[Changes in lymphocyte subsets s and treatment with beta interferon in active multiple sclerosis].

INTRODUCTION

We report that interferon beta decreases CD8 T cells percentage and increases CD4/CD8 cell's rate in vivo in Multiple Sclerosis (MS) patients.

PATIENTS AND METHODS

We studied 40 patients (22 women and 18 men) with clinically definite active MS who received IFN beta. Twenty-six were treated with nIFN (9 MU/week) and 14 with rIFN (28 MU/week). All patients except two with secondary progressive forms presented relapsing remitting courses. Mean age and mean age at onset were 36.5 +/- 9 and 27.8 +/- 7 years respectively. Mean EDSS score was 2.96 +/- 1.8. Patients were reviewed at four weeks and every eight weeks and periodical studies of immunity were performed. T cell subpopulations (CD3, CD4, CD8 and NK) were studied byflow cytometry.

RESULTS

The evolution of CD8 T cell percentage showed a statistically significant decrease in all blood samples after 20 weeks of treatment with rIFN (24.3 +/- 8 vs 34.7 +/- 5 in the control group) and after 36 weeks for nIFN beta group (25.7 +/- 6 vs 33.0 +/- 4 in the control group). No changes were detected in CD4 T cell subset. The evolution of CD4/CD8 T cell rate showed an increase over the cut-off (2.200) in all blood samples after 20 weeks of treatment with rIFN (2.302 +/- 1.12, 2.332 +/- 0.99 and 2.488 +/- 1.61 for 20, 28 and 36 weeks respectively) and after 52 weeks for nIFN beta group (2.128 +/- 1.07, 2.346 +/- 1.09 and 3.168 +/- 3.87 for 52, 60 and 68 weeks respectively).

CONCLUSIONS

Both nIFN and rIFN beta are able in vivo to decrease CD8 percentage of T cells and increase CD4/CD8+ T cell rate. The increase in the rate is produced earlier in the rIFN treated group.