Programmed Death Ligand-1 is Frequently Expressed in Primary Acute Myeloid Leukemia and B-Acute Lymphoblastic Leukemia.

BACKGROUND: The introduction of checkpoint inhibitors in solid cancer therapy showed successful results. The role of Programmed Death-1/Programmed Death-Ligand 1 (PD1/PD-L1) in hematologic malignancies is currently being investigated and clinical trials are ongoing. Preliminary findings showed conflicting results. In this study, we examined the degree of PD-L1 and PD-L2 expression in primary acute leukemia patients. METHODS: Flow cytometry expression of PD-L1 and PD-L2 was evaluated in de novo acute leukemia in the collaborating institutions between 2018 - 2020. RESULTS: One hundred forty patients were identified. PD-L1 was positive in 34/70 (49%) of AML, 25/50 (50%) of B-ALL, and none (0/20) of T-ALL patients. In contrast, PD-L2 was solely expressed in eight (19%) AML patients. The expression of PD-L1 showed statistically significant correlation with the type of acute leukemia (AML and B-ALL > T-ALL, p < 0.001) and with age group (adults > children, p = 0.048), but not with blast count, immunophenotype or cytogenetic mutations. The positivity for PD-L1 was associated with worse overall survival in AML, but not in B-ALL. CONCLUSIONS: The expression of PD-L1 is common among newly diagnosed AML and B-ALL patients and is not restricted to relapsed cases as previously described. PD-L2 is less commonly expressed and is accompanied by PD-L1 expression. Positive PD-L1 patients may benefit from treatment with immune checkpoint inhibitors, especially in AML. Further studies are recommended.

Central macular thickness in patients with sickle cell disease and no signs of retinopathy: a cross-sectional study of Jordanian patients.

OBJECTIVES: To measure central macular thickness in Jordanian patients with sickle cell disease who did not have retinopathy and compare the findings with age- and sex-matched controls using spectral domain optical coherence tomography (SDOCT). METHODS: In this cross-sectional study, participants underwent visual acuity testing, slit-lamp bio-microscopy, dilated ophthalmoscopy, and SDOCT imaging to measure central macular thickness. Macular quadrant measurements and thickness difference indexes (TDIs) were compared between groups. RESULTS: Twenty eyes with sickle cell disease and 20 control eyes were enrolled. The median visual acuity in both groups was 20/20. The mean macular thickness was significantly lower in eyes with sickle cell disease than in matched controls (mean difference, 22.15 ± 6.44 µm). Peripheral quadrants were all significantly thinner in eyes with sickle cell disease, especially in superior and temporal quadrants. TDIs were lower in eyes with sickle cell disease than in control eyes. CONCLUSIONS: Eyes with sickle cell disease that had no clinical evidence of retinopathy exhibited significantly lower central macular thickness in all quadrants, compared with eyes in age- and sex-matched controls. SDOCT is a non-invasive imaging modality that can detect preclinical changes in eyes with sickle cell disease and can be used to screen and monitor the disease process.