The immunological tolerance balance disturbances, including the presence of specific autoantibodies and the loss of function of some organs, negatively affects the health of patients with autoimmune diseases (ADs) [
The study has been approved by the Bioethics Committee (Medical University of Bialystok, R-I-002/334/2018) and conducted in accordance with the Helsinki Declaration. All participants have signed informed consent forms.
Molecular studies were conducted in a group of 94 subjects with MS (47 males and 47 females, mean age
The clinical characteristic of MS subject group.
Characteristics | MS subjects, | Women, | Men, |
---|---|---|---|
Age at onset (years) | |||
Disease duration (years) | |||
EDSS |
Data is presented as
The ages of onset and duration of the disease were analysed. The clinical condition of MS subjects was evaluated using Kurtzke’s Expanded Disability Status Scale (EDSS), at the time of diagnosis, before any treatment was provided.
Genomic DNA was isolated with the Qiagen column separation method (QIAamp DNA Blood Mini Kit, Qiagen, Germany) according to the manufacturer’s protocols, and then the purity and concentration of the obtained preparations were evaluated by spectrophotometric method using the NanoDrop 2000 device (Thermo Fisher Scientific, USA). All DNA samples were normalised to 50 ng/
The genotypes and allele frequencies in the studied groups.
Gene | SNV | Genotypes/allele | MS ( | HC ( | OR (95% CI) | |||
---|---|---|---|---|---|---|---|---|
Frequency | Frequency | |||||||
rs7093069 | CC | 57 | (60.64%) | 69 | (43.12%) | NS | ||
CT | 36 | (38.8%) | 83 | (51.88%) | 0.016 | 0.52 | ||
TT | 1 | (1.06%) | 8 | (5.0%) | 0.047 | 0.15 | ||
C | 150 | (0.80) | 221 | (0.69) | 0.0053 | 0.56 | ||
T | 38 | (0.20) | 99 | (0.31) | ||||
rs12722598 | TT | 80 | (85.11%) | 156 | (97.5%) | NS | ||
TC | 14 | (14.89%) | 3 | (1.88%) | 0.06 | 4.2 | ||
CC | — | 1 | (0.62%) | NS | ||||
T | 174 | (0.93) | 315 | (0.99) | 0.001 | 0.2 | ||
C | 14 | (0.07) | 4 | (0.01) | ||||
rs3087243 | GG | 0 | (0.00%) | 69 | (43.12%) | 0.00 | 0.0038 | |
GA | 30 | (31.91%) | 77 | (48.12%) | 0.00 | 0.087 | ||
AA | 64 | (68.09%) | 14 | (8.75%) | NS | |||
G | 30 | (0.16) | 215 | (0.67) | 0.00 | 0.09 | ||
A | 158 | (0.84) | 105 | (0.33) | ||||
rs231775 | AA | 36 | (38.30%) | 51 | (31.88%) | NS | ||
AG | 45 | (47.87%) | 82 | (51.25%) | NS | 0.78 | ||
GG | 13 | (13.83%) | 27 | (16.88%) | NS | 0.68 | ||
A | 117 | (0.62) | 184 | (0.58) | NS | |||
G | 71 | (0.38) | 136 | (0.43) | ||||
rs5742906 | CC | 71 | (75.53%) | 109 | (68.13%) | NS | ||
CT | 20 | (21.28%) | 40 | (25.00%) | NS | 0.77 | ||
TT | 3 | (3.19%) | 11 | (6.88%) | NS | 0.41 | ||
C | 162 | (0.86) | 258 | (0.81) | 0.069 | |||
T | 26 | (0.14) | 62 | (0.19) | ||||
rs1883832 | TT | 7 | (7.45%) | 10 | (6.25%) | NS | ||
TC | 23 | (24.47%) | 59 | (36.88%) | 0.0477 | 0.55 | ||
CC | 64 | (68.09%) | 91 | (56.88%) | NS | 0.99 | ||
T | 37 | (0.20) | 79 | (0.25) | NS | |||
C | 151 | (0.80) | 241 | (0.75) | ||||
rs1748033 | TT | 7 | (7.45%) | 13 | (8.13%) | NS | ||
TC | 45 | (47.87%) | 58 | (36.25%) | 0.068 | 1.64 | ||
CC | 42 | (44.68%) | 89 | (55.63%) | NS | 1.14 | ||
T | 59 | (0.31) | 84 | (0.26) | NS | |||
C | 129 | (0.69) | 236 | (0.74) |
For all calculations, the Stata 15 software was used. Since our sample was small, for all the comparisons, we used the Chi2 test confirmed with Fisher’s exact test to confirm the results. If possible, we reported the
The frequency of the polymorphic T allele of rs7093069 was significantly higher (
We also observed a protective effect of allele T in rs12722598 (Table
Of the three polymorphisms tested in the CTLA4 gene, our study showed significant differences in allele and genotype frequencies only for rs3087243. The frequency of allele G was higher in the group of healthy control subjects compared to the group of individuals with MS (
Our analysis of the rs1883832 polymorphisms in the CD40 gene did not show any significant differences in the homozygous genotypes and allele frequencies between the studied groups. We only observed that healthy control individuals carried the heterozygous TC genotype significantly more often than the subjects with diagnosed with MS (59 vs. 23 individuals, respectively,
We did not observe any significant differences between the studied groups in the frequencies of alleles and the genotypes of rs1748033 in the PADI4 gene (Table
