All Thiopurines Are Equal but Some Thiopurines Are More Equal Than Others

To the Editor With interest, we read the clinically important article by Ertz-Archambault et al¹ describing the association of immunosuppressive therapy for autoimmune diseases with the development of myelodysplastic syndrome and acute myeloid leukemia. As a key point, the authors state that azathioprine sodium was the only agent associated with a significant risk.