Anticardiolipin antibodies in acute myeloid leukemia: prevalence and clinical significance.

This prospective study was designed to explore the prevalence and the clinical and prognostic significance of anticardiolipin (ACL) antibodies in patients with acute myeloid leukemia (AML). The study includes 37 consecutive AML patients >15 years old without previous history of thromboembolism, recurrent fetal loss, or autoimmune disease and with no evidence of infection at the time of enrollment. ACL antibodies were found in 25 patients (68%). None of the patients had high positive titers; 8 had moderately positive while 17 had low positive ACL antibody titers. ACL antibody positivity did not predict response to chemotherapy and was not correlated with age, gender, FAB class, platelet and white blood cell counts at presentation, and the risk of thromboembolism. ACL antibody titers did correlate, however, with AML activity in the majority of patients (93%) during 4-19 months of follow up. These results demonstrate a high prevalence of ACL antibodies in AML patients and suggest that serum ACL antibodies may be a useful adjunct in predicting relapse and documenting disease activity and therapy response.