Alzolibani Abdullateef A, Al Robaee Ahmad A, Al Shobaili Hani A, Bin Saif Ghada, Al-Saif Fahad, Ali Ahmed, Settin Ahmad
aDermatology Department bResearch Center, College of Medicine, Qassim University cDermatology Department, College of Medicine, King Saud University, Riyadh, Saudi Arabia.
J Egypt Public Health Assoc. 2015 Mar;90(1):20-3. doi: 10.1097/01.EPX.0000461326.05328.d3.
Immunogenetic factors are known to play a role in the pathogenesis of alopecia areata (AA). This study aimed at investigating the association between AA with the polymorphisms of interleukin-4 (IL-4) promoter and receptor (IL-4R) genes.
This work is a case-control study that was conducted on 76 AA patients from Qassim region, Saudi Arabia. Patients were compared with 93 normal healthy controls from the same locality. Genomic DNA was extracted and processed using real-time PCR amplification for characterization of IL-4 -590 T>C and IL-4R Q551R A>G gene polymorphisms.
Cases of AA showed a higher frequency of the IL-4 -590 CC homozygous genotype compared with controls (63.2 vs. 53.8%, P>0.05) with a lower frequency of the TT genotype (5.3 vs. 10.8%); yet, both were statistically nonsignificant (P>0.05). Regarding the IL-4R Q551R A>G polymorphism, cases and controls showed nearly equal frequencies of all variants, that is, with no significant difference. Although the frequency of the IL-4 C and the IL-4R A alleles was higher among cases than among controls (78.9 vs. 71.5% and 78.8 vs. 72.6%, respectively), this was also statistically nonsignificant (P>0.05). Comparing case subgroups in terms of their age of onset, sex, disease severity, consanguinity, and family history showed no statistically significant difference regarding the studied genetic variant.
IL-4 -590 and IL-4R Q551R gene polymorphisms are not associated with the susceptibility and the clinical pattern of AA in Saudi patients. We recommend further research studies involving the estimation of cytokines both in the serum and in the local skin lesions or in cultured skin cells to figure out whether Th1 or Th2 pathways play a specific role in the pathogenesis of AA.
免疫遗传因素在斑秃（AA）的发病机制中发挥作用。本研究旨在调查AA与白细胞介素4（IL-4）启动子及受体（IL-4R）基因多态性之间的关联。
本研究为病例对照研究，对来自沙特阿拉伯卡西姆地区的76例AA患者进行了研究。将患者与来自同一地区的93名正常健康对照进行比较。提取基因组DNA，并使用实时PCR扩增对IL-4 -590 T>C和IL-4R Q551R A>G基因多态性进行鉴定。
与对照组相比，AA患者中IL-4 -590 CC纯合基因型的频率更高（63.2%对53.8%，P>0.05），TT基因型的频率更低（5.3%对10.8%）；然而，两者在统计学上均无显著差异（P>0.05）。关于IL-4R Q551R A>G多态性，病例组和对照组所有变体的频率几乎相等，即无显著差异。尽管病例组中IL-4 C和IL-4R A等位基因的频率高于对照组（分别为78.9%对71.5%和78.8%对72.6%），但这在统计学上也无显著差异（P>0.05）。比较病例亚组在发病年龄、性别、疾病严重程度、近亲结婚和家族史方面，所研究的基因变体无统计学显著差异。
IL-4 -590和IL-4R Q551R基因多态性与沙特患者AA的易感性及临床模式无关。我们建议进一步开展研究，包括评估血清、局部皮肤病变或培养的皮肤细胞中的细胞因子，以确定Th1或Th2途径在AA发病机制中是否发挥特定作用。
