Early blood-brain-barrier permeability changes in the normal-appearing white matter of a marmoset model of MS

Wednesday, October 26, 2011 — Poster Session III
10:00 a.m. – Noon	Natcher Conference Center	NINDS	IMAG-24

Authors

• P Maggi
• MI Gaitán
• EM Sweeney
• J Senseney
• C Shea
• L Massacesi
• S Jacobson
• A Silva
• DS Reich

Abstract

Background: Longitudinal relaxation time (T1) maps obtained before and after gadolinium (Gd) can estimate even subtle changes in blood-brain-barrier (BBB) permeability, which in MS are associated with inflammation. We investigated the evolution of BBB permeability in the normal-appearing white matter (NAWM) of marmoset EAE. Methods:One marmoset was immunized with human white matter homogenate (WMH; A1), another with recombinant human myelin oligodendrocyte glycoprotein (rh-MOG; A2).We performed high-resolution T1-weighted imaging and T1 maps before and after Gd injection on a 7T/30cm Bruker scanner. The gadolinium enhancement ratio (GER=(T1pre-T1post)/T1pre) was used to estimate BBB permeability. Results:In A1, lesion load reached 4.8mm^3 (day 53); in A2, 93 mm^3 (day 57). In A1, we observed a 4.0% mean increase in GER after immunization. GER reached its maximum value at day 29, when the lesion load was 0.8 mm^3. In A2, we observed a 1.1% GER increase after immunization, which occurred at day 57 and coincided with the maximum lesion load. Conclusions: T1 maps before and after Gd injection revealed increasing BBB permeability within NAWM early in disease. Our findings suggest that the mechanisms of disease are substantially different in the two models and may have implications for our understanding of MS.

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