US researchers develop custom blood cells in lab

In a first, researchers from the Johns Hopkins University have successfully engineered custom blood cells after correcting a genetic error in stem cells from patients with sickle cell disease.

"It may be possible in the not-too-distant future to provide patients with sickle cell disease with an exciting new treatment option," said Linzhao Cheng, member of the institute for cell engineering at the Johns Hopkins.

This method of generating custom blood cells may also be applicable for other blood disorders.

Patients with sickle cell disease need frequent blood transfusions and currently have few options.

The problem is that over time, patients' bodies often begin to mount an immune response against the foreign blood.

"Their bodies quickly kill off the blood cells so they have to get transfusions more and more frequently," Cheng added.

To solve that problem, the researchers started with patients' blood cells and reprogrammed them into so-called induced pluripotent stem cells which can make any other cell in the body and grow indefinitely in the laboratory.

They then used a relatively new genetic editing technique called CRISPR to snip out the sickle cell gene variant and replace it with the healthy version of the gene.

The final step was to coax the stem cells to grow into mature blood cells.

The edited stem cells generated blood cells just as efficiently as stem cells that hadn't been subjected to CRISPR, the researchers found.

According to Cheng, to become medically useful, the technique of growing blood cells from stem cells will have to be made even more efficient and scaled up significantly.

The results appeared in the journal Stem Cells.