The researchers evaluated the effects of infliximab on the gut and peripheral immune system functions in Crohn's disease patients. They reported their findings in April's issue of Alimentary Pharmacology and Therapeutics.
Biopsies and blood samples from three clinical trials of infliximab in Crohn's disease were analyzed.
Pharmacokinetics, changes in leucocyte counts and T-cell subsets, T-cell function, and cytokine profiles of lamina propria mononuclear cells (LPMC) and peripheral blood mononuclear cells (PBMC) were analyzed.
Infliximab had a serum half-life of 9.5 days and was still detectable in serum 8 weeks after infusion.
|Following infliximab therapy, monocytes and lymphocytes were increased, but neutrophils decreased.|
|Alimentary Pharmacology and Therapeutics|
Leucocyte counts showed consistent changes from baseline toward normal values after therapy.
Monocytes and lymphocytes were modestly increased, while neutrophils were decreased 4 weeks after treatment.
The researchers found that lymphocyte subsets and T-cell proliferative responses were not altered after therapy.
The proportion of PBMCs capable of producing IFN-gamma and TNF-alpha did not change, while Th1 cytokine production by stimulated LPMC was decreased after infliximab therapy.
Dr F. Cornillie of Centocor Inc., Belgium, concluded on behalf of the group, "The clinical efficacy of infliximab is based on local anti-inflammatory and immunomodulatory effects in the bowel mucosa, without generalized suppression of systemic immune functions in Crohn's disease patients."