*Meelad A.Al-Nasiri1   ,    Ehab D. Salman2    ,     Ali H. Ad’hiah3

1-Sera and vaccine institute / ministry of health

2 Department of Biotechnology, College of Science, University of Baghdad, Baghdad, Iraq.

3 Tropical-Biological Research Unit, College of Science, University of Baghdad, Baghdad, Iraq

Correspondence author: Meelad A. Al-Nasiri; E-mail: melodyalaziz@gmail.com


Multiple sclerosis is a neurodegenerative autoimmune disease caused by a demyelination in neuronal axon results in multifocal lesions in especially white matter. Genetic, epigenetic and environmental factors play a pivotal role in the pathogenesis of MS. The current study focused on the immunogenetic association of IFNγ to MS pathogenesis. IFNγ is a proinflammatory cytokine that contribute to enhance Th1-cell immune response upon infection and is considered as exacerbation factor in relapsing-remitting MS (RRMS) patients. The current study focused on the association between serum level of this cytokine and single nucleotide polymorphism (SNP) genotypes/alleles at locus +874 of IFNG gene. Sixty eight Iraqi RRMS patients were enrolled in this study and they were categorized into two group: IFNB            pre-medicated and IFNB post-medicated patients. Twenty Iraqi healthy individuals were chosen as control group .The results showed a significant decreased mean serum levels in RRMS patients  in pre-medication and post-medication RRMS patients as compared to control group (68.8 ± 3.3 and 68.5 ± 4.46 vs. 91.8 ± 10.5, P=0.015) pg/ml respectively . The results demonstrated that there was insignificant difference between observed and expected genotype frequencies of IFNG gene SNP at position +874. In addition, there was insignificant variation between patients and controls in the distribution of these genotypes and alleles. The results also revealed that there was no impact of  IFNG gene SNP at locus +874 on the serum level of this cytokine in RRMS patients but the highest serum level was recorded for carriers of TT genotype in both patients and control group (77.72 ± 7.54, 114.8±24.03) pg/ml respectively. Meanwhile, a significant increase of control group serum level corresponding TT genotype compared to that corresponding AA genotype (114.8±24.03 vs. 66.67±10.87, P= 0.004) pg/ml respectively. Furthermore, it was observed that a significant decrease of patients’ IFNγ serum level corresponding both AT and TT genotypes as compared to those in control group (64.9±4.33 vs. 90.42 ± 12.58 , P=0.042; 77.72± 7.54 vs. 114.8±24.03 , P=0.008) pg/ml respectively. Briefly, the results indicated that IFNG has no serious effect on the MS predisposition and the low levels of IFNγ in RRMS patients may be attributed to the remitting state of the patients and the variation of cytokine expression between different individual and the complexity of biological relationship between different cytokines in the MS patients .