V Muratov ¹, J Lundahl, A K Ulfgren, K Elvin, I Fehrman, N Ahlborg, A Ost, N Hittel, A Saniabadi, R Löfberg, Int J Colorectal Dis . 2006 Sep;21(6):493-504.

Leukocyte apheresis is a novel and safe nonpharmacological adjunct therapy that may prove useful in steroid refractory or dependent patients when conventional drugs have failed. Down-regulation of IFN-gamma in mucosal biopsies and in peripheral leukocytes may be a predictive marker for sustained, long-term response.

https://pubmed.ncbi.nlm.nih.gov/16538495/