Impact of disease-modifying treatments in North African migrants with multiple sclerosis in France

Background Multiple Sclerosis in North African migrants (MS-NA) is more aggressive with mostly primary progressive forms and cerebellar symptoms. Despite an earlier onset in NA patients, the disease progresses more rapidly, with a higher proportion showing incomplete recovery from the first relapse, a shorter time between the first two relapses, a higher number of relapses in the first 5 years, and a shorter time to reach an EDSS of 4.0 and 6.0. We collected data and studied the impact of disease-modifying therapies (DMT) in NA patients with MS, among the 4144 MS patients treated in our MS clinics. Methods We performed a descriptive population-based study of MS-NA patients. Data were crossed with expected age-and gender-matched characteristics available in our EDMUS databases for the period 1995 -2007. Results A total of 133 patients, representing 66% of the MS-NA patients included in the database were identified: mean age at the first documented symptom: 29.7 years; mean time from diagnosis to the beginning of DMT: 1.2 years. 40% of MS-NA patients had an EDSS > 3 at the beginning of treatment (vs. 25%; P = 0.002). A majority of patients were treated initially with immunomodulatory drugs (MS-NA: 48% vs. CT: 51%, P = 0.8). NA patients were treated earlier after diagnosis (1.3 years vs. 4.5 years, P = 0.003), with the frequent use of immunosuppressive drugs: for remitting forms, mitoxantrone (18.5% vs. 7.8%, P = 0.0001) and for progressive forms, cyclophosphamide (38% vs. 28%, P = 0.003). Conclusions Considering EDSS follow-up during DMT, MS-NA patients appear as responsive as other MS patients to treatment, despite the earlier treatment prescription and the more frequent use of immunosuppressors.