Expert Perspectives on the Optimal Management of Sickle Cell Disease - Episode 8
Insight on the screening and monitoring for red blood cell transfusion for the management of sickle cell disease.
Ifeyinwa (Ify) Osunkwo, MD, MPH: Pat, let’s talk about transfusion therapy. We’ve heard about it used for stroke, for acute chest syndrome, acutely but also chronically. Can you talk about how you screen and monitor people who are on transfusions? Who should be on chronic transfusions with sickle cell disease?
Patrick McGann, MD, MS: It’s before all the medicines we’ve talked about, it’s all we used to have, and it’s still an important component to therapy even when we do have medications like the ones we’re talking about. There are acute reasons, like you mentioned, for transfusion in young children, splenic sequestration that happens, where blood gets trapped in the spleen and your hemoglobin drops to 4 or 5 [g/dL]. In the setting of acute chest syndrome, parvovirus infection in young children, in older patients who get sick with crises and have kidney problems and have a low hemoglobin at baseline. Patients who have acute anemia will often have a need for blood transfusion. Chronic transfusion is used in about 10% or 20% of the population, in the pediatric world at least. The historical reason was to prevent either a first or second stroke. Abdullah had mentioned TCDs [transcranial doppler ultrasounds], and if you have an abnormal TCD exam it means your risk of stroke is high. At this point we recommend transfusion for at least a year to minimize that stroke. Data from the TWiTCH trial show that we can eventually transition off to hydroxyurea if everything else looks good. Patients who’ve had a first stroke, already had an overt stroke, their risk of a second stroke is very high, and chronic blood transfusions for the rest of their life basically every month is the best option we have so far, unless there’s another curative therapy like bone marrow transplant or possibly gene therapy available to those patients.
There are acute risks to transfusion, like volume overload, a transfusion reaction, infections that can be passed along despite our screening measures. There’s a chance you can develop an antibody to the blood that’s transfused to you, which can become a big problem and make it difficult to transfuse in the long term. We’re much more careful with how we transfuse these days. Before it may have been that you’d be transfused whenever you’re in with a pain crisis. Transfusion doesn’t seem to help with a lot of the acute events, so we’re using it more carefully now, but there’s still an important role for transfusion for acute complications, for chronic transfusion reasons. Patients who are transfused every month, one of the biggest problems is iron overload. When you give blood every month you get iron that develops in your organs, your liver primarily. Sometimes it’s in your heart if it’s really bad. We have medications to stop that, but again, patients must take those medicines. Sometimes you do what’s called an exchange transfusion, where you do erythrocytapheresis, where you throw away the bad red blood cells and sickle the red blood cells and transfuse back healthy ones so there’s less iron burden. We’re getting more technical with how we do this, but it’s still an important component of sickle cell therapy despite these other advancements.
Ifeyinwa (Ify) Osunkwo, MD, MPH: Thank you, Pat. I remember in my first faculty position, one of my most traumatic experiences taking care of patients with sickle cell disease was a 14-year-old male who presented with caput medusae. He had the veins on his belly, big stomach, liver cirrhosis. He died within a month of coming into care. He’d been in an outlying hospital getting transfused for different reasons on a regular basis. But he was 14 years old, and so while they don’t see their ferritin levels being high, they don’t see the effects of iron, it’s doing damage to your body, with the sickle cells doing damage to your body. Again, it freaked me out as a junior faculty member that this can happen so early in a child’s life.
So just like what Pat mentioned, I want to reiterate that blood transfusion is one of the cornerstone treatments of sickle cell disease in the acute setting and serves a lot of people in the chronic setting. It’s important that providers foster and encourage people to donate blood because if there’s no blood available they wouldn’t have it to be used when they need it. We do know that there’s a lot of similarity in an African American blood donor’s profile to that of a person with sickle cell disease. We encourage minority blood donation. And when you do transfuse, and do matched blood cells that are sickle negative. It may seem simple and intuitive, but if you don’t see sickle cell disease a lot, you may not think about this off the top of your head. Again, sickle negative blood, antigen match the blood, and monitor the patients for iron overload by measuring the ferritin levels.
Transcript Edited for Clarity