Shannon Walker, MD, explains how inhibitors affect hemophilia management, why routine screening is important, and how nonfactor prophylaxis may change the timing of factor exposure and inhibitor development.
How do you approach inhibitor screening and management?
Transcript
So, inhibitors are definitely something that complicate the management of hemophilia. We screen for the inhibitors or these neutralizing antibodies in our routine, kind of regular clinic follow-up.
And there are definitely, you know, a reason why we ask patients to come into clinic so that we can get these labs and kind of monitor for inhibitor development.
We routinely check them at every clinic visit after they’ve had any sort of factor exposure. So, you know, knowing that any sort of factor exposure is a risk for inhibitor development, we just screen them when they come into clinic, usually at least annually with any sort of factor exposure, and sooner if kind of the timing is right.
We don’t necessarily differentiate between our hemophilia A and B patients when we’re talking about inhibitor screening, even though factor IX inhibitors are less common. You know, they can be more dramatic. And so, we would hate to — to miss that. And so, we screen those patients in our clinic for that as well.
We generally check inhibitors throughout their kind of clinical care in the pediatric setting. You know, one of the things that has come up with some of the new factor products in terms of the, you know, the nonfactor prophylaxis products that we have patients on is that patients are having a lower number of factor exposures overall.
And so, we used to have patients, you know, who would reach 50 factor exposures, you know, by the time they started kindergarten, because that’s just — you know, toddlers are wild, and kids get injured, and etc. And now, if they’re on some of our nonfactor prophylactic products, you know, they might be leaving our practice to go to the adult clinic, and they’ve not reached 50 factor exposures because they just haven’t needed it.
And so, how do we manage, you know, inhibitor timing and those sorts of things? We still check for them regularly, even in the adult clinic here.
They’re still routinely screening for inhibitors just to make sure that we’re not missing anything and that we can kind of clinically address anything and provide safe treatment for those patients, regardless of — of what’s going on.
But I do think that some of the new factor products have changed the time frame of the factor exposures, and how that changes inhibitor development and when and how we should be screening is, I think, a question that’s still being evaluated within the hemophilia community and may change over time.
