According to the 2017 BJH guidelines and the 2020 International Consensus Meeting on AIHA, an antithrombotic prophylaxis with low-molecular-weight heparin is recommended for inpatients with acute hemolysis (grade 1C and 99% agreement respectively) and should be considered for outpatients with acute hemolysis associated with severe anemia (Hb < 8.5 g/dL) (grade 2C and 97% agreement, respectively) [103,104], particularly in the presence of concomitant risk factors for VTE, such as previous events, reduced mobility, thrombophilia abnormalities, age, active cancer. This evidence concerns the gene GSTM1 and anemia (phenotype).