Longitudinal assessment of rates of brain and retinal atrophy in African American versus Caucasian American patients with Multiple Sclerosis (S47.003)

Objective: To assess differences in brain MRI and retinal OCT atrophy rates between AAMS and CAMS

Background: African Americans with MS (AAMS) demonstrate higher inflammatory disease activity and faster disability accumulation as compared to Caucasian Americans with MS (CAMS). Optical Coherence Tomography (OCT) is a tool used for measuring structural retinal changes. Recent studies support its utility for tracking neurodegeneration and disease progression in-vivo in MS. AAMS have greater retinal structure injury cross-sectionally and longitudinally in the peripapillary retinal nerve fiber layer (p-RNFL) and ganglion cell+inner plexiform layer (GCIP). Despite prior work, there is a paucity of study of differences in brain sub-structure volumes over time in AAMS vs CAMS. Similarly, longitudinal assessment of outer retinal layer by race remains incompletely characterized.

Design/Methods: Twenty-eight AAMS and 28 matched CAMS were tracked with brain MRI for a mean duration of 4.61 years. Annual contrast-enhanced 3T brain MRI was performed. Additionally, 116 AAMS and 116 matched CAMS were tracked with OCT for a mean duration of 4.43 years. Validated image segmentation algorithms developed at Johns Hopkins University were used to analyze the MRI and OCT data. Statistical analyses were performed using mixed-effects linear regression models

Results: Whole brain, gray and white matter atrophy rates were significantly different between races, AAMS patients exhibiting atrophy rates approximately twice as fast as CAMS patients (p-values 0.010, 0.002 and 0.014 respectively). Moreover, thalamic atrophy was markedly faster in AAMS vs CAMS(−1.38%/year vs −0.57%, p-value 0.016). Retinal layer atrophy rates were significantly faster in AAMS vs CAMS; p-RNFL −1.12% vs −0.74% and GCIP −0.72% vs −0.42%; p-values 0.016 and 0.017 respectively)

Conclusions: AAMS exhibits more rapid neurodegeneration with accelerated brain and retinal neuro-axonal loss than CAMS. These results corroborate the more rapid clinical progression observed in AAMS vs CAMS, raising the possibility that AAMS may benefit from a more aggressive therapeutic approach.

Study Supported by: This study was funded by Race to Erase MS (to S.S.), NIH (5R01NS082347-02 [to PAC and SS]), National MS Society (RG-1606-08768 to SS) and Walters Foundation (to EMF, LJB and PAC)

Disclosure: Dr. Gonzalez Caldito has nothing to disclose. Dr. Saidha has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, Novartis, EMD Serono, Genentech. Dr. Sotirchos has nothing to disclose. Dr. Dewey has nothing to disclose. Dr. Cowley has nothing to disclose. Dr. Glaister has nothing to disclose. Dr. Fitzgerald has nothing to disclose. Dr. Nguyen has nothing to disclose. Dr. Rothman has nothing to disclose. Dr. Ogbuokiri has nothing to disclose. Dr. Kimbrough has nothing to disclose. Dr. Frohman has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Genzyme, Acorda. Dr. Frohman has nothing to disclose. Dr Balcer has nothing to disclose. Dr. Crainiceanu has nothing to disclose. Dr. Pham has nothing to disclose. Dr. Prince has nothing to disclose. Dr. Calabresi has nothing to disclose.