RESUMO
OBJECTIVE: To explore the value of galactose-deficient IgA1 (Gd-IgA1) in the early diagnosis of Henoch-Schönlein purpura nephritis (HSPN) in children. METHODS: A total of 67 hospitalized children who were definitely diagnosed with HSPN between January and April 2018 and 58 hospitalized children with Henoch-Schönlein purpura (HSP) were enrolled in the study. Twenty children undergoing routine physical examinations served as controls. The levels of serum and urine Gd-IgA1 were determined using ELISA. The receiver operating characteristic curve was used to analyze the value of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in the diagnosis of HSPN. RESULTS: The level of serum Gd-IgA1 and urine Gd-IgA1/urine creatinine ratio in children with HSP or HSPN were significantly higher than those in healthy control group (P<0.01), with a significantly greater increase observed in children with HSPN (P<0.01). Serum Gd-IgA1 ≥1 485.57 U/mL and/or urine Gd-IgA1/urine creatinine ratio ≥105.74 were of favorable value in the diagnosis of HSPN. During the six-month follow-up of the 49 children with HSP, the incidence of HSPN was 47% (23/49), which included a 100% incidence in children with serum Gd-IgA1 ≥1 485.57 U/mL and a 73% incidence in children with urine Gd-IgA1/urine creatinine ratio ≥105.74. CONCLUSIONS: Serum and urine Gd-IgA1 is of favorable clinical value in the early diagnosis of HSPN.