Abnormal IgG cardiolipin antibody titers in patients with Raynaud's phenomenon and/or related disorders: prevalence and clinical significance

Background: The prevalence of antibodies to cardiolipin (a-CL) in patients with Raynaud's phenomenon (RP) and/or related disorders (rD) is not known. Objective: The purpose of this study was to determine the prevalence of these antibodies. Methods: We assayed IgG a-CL in 230 consecutive patients with RP/rD and compared the results with those in a series of 230 control blood donors. Results: Sixteen percent of patients were a-CL positive versus 7.8% of the control donors ( p = 0.014). The prevalence of a-CL positivity was 8.7% for primary RP, 10.5% for secondary RP, 8% for chilblains, 25% for essential acrocyanosis, 20% for connective tissue diseases, and 17% for undifferentiated connective tissue diseases. Among patients with digital necrosis, 24% were a-CL positive. Conclusion: The prevalence of abnormal a-CL titers is higher in patients with RP/rD than in control donors, especially in patients with a connective tissue disease. (J Am Acad Dermatol 1998;38:555-8.)