To analyze the associations between crescent proportion and renal pathology, laboratory indicators, and prognosis in children with IgA vasculitis with nephritis (IgAVN), and to assess the impact of different treatment strategies on urinary protein and prognosis.

A total of 329 children with IgAVN and crescent formation were stratified by crescent proportion into a crescent <25% group and a crescent ≥25% group. Relationships of crescent proportion and treatment strategies with pathological features, laboratory testing results and outcomes were evaluated.

Compared with the crescent <25% group, the crescent ≥25% group showed higher urine occult blood, urine protein, urinary N-acetyl-β-D-glucosaminidase, and serum urea levels, with decreased renal function and higher acute tubulointerstitial injury scores (P<0.05). Steroids combined with tripterygium glycosides, mycophenolate mofetil or Kunxian capsule all reduced the urine protein/creatinine ratio (P<0.001). The steroid plus Kunxian capsule regimen was associated with the best prognosis (P<0.05).

A higher crescent proportion is associated with more severe renal injury in pediatric IgAVN. Steroids combined with Kunxian capsule improves prognosis.