Expression of programmed death ligand‑1 in B‑cell acute lymphoblastic leukemia

Background Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy in the world. Patients with good prognostic factors have excellent survival rates with further improvement over the last decades. However, refractory ALL and relapsed ALL after hematopoietic stem cell transplantation are still associated with a poor prognosis. Immune checkpoints have gained attention in recent years in the field of oncology as a mechanism of cancer to evade immunity, but their status in B‑ALL has yet to be investigated. Aim The aim was to assess programmed death ligand‑1 (PDL‑1) expression in newly diagnosed B‑cell acute lymphoblastic leukemia (B‑ALL). Materials and methods This study was directed on 45 patients with newly diagnosed B‑ALL. Surface expression of PDL‑1 on the blast cells was evaluated by multicolor flow cytometry. Results The study participants exhibited a mean PDL‑1 expression of 16.28%, ranging from 8.5 to 70.45%. Conclusion This study has revealed that patients with newly diagnosed B‑ALL could express PDL‑1 to allow cancer cells to evade the immune system, demonstrating PD‑1/PDL‑1 as a universal target for therapy.