AIM: To explore the changes and significance in JIA-U and to detect the levels of CDld^(hi)CD5⁺CD19⁺ regulatory B cells(Breg)in the peripheral blood of children with juvenile idiopathic arthritis-associated uveitis(JIA-U).

METHODS: From April 2018 to May 2020, 95 children with JIA-U were selected as JIA-U group; 70 children with juvenile idiopathic arthritis(JIA)were selected as JIA group, and all of them were diagnosed and treated in our hospital; another 75 healthy children in the same period were selected as the control group. The ratio of CDld^(hi)CD5⁺CD19⁺Breg in peripheral blood was detected by flow cytometry; the level of IL-10 in peripheral blood was detected by ELISA; the correlation between CDld^(hi)CD5⁺CD19⁺Breg ratio and the expression of IL-10, the severity of JIA-U patients was analyzed by Pearson correlation coefficient method; the influencing factors of JIA-U were analyzed by Logistic regression.

RESULTS: Compared with the control group, the proportion of CDld^(hi)CD5⁺CD19⁺Breg in peripheral blood of children in JIA group and JIA-U group was significantly lower(all P<0.01), while the level of IL-10 was significantly higher(all P<0.01); compared with JIA group, the proportion of CDld^(hi)CD5⁺CD19^+Breg in JIA-U group was significantly lower(P<0.01), while the level of IL-10 was significantly higher(P<0.01); compared with the stationary phase, the ratio of CD1d^(hi)CD5⁺CD19⁺Breg in the active phase of JIA and JIA-U patients was significantly reduced(all P<0.01), and the IL-10 level was significantly increased(all P<0.01); the ratio of CDld^(hi)CD5⁺CD19⁺Breg was negatively correlated with the expression of IL-10 and the severity of JIA-U; multivariate analysis showed that low proportion of CDld^(hi)CD5⁺CD19⁺Breg, less-joint JIA subtype, duration of arthritis < 4a, high levels of IL-10 were risk factors for JIA-U.

CONCLUSION: The proportion of CDld^(hi)CD5⁺CD19⁺Breg in peripheral blood of children with JIA-U is significantly decreased, which may be involved in the occurrence and development of JIA-U, and has the potential to be used as an index to judge the severity of JIA-U.