Objective To identify the biomarkers for early rheumatoid arthritis(RA)diagnosis and explore the possible immune regulatory mechanisms.Methods The differentially expressed genesin RA were screened and functionally annotated using the limma,RRA,batch correction,and clusterProfiler.The protein-protein interaction network was retrieved from the STRING database,and Cytoscape 3.8.0 and GeneMANIA were used to select the key genes and predicting their interaction mechanisms.ROC curves was used to validate the accuracy of diagnostic models based on the key genes.The disease-specific immune cells were selected via machine learning,and their correlation with the key genes were analyzed using Corrplot package.Biological functions of the key genes were explored using GSEA method.The expression of STAT1 was investigated in the synovial tissue of rats with collagen-induced arthritis(CIA).Results We identified 9 core key genes in RA(CD3G,CD8A,SYK,LCK,IL2RG,STAT1,CCR5,ITGB2,and ITGAL),which regulate synovial inflammation primarily through cytokines-related pathways.ROC curve analysis showed a high predictive accuracy of the 9 core genes,among which STAT1 had the highest AUC(0.909).Correlation analysis revealed strong correlations of CD3G,ITGAL,LCK,CD8A,and STAT1 with disease-specific immune cells,and STAT1 showed the strongest correlation with M1-type macrophages(R=0.68,P=2.9e-08).The synovial tissues of the ankle joints of CIA rats showed high expressions of STAT1 and p-STAT1 with significant differential expression of STAT1 between the nucleus and the cytoplasm of the synovial fibroblasts.The protein expressions of p-STAT1 and STAT1 in the cell nuclei were significantly reduced after treatment.Conclusion CD3G,CD8A,SYK,LCK,IL2RG,STAT1,CCR5,ITGB2,and ITGAL may serve as biomarkers for early diagnosis of RA.Gene-immune cell pathways such as CD3G/CD8A/LCK-γδ T cells,ITGAL-Tfh cells,and STAT1-M1-type macrophages may be closely related with the development of RA.

Objective To identify the biomarkers for early rheumatoid arthritis(RA)diagnosis and explore the possible immune regulatory mechanisms.Methods The differentially expressed genesin RA were screened and functionally annotated using the limma,RRA,batch correction,and clusterProfiler.The protein-protein interaction network was retrieved from the STRING database,and Cytoscape 3.8.0 and GeneMANIA were used to select the key genes and predicting their interaction mechanisms.ROC curves was used to validate the accuracy of diagnostic models based on the key genes.The disease-specific immune cells were selected via machine learning,and their correlation with the key genes were analyzed using Corrplot package.Biological functions of the key genes were explored using GSEA method.The expression of STAT1 was investigated in the synovial tissue of rats with collagen-induced arthritis(CIA).Results We identified 9 core key genes in RA(CD3G,CD8A,SYK,LCK,IL2RG,STAT1,CCR5,ITGB2,and ITGAL),which regulate synovial inflammation primarily through cytokines-related pathways.ROC curve analysis showed a high predictive accuracy of the 9 core genes,among which STAT1 had the highest AUC(0.909).Correlation analysis revealed strong correlations of CD3G,ITGAL,LCK,CD8A,and STAT1 with disease-specific immune cells,and STAT1 showed the strongest correlation with M1-type macrophages(R=0.68,P=2.9e-08).The synovial tissues of the ankle joints of CIA rats showed high expressions of STAT1 and p-STAT1 with significant differential expression of STAT1 between the nucleus and the cytoplasm of the synovial fibroblasts.The protein expressions of p-STAT1 and STAT1 in the cell nuclei were significantly reduced after treatment.Conclusion CD3G,CD8A,SYK,LCK,IL2RG,STAT1,CCR5,ITGB2,and ITGAL may serve as biomarkers for early diagnosis of RA.Gene-immune cell pathways such as CD3G/CD8A/LCK-γδ T cells,ITGAL-Tfh cells,and STAT1-M1-type macrophages may be closely related with the development of RA.

Objective:To analyze clinical significance of peripheral blood neutrophil CD64(nCD64)index in patients with anti-neutrophil cytoplasmic antibody(ANCA)-associated vasculitis(AAV).Methods:The clinical data of 98 AAV patients admitted to the First Medical Center of Chinese People's Liberation Army General Hospital from February 1,2023 to February 29,2024 were retrospectively selected,and they were divided into the high-value group(nCD64 index＞1.82,28 patients)and the normal-value group(nCD64 index≤1.82,70 patients)based on the nCD64 index.Ethylenediaminetetraacetic acid(EDTA)-anticoagulated venous blood specimens were collected from patients in both groups,and the mean fluorescence intensity of CD64 expression on the surfaces of polymorphonuclear leukocytes(PMN),lymphocytes(Lym)and monocytes(Mo)was detected by flow cytometry.Clinical manifestations,relevant examination data of hospital,and survival situation of patients with regular follow-up were compared between the two groups.Results:Spearman correlation analysis showed that peripheral blood nCD64 index was positively correlated with Birmingham vasculitis activity score(BVAS)in AAV patients(r=0.216,P＜0.05).There were no statistically significant differences in white blood cells(109/L),blood creatinine(μmol/L),CD8+lymphocytes(amount/μl),CD3-CD16+CD56+lymphocytes(amount/μl),blood sedimentation and interleukin 6 between the two groups.The mean values of BVAS,neutrophils(109/L),CD8+CD28-lymphocytes(％)were respectively(14.96±8.62),(7.51±4.56),(22.16±13.28)in high-value group,which were significantly higher than those[(11.88±7.39),(6.32±3.60)and(17.32±11.27)]in normal-value group,and the mean values of lymphocytes(109/L),platelets(109/L),hemoglobin(g/L),CD3+lymphocytes(amount/Al),CD4+lymphocytes(amount/μl),CD8+CD28+lymphocytes(％)were respectively(1.52±1.01),(216.84±92.32),(106.26±21.99),(1401.15±658.22),(618.43±420.50)and(12.43±5.98)in high-value group,which were significantly lower than those[(1.98±0.95),(248.20±97.21),(114.30±24.71),(1815.43±657.29),(969.15±385.72)and(15.77±7.66)]in normal-value group,and the differences of them between two groups were statistically significant(t=-2.68,-2.04,-2.54,3.25,2.26,2.34,2.02,2.84,3.02,P＜0.05),respectively.Neutrophil/lymphocyte ratio and C-reactive protein of high-value group were higher than those of normal-value group,and eosinophils of high-value group were lower than that of normal-value group,and the differences of them between two groups were statistically significant(Z=-3.370,-2.396,-4.462,P＜0.05),respectively.Conclusions:Peripheral blood nCD64 index is positively correlated with BVAS in AAV patients,which involve in multiple immune cells and inflammatory factors.It has clinically application value in monitoring the disease progression and assessing the prognosis.