If you stop taking Tecfidera, how long does it take for lymphocyte levels to return to normal?

Question:
​My wife is taking Tecfidera. She has a mild case of Type 2 Diabetes (15units of insulin/day), and has psoriasis that the Tecfidera has completely removed. She is going in for a 12 hr abdominal surgery. Her absolute lymphocite count is at a steady 500. There is a question of how that may affect the fighting of infection after surgery. Also if a person stops taking Tecfidera: how long does it take to bring the lymphocite levels up and at what rate? Also how soon will the MS symptoms begin to return? And how soon will the psoriasis begin to return? Averages for most people?

Answer:
These are all excellent questions; let’s take them one at a time:

1. A slightly low lymphocyte count should have little effect on her recovery from surgery. Most post operative infections are from bacteria and require adequate, functioning neutrophils, another type of white blood cell not affected by Tecfidera, to prevent.
2. Lymphocyte counts can take weeks or months to return to a normal level after stopping tecfidera; sometimes, lymphocyte counts remain low indefinitely. Generally speaking the longer a person remains on Tecfidera after their lymphocyte counts become low, the longer it takes for the lymphocyte count to return to normal.
3. No one knows how long it takes for MS disease activity to return after stopping Tecfidera, but there are no reports yet of a rebound of MS activity. The only way we would know the answer to this question is if we purposefully stopped Tecfidera in a large group of patients and monitored them with frequent imaging and visits for a return of disease activity; as you can imagine no one is willing to do this at this time. There is little reason to believe based on anecdotal experience that there is a rapid return of disease activity 

Revere (Rip) Kinkel MD
Professor of Clinical Neurosciences
Director of the Multiple Sclerosis Program
Clinical Neurosciences Director
University of California San Diego