Clinical outcome of relapsing-remitting multiple sclerosis among Hong Kong Chinese

Abstract

Objective: To study the long-term clinical outcome of local relapsing remitting multiple sclerosis (RRMS) patients. Methods: Records of local patients with RRMS for at least 10 years were retrospectively reviewed. All patients had at least two magnetic resonance imaging (MRI) brain scans and MRI spinal cord, and cerebrospinal fluid (CSF) analysis for oligoclonal bands (OCB).All patients fulfilled revised McDonald’s criteria for RRMS. Clinical, neuroradiological and serological data were studies, the latest Expanded Disability Status Scale (EDSS) score and EDSS score at 10 years after onset were abstracted. Patients lost to follow-up had latest EDSS score evaluated via telephone interviews with the patients by a neurologist. Results: 50 RRMS patients were studied.40 (80 %) were female.The mean onset age was 26.7 years (range 12–43 years) and the mean duration of disease was 17.8 years (range 10–31 years). 44 (88 %) were CSF OCG positive. 10 (20 %) patients received azathioprine (AZT) for a mean duration of 10 years (range 5–13), 24 (48 %) patients received beta-interferon (bIFN) for a mean duration of 8 years (range 1–12 years); one patient received AZT for 10 years then bIFN for 10 years. At 10 years after onset, 10 (20 %) had EDSS of 2 or less, 24 (48 %) had EDSS > 2–4.0, 16 (32 %) had EDSS > 4 and 12 (24 %) had EDSS of 6 or more (range 6–7.0). The latest EDSS score at a mean disease duratiion of 17.8 years (range 10–31 years), 10 (20 %) had EDSS of 2 or less, 12 (24 %) had EDSS > 2–4.0, 28 (56 %) had EDSS > 4 and 24 (48 %) had EDSS of 6 or more (range 6–8.0). There is no significant difference in the clinical, radiological, serological and treatment characteristics between patients in different clinical outcome groups according to the EDSS score. 14 (28 %) patients developed secondary progression at 10 years after onset,and 20 (40 %) developed secondary progression at the latest follow-up of mean duration 17.8 years. None of 10 patients with EDSS of 2 or less at 10 years had EDSS > 2.0 upon the latest follow. Conclusion: 32 % and 56 % of local RRMS patients had significant neurological disability (EDSS > 4) at 10 years and a mean of 17.8 years after onset respectively, despite that 68 % of patients received either bIFN (48 %) or azathioprine (20 %) for years. Local RRMS patients tend to develop significant long-term neurological disability even with conventional immmunomodulatory therapies. Early novel or combination therapies need to be considered for our RRMS patients.