Faculty Collaboration Database

Red cell exchange transfusions lower cerebral blood flow and oxygen extraction fraction in pediatric sickle cell anemia. Blood 2018 Mar 01;131(9):1012-1021

Date

12/20/2017

Pubmed ID

29255068

Pubmed Central ID

PMC5833262

DOI

10.1182/blood-2017-06-789842

Scopus ID

2-s2.0-85047733115 (requires institutional sign-in at Scopus site)   66 Citations

Abstract

Blood transfusions are the mainstay of stroke prevention in pediatric sickle cell anemia (SCA), but the physiology conferring this benefit is unclear. Cerebral blood flow (CBF) and oxygen extraction fraction (OEF) are elevated in SCA, likely compensating for reduced arterial oxygen content (CaO₂). We hypothesized that exchange transfusions would decrease CBF and OEF by increasing CaO₂, thereby relieving cerebral oxygen metabolic stress. Twenty-one children with SCA receiving chronic transfusion therapy (CTT) underwent magnetic resonance imaging before and after exchange transfusions. Arterial spin labeling and asymmetric spin echo sequences measured CBF and OEF, respectively, which were compared pre- and posttransfusion. Volumes of tissue with OEF above successive thresholds (36%, 38%, and 40%), as a metric of regional metabolic stress, were compared pre- and posttransfusion. Transfusions increased hemoglobin (Hb; from 9.1 to 10.3 g/dL; P < .001) and decreased Hb S (from 39.7% to 24.3%; P < .001). Transfusions reduced CBF (from 88 to 82.4 mL/100 g per minute; P = .004) and OEF (from 34.4% to 31.2%; P < .001). At all thresholds, transfusions reduced the volume of peak OEF found in the deep white matter, a location at high infarct risk in SCA (P < .001). Reduction of elevated CBF and OEF, both globally and regionally, suggests that CTT mitigates infarct risk in pediatric SCA by relieving cerebral metabolic stress at patient- and tissue-specific levels.

Author List

Guilliams KP, Fields ME, Ragan DK, Eldeniz C, Binkley MM, Chen Y, Comiskey LS, Doctor A, Hulbert ML, Shimony JS, Vo KD, McKinstry RC, An H, Lee JM, Ford AL

Author

Dustin K. Ragan PhD Assistant Professor in the Radiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adolescent
Anemia, Sickle Cell
Blood Flow Velocity
Cerebrovascular Circulation
Child
Child, Preschool
Erythrocyte Transfusion
Female
Humans
Magnetic Resonance Angiography
Male
Oxygen