[Clinicopathological significance and prognostic value of serum 25-hydroxyvitamin D level in children with IgA vasculitis nephritis].

Objectives: To study the significance of serum 25-hydroxyvitamin D [25-(OH)D] level in the clinicopathological characteristics and prognosis of children with immunoglobulin A vasculitis nephritis (IgAVN).

Methods: A retrospective analysis was conducted on the clinical data of children with IgAVN who underwent renal biopsy at Suzhