Objective To investigate the levels and clinical significance of serum S100A8/A9 and interleukin-31 (IL-31) in children with Henoch Schonlein purpura nephritis (HSPN).

Methods A total of 96 patients with HSPN were selected as the HSPN group, according to International Study of Kidney Disease in Children (ISKDC) grade standard, 12 cases were of grade ≤IIa, 28 cases were of grade IIb, 31 cases were of grade IIIa, and 25 cases were of grade IIIb. At the same time, 90 healthy children were selected as the control group. The expression levels of S100A8/A9 and IL-31 in serum were detected by enzyme-linked immunosorbent assay (ELISA). Pearson method was used to analyze the correlation between S100A8/A9 and IL-31 in serum of HSPN patients, and the ROC curve was drawn to analyze the diagnostic value of S100A8/A9 and IL-31 for HSPN.

Results Compared with the control group, the expression levels of IL-4 and TNF in the HSPN group were obviously higher (P ＜ 0.05); the expression levels of S100A8/A9 and IL-31 in serum of the HSPN group were obviously higher than those of the control group (P ＜ 0.05); the expression levels of S100A8/A9 and IL-31 in grade IIIb HSPN patients were obviously higher than those in grade ≤IIa, grade IIb and grade IIIa, the expression levels in grade IIIa were obviously higher than those in grade ≤IIa and grade IIb, and the expression levels in grade IIb were obviously higher than those in grade ≤IIa (P ＜ 0.05). Correlation analysis showed that serum S100A8/A9 and IL-31 expression levels in HSPN children with different renal pathological grades were positively correlated (P ＜ 0.05). The AUC of HSPN diagnosed by both methods was higher than that of S100A8/A9 and IL-31 (P ＜ 0.05).

Conclusion S100A8/A9 and IL-31 are highly expressed in the serum of children with HSPN, and they are positively correlated. The combination of S100A8/A9 and IL-31 has clinical value in the diagnosis of HSPN.