CD123, a membrane-bound interleukin-3 receptor, is overexpressed in many hematological malignancies, and it has been found useful in characterizing both acute myeloid leukemia (AML) and B-acute lymphoblastic leukemia (B-ALL). CD123 expression also appears positively correlated with the presence of minimal residual disease (MRD) after treatment, and may be useful as a marker of treatment success, according to a report presented online in Clinical Lymphoma, Myeloma and Leukemia.

Nupur Das, MD, and colleagues from the Dr B.R. Ambedkar Institute Rotary Cancer Hospital, New Delhi, India, evaluated the pattern of CD123 expression across different subtypes of acute leukemia to assess its utility as a diagnostic marker, and to assess its impact on MRD assessment and early treatment outcome.

The evaluated the expression of CD123 in 757 samples of acute leukemia (479 treatment-naive and 278 follow-up samples) and compared the results with post-induction morphological remission (CR) and measurable residual disease (MRD) status.

The researchers used cut-offs of 5%, 10%, and 20% CD123-expression positive results to define a case as CD123 positive. On this basis, expression of CD123 was observed in 75.6%, 66.2%. and 50% of AML samples and 88.6%, 81.8%, and 75% of B-ALL samples respectively. They also found that none of the 12 T cell acute lymphoblastic leukemia (T-ALL) cases expressed CD123.

In addition, they found that CD123 expression was associated with MRD-positive status in both B-ALL (P < .001) and AML (P = .001).

“MRD is already an established post-treatment prognostication tool in acute leukemia and hence, the positive correlation of CD123 expression with MRD positivity in AML signifies its utility as an important marker to assess early response to therapy,” the researchers stated.

The authors reported that they had no conflicts of interest.

SOURCE: Das N et al. Clin Lymphoma Myeloma Leuk. 2020 May 10; doi.org/10.1016/j.clml.2020.05.004.