Emerging Therapies in the Management of Sickle Cell Disease - Episode 1
Biree Andemariam, MD: Michael, what you just informed our audience about, particularly those who may not have a lot of experience taking care of individuals with sickle cell disease, is heartbreaking and devastating. It really does align with what our panelists have described about the path of physiology, what Julie called a blood vessel disease in the background of a blood disease.
Some of the statistics that you cited: 11% stroke risk, 10% pregnancy-related mortality in low-income settings, 30% depression, the amount of suffering related to priapism, end-stage renal disease mortality. What about quality of life in these individuals? Wally, what does the impact of what Michael explained to us have on the individual living with sickle cell disease?
Wally Smith, MD: Health-related quality of life in sickle cell disease is poor, even in young adults. It might even be age dependent, meaning that the transition age group may have the worst health-related quality of life with their suffering and the shock of leaving home. There’s the shock of often not having insurance as adults when they had them as children. There’s the shock of having to fend for themselves now and managing all those complications that Mike and others have talked about.
Then the organic problem of organ failure starts to take a toll on their physical health-related quality of life. If you add up depression, PTSD [post-traumatic stress disorder], organ failure, worsening cognitive function together, the health-related quality of life in patients with sickle cell disease is somewhere around that of dialysis patients—or maybe a little better—according to 1 of the comparative studies we did.
Biree Andemariam, MD: Somewhere around that of being someone on dialysis. Julie, in light of everything Michael and Wally told us about the acute and chronic manifestations and the impact on quality of life, where are we with sickle cell and life expectancy in this country or even globally?
Julie Kanter, MD: I’ll answer your question in 1 minute. I want to first respond to my colleagues because, while this disease is incredibly serious and has multiple complications, there are also people who are living very well and very strong with sickle cell disease. Sometimes we neglect to talk about how if individuals are taught how to take care of themselves and are seeing a sickle cell specialist, this disease can be managed.
We see many affected individuals who are doctors, nurses, lawyers, and other able-bodied individuals. There are a lot of complications and a lot of unmet needs, but there are also a lot of wins. We do know that if you’re seeing a specialist, you can have better outcomes, and that’s really important when you look at our overall life expectancies. When you compare life expectancies, in different countries but also among different institutions, a lot of what predicts outcomes is what type of specialist you’re seeing and access to care you have.
What I harp on is access to care. The most important thing we can do is to make sure everybody with a sickle cell disease diagnosis is able to see a specialist, whether they’re here or in sub-Saharan Africa, and that we can get the very best options for those individuals.
In the United States and other high-income countries, we’ve seen a couple of studies that show us a range in life expectancy. From the lower end we saw out of the Sickle Cell Data Collection [program] and really important data out of the CDC project in California, where we’re seeing an average life expectancy of 41 to 44 years of age. There are more recent data that we’ve seen out of Tennessee that put that age of life expectancy a bit higher. Then we have some information out of England that suggests perhaps even a higher life expectancy.
We can compare that with sub-Saharan Africa, where unfortunately, we still have more than half our kids dying before they’re 10. That is really neglectful on our parts because we can make a huge difference with newborn screening, early diagnosis, and early treatment. The range really depends on what type of access to care you have.
Biree Andemariam, MD: Elliott and Michael, I’d like you to both chime in because Julie did mention your states of California and Tennessee, so unpack that for us a little.
Michael DeBaun, MD, MPH: Go ahead, Elliott.
Elliott Vichinsky, MD: Thank you, Michael. I just wanted to comment that after practicing for many years, I would say that the ethical challenge in this country has been taking care of chronically ill people. The health inequities and disparity are best illustrated in sickle cell disease. The real problem for sickle cell in this country has been lack of access to getting the minimum standard of care available. I would say that in working in a community and with many universities, the majority of patients don’t get appropriate care or access to appropriate care.
In my region this is the No. 1 cause of death. It’s the lack of getting access to well-established standard-of-care practices that could prevent or minimize outcomes. It’s a tragedy. Sickle cell is the best and worst of health care. As we develop these new treatments, we really have to get at this incredible disparity in survival, which in my opinion is because of a lack of access. It can’t be kept in the closet.
Michael DeBaun, MD, MPH: I just wanted to comment quickly about 2 studies that Julie mentioned. The first 1 was out of the United Kingdom, where they have a life span in the mid-60s for sickle cell disease. The initial attribution was that they have the National Health Service with a social service network, and anybody who needs medical care will receive medical care. It turns out that there was a statistical approach that they used to make an assumption. We repeated that analysis with who my peers would say are 2 reasonably knowledgeable hematologists, Dr Kenneth Ataga [at the University of Tennessee Health Science Center] and Dr Adetola Kassim [at Vanderbilt-Ingram Cancer Center].
These are adults who were treated with optimal medical therapy. Sixty percent were on hydroxyurea, and as you all know, that’s a much higher rate than you would expect in the general population. Among those who were not on hydroxyurea, they either did not want it because they were trying to get pregnant, they were on transfusions, or they had SC [sickle–hemoglobin C] disease. It’s really a high percentage.
In that group, the median survival was age 48. Among those patients, there was no statistically significant difference between those with SC and SS [sickle cell anemia]. Although there was a numerical difference, patients with SC were still dying earlier than you would’ve expected. I don’t want to ignore this population, because we often tend to focus on the complications as it relates to SS and sickle beta zero thalassemia and not SC.
Julie Kanter, MD: That’s so true. That’s an area where we all need to improve our outcomes. One of the things we found in some of our research, especially with our kids with SC disease, is that they often don’t feel poorly or have a lot of these complications. By the time they get to adult care, often in their early 20s, it’s really a failure not so much of transition. It’s that they weren’t seen in their late teens to transition, so by the time they get to us, sometimes they have organ complications or other issues. We need to do a better job of taking care of those patients when they’re younger to get them in steady hands when they’re older too.
Biree Andemariam, MD: I agree with you 100%, having taken care of adults with sickle cell disease my whole professional life. I was always astounded by the labeling of children with SC as having a mild phenotype. Michael and Julie, you’re absolutely right. By the time they get to adulthood, all bets are off, and the statistics that both of you outlined for us tell that same story.
Transcript Edited for Clarity