Abstract
This study aimed to discover novel serum biomarkers for IgA vasculitis with nephritis (IgAVN). The serum of IgA vasculitis (IgAV) patients without nephritis and IgAVN patients not treated with glucocorticoids was analyzed for 440 proteins using a novel quantitative planar protein microarray. To verify the biomarkers, semiquantitative immunofluorescence analysis was performed on selected differential cytokines in a separate cohort of kidney tissue samples. A total of 41 proteins were differentially expressed between the IgAVN and IgAV groups out of the 440 proteins analyzed. Five differentially abundant proteins, including VEGF R3, ADAM12, TIM-3, IL-12p40, and CEACAM-5, were further validated by semiquantitative immunofluorescence analysis in kidney tissue from independent cohorts. ADAM12, TIM-3, IL-12p40, and CEACAM-5 were expressed in kidney tissue. A linear relationship was observed between the pathological grade of IgAVN and the expression levels of ADAM12 and CEACAM-5. Furthermore, while the prognosis of children with IgAVN may have a linear relationship with CEACAM-5, the results did not indicate a significant statistical difference, which may be related to the sample size. The expression of ADAM12 and CEACAM-5 were positively correlated with the pathological grade. More importantly, we found that CEACAM-5 may be related to the prognosis of IgAVN, which could serve as a significant biomarker for assessing disease severity and monitoring disease progression.