Sickle Cell Disease
Gwendolyn Poles, DO, is a retired primary care physician and a sickle cell patient. She is Board President for the South Central Pennsylvania Sickle Cell Council and answers your questions below:
Q: What is Sickle Cell Disease?
A: It is an inherited, genetic disease. You don’t catch it. Both parents have to be carriers for what is called the trait. Any child born today with the disease is diagnosed through newborn screenings.
It gets its name because your red blood cells are the shape of a crescent or a sickle. It affects circulation of the blood. As a result of that, damage occurs within the blood vessels, which can cause really severe painful events. Even with controlling the pain, organ damage can and does occur. This causes everything from strokes to kidney failure, or problems with the heart, lungs, and eyes.
Q: What treatment options exist?
A: Luckily, there are a number of options today. When I was growing up, there was literally no treatments other than controlling the pain and monitoring for organ damage.
In the early 1980s, studies showed that giving children weight-based doses of penicillin twice a day reduced infections and expanded life dramatically. Most children before this died as early as 5 years old because of severe infections.
The second therapeutic in the 1990s proved helpful in preventing strokes. They began giving children blood transfusions. When they kept the percentage of the sickle hemoglobin low and the normal hemoglobin (red blood cells) high, children would not have a reoccurring stroke. The incidence of stroke in children went from 25 percent to 2 percent.
Chronic organ damage
Hydroxyurea helped reduce the number of high pain events if patients took it on a regular basis. That has improved the lives of both children and adults. We also found that it impacted some of the chronic organ damage.
There are still things like pulmonary hypertension – which affects the lungs – that have not improved. So we still have a long ways to go because there are so many organs that can be damaged.
New medicine in the last three years
L-glutamine (brand name, Endari), a new oral drug approved about three years ago that decreases the frequency of acute painful events called vaso-occlusive crises. This is pharmaceutical grade L-glutamine vs the over-the-counter version.
Crizanlizumab (brand name Adakveo), approved last year, also prevents the painful vaso-occlusive crisis. This is an intravenous drug given monthly.
The other new oral treatment approved this year is Voxelotor (brand name, Oxbryta) which inhibits the sickling of the red blood cells, improves the red blood cells deformability thus decreasing the destruction of the fragile red blood cells resulting in an increase in the baseline hemoglobin (blood count).
Finally several companies are developing gene therapies to replace or alter the abnormal beta globin gene that causes SCD with a normal gene sequence or alternative beta globin gene. There are also other gene therapies being explored.
Q: Why does the public still not know much about sickle cell disease?
A: The answer has varied over time. When I was growing up, there just really wasn’t much knowledge about the disease from even the medical community.
The unfortunate underlying truth is because it affects predominantly people of color, particularly African-Americans, getting the attention, research, and resources has been very challenging.