Expression of B7-H6 in chronic myeloid leukemia and its clinical significance

Objective: To examine the expression level of B7-H6 in chronic myeloid leukemia (CML) patients and to explore its clinical significance.

Methods: Two hundred twenty-eight CML patients were included and peripheral blood (PB) and bone marrow (BM) mononuclear cells were collected for B7-H6 mRNA expression analyses by quantitative real time polymerase chain reaction (PCR).

Results: The expression of B7-H6 mRNA was successfully detected in all PB and BM samples. According to the clinical characteristics of CML patients, no difference was found in the B7-H6 level of PBMCs. However, a significantly decreased B7-H6 level was noted in BM samples from CML with BCR-ABL1/ABL > 0.1% (10 copies of BCR-ABL1/10000 copies of ABL) compared to ≤ 0.1% (P < 0.0001), and a negative correlation was found between the expression level of B7-H6 in BM and the number of BCR-ABL1/ABL transcripts (r = -0.26, P = 0.0057). A significant difference in PFS was observed between patients with high expression level of B7-H6 and low expression level in BM (χ² = 12.53, P = 0.0004).

Conclusion: The expression of the B7-H6 gene in CML is correlated with BCR-ABL1 copy number and responsiveness to treatment, and monitoring of B7-H6 expression may be used to predict CML prognosis, progression, and treatment efficacy evaluation.