Sickle cell disease (SCD) is caused by a variant hemoglobin molecule that polymerizes inside red blood cells (RBCs) in reduced oxygen tension. Treatment development has been slow for this typically severe disease, but there is current optimism for curative gene transfer strategies to induce expression of fetal hemoglobin or other nonsickling hemoglobin isoforms. All SCD morbidity and mortality arise directly or indirectly from polymer formation in individual RBCs. Identifying patients at highest risk of complications and treatment candidates with the greatest curative potential therefore requires determining the amount of polymer in individual RBCs under controlled oxygen. Here, we report a semiquantitative measurement of hemoglobin polymer in single RBCs as a function of oxygen. The method takes advantage of the reduced oxygen affinity of hemoglobin polymer to infer polymer content for thousands of RBCs from their overall oxygen saturation. The method enables approaches for SCD treatment development and precision medicine.
|Original language||English (US)|
|Number of pages||7|
|Journal||Proceedings of the National Academy of Sciences of the United States of America|
|State||Published - Dec 10 2019|
Bibliographical noteFunding Information:
ACKNOWLEDGMENTS. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nano Coordinated Infrastructure Network under Award ECCS-1542202. This work was supported by National Heart, Lung, and Blood Institute Grants HL130818 and HL132906. We thank Chhaya Patel and Hasmukh Patel for assistance with blood sample collection, Carlo Brugnara and Frank Bunn for helpful discussions, and the editor and 2 anonymous reviewers for helpful comments and suggestions.
- Hemoglobin polymerization
- Oxygen affinity
- Sickle cell disease