P193. Mitochondrial enzymes activity of peripheral lymphocytes in children with IBD
S. Petrichuk1, L. Kuznetsova1, G. Semenova1, T. Izmailova1, O. Kurbatova1, 1Scientific Center of Children's Health, Cytochemical laboratory, Moscow, Russian Federation
It is known that IBD is accompanied with intoxication, nutrients, vitamins and mineral deficiency, which lead to inadequate metabolic and energetic supply of all cells and tissues Lymphocytes play an important role in the immune mediated inflammation. Theirs functional activities depends on the energetic metabolism activity. Mitochondrial enzymes activity (respiratory chain enzymes activity) reflects cell energetic process intensity. Investigation of the lymphocytes mitochondrial enzymes activity can be useful for inflammation intensity evaluation.
We studied 44 children with Crohn's disease (CD) and 26 patients with ulcerative colitis (UC) at the age from 10 to 18 years, who received infliximab for a long period. We investigated lymphocytes mitochondrial enzymes – succinate dehydrogenase (SDH) and NADH dehydrogenase (NADH-D) – activity by quantitative citochemical method, based on the n-nitrotetrazolium violet ability to form insoluble formazan granules during enzymic reduction. We applied 2 modifications of this method – using flow cytometer Beckman Coulter FC500 (USA) and hardware and software complex Morphology (Videotest, Russia). Clinical effect of the therapy was assessed using pediatric Crohn's disease activity index (PCDIA) and pediatric ulcerative colitis activity index (PUCAI).
We found out that children with the high baseline lymphocytes mitochondrial enzymes activity had better curative effect of infliximab than children with low dehydrogenases activity. Lymphocytes main subsets size changes characterized with absolute and relative B-lymphocytes number decrease in 95% children with CD and 75% patients with UC. At the disease manifestation we observed SDG activation in all lymphocytes subsets, most expressed in cytolytic T-lymphocytes (CTL) and NK-cells (NK) (+36% and +35% from the norm). First remission was characterized with increased CTL SDG activity (+12% from the norm), SDG decreased activity in B-cells and T-helpers (−19% and −10% from the norm respectively). At relapses we registered less SDG activation in CTL and NK subsets (+23% and +30% from the norm), the remission at this case characterized with the SDG decreased activity in all subsets. We showed that long duration causes gradual lymphocytes mitochondrial dehydrogenases activity decrease.
Our results proved that the level of lymphocytes energetic processes depends on the disease stage and duration.