Value of IgA anticardiolipin and anti-β2-glycoprotein I antibody testing in patients with pregnancy morbidity
- 1Lupus Research Unit, The Rayne Institute, St Thomas’ Hospital, London, UK
- 2Department of Medicine I, Hospital Santa Maria, Lisbon, Portugal
- 3Rheumatology Department, Hospital Universitario Reina Sofia, Cordoba, Spain
- Correspondence to:
Dr M A Khamashta, Lupus Research Unit, The Rayne Institute, St Thomas’ Hospital, London SE1 7EH, UK;
- Accepted 13 November 2002
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.
- aβ2GPI, anti-β2-glycoprotein I
- aCL, anticardiolipin antibodies
- aPL, antiphospholipid antibodies
- BSA, bovine serum albumin
- ELISA, enzyme linked immunosorbent assay
- LA, lupus anticoagulant
- PAPS, primary antiphospholipid syndrome
- PBS, phosphate buffered saline
- SLE, systemic lupus erythematosus