Association of Choroid Plexus Inflammation on MRI With Clinical Disability Progression Over 5 Years in Patients With Multiple Sclerosis

Background. Inflammation of the choroid plexus (CP) has been reported in multiple sclerosis (MS). The association between CP inflammation and clinical disability progression is still under debate . Objectives. To assess the relationship between measures of CP inflammation and investigate their associations with clinical disability progression in MS. Methods. In this retrospective analysis of a longitudinal study, 174 MS patients (118 with relapsing remitting MS (RRMS) and 56 with progressive MS (PMS) ) and 56 healthy controls (HCs), group matched for age and sex, were imaged on a 3T MRI scanner at baseline and after an average of 5.5 years of follow-up. T2 lesion volume (T2-LV) was assessed. Regional tissue volumes were calculated. CP volume was measured and pseudo T2 (pT2) mapping was performed to asses CP inflammation. Group comparisons and correlations were adjusted for age and sex. Results. MS patients presented with significantly larger CP volume (p = 0.01) and increased CP pT2 (< 0.001) at baseline, when compared to HCs. CP volume and CP pT2 did not significantly increase over the follow-up in the MS sample. However, baseline CP pT2 was associated with clinical disability progression at follow-up (p = 0.001), even after controlling for all other factors significantly associated with disability progression (p = 0.030), including T2-LV, normalized brain volume, normalized gray matter volume and normalized thalamic volumes . Changes in CP volume and CP pT2 were not related to changes in clinical parameters such as relapse rate over the course of the follow-up. Discussion. CP inflammation, as evidenced by MRI, is clinically relevant in multiple sclerosis. CP inflammation may have a relevant role in driving disease progression.