Circulating lymphocyte subsets as prognostic markers in multiple sclerosis: a first step towards systems immunology

The clinical care of multiple sclerosis (MS) patients has evolved dramatically. Despite these advancements, much remains unknown or suboptimal in our knowledge of MS. Currently, the choice to intensify treatment is based on clinical relapse or MRI activity, which are both retrospective measurements, i.e., the choice to intensify treatment can only come after new activity is recorded.
The main goal of this research was to explore prognostic value of the lymphocyte composition in the blood of MS patients. As this research was performed in a cohort receiving high-dose vitamin D supplementation, this thesis also aimed to further elucidate the effects of vitamin D in MS.
Starting with vitamin D, certain genetic subgroups respond differently to vitamin D supplementation. As vitamin D shows a protective role in MS, this has implications for future trials.
Regarding lymphocytes, we report several markers in the immune system to be related to future disease activity, namely the ratio between natural killer cells and T cells, as well as certain B cells. As the composition of the immune system of MS patients is related to future disease activity, lymphocytes may be used to predict future disease activity in MS patients.