[Anti-beta 2 glycoprotein 1 antibodies in idiopathic livedo reticularis]

Idiopathic livedo reticularis can be a sign of systemic disease since certain complications are frequently associated: cerebral thrombotic events in Sneddon's syndrome, necrotic ulcerations of the lower limbs. Antiphospholipid antibodies have been found in 0 to 85 p. 100 of patients with Sneddon's syndrome and anti-beta 2-glycoprotein 1 antibodies in 65 p. 100 of a series of 20 cases with Sneddon's syndrome. The aim of our study was to determine the prevalence of anti-beta 2-glycoprotein 1 antibodies in idiopathic livedo reticularis.

Twelve patients in a series of 17 with idiopathic livedo reticularis seen between 1981 and 1992 were studied progressively. All underwent a clinical examination and simple laboratory tests with search for anticardiolipin antibodies, lupus type circulating anticoagulant and anti-beta 2-glycoprotein 1 antibodies.

Eight of our 12 patients (60 p. 100) were positive for anti-beta 2-glycoprotein 1 antibodies, 3 of whom also had episodes of thrombosis similar to those described in antiphospholipid syndrome. Only one of the 8 patients also had anticardiolipin antibodies and no chronic manifestation of thrombosis.

beta 2-glycoprotein 1 is a cofactor which increases anticardiolipin antibody adhesion to cardiolipin in ELISA. Anti-beta 2-glycoprotein 1 antibodies are associated with thrombosis and antiphospholipid antibodies with lupus. Our results would suggest that the prevalence of anti-beta 2-glycoprotein 1 antibodies is high in idiopathic livedo, but, due to the small number of patients, do not allow confirmation that anti-beta 2-glycoprotein 1 antibodies are associated with thrombosis. Anti-beta 2-glycoprotein 1 antibody assay would be justified in routine evaluation of patients with livedo and at follow-up examinations.