Fingolimod efficacy in multiple sclerosis associated with Sjogren syndrome

Is antibody titer useful to verify the immunization after VZV Vaccine in MS patients treated with Fingolimod? A case series

BACKGROUND

Fingolimod (FTY720, Gilenya) is a second line therapy to treat relapsing MS not responding to first-line treatments and/or with a high disease activity (according to Italian Regulatory authorities). Before starting Fingolimod, patients' immunity to varicella zoster virus (VZV) needs to be assessed and seronegative patients vaccinated. To test susceptibility and response, IgG antibodies are tested after immunization. Since Fingolimod determines a reduction of circulating B lymphocytes and immunoglobulins, we aimed at describing the trend of VZV antibodies in seronegative vaccinated patients with MS before and after treatment.

METHODS

A total of 23 patients vaccinated for VZV before starting Fingolimod treatment, were recruited in this observational retrospective study involving five MS Centers in Campania (Italy). Of these, 12 patients were excluded for missing data. Patients received two doses of Varivax® Vaccine. After vaccination patients were re-tested and were all positive for IgG-VZV. We re-tested IgG-VZV in the same laboratory after a mean time of 2.42 years from Fingolimod therapy start.

RESULTS

During Fingolimod therapy we observed a global reduction of antibody titer and a disappearance in 7/11 patients. Titer disappearance was more probable in patients with lower post-vaccination titer. Of the 7 patients with vanishing IgG-VZV, three suspended Fingolimod for adverse event. In two of them, we observed a reappearance of antibody titer after treatment cessation. In one patient chickenpox infection occurred one year later.

DISCUSSION AND CONCLUSIONS

Our observational study shows that Fingolimod could influence antibody titer probably through its effect on B lymphocytes, but the efficacy of the vaccination should be verified. In conclusion, it is necessary to pay attention to therapies acting on B lymphocytes as they could influence the antibody titer and efficacy of vaccination making the search for other markers of vaccine efficacy desirable such as cell-mediated immunity with proliferation and induction of memory T lymphocytes in response to viral glycoproteins.

Sjögren syndrome

Sjögren syndrome (SjS) is a systemic autoimmune disease that primarily affects the exocrine glands (mainly the salivary and lacrimal glands) and results in the severe dryness of mucosal surfaces, principally in the mouth and eyes. This disease predominantly affects middle-aged women, but can also be observed in children, men and the elderly. The clinical presentation of SjS is heterogeneous and can vary from sicca symptoms to systemic disease (characterized by peri-epithelial lymphocytic infiltration of the affected tissue or the deposition of the immune complex) and lymphoma. The mechanism underlying the development of SjS is the destruction of the epithelium of the exocrine glands, as a consequence of abnormal B cell and T cell responses to the autoantigens Ro/SSA and La/SSB, among others. Diagnostic criteria for SjS include the detection of autoantibodies in patient serum and histological analysis of biopsied salivary gland tissue. Therapeutic approaches for SjS include both topical and systemic treatments to manage the sicca and systemic symptoms of disease. SjS is a serious disease with excess mortality, mainly related to the systemic involvement of disease and the development of lymphomas in some patients. Knowledge of SjS has progressed substantially, but this disease is still characterized by sicca symptoms, the systemic involvement of disease, lymphocytic infiltration to exocrine glands, the presence of anti-Ro/SSA and anti-La/SSB autoantibodies and the increased risk of lymphoma in patients with SjS.