Severe Autoimmune intravascular hemolytic anemia in patients receiving Alemtuzumab for Multiple sclerosis

Alemtuzumab and autoimmune haemolytic anaemia: Coincidence or causation?

“…Reports have recently implicated alemtuzumab, a monoclonal antibody that targets CD52 and is often used as a treatment for both multiple sclerosis and chronic lymphocytic leukaemia, in the development of autoimmune haemolytic anaemia (AIHA). Notably, a recent review by Sharma et al described a potential case of alemtuzumab‐induced AIHA encountered by them and focused on nine additional reported cases in the literature [2]. While the referenced case describes a patient with what seems compatible with the development of warm AIHA (WAIHA), the absence of additional testing—including indirect antiglobulin test (IAT) to assess for antibodies in the plasma, and elution or adsorption studies to evaluate the red blood cell (RBC)‐bound IgG specificity—limits the ability to definitively subclassify the AIHA.…”

“…Instead, it has been speculated that alemtuzumab may induce AIHA via unbalanced immune reconstitution following immune downregulation by the drug [2]. This theory deserves further investigation, as it would represent a paradoxical effect of alemtuzumab, a novel therapeutic option for patients with refractory AIHA [5,6].…”