The analysis of allele and genotype frequency distribution within MS subjects did not show any significant differences between men and women (data not shown). We did not notice any associations between the studied variants, and the age of onset, the duration of the disease, or the disability status (data not shown), including sex stratification.
The rapid technology development and novel models of collaboration between research groups have enabled to discover several genetic risk factors that have been associated with MS. However, due to the fact that the heredity of the disease has not fully been determined yet, the researchers are currently focusing on identifying alleles and genotypes, related pathways, epigenetic mechanisms, and gene-environment interactions, which may have an impact on MS development and progress [
In our study, we found that a T allele of the rs7093069 in the IL2RA gene was significantly more often carried by the healthy control individuals than by participants with MS, which suggests that it may have a protective effect on MS development. Also, the CT and TT genotypes distribution was significantly higher in the healthy control group subjects than in individuals diagnosed with MS, which indicates that carrying the T allele may have a strong significant protective effect against MS development. The IL2RA gene has been associated with differences in immune cell populations in subjects with MS, and Hartmann et al. found that individuals carrying the IL2RA risk alleles present a significantly increased propensity of TH (T helper) cells to develop into GM-CSF- (granulocyte-macrophage colony-stimulating factor-) producing memory TH-cells and linked this genetic risk factor with a functional feature of TH-cells in MS [
We have also observed significant differences between healthy control subjects and individuals with MS in the allele and genotype frequencies in rs3087243 of the CTLA-4 gene. The G allele, as well as the GG and GA genotypes, was significantly more common among healthy control participants than in subjects with MS. Interestingly, the GG genotype has been identified only in the group of healthy subjects. The CTLA-4 gene has been associated with susceptibility to MS also by Kantarci et al. in the North American MS genomic screen population [
Our analysis of the rs1883832 polymorphisms in the CD40 gene has shown that only the heterozygous TC variant is more common among healthy individuals compared to subjects with MS, without any differences between homozygous variant frequencies. Although the T allele of rs1883832 has been previously associated with increased susceptibility to MS [
In our study population, we did not notice any significant differences between cases and control group in the frequencies of alleles and genotypes of rs1748033 in the PADI4 gene. Our results are in line with the study by Tommasi et al. [
Also, we did not notice any crucial differences between studied genotypes in the clinical manifestations of MS that could be explained by the limited samples described herein. Moreover, the cerebral activity and connectivity of neural circuits responsible for locomotor functions, that are included in the EDSS scoring, depend also on the other factors that we have not investigated in our study, such as serum concentrations of vitamin D [
In summary, despite the relatively small study group, our results show that some of the investigated SNVs within the IL2RA, CTAL4, and CD40 genes are more common in MS individuals, and others may have a protective role, indicating the need and importance of further investigation.
The data used to support the findings of this study are available from the corresponding author upon request.
The authors declare that they have no competing interests.
MC is responsible for conceptualisation, methodology, investigation, and writing—original draft preparation. NWK is responsible for methodology and investigation. EAP is responsible for writing—original draft preparation. OZ is responsible for methodology and statistical analysis. KKT and RP are responsible for investigation. AJK, JK, and AK is responsible for supervision. Authors read and approved the final manuscript.
We thank the Medical University of Bialystok staff for their contributions and help with data collection and laboratory analysis.