Autoimmune Cytopenias

This retrospective review of data from a cohort of 77 patients with autoimmune hemolytic anemia (AIHA) evaluated whether thromboembolic events in this population were related to complement activation. All patients had a positive direct antiglobulin test (DAT) and hemolytic parameters, had been screened for thromboembolic events (TEE), and were stratified into groups with and without complement activation based on positivity for complement as determined by DAT. In the cohort, 66% had warm AIHA, 17% had cold-AIHA, 7% had mixed AIHA, and 10% had atypical AIHA. Primary AIHA was diagnosed in 44% and 56% had secondary AIHA. TEE occurred in 26% of patients. Among patients wih TEE, 80% had warm AIHA and 10% had cold AIHA. Hemolysis parameters were similar in patients with vs without TEE. The investigators reported "no correlation with complement activation as evidenced by a positivity for complement in the monospecific DAT with the occurrence of TEE." They concluded that, based on their findings, "prophylactic anticoagulation might be considered as soon as the diagnosis of AIHA is confirmed."