Correlation between the course of kidney injury and clinicopathology and prognosis of children with Henoch-Schönlein purpura nephritis.

Purpose: Henoch-Schönlein purpura nephritis (HSPN) has a poor prognosis and variable pathophysiology. The present study aimed to analyze the kidney injury, clinicopathology, and prognosis of HSPN children.

Methods: This retrospective study examined 249 children with HSPN. The patients' pathological and clinical data were collected. The patients were divided into the following groups according to the duration of their kidney injury: groups with disease duration of < 2 weeks, 2 weeks to 1 month, 1-2 months, 2-4 months, 4-6 months, and ≥ 6 months. The clinicopathological and prognostic relationships were examined between the groups.

Results: We enrolled 249 children with HSPN (average age of 10.12 ± 3.01 years). There were 161 boys (64.66%) and 88 girls (35.34%). Altogether, 191 children (76.71%) developed kidney injury within 2 months. A total of 37 children (14.86%) showed recurrent renal damage after 6 months. Most patient groups exhibited hematuria and proteinuria, with type III pathology being the most common. During 2 weeks and 1 month of kidney injury, the acute pathology index peaked and then decreased; then, it increased again after 4 months as recurrence occurred. The chronic pathology index was the highest in the group with a disease duration of 2-4 months and it increased with increasing disease duration. The prognosis worsens with the disease duration.

Conclusion: Children with HSPN showed disease remission after a duration of 4-6 months. The acute and chronic pathology indexes peaked between 2 weeks to 1 month and 2-4 months, respectively. Patients with kidney injury occurring within a month had a much higher remission rate.