Dimethyl fumarate has a risk of low blood white cell counts

Khatri BO, Garland J, Berger J, Kramer J, Sershon L, Olapo T, Sesing J, Dukic M, Rehn E The effect of dimethyl fumarate (Tecfidera™) on lymphocyte counts: A potential contributor to progressive multifocal leukoencephalopathy risk. Mult Scler Relat Disord. 2015; 4:377-9. doi: 10.1016/j.msard.2015.05.003. Epub 2015 May 14.

Dimethyl fumarate (Tecfidera™) is an effective therapy for relapsing forms of multiple sclerosis (MS). Our study suggests that this drug may have immunosuppressive properties evidenced by significant sustained reduction in CD8 lymphocyte counts and, to a lesser extent, CD4 lymphocyte counts. This observation is relevant in light of the recent case of progressive multifocal leukoencephalopathy in a patient receiving this drug.

It is true that DMF can cause a reduction of white blood cell counts and those people developing PML have had persistently reduced white blood cell counts. So monitoring blood lymphocytes for the presence of  leukopenia/leucopaenia will be part of this. 

The Neuros in the team have discussed puting out management protocols on the blog, for the benefit of other neuros out there, hopefully they will appear soon.

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  • Hi MouseDoctor,

    This is my first post here so I first want to thank everybody for the amount of information available here.

    I'm on Tec for 5 weeks now. Currently experiencing a relapse (vision & audition) but not the subject here.

    I don't know what the formal process during the first under-tec-months ils. My neuro asked for a full blood analysis including lymphocites every 4 weeks. Not targeting CD4 nor CD8 specifically though.

    AFAIK, the case of PML on Tec occuring last december (is that the one you are talking about?) was very specific, with a severe lymphocytopenia. What is your thought about that?

    Many thanks

    • Dear Christian
      Welcome to the Blog…I hope you have a swift recovery and I would like to say I really enjoyed the switchback on youtube ..awesome.

      The case with tec and gilenya was associated with long term leucopaenia and I understand this takes some time with tecfidera.

      I'm not a neuro and maybe profG can comment on our management profile but things get delayed with the summer holidays, but not sure if CD4/CD8 phenotyping os part of this management profile yet.

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