Clumps of red and white blood cells may contribute to sickle cell disease

Normal red blood cells don’t interact with white blood cells. But Brittain first showed in lab tests with isolated cells that young red blood cells (reticulocytes) would interact with white blood cells and form aggregates with them. Then, she looked for such clumps in blood samples from 14 people with sickle cell disease. All the patient samples studied had clumps, though some had only a few, while others had thousands. She didn’t see clumps in samples from patients without sickle cell disease.

Brittain said other researchers may have disrupted the aggregates because blood collection tubes usually contain an anticoagulant that ties up calcium, which often plays a role in cell adhesion. She saw the aggregates only when she used an anticoagulant that doesn’t remove calcium.

Brittain and her colleagues plan further study of the phenomenon, including the conditions that might determine the number of aggregates in the blood, and whether they are affected by the drug hydroxurea, which is commonly used to treat sickle cell disease.

In addition to Brittain, other authors of the study are: Leslie V. Parise, Ph.D., department chair and professor of biochemistry and biophysics; Dr. Kenneth I. Ataga, assistant professor of medicine; Dr. Eugene P. Orringer, professor of medicine; and Dr. Christine M. Knoll, a fellow in pediatric hematology and oncology.

Support for the research came from National Heart, Lung, and Blood Institute, a component of the National Institutes of Health and the General Clinical Research Center at UNC.

The study can be found at: http://www.blackwell-synergy.com.

Note: Brittain can be reached at (919) 962-1058 or ;
Parise can be reached at (919) 966-2238 or .