S111: BRAIN PERFUSION CHANGES IN BETA-THALASSEMIA
Authors: R Manara, S Ponticorvo, I Tartaglione, A Canna, A Russo, M Fedele, M Rocco, M Cirillo, S Perrotta, F Esposito
Journal: HemaSphere (2022)

Background: Brain involvement in hereditary hemoglobinopathies (e.g. sickle cell disease, beta-thalassemia, spherocytosis) is commonly attributed to anemia-related relative hypoperfusion. Supratentorial and infratentorial vascular watershed regions seem to be especially vulnerable, but data are very scarce. Aims: We investigated a large beta-thalassemia sample with arterial spin labelling in order to characterize regional perfusion changes and their correlation with phenotype and anemia severity. Methods: We performed a multicenter single-scanner cross-sectional MRI study analyzing non-invasively in 71 beta-thalassemia patients and 56 healthy controls the brain perfusion changes. Clinical phenotype, age, hemoglobin levels, cognitive functioning and parenchymal lesions were also recorded. Results: Brain perfusion was globally increased in beta-thalassemia patients compared to healthy controls; using age and sex as covariates and scaling the perfusion maps for the global cerebral blood flow, beta-thalassemia patients showed: hyperperfusion in the white matter of the centrum semiovale bilaterally, located in the watershed regions between the vascular territories of the main cerebral arteries (Fig-1a) and in the cerebellar white matter corresponding to the cerebellar watershed regions. Subdividing patients according to anemia severity (hemoglobin level < or > 9.5g/dL), the hyperperfusion clusters persisted exclusively in the subgroup with lower hemoglobin levels. Summary and Conclusion: The relative hyperperfusion observed in vascular watershed territories does not support the previous hypothesis of a selective parenchymal hypoperfusion in the pathogenesis of brain injury in hereditary hemoglobinopathies. A careful management of anemia severity seems to be pivotal for preventing perfusion dysfunction, at least in beta-thalassemia.Fig-1.: Analysis of brain perfusion correcting for global rCBF. Upper row (panels a,b,c) shows t-maps of significantly globally increased perfusion in patients vs healthy controls (HC). Panel a. contains T-maps of the statistical contrast HC vs. thalassemia patients. Panel b. contains T-maps of the statistical contrast HC vs. transfusion dependent (TDT) thalassemia patients. Panel c. contains T-maps of the statistical contrast HC vs. non-transfusion dependent (NTDT) thalassemia patients.References 1. Choi, Soyoung, Richard M. Leahy, and John C. Wood. 2020. “Lower White Matter Volume in Beta-Thalassemia Associated with Anemia and Cognitive Performance.” American Journal of Hematology. 2. Choi, Soyoung, Sharon H. O’Neil, Anand A. Joshi, Jian Li, Adam M. Bush, Thomas D. Coates, Richard M. Leahy, and John C. Wood. 2019. “Anemia Predicts Lower White Matter Volume and Cognitive Performance in Sickle and Non-Sickle Cell Anemia Syndrome.” American Journal of Hematology 94 (10): 1055–65. 3. Manara R, Talenti G, Rampazzo P, Ermani M, Montanaro M, Baracchini C, Teso S, Basso G, Sainati L, Colombatti R. Longitudinal evaluation of cerebral white matter hyperintensities lesion volume in children with sickle cell disease. Br J Haematol. 2017 Feb;176(3):485–487. doi: 10.1111/bjh.13962. Epub 2016 Mar 27. PMID: 27018310.