Studies comparing ocrelizumab’s effects on advanced magnetic resonance imaging metrics (AMRIMs) between black and white people with multiple sclerosis (pwMS) are limited. AMRIMs, including magnetization transfer ratio (MTR), fractional anisotropy (FA), mean diffusivity (MD), and the ratio of total N-acetyl-aspartate concentration/total creatine concentration (tNAA/tCr) using proton magnetic resonance spectroscopy (¹H-MRS), assess brain pathology in MS.

The median age of black pwMS (n=6) was 37.7 years±6.2, and white (n=6) was 46.8 years±10.5 (p=0.128).  Mean change in the MTR of normal-appearing white matter (NAWM) from baseline to month 12 was significantly different between black (-0.56%±1) and white pwMS (1.04%±0.98)  (p=0.02). On the contrary, mean change in MTR in normal-appearing grey matter (NAGM) from baseline to month 12 was non-significant, -0.4%±1.5 in black and 1.2%±1.1 in white pwMS. In MS lesions, mean MTR change in blacks was 1.7%±1.3 and whites 2.4%±1.8, the mean FA change in blacks was 0.06±0.03 and whites 0.03±0.03, and the mean MD change in blacks was -0.04 x10^-3 mm²/s ±0.04 and whites -0.06 x10^-3 mm²/s ±0.06. Mean change in WM tNAA/tCr from baseline to month 12 was 0.06±0.1 in blacks and 0.05±0.1 in whites. No significant difference in the mean change in FA and MD in NAGM and NAWM between the two groups.

Our small sample suggests ocrelizumab may impact NAWM MTR differently in Black and White pwMS. Larger studies with extended follow-up are needed to explore potential differences in AMRIMs.