Previous studies have demonstrated associations of both IgG and IgM aPS/PT to APS-related events,6,7 but only few researchers reported multivariate adjustments for the criteria aPL31,32 and/or conventional thrombotic risk factors.20,33 In the current study, occurrence of IgM aPS/PT was the strongest risk factor for VTE in univariable analysis of Swedish SLE patients. This evidence concerns the gene CD40LG and systemic lupus erythematosus.