Childhood multiple sclerosis: clinical features and demonstration of changes in T cell subsets with disease activity.

Using monoclonal antibodies that identify T cell subsets in human beings (T4 = inducer cell; T5 = suppressor/cytotoxic cell), we have previously shown that most patients with multiple sclerosis (MS) have decreased T5 cells and an elevated T4:T5 ratio during periods of disease activity. We have recently studied three children with MS beginning at 4 years 11 months, 101/2 years, and 2 years 11 months of age. Clinical symptoms included a relapsing brainstem syndrome in the first, Devic syndrome and recurrent optic neuritis in the second, and multiple attacks with accumulating neurological deficits in the third. Two of these children represent the youngest cases of MS yet reported. In each child, circulating T5 cells were reduced or absent during an acute exacerbation of disease; following stabilization, T5 cells returned and the T4:T5 ratio became normal. No changes in T cell subsets were seen in a group of age-matched healthy children or in children suffering from other neurological diseases. Our finding that young children with active MS have a pattern of T cell abnormalities identical to that of adult MS patients suggests that the same pathophysiological process which causes MS in adults occurs in young children as well.