New insights into the clinical utility of LMO2

This thesis offers novel information on the clinical utility of LMO2, shown in three different studies. In the first one, we generated a round-robin testing validating the interobserver and interlaboratory reproducibility of LMO2. In the second, we assessed LMO2 mRNA expression by chromogenic in situ hybridization (CISH) in normal tissue and in a series of agressive large B-cell lymphomas (aLBCL). Normal tonsil tissue showed high levels of LMO2 mRNA in the light zone of the germinal center and low levels of LMO2 in MYC-R aLBCL cases. In the third study, we asked whether the combined profile of CD10/LMO2/MYC is useful to detect MYC-R, improving LMO2 and MYC individual results. A scoring system and algorithm were generated and both associated with the presence of MYC-R. In conclusion, these findings place LMO2 as a useful and reproducible marker to screen MYC-R, especially by combining CD10/LMO2/MYC markers. Moreover, LMO2 mRNA expression by CISH, captures many of the reported biologic features of LMO2, offering a reasonable explanation for the downregulation of LMO2 in MYC-R aLBCL.