title: Increased disease severity in non-Western immigrants with multiple sclerosis in Oslo, Norway.
abstract: OBJECTIVE
  Non-Western immigrants to Norway acquire an increased risk of multiple sclerosis (MS) after migration. Ethnicity and the presence of oligoclonal bands (OCBs) in the cerebrospinal fluid (CSF) might influence the disease course. The aim of this study was to investigate differences in disease severity and in the presence of OCBs in ethnic Norwegian and immigrant MS patients.
  
  
  METHODS
  Clinical data and CSF findings from 47 non-Western immigrants with MS were compared with those from 447 Norwegian and 48 immigrant patients from Western countries.
  
  
  RESULTS
  The non-Western immigrants had a higher mean Multiple Sclerosis Severity Score (MSSS) than the Norwegian patients (5.68 vs. 4.13, P = 0.001). Age at onset was 4 years lower amongst the non-Western immigrants (P = 0.001). After adjusting for year of birth, age at onset, gender and disease course, the mean difference in MSSS between the groups was 2.17 (P < 0.001). Amongst the non-Western immigrants, 70% received disease-modifying drugs, compared with 48% of the Norwegian patients (P = 0.005). In both groups, 88% were OCB-positive.
  
  
  CONCLUSIONS
  Non-Western immigrants with MS had an increased disease severity compared with native Norwegians and immigrants from Western countries. The presence of OCBs in the CSF was not different between the groups.
authors.affiliation: Department of Neurology, Oslo University Hospital, Oslo, Norway; Institute of Clinical Medicine, University of Oslo, Oslo, Norway.
authors.forename: P
authors.initials: P
authors.lastname: Berg-Hansen
authors.forename: C
authors.initials: C
authors.lastname: Smestad
authors.forename: L
authors.initials: L
authors.lastname: Sandvik
authors.forename: H F
authors.initials: HF
authors.lastname: Harbo
authors.forename: E G
authors.initials: EG
authors.lastname: Celius
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D002648:Child; D054242:Emigrants and Immigrants / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000134:cerebrospinal fluid / Q000453:epidemiology*; D009664:Norway / Q000453:epidemiology; D043025:Oligoclonal Bands / Q000134:cerebrospinal fluid; D055815:Young Adult
chemical_list: D043025:Oligoclonal Bands
keywords: epidemiology; ethnicity; migration; multiple sclerosis; oligoclonal bands; prognosis