Increased expression of LC3 in peripheral blood mononuclear cells is related to disease status in patients with rheumatoid arthritis

: Objective To detect the mRNA and protein expression of microtubule-associated protein 1 light chain 3 (LC3) in peripheral blood mononuclear cells (PBMCs) of patients with rheumatoid arthritis (RA), and to investigate its relationship with RA. Methods Twenty-two patients with RA and 16 healthy subjects with matching gender and age as controls were included in the study. PBMCs were isolated by density gradient centrifugation. The level of LC3 mRNA in PBMCs was detected by real-time fluorescent quantitative PCR. The protein level of LC3 in PBMCs was detected by Western blot analysis. The expression of LC3 protein in PBMCs was detected by immunofluorescence staining. Pearson analysis was used to analyze the correlation between LC3 expression and clinical parameters of RA patients. Results Compared with the normal control group, the levels of LC3 mRNA and protein in PBMCs of RA patients went up significantly, and the expression of LC3 significantly increased in PBMCs. The mRNA expression level of LC3 was obviously positively correlated with erythrocyte sedimentation rate (ESR, r=0.7480), 28 joint disease activity (DAS28, r=0.5016), C-reactive protein (CRP, r=0.6518), and rheumatoid factor (RF, r=0.7232). Conclusion The expression of LC3 is up-regulated in RA patients and is associated with ESR, DAS28, CRP and RF.