Extracorporeal Photopheresis of Patients With Crohn's Disease Using 5-aminolevulinic Acid

5-aminolevulinic acid (30 mg/ml) will be added to mononuclear cells in a dose of 3 millimolar and incubated for 1 hour

The mononuclear cells incubated with 5-aminolevulinic acid for 1 hour will be exposed to blue light.

The treated cells are transferred back to the patient as a standard blood transfusion

The mononuclear cells are collected using the Spectra Optia with the Continuous Mononuclear Cell Collection protocol. 90 ml of mononuclear cells will be collected and 100 ml of 0,9% saline will be added to dilute the cells before incubation with drug and photopheresis.