Association between CD20+ T lymphocytes and neuropsychological findings in multiple sclerosis.

Background and purpose: CD20⁺ T lymphocytes are a subset of circulating T cells presenting the CD20⁺ receptor, a molecular marker of B lineage. CD20⁺ T lymphocytes are thought to play a pivotal role in multiple sclerosis (MS) pathology, especially at progressive stages. We aimed to investigate the correlation between CD20⁺ T lymphocytes and neuropsychological features (i.e., cognition, depression, anxiety, fatigue, and sleep quality) in MS patients.

Methods: We enrolled 90 MS patients. Each patient underwent cognitive assessment (Brief International Cognitive Assessment for Multiple Sclerosis) and psychometric assessment (modified Fatigue Impact Scale, Beck Anxiety Inventory, Beck Depression Inventory, Pittsburgh Sleep Quality Index). Cognitive status was defined through the cerebral functional score.

Results: Forty-four of 90 patients were relapsing-remitting (49%) and 46 were progressive patients (51%). Seventy patients (18.9%) showed CD20⁺ T lymphocytes in peripheral blood with a mean level of 0.38 ± 1.2%. Patients with CD20⁺ T lymphocytes were more likely to be at progressive phases (76.5% vs. 23.5%, p = 0.02) and showed a higher Expanded Disability Status Scale score (median [range] = 6.0 [1.5-7.5] vs. 3.5 [1-7.5], p = 0.001). Moreover, patients with CD20⁺ T lymphocytes showed worse cognitive functioning (p = 0.004), higher global fatigue symptoms (p = 0.02), higher cognitive fatigue (p = 0.01), higher psychosocial fatigue (p = 0.005), and a trend toward worse sleep quality (p = 0.06).

Conclusions: The presence of CD20⁺ T lymphocytes in the peripheral blood of MS patients was associated with worse neuropsychological functioning and progressive disease stages. Peripheral CD20⁺ T lymphocytes could potentially serve as markers for both disease progression and development of fatigue in MS patients.