Fluctuations in T helper subpopulations in relapsing‐remitting multiple sclerosis

Patients with active multiple sclerosis (MS) have been reported to have a depletion of CD4⁺ CD45R⁺ cells, the immature resting CD4⁺ subpopulation. Using Leu 3a(anti‐CD4) and Leu 18(anti‐CD45R), the frequencies and absolute numbers of CD4⁺ CD45R⁺ and CD4 ⁺ CD45R^‐ subsets were measured in 30 patients with MS and 17 healthy controls. These subsets were monitored every 6 weeks over a 6 month period. CD4⁺ CD45R‐ cells were found to be increased in relapse compared to remission (p < 0.005) while CD4⁺ CD45R⁺ levels were not significantly altered in relapse. However, the CD4⁺ subset ratio (CD4⁺ CD45R‐/CD4⁺ CD45R⁺) was significantly higher in relapse compared with remission (p < 0.002). Furthermore, these findings were upheld when data from the same 6 patients in relapse and remission was compared. Increased disease activity was not associated with changes in any of the other parameters measured (total T cells, total CD4⁺ cells, suppressor cells or activated T cells). These results sugest that relapse in MS is accompanied by the conversion of CD4⁺ CD45R⁺ resting cells to CD4⁺ CD45R‐ primed cells.