Key clinical point: Natural killer (NK) cell subsets, particularly CD56bright NK cells, were associated with relapse outcomes after tyrosine kinase inhibitor (TKI) discontinuation in patients with chronic-phase chronic myeloid leukemia (CML-CP). Moreover, interferon- a therapy gradually increased levels of CD56bright NK cells.
Major finding: Among patients who did not receive interferon- a therapy, the nonrelapsed vs relapsed patients had a significantly higher proportion of CD3-CD56+ NK cells ( P = .016), particularly CD3-CD56dimCD16+ NK cells ( P = .017), at 1 month after TKI discontinuation. Patients who received interferon- a therapy showed an increase in CD56bright NK cells at 3- and 6- months post-therapy vs pre-therapy ( P < .05).
Study details : Findings are from a retrospective analysis of 34 patients with CML-CP who discontinued TKI therapy after 3 or more years and at least 2 years of MR4.5. Twelve patients received interferon- a therapy post-TKI discontinuation.
Disclosures: This study was supported by the Capital Characteristic Clinic Project Foundation. The authors declared no conflict of interests.
Source: Kong J et al. Ann Hematol. 2021 Jul 19. doi: 10.1007/s00277-021-04606-9 .