Sickle Cell Disease and Gene Therapy: A New Hope?

An estimated 100,000 people in the United States live with sickle cell disease — a debilitating and life-threatening blood condition that predominantly affects people of African and Mediterranean descent, and Hispanic-Americans from Central and South America.

For years, those who suffer from the disease have been treated with temporary solutions or with bone marrow transplantation from a donor, but new advances in gene therapy have opened doors to a possible cure using the patient’s own cells. Dr. Ofelia Alvarez, director of the Pediatric Sickle Cell Program at the University of Miami Miller School of Medicine, explains the potential breakthrough.

What is sickle cell disease?

Sickle cell disease is an inherited chronic blood illness.  It occurs when a person inherits the defective hemoglobin gene from each parent. Hemoglobin is the protein inside the red blood cells that carries oxygen in the body. Because of this gene mutation, the abnormal hemoglobin, called hemoglobin S, becomes unstable when it releases oxygen. Then the hemoglobin molecules begin to stack together to form many solid hemoglobin chains changing the shape of the red blood cell to a half-moon or sickled shape. Sickled red blood cells can stop blood flow to different parts of the body resulting in extreme pain or tissue damage.

What is the new research?

It’s called gene therapy.

The idea is that stem cells are obtained by taking bone marrow or blood from the same patient we are trying to cure. This stem cell product is sent to a lab that will genetically modify the hemoglobin inside the red blood cells to alter the mutation or make changes in the ability of the genes to make more hemoglobin F, the hemoglobin fetuses produce. By increasing fetal hemoglobin, the person will not experience sickle cell complications. The new, engineered product is infused back into the patient through a transplant after a brief chemotherapy treatment. Within weeks, the engineered stem cells begin producing new, healthier blood.

How effective is gene therapy?

Some patients have participated in gene therapy clinical trials in the United States and other countries. Gene therapy for sickle cell disease is in its early stages, but so far there have been promising results.

What do your patients say about this breakthrough?

We have spoken with many patients who are hopeful about the potential cure. The University of Miami is preparing to be one of the sites to conduct research in gene therapy. At the University, we want to be on the cutting edge of research, so I think we owe it to our patients to provide the newest kinds of cures.

Do you think gene therapy can pave the way to help treat other kinds of diseases in the future?

Yes. Right now, there are other conditions in hematology like beta-thalassemia that can be treated using the same technique. Also, gene therapy studies have been conducted here at UM to potentially treat hemophilia, a disorder in which blood doesn’t clot normally.

Updated by UHealth Collective
Originally written by Amanda M. Perez for Inventum

Originally published on: February 08, 2019

Tags: blood illness, Dr. Ofelia Alvarez, gene therapy, sickle cell disease