AUTHOR=Yu Bing , Yin Yi-xin , Tang Yan-ping , Wei Kang-lai , Pan Zhi-gang , Li Ke-Zhi , Guo Xian-wen , Hu Bang-li 

TITLE=Diagnostic and Predictive Value of Immune-Related Genes in Crohn’s Disease

JOURNAL=Frontiers in Immunology

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2021.643036

DOI=10.3389/fimmu.2021.643036

ISSN=1664-3224

ABSTRACT=<p>Abnormal immune cell infiltration is associated with the pathogenesis of Crohn’s disease (CD). This study aimed to determine the diagnostic and predictive value of immune-related genes in CD. Seven Gene Expression Omnibus datasets that analyzed the gene expression in CD tissues were downloaded. Single-sample gene set enrichment analysis (ssGSEA) was used to estimate the infiltration of the immune cells in CD tissues. Immune-related genes were screened by overlapping the immune-related genes with differentially expressed genes (DEGs). The protein-protein interaction (PPI) network was used to identify key immune-related DEGs. Diagnostic value of CD and predictive value of anti-TNFα therapy were analyzed. Immunohistochemical (IHC) assay was used to verify gene expression in CD tissues. There were significant differences among CD tissues, paired CD tissues, and normal intestinal tissues regarding the infiltration of immune cells. <italic>AQP9</italic>, <italic>CD27</italic>, and <italic>HVCN1</italic> were identified as the key genes of the three sub-clusters in the PPI network. <italic>AQP9</italic>, <italic>CD27</italic>, and <italic>HVCN1</italic> had mild to moderate diagnostic value in CD, and the diagnostic value of <italic>AQP9</italic> was better than that of <italic>CD27</italic> and <italic>HVCN1</italic>. AQP9 expression was decreased in CD after patients underwent anti-TNFα therapy, but no obvious changes were observed in non-responders. <italic>AQP9</italic> had a moderate predictive value in patients who had undergone treatment. IHC assay confirmed that the expression of <italic>AQP9</italic>, <italic>CD27</italic>, and <italic>HVCN1</italic> in CD tissues was higher than that in normal intestinal tissues, and <italic>AQP9</italic>, <italic>CD27</italic> was correlated with the activity of CD. Immune-related genes, <italic>AQP9</italic>, <italic>CD27</italic>, and <italic>HVCN1</italic> may act as auxiliary diagnostic indicators for CD, and <italic>AQP9</italic> could serve as a promising predictive indicator in patients who underwent anti-TNF therapy.</p>