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

Apr 28, 2008

It’s long been known that patients with sickle cell disease have malformed, “sickle-shaped” red blood cells – which are normally disc-shaped – that can cause sudden painful episodes when they block small blood vessels.

Now, researchers at the University of North Carolina at Chapel Hill School of Medicine have shown that blood from sickle cell patients also contains clumps, or aggregates, of red and white blood cells that may contribute to the blockages.

The study, published on-line April 18 in the British Journal of Haematology, marks the first time that aggregates made up of red blood cells and white blood cells have been found in whole blood from sickle cell patients. The study also shows how the red and white blood cells adhere to one another: the interaction is mediated by a particular protein, integrin alpha four beta one.

First author Julia E. Brittain, Ph.D., a research assistant professor in the medical school’s department of biochemistry and biophysics, said further study could lead to new treatments for the disease. “If the blockages are caused by these chunks of aggregates that are circulating in the blood, and we know how the aggregates are sticking together, we potentially could design drugs to disrupt the aggregates so that they pass through the blood vessel more freely,” she said.

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.

Source: University of North Carolina at Chapel Hill

Explore further: Human stem cell model reveals molecular cues critical to neurovascular unit formation

Related Stories

NSA winds down once-secret phone-records collection program

4 hours ago

The National Security Agency has begun winding down its collection and storage of American phone records after the Senate failed to agree on a path forward to change or extend the once-secret program ahead of its expiration ...

Pipeline that leaked wasn't equipped with auto shut-off

4 hours ago

The pipeline that leaked thousands of gallons of oil on the California coast was the only pipe of its kind in the county not required to have an automatic shut-off valve because of a court fight nearly three ...

Uber drivers fined in Hungary

5 hours ago

The Hungarian tax authority fined Uber drivers in its first probe against the ride-sharing service which the economy ministry said Saturday "ignores passenger safety" and must be made to follow regulations.

Recommended for you

Scientists turn blood into neural cells

May 21, 2015

Scientists at McMaster University have discovered how to make adult sensory neurons from human patients simply by having them roll up their sleeve and providing a blood sample.

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.