Dados do Trabalho

Título

Factors related to JC virus seroprevalence and seroconversion in patients treated with Natalizumab

Resumo

Introduction: Natalizumab (NTZ) is a monoclonal antibody effective in treatment of relapsing-remitting multiple sclerosis (RRMS), however high in title the antibody against the John Cunningham virus (JCV), the antibody can often limit the drug use due to the risk of developing progressive multifocal leukoencephalopathy (PML).
Goals: This retrospective study has the objective of evaluating the relationship between sero-prevalence and epidemiological factors, previous therapy used and treatment time in the MS population studied.
Methods: Anti-JCV levels were evaluated in 30 patients diagnosed with multiple sclerosis and followed up at a treatment center in the city of Recife, and with known serological status at the initiation of treatment, and who kept follow-up in that service. All patients studied had no symptoms suggestive of PML and were on Natalizumab monotherapy. Serum tests were performed using the enzyme-linked immunosorbent method (ELISA) at the initiation of treatment, followed by annual control tests.
Results: The majority (73.4%), were female. The highest percentage of patients (36.6%) were over 50 years old at the time of the survey. Most patients (46%) were dark-skinned. Baseline positivity was 16.6%, and overall seroconversion was 23%. Of the baseline positive patients, 100% had been using immunosuppressants for a period greater than 2 years. In the group of patients who seroconverted during treatment, 76% had also used immunosuppressants previously. The most used immunosuppressant was interferon beta 1a (INF-β1a) 22 or 44 μg subcutaneously three times a week. It not possible to have a relationship between seroprevalence and increasing age, as also no relationship was identified between the time of exposure to medication and seropositivity.
Conclusion: There was variation in seroconversion rates in the different cohorts studied, but the rate found in this study is like those found in European and American countries. There is a strong correlation between seroprevalence and previous use of immunosuppressants. None of the patients in the group developed PML. For patients with anti JC titers above 1.5 associated with infusion time longer than two years, a modification of the interval between infusions was defined.