Report from the 1st Congress of the European Academy of Neurology, Berlin, Germany, June 20-23, 2015 – There is an implied association between psoriasis and multiple sclerosis, as evidenced by an increased incidence of psoriasis in MS patients, and the efficacy of psoriasis treatments such as fumarates in MS. The relationship between psoriasis and MS was explored further in a retrospective database analysis from a single MS centre in Israel (Miron et al. EAN 2015; F2168).
Outcomes were compared for 26 MS patients with comorbid psoriasis and 100 MS-only patients. Mean age at diagnosis was 26.3 years for psoriasis and 35.6 years for MS in the MS-P group, and 36.8 years in the MS-only group. Mean EDSS score at MS onset was 2.5 for both groups, but a higher proportion of MS-P patients had primary-progressive MS (23% vs. 8%). Mean follow-up was 12.5 years.
Disease progression in RRMS patients was significantly slower in the MS-P versus MS-only group, as assessed by time to second relapse (3.4 vs. 1.7 years), time to EDSS 4.0 (8.3 vs. 5.2 years), and time to EDSS 6.0 (12.4 vs. 6.9 years). Differences did not appear to be attributable to use of disease-modifying therapies for MS: there was a trend to lower use of DMTs in the MS-P group (70% vs. 87%).
One possible explanation for the difference in long-term outcomes was investigated in a separate study by the same group (Miron et al. EAN 2015; abstract F2167). Peripheral blood mononuclear cell (PBMC) gene expression was compared in MS-P, MS-only and psoriasis-only patients versus healthy controls. MS-P patients demonstrated a decreased expression of inflammatory and proliferative pathways compared to MS-only patients. For example, MS-P patients had decreased expression of mTOR (mammalian target of rapamycin), which is involved in T cell activation and proliferation, and inhibition of regulatory T cell development (Dello Russo et al. Glia 2013;61:301-311). However, additional research is needed to clarify the immune interactions of MS and psoriasis.
Comment
Dr. Daniel Selchen: The development of MS treatments that are related to drugs similar to agents used for other conditions creates a window for looking at the biological relationships between different autoimmune diseases. With regard to psoriasis, dimethyl fumarate appears to be an effective agent for treating psoriasis and teriflunomide may have some promise. The fascinating research described above could lead to further treatment advances by expanding our knowledge of immune interactions/pathways.