Premium
Increased expression of immune checkpoint programmed cell death protein‐1 ( PD ‐1) on T cell subsets of bone marrow aspirates in patients with B‐Lymphoblastic leukemia, especially in relapse and at diagnosis
Author(s) -
Park Sang Hyuk,
You Eunkyoung,
Park ChanJeoung,
Cho YoungUk,
Jang Seongsoo,
Im HoJoon,
Seo JongJin,
Park HanSeung,
Lee JungHee
Publication year - 2020
Publication title -
cytometry part b: clinical cytometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 61
eISSN - 1552-4957
pISSN - 1552-4949
DOI - 10.1002/cyto.b.21879
Subject(s) - cd8 , medicine , bone marrow , t cell , flow cytometry , cd3 , immune system , immune checkpoint , leukemia , immunophenotyping , immunology , immunotherapy
Background We analyzed expression profiles of immune checkpoint receptors on T cell subsets and ligands on leukemic blasts in patients with B‐lymphoblastic leukemia (B‐ALL). Methods Total 149 bone marrow (BM) samples obtained from 65 B‐ALL patients with four different clinical status (41 at diagnosis, 54 in complete remission [CR], 34 in persistence, and 20 in relapse), and 32 BM control samples were prospectively enrolled. Expression of immune checkpoint receptor (programmed cell death protein‐1 [PD‐1]) on T cell subsets and ligands (PD‐L1, PD‐L2) on leukemic blasts was evaluated by flow cytometry, and was compared between patient subgroups. Results Relapsed patients demonstrated highest PD‐1 expression proportion and intensity on CD3 + CD4 + T cells with statistical significance when compared to patients in persistence/CR/BM controls ( p = .027/<.001/<.001 and .012/.001/<.001, respectively). Newly diagnosed patients showed significantly lower PD‐1 expression proportion on CD3 + CD4 + T cells than relapsed patients ( p < .001), but their intensity was not significantly different. Relapsed patients showed significantly higher PD‐1 expression proportion and intensity on CD3 + CD8 + T cells than patients in CR/BM controls ( p = .022/.045 and .049/.005, respectively), but PD‐1 expression status on them were not significantly different between relapsed and newly diagnosed patients. PD‐L1/L2 expression on leukemic blasts was not significantly different between patient subgroups. Conclusions In BM aspirates from B‐ALL patients, PD‐1 expression on T‐cell subsets is increased at diagnosis, and to a greater extent, at relapse. These data suggest the potential usefulness of PD‐1 blockade in the treatment of B‐ALL, particularly at relapse.