Sub classification and clinico-hematological correlation of 40 cases of acute erythroleukemia - can proerythroblast/myeloblast and proerythroblast/total erythroid cell ratios help subclassify?

The clinico-hematological profile of 40 cases of acute erythroleukemia (AEL) was evaluated. These were subclassified into three types, namely AML M6a, M6b and M6c based on the myeloblast and proerythroblast percentages. The proerythroblast percentage has been shown to be a prognostic indicator by several studies. As AEL is biologically an "erythroid predominant" disease, two ratios (PE/MB, PE/TEC) with proerythroblasts as numerator have been formulated. An attempt has been made to assess the difference in these ratios in subclassified AEL. There were 29 M6a, 2M6b,and 9 M6 c patients, which were subclassified using the criteria proposed by Mazzella et al. The incidence of AEL in our study was 3.7%, predominantly affecting males with a predilection to younger age in contrast to Western studies. Both PE/MB and PE/TEC ratios were higher in M6b and M6c in comparison to M6a. The subclassification of AEL becomes essential especially in the era of lineage-targeted therapies, which can lead to the development and use of erythroid specific treatments in the near future.