Lyme arthritis in Spain

These results support and extend the observations of Gharavi et al.' They provide further evidence that antidsDNA and anticardiolipin antibodies are to some extent discrete populations in the patients with principally IgGl and IgG3 anticardiolipin binding-that is, the principal subclasses of IgG anti-dsDNA, showed no DNA binding. These results also emphasise the heterogeneity of anticardiolipin/antiphospholipid antibodies: patients with and without SLE show different affinities for different phospholipids,2 different effects on in vitro coagulation studies,3 and have different clinical correlations.3 It would also seem that they show different IgG subclass distribution. We feel it is unlikely that the difference between our groups reflects either the marked sex difference or the higher total IgG anticardiolipin in the SLE groups: the subclass ratios within each group were similar for both high and low total IgG anticardiolipin and for both men and women. Data from our laboratory suggest that the IgG subclass distribution of these sera is the same for the binding of three other phospholipids with widely differing charge: phosphatidylserine, phosphatidylinositol, and phosphatidylethanolamine (Snowden et al, unpublished data).