A study, published at ECTRIMS 2017, has revealed that serum vitamin D levels could be involved in the regulation of the replication/reactivation of Epstein-Barr virus (EBV) in multiple sclerosis (MS) patients.
Low levels of vitamin D serum have been described as one of the possible environmental factors involved in the development of MS. In addition, EBV and human herpesvirus 6 (HHV-6) infection have also been proposed as MS triggers. It has been suggested that vitamin D levels could have an impact on the status of these viruses.
As a result, scientists set out to analyse the replication/reactivation of EBV and HHV-6 in MS patients regarding serum vitamin D levels, in order to investigate the possible relationship between vitamin D levels and viral status.
200 MS patients were included in this retrospective longitudinal study and were followed up after one year. Two peripheral blood and serum samples were collected from each patient, in such a way that data were obtained from both semesters of the year. DNA was extracted from blood in order to analyse EBV and HHV-6 viral load, as well as vitamin D levels.
The median value vitamin D in the first semester of the year among the MS patients included in the study was 17.5 ng/ml (ranging between 15.5 ng/ml in March and 19.3 ng/ml in June); the median value vitamin D in the second semester of the year was 24.6 ng/ml (ranging between 19.6 ng/ml in December and 28.4 ng/ml in September).
The results showed that serum vitamin D had an impact on EBV but not on HHV-6 viral load. 22% of patients with serum vitamin D levels >11 ng/mL tested positive for EBV compared with 4% of patients with serum vitamin D levels <20 ng/mL (P =.03). These differences did not occur in the second half of the year.
Scientists concluded that the results indicate that vitamin D levels could be involved in the regulation of EBV in MS patients. In addition, the viral load seems to be higher when vitamin D levels in serum are low. They feel that further studies, also in healthy controls, are required.