FADD is upregulated in relapsing remitting multiple sclerosis

To elucidate the role of tumor necrosis factor (TNF) receptor signal transduction in multiple sclerosis (MS).

We performed a cross-sectional analysis of the gene expression of TNF receptor-associated death domain protein (TRADD) and Fas-associated death domain protein (FADD) in peripheral blood leukocytes of 23 relapsing remitting (RR), 19 secondary progressive (SP) and 12 primary progressive (PP) MS patients, as well as of 29 healthy controls by quantitative RT-PCR. Additionally, we monitored a subgroup of 15 RR MS patients longitudinally every 3 months over the time period of 9 months.

FADD expression was significantly elevated in RR MS patients compared to the other disease courses (p < 0.048). The median of FADD expression was elevated in the RR MS patient groups compared to the healthy group, but this was not significant (p < 0.053). The median of TRADD expression was elevated in the patient groups compared to the healthy group, but this was not significant (p < 0.14). Neither variable changed significantly over the time course of 9 months.

FADD elevation in leukocytes might be interpreted as the molecular equivalent of an elevated general inflammatory activity in RR MS patients compared to other disease courses. FADD elevation in RR MS reinforces the concept that different pathophysiological and immunological processes sustain RR MS and SP or PP MS.