Effect of glatiramer acetate on cerebral grey matter pathology in patients with relapsing-remitting multiple...

In this two year longitudinal study we compare the progression of grey matter (GM) damage in MS patients treated with glatiramer acetate (GA) for relapsing-remitting multiple sclerosis (RRMS) respect to untreated patients.

We studied thirty-five treated with GA and thirty-five untreated RRMS subjects matched for age, gender, disease duration and EDSS. Each patient underwent neurological examination every 6 months and 3-Tesla MRI at study entry (T₀), after 1 year (T₁) and 2 years (T₂). At T₀, T₁ and T₂, the number of new cortical lesions (CLs) was assessed on double inversion recovery images. By using the longitudinal stream of FreeSurfer, the cortical thickness and volume changes of several cerebral structures were evaluated after 2 years.

The mean number of new CLs was significantly lower in GA group compared to untreated patients both at T₁ (0.9 ± 1.0 vs 1.7 ± 1.0, p < 0.05) and at T₂ (1.4 ± 1.3 vs 2.9 ± 1.8, p < 0.001). Volume loss of thalamus (-0.5% ± 0.2% vs. -1.1% ± 0.4%; p < 0.001), globus pallidus (-4.4% ± 3.1% vs. -8.2% ± 4.5%; p < 0.001), hippocampus (-0.7% ± 0.3% vs. -1.5% ± 0.5%; p < 0.001) and cerebellum (-0.5% ± 0.3% vs. -0.9% ± 0.4%; p < 0.001) was also lower in the GA group. A more pronounced cortical thinning was observed in cingulate (p = 0.04), cuneus and frontomarginal gyrus (p = 0.01 for both comparisons) of the untreated patients.

Our findings suggest that GA exerts its immunomodulatory action at the level of GM either reducing the accumulation of CLs and slowing down the GM atrophy progression. Despite a confirmation in a larger sample size is required, our results suggest a possible effect of GA on GM damage.