Anticardiolipin antibodies of IgG and IgM isotypes reflect different forms of recent thromboembolic events

ar642 ARJ Meeting abstract Anticardiolipin antibodies of IgG and IgM isotypes reflect different forms of recent thromboembolic events Locht H Wiik A

Department of Autoimmunology, Statens Serum Institut, Copenhagen, Denmark

Arthritis Res Ther 23rd European Workshop for Rheumatology Research The organizer would like to thank the following companies who have generously supported the 23rd European Workshop for Rheumatology Research: Abbott, Amgen, Aventis, Merck Sharp and Dohme, Novartis, Pharmacia, Schering-Plough, Wyeth Meeting abstracts 23rd European Workshop for Rheumatology Research Marseille, France

27 February – 2 March 2003

1478-6354 2003 5 Suppl 1 12 10.1186/ar642 24 2 2003

Objective

To correlate the distribution and levels of anticardiolipin (ACA) and anti-β₂-glycoprotein 1 (a-β₂-glp 1) antibodies of IgG and IgM isotypes to the clinical spectrum of recent (within <6 months) thromboembolic events.

Method

During one year, all sera positive for IgG or IgM ACA submitted on a routine basis from hospitals or primary-care physicians from all parts of Denmark were recorded. Information about thromboembolic events and any underlying rheumatic disease was obtained by questionnaires from the referring physicians. Sera were analysed for IgG/IgM ACA and a-β₂-glp 1 antibodies by in-house ELISA assays, and the results were expressed in arbitrary units.

Results

One hundred and sixty-two patients fulfilled criteria for recent thromboembolic disease. Cerebrovascular infarction (CVI) was present in 82 patients, deep venous thrombosis (DVT) in 34, pulmonary embolism (PE) in 14, myocardial infarction (MI) in 4, and other thromboses in 28 patients. Isolated IgG ACA was found in 31 of 48 patients with DVT+PE (65%), but in only 21 of 82 patients with CVI (26%) (P = 0.00002). In contrast, isolated IgM ACA was found in 9 (19%) of patients with DVT+PE, but in 46 (56%) CVI patients (P = 0.00007). IgG a-β₂-glp 1 antibodies were found in 13 (16%) CVI patients and 23 (48%) DVT+PE patients (P = 0.0002).

Conclusion

IgG and IgM ACA isotypes seem to define different clinical subsets of patients with recent thromboembolic events, with IgG ACA being most prevalent in the group having DVT+PE whereas IgM ACA is found primarily among CVI patients. There was a linear correlation between levels of IgG a-β₂-glp 1 antibodies and IgG ACA.