Th1/Th2 cytokine patterns and clinical profiles during and after pregnancy in women with multiple sclerosis.

Pregnancy in multiple sclerosis (MS) patients is associated with a lower risk of progression and lower rate of exacerbation. These beneficial effects are reversed postpartum. Considering that the pathogenesis of MS appears to involve cell-mediated immune reactivity, and that pregnancy is accompanied by a depressed cell-mediated immunity, it has been proposed that the lower relapse rate and risk of progression of MS during pregnancy may be due to a pregnancy-associated down-regulation of cell-mediated immunity. In addition, pregnancy results in a shift towards a T helper (Th) 2 cytokine profile, which is presumably protective for MS. This study was aimed at investigating the relationship between clinical status of MS and cytokine levels in eight patients with MS who were followed through pregnancy and after delivery. Peripheral blood lymphocytes from these women were stimulated with a mitogen at different time points during and after gestation and the levels of Th1 cytokines (IFNgamma, TNFalpha) and Th2 cytokines (IL-4, IL-10) were estimated by ELISA. It was established that six of the eight MS patients studied showed a distinct shift from a Th2 cytokine bias during pregnancy towards a Th1 cytokine bias after delivery. These results suggest a possible association between decreased incidence of exacerbation of MS in pregnancy and a pregnancy-induced shift towards Th2 cytokine bias.