Auer rods and myeloperoxidase: an approach for investigating changes at the molecular level in acute myeloid leukaemia (AML).

Auer rods are cytoplasmic inclusions found only in the leukaemic cells of some cases of acute myeloid leukaemia (AML). The ultrastructure of Auer rods is different in different sub-types of the disease and it is suggested here that this may be a consequence of the Auer rods consisting of different crystalline forms of the enzyme myeloperoxidase. There is statistical evidence to indicate that patients with Auer rods have a more favourable prognosis than those without. It is proposed that an investigation of the factors that determine the form, if any, of the crystallisation of myeloperoxidase will lead to a better understanding of the molecular events underlying the different types of AML. In the long term this may in turn lead to a therapeutic advance.