Ethnic groups, geographical regions and MS
Non-parametric analysis of seasonality in birth and MS risk in second generation of migrants in Kuwait(26/08 14)
There are inconsistent reports about multiple sclerosis (MS) risk among migrants from low to high MS risk geographical regions. This study assessed the overall MS incidence and evaluated seasonality in birth and subsequent MS risk later in the life in second generation of migrants born and lived in Kuwait.
Methods: We assessed the overall and gender-specific MS risk in second generation of migrants born and lived in Kuwait between January 1, 1950 and April 30, 2013.
Data on migrant MS patients diagnosed and registered in Kuwait National MS Registry were used. Hewitt's non-parametric test was carried out to evaluate the seasonality in migrant MS births in comparison with the second generation migrant births in general population.
Results: During the study period, an overall risk of migrant MS births (per 100,000 non-Kuwaiti births in general population) as 23.8 (95% CI: 20.8 - 27.0).
Gender-specific MS risk showed that non-Kuwaiti female had statistically significant (p=0.003) higher risk (28.6; 95% CI: 24.2 - 33.7) than non-Kuwaiti males (18.7; 95% CI: 15.1-23.0). The month-specific distribution of migrant MS births compared with migrant births in general population did not differ significantly (2 goodness-of-fit test statistic=9.51, p=0.575).
Hewitt's non-parametric test revealed an evidence of slight but statistically non-significant (p=0.090) increased tendency of migrant MS births during September through February.
Conclusions: The proportion of migrant MS births (per 100,000 migrant births in general population) over the study period was 23.8 (95% CI: 20.8 - 27.0), which was statistically significantly higher than the previously reported Kuwaiti national MS births (16.2; 95% CI: 15.1-17.4) in Kuwait. Non-parametric analysis showed slight but statistically non-significant increased tendency of migrant MS births from September through February.
Knowledge of MS risk factors and how and when they act among genetically vulnerable individuals from gestation to early adulthood will help design prevention strategies.
Author: Saeed AkhtarRaed AlroughaniAhmad Al-ShammariJarrah Al-AbkalYasser Ayad
Credits/Source: BMC Neurology 2014, 14:170
Source: 7thSpace Interactive © 2014 7thSpace Interactive (26/08 14)
Clinical features and disability progression in multiple sclerosis in Tunisia: Do we really have a more aggressive disease course?
Sidhom Y, Damak M, Riahi A, Hizem Y, Mrissa R, Mhiri C, Gouider R.
BACKGROUND: Few epidemiological data are available on multiple sclerosis (MS) patients in North Africa (NA). Studies of immigrants from NA showed a more aggressive course compared to European patients.
OBJECTIVE: The aim of this study is to describe clinical and long term course characteristics of MS in Tunisia and to compare it to European cohorts.
METHOD: A total of 437 MS patients from three hospital based cohorts in Tunisia and having prospective follow up between 2010 and 2012 were analyzed. We considered as endpoints the time to reach EDSS scores of 3, 4 and 6 in the different clinical forms of MS and the beginning of a secondary progressive (SP) phase.
RESULTS: Sex ratio was 2.34. Mean age of onset was 30.3years. The course was relapsing-remitting (RR) in 91% of patients and primary progressive (PP) in 9%. The most frequent isolated onset symptoms were respectively motor (28%), optic neuritis (20%) and sensory (16%) dysfunction. Median time to SP onset was 19.1years. Median times from onset of multiple sclerosis to assignment of a score of 3, 4 and 6 were 8, 10.7 and 15years respectively. Benign form of MS represented 31.5%. Median interval from the onset of the disease to EDSS score of 3, 4 and 6 was shorter in PP-MS than in RR-MS. However, there was no difference between these two groups for the median time from the assignment of EDSS 4 to the assignment EDSS 6.
CONCLUSIONS: Our study shows that Tunisian MS patients have a quite similar clinical feature to European patients. Still, larger MS multicenter cohort studies in NA with longer follow-up duration could clearly respond to the issue.
Source: J Neurol Sci. 2014 Aug 15;343(1-2):110-4. doi: 10.1016/j.jns.2014.05.049. Epub 2014 Jun 2 & Pubmed PMID: 24980939 (25/07/14)
The purpose of this study was to determine the incidence of clinically isolated syndrome (CIS), a potential precursor of multiple sclerosis (MS), and whether it varies by race/ethnicity in a multi-ethnic, population-based cohort. We conducted a retrospective cohort study of over 9 million person-years of observation from the multi-ethnic, community-dwelling members of Kaiser Permanente Southern California Health Plan from January 1, 2008 to December 31, 2010.
Incidence of CIS and risk ratios comparing incidence rates between racial/ethnic groups were calculated using Poisson regression. We identified 468 newly diagnosed CIS cases that did not meet McDonald criteria for MS.
The average age at diagnosis was 39.0 years (range 2.7-85.8) and 68.8 % were women. The female preponderance was more pronounced among black (75.7 %) and Hispanics (70.5 %) than in white and Asian individuals with CIS (66.5 and 54.5 %, respectively; P = 0.14).
The most common presenting symptom in Hispanics was optic neuritis (P = 0.008), and in blacks, transverse myelitis (P = 0.07). Incidence of CIS was lower in Hispanics (3.8, 95 % CI 3.2-4.4, P < 0.0001) and Asians (2.4, 95 % CI 1.5-3.6, P < 0.0001) and similar in blacks (6.8, 95 % CI 5.3-8.5, P = 0.30) compared with whites (5.9, 95 % CI 5.1-6.7).
The incidence of CIS varies by race/ethnicity and sex in a similar pattern to MS. In addition, the clinical presentation of CIS varies by race/ethnicity. These findings strengthen the probability that the old belief that blacks have a decreased risk of MS is no longer true.
These findings highlight that studies that include minorities are likely to lead to important insights into the etiology and prognosis of CIS and MS.
Langer-Gould A, Brara SM, Beaber BE, Zhang JL.
Sources: J Neurol. 2014 Apr 29. [Epub ahead of print] & Pubmed PMID: 24777692 (02/05/14)