Lymphopenia in treatment-naive relapsing multiple sclerosis

Lymphopenia accompanies some autoimmune diseases. A number of studies, but not others, have suggested that lymphopenia occurs in treatment-naive multiple sclerosis (MS), so the issue remains unresolved. This is important since lymphopenia may identify an immunologically distinct subset of MS. Also, lymphopenia may emerge as a risk factor for serious viral infections of the brain during dimethyl fumarate treatment. We therefore embarked on a retrospective controlled study of pre-treatment lymphopenia in relapsing MS