twenty one patients had IgG/M aCL and/or LA, but only 19 fulfilled Sapporo criteria for APS.

Results: IgA aCL were found in 12, 6, and 14 patients from the groups with PAPS, unexplained pregnancy morbidity, and SLE, respectively. Most patients had these antibodies together with IgG/IgM aCL. Three patients from the group with unexplained pregnancy morbidity and two with SLE had IgA aCL alone. IgA aβ₂GPI was present in one patient from each group. All IgA aβ₂GPI were present together with IgG and/or IgM aβ₂GPI.

Conclusions: The prevalence of IgA aCL is high in patients with pregnancy morbidity, although IgA aCL are usually present together with IgG and/or IgM aCL. IgA aβ₂GPI are not useful in identifying additional women with APS and pregnancy morbidity.