Strategies to Help Diagnose Sickle Cell Disease
JANUARY 29, 2020
Ify Osunkwo, MD, MPH: Julie, how is sickle cell diagnosed? You go to a doctor and you want to figure out if you have sickle cell disease or sickle cell trait, what tests do they do? How do you know that you have sickle cell disease?
Julie Kanter, MD: That’s a good question. In the United States, and several other high resource countries, a lot of individuals are diagnosed by newborn screening. In fact, now everybody is diagnosed by newborn screening. Within the first 24 hours of life you undergo a blood test that can diagnose a myriad of different diseases, including sickle cell disease. Now this only started in the United States, in every state, in the year 2000. We sometimes see adults who were not diagnosed at birth. In fact, if they had had more mild symptoms, they may not be diagnosed until their 30s.
You mentioned something important. You asked about sickle cell trait, and we didn’t really talk about that. Sickle cell trait is when you only inherit 1 copy of the sickle hemoglobin. The other 1 is the normal hemoglobin A. That’s important because those individuals don’t display symptoms of sickle cell disease, but they’re carriers.
Sometimes they will come in and ask to be tested, and what we do is call the hemoglobin electrophoresis, or another test called HPLC [high performance liquid chromatography]. In both of those we can identify what types of hemoglobin are there. It’s important to know though that measuring the number or percent of hemoglobin doesn’t measure the severity of the disease. I’ve seen that misunderstood a few times.
Ify Osunkwo, MD, MPH: A patient shows up to the doctor’s office and they want to know their diagnosis. They get an HPLC or electrophoresis, and how do you educate them about their diagnosis? What are the things you’re going to tell them, what to look forward to, what their lifespan would typically be in this country; or if you live in low resource country, what is that education like?
Julie Kanter, MD: Well, sometimes that’s a very long discussion. I think it’s important to know that it’s very different depending on where you live and what access to care you have. We certainly encourage everyone living with sickle cell disease, they need to see a sickle cell disease expert. We also want to make sure they see the primary care doctor. But everyone should have a sickle cell physician as well. It’s important that we can give them education about what to expect in terms of pain, but also organ function. We really want to make sure everybody gets screening. We want to check eyes, hearts, lungs, and kidneys. Unfortunately, individuals with sickle cell can get other problems too. I recently had a patient who said, “Wow, do I still need a colonoscopy, because I have sickle cell disease?” Unfortunately, it doesn’t give you a break.
Ify Osunkwo, MD, MPH: Well, thank you very much. Biree, how old is the oldest person you’ve diagnosed with sickle cell disease, because you’re an adult hematologist.
Biree Andemariam, MD: A new diagnosis?
Ify Osunkwo, MD, MPH: New diagnosis.
Biree Andemariam, MD: Almost 70 years old. Someone who traveled to my state of Connecticut from Jamaica who was then diagnosed as having SC [sickle cell] disease, had a lot of arthritis her entire life and a couple of knee replacements, but no one had ever bothered, no one had ever put the pieces together. It happens.
Ify Osunkwo, MD, MPH: You can be 40, 50, 60 and not know you have sickle cell disease, and you should have your doctor do the test that Julie had mentioned. Matt, in terms of who can get sickle cell disease, typically people think this a black disease, only African Americans or people of African descent. Have you had any other ethnicities represented in your practice with sickle cell disease?
Matthew Heeney, MD: Certainly. The origin of the sickle mutation appears to be from equatorial parts of the world, including sub-Saharan Africa, but also the Arabian Peninsula, so those of Arabic heritage but also those of the Indian subcontinent. It really is quite a cosmopolitan disease from that point of view. However, in the United States over 90% of the patients affected tend to be of African origin. Certainly we also see folks of other Hispanic origins, whether that be African-Caribbean, or South or Central American, or even those from the Mediterranean, it’s not uncommon to see in the Middle East through Greece and Italy and even in Spain.
Transcript edited for clarity.