ABSTRACT
Public concern about possible increases in the risk of multiple sclerosis associated with hepatitis B vaccination has led to low vaccination coverage. We investigated whether this vaccination after a first episode of acute CNS inflammatory demyelination in childhood increased the risk of conversion to multiple sclerosis. We studied the French Kid Sclérose en Plaques (KIDSEP) neuropaediatric cohort of patients enrolled between 1994 and 2003 from their first episode of acute CNS inflammatory demyelination (inclusion in the cohort) until the occurrence of a second episode, up to 2005. A Cox proportional hazards model of time-dependent vaccine exposure was used to evaluate the effect of vaccination (hepatitis B, tetanus) during follow-up on the risk of second episode occurrence (conversion to multiple sclerosis). The cohort included 356 subjects with a mean follow-up of 5.8 years (SD 2.7). Relapse occurred in 146 (41%) subjects during follow-up; 33 subjects were exposed to hepatitis B vaccine and 28 to tetanus vaccine at some time during follow-up. The adjusted hazard ratio (HR) for relapse occurring within 3 years of hepatitis B vaccination was 0.78 (0.32-1.89) and during any time period was 1.09 (0.53-2.24). The adjusted HR for relapse occurring within 3 years of tetanus vaccination was 0.99 (0.58-1.67) and during any time period was 1.08 (0.63-1.83). We conclude that vaccination against hepatitis B or tetanus after a first episode of CNS inflammatory demyelination in childhood does not appear to increase the risk of conversion to multiple sclerosis, although the possibility of a small increase in risk cannot be excluded.
Subject(s)
Central Nervous System Diseases/immunology , Demyelinating Diseases/immunology , Hepatitis B Vaccines/adverse effects , Multiple Sclerosis/chemically induced , Acute Disease , Age of Onset , Child , Child, Preschool , Cohort Studies , Demyelinating Autoimmune Diseases, CNS/immunology , Female , Hepatitis B/prevention & control , Humans , Infant , Male , Multiple Sclerosis/immunology , Myelitis, Transverse/immunology , Odds Ratio , Recurrence , Risk Factors , Tetanus/prevention & control , Tetanus Toxoid/adverse effectsABSTRACT
OBJECTIVE: The goal was to identify prognostic factors for an early severe course in a cohort of patients with childhood-onset multiple sclerosis, for the construction of a predictive tool. METHODS: The cohort consisted of 197 children from the French Kid Sclérose en Plaques neuropediatric cohort with relapsing/remitting multiple sclerosis beginning before the age of 16 years. Patients were included from 1990 to 2003. We used multivariate survival analysis (Cox model) to evaluate the prognostic value of clinical, MRI, and biological covariates at onset for the occurrence of a third attack or severe disability ("severity" outcome). RESULTS: The cohort was monitored for a mean of 5.5 +/- 3.6 years. The "severity" outcome was recorded for 144 patients (73%). The risk of severity was higher for girls, for a time between the first and second attacks of < 1 year, for childhood-onset multiple sclerosis MRI criteria at onset, for an absence of severe mental state changes at onset, and for a progressive course. A derived childhood-onset multiple sclerosis potential index for early severity was found to have a positive predictive value for severity of > 35% for the upper 2 quartiles. CONCLUSIONS: The clinical and MRI prognostic factors for early severity that were identified were used as the basis of a predictive tool, which will be validated in another cohort. This tool should make it possible to identify subgroups at risk of early severe disease and should facilitate therapeutic studies.
