Abstract: Objective　To explore the relationship of infection with blood pressure and immunological indicators in children with IgA nephropathy (IgAN). Methods　The clinicopathological data of 108 children with IgAN diagnosed by renal biopsy from January 2006 to December 2013 were collected. The patients were divided into the infected group (66 cases) and the non-infected group (42 cases) depending on whether there was infection prior to the onset. Blood pressure, serum levels of immunoglobulin and complement, and the deposition intensity of immunoglobulin and complement in renal tissue were compared between the two groups. Results　Compared with the non-infected group, the infected group had a higher proportion of gross hematuria, a greater pulse pressure, and higher serum IgA and IgG levels, and differences were statistically significant (P<0.05). There were statistically significant differences in the distribution of IgM and C3 deposition intensity in renal tissues between the two groups (P<0.05). The proportion of children with negative IgM deposition intensity was higher, and the proportion of children with C3 deposition intensity "++" was higher. Infection was positively correlated with gross hematuria, pulse pressure, serum IgA and IgG levels, and renal C3 deposition intensity (P<0.05), and negatively correlated with renal IgM deposition intensity (P<0.01). Conclusions　IgAN is often accompanied by infection before the onset in children, and infection is associated with pulse pressure, serum IgA and IgG, and IgM and C3 deposition intensity in renal tissue. These characteristics are significant in guiding the prevention and treatment of IgAN in children.

Key words: IgA nephropathy;　blood pressure;　immunoglobulin;　complement;　child