RHAMM/CD168 is a cell surface receptor for hyaluronan, a glycoaminoglycan that plays a fundamental role in cell growth, differentiation and motility. It is one of the leukemia-associated antigens (LAA) identified in patients with myeloid leukemias.
We aimed: at studying the frequency of expression of RHAMM/CD168 in Egyptian patients with CML, both in chronic phase and accelerated/blastic phase, as a potential target structure for cellular immunotherapies, and to compare it with available western records.
Patients and methods: RHAMM expression was tested by RT-PCR in peripheral blood mononuclear cells of 60 CML patients divided into 2 groups, group A: 44 chronic phase CML patients, group B: 16 accelerated/ blastic phase patients as well as 15 healthy volunteers.
Our results: Demonstrated that 14/44 (31.8%) of chronic CML patients showed positive RHAMM expression in contrast to 15/16 ( 93.7%) in the accelerated/blastic phase patients. Moreover within the chronic phase patients the RHAMM positive patients had a significantly higher level of bcr-abl/abl ratio. This highlighted the contribution of RHAMM expression with CML disease progression.
Conclusion: Our work demonstrated a similar proportion of RHAMM expression in both Egyptian and western CML patients. This may pave the way for subsequent studies suggesting the concomitant use of RHAMM R3 peptide vaccination with conventional CML therapy especially in accelerated phase, in order to achieve complete molecular remission for our patient.