“…8 While the authors report that biphasic hemolysis was present in the DL test, it would have been informative to know whether hemolysis was also observed in the patient samples maintained at cold and/or warm temperature, as this would give credence to the presence of a clinically significant cold and/or warm autoantibody. Of note, a negative DL test does not necessarily exclude a diagnosis of PCH in the appropriate clinical context 9 ; low and undetectable DL antibody titers are the most common cause of false-negative results. 8 Methods to enhance the detectability of these low-titre antibodies include enzyme treatment of reagent RBCs, which will increase the exposure of the P antigen, thereby potentially allowing for heightened binding of the DL antibody.…”