Background: Besides the central role of the adaptive immune system, a disturbance of innate immune system is also suggested to be involved in the pathogenesis of multiple sclerosis (MS). CD14, a receptor upregulated in activated microglia, is known to be an essential mediator of inflammation in innate immune responses. Therefore, in this study we aimed to assess possible roles of CD14-159 and -260 gene polymorphisms in MS susceptibility and the effects of those polymorphisms to its protein producing capacity in Iranian population.
Methods: In this case control study, CD14-159 and -260 polymorphisms were genotyped using polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) in 200 MS patients and 200 healthy controls matched in age and gender. Serum levels of soluble CD14 (sCD14) was determined by enzyme-linked immunosorbent assay (ELISA).
Results: There were significant differences in genotype distribution of CD14-159 and -260 polymorphisms between patients and controls (P = 0.01, for-both). Mean serum level of sCD14 was significantly higher in MS patients than in control subjects (3340.30 ± 612.50 ng/ml vs 2353.73 ± 539.07 ng/ml; P < 0.01).
Conclusion: In summary, we conclude that CD14-159 and -260 polymorphisms are associated with the risk of MS in Iranian population and affects CD14 promoter activity, thereby regulating CD14 expression. Furthermore, our study provides preliminary evidence for the activation of innate immunity in the pathogenesis of MS. In addition, the findings of the present study suggest serum level of sCD14 as candidate biomarker of MS severity.
Keywords: CD14 polymorphism; ELISA; innate immunity; multiple sclerosis; polymerase chain reaction; soluble CD14.