Presence of the HLADR13 allele among Mexican Mestizos suggests a protective factor against relapsing-remitting multiple sclerosis (RRMS)

Background and objective: Multiple sclerosis (MS) is a chronic demyelinating disease that affects the central nervous system. Researchers have looked for an association between relapsing-remitting MS (RRMS) and human leukocyte antigen (HLA) as risk or protective factor associated to ethnicity, which may add a partial explanation to disease heterogeneity and geographical variations. We described the frequency of the HLA-DR alleles in Mexican Mestizo (RRMS) patients.

Patients and methods: We included 143 RRMS patients and 377 healthy controls, both Mexican Mestizos. Previous signing informed consent, we record demographic and clinical characteristics of the participants. Genetic profile was made, and HLA frequencies in both groups were compared.

Results: RRMS patients were 39.8% male and 60.2% female, mean age was 35 years. While, controls were 48%male and 52% women, mean age was 38 years. The most frequent allele found in subjects with RRMS was DR 15 (p=0.006, OR=2.2, 95% CI: 1.3-3.6). DR 13 allele was more frequent among healthy subjects than RRMS patients (p=0.050) with a protective OR 2.6, (95% CI: 1.3-5.2, p=0.050).

Conclusion: In our study we found HLA DR 13 was more frequent in healthy controls than in RRMS patients, suggesting a protective factor among Mexican Mestizo population.