Different HLA class II (DRB1 and DQB1) alleles determine either susceptibility or resistance to NMO and multiple sclerosis among the French Afro-Caribbean population

Background:Despite similarities, neuromyelitis optica (NMO) can be distinguished from multiple sclerosis (MS) by clinical, radiological and serological findings. Objective:This case-control study aimed to determine whether patients with NMO or with MS in an Afro-Caribbean population originating from French West Indies shared the same or different HLA class I and II pattern distribution. Methods:The association with HLA class II (DRB1 and DQB1) alleles was tested in 42 NMO patients, 163 MS patients and 150 healthy controls. HLA-DRB1 and DQB1 typing was undertaken on genomic DNA extracted from peripheral blood leucocytes. Results:By comparison with healthy controls, significantly increased frequency of HLA-DRB1*03 (26.2% vs. 13%, odds ratio 2.4, 95% confidence interval 1.31–4.28, p after correction, cp 0.045) was observed in patients with NMO. By contrast, in MS patients, HLA-DRB1*15 (24.8% vs. 13%, odds ratio 2.21, 95% CI 1.45–3.36, cp