CD180 is a Toll-like receptor expressed primarily in B-cell groups and has been identified as a potential therapeutic target in diseases such as B-cell non-Hodgkin lymphoma. However, the expression profile of CD180 and its clinical significance in patients with Acute Myeloid Leukemia (AML) remain largely uncharacterized. While the only existing study in the literature has reported high CD180 expression in a subset of AML samples, these findings have not been validated by other studies. Therefore, the objective of this study is to determine the presence and level of CD180 expression on leukemic blasts at the time of diagnosis in a cohort of AML patients.

Between November 15, 2024 and December 31, 2024, five patients diagnosed with Acute Myeloid Leukemia at the Ege University Immunology Laboratory were included in this study.Informed consent was obtained from all patients. Peripheral blood or bone marrow samples were collected at the time of diagnosis. Flow cytometry was used to determine the percentage of leukemic blasts and to evaluate the expression of CD180 on these cells. Demographic, clinical, and molecular data obtained from patient records were used for patient follow-up analyses, Türkiye.

In this study, data from a total of five AML patients, including four newly diagnosed and one with refractory disease, were evaluated. The median age of the cohort was 65 years (range: 20–66), and the patients' blast percentages ranged from 50% to 95%. Initial laboratory findings included a White Blood Cell (WBC) count ranging from 1.45 to 87.92 × 10⁹/L, a platelet count from 25 to 206 × 10³/µL, and a hemoglobin (Hb) value from 6.8 to 12.2 g/dL.

Flow cytometry analysis revealed that very low-density CD180 expression was present on leukemic blast cells in all five patients examined. According to molecular and cytogenetic data, three patients (ASXL1 mutation and BCR::ABL1 fusion gene) were included in the ELN Adverse Risk Group, while the remaining two patients were included in the ELN Intermediate Risk Group. Based on clinical follow-up results, one patient in the adverse risk group was deceased after 2 months, and another was deceased after 27 months. All patients in the intermediate risk group were alive at the end of an 8-month follow-up period.

In conclusion, our findings demonstrate the low-density of CD180 expression on leukemic blasts in all five AML patients examined. This observation contradicts the findings of the only study in the literature. Therefore, further studies involving larger patient groups are needed to accurately determine the presence of CD180 on AML blasts.