Anti–β2‐glycoprotein I antibodies in pediatric systemic lupus erythematosus and antiphospholipid syndrome

• Published in: Arthritis and rheumatism 2002-08, Vol.47 (4), p.414-420
• Main Authors: von Scheven, Emily, Glidden, David V., Elder, Melissa E.
• Format: Article
• Language: eng ; jpn
• Subjects: Anticardiolipin; Antiphospholipid; Lupus anticoagulant; Pediatric; β2GPI
• ISSN: 0004-3591; 1529-0131
• DOI: 10.1002/art.10510

Objective To determine whether serum β2‐glycoprotein I antibody (anti‐β2GPI) detection improves identification of pediatric subjects at risk for antiphospholipid syndrome (APS). Methods Serum antiphospholipid antibodies (aPL) were identified by anticardiolipin enzyme‐linked immunosorbent assay (ELISA), lupus anticoagulant assays, and syphilis screening in children with primary APS, systemic lupus erythematosus (SLE), or SLE plus APS. Anti‐β2GPI level and isotype were determined by β2GPI ELISA and correlated with clinical manifestations and other aPL assays. Results One hundred‐ten subjects under 22 years of age and of mixed ethnicity were evaluated. Fifty‐seven had SLE (including 14 with APS), 25 had primary APS, 16 had SLE‐like APS, 6 were healthy children with aPL detected incidentally, 4 had other rheumatic diseases and 2 had other conditions. Anti‐β2GPI were detected in 48% of SLE subjects and did not improve aPL detection over standard tests. Anti‐β2GPI were associated with stroke (P = 0.014), but not with other APS manifestations, and were rarely detected in primary APS. Among subjects with APS manifesting as chronic thrombocytopenia, anti‐β2GPI distinguished subjects with SLE from those with primary APS. Conclusions With the exception of stroke, anti‐β2GPI detection does not improve identification of pediatric APS over that of traditional aPL assays. Anti‐β2GPI are rare in pediatric primary APS, but may predict evolution of chronic thrombocytopenia to SLE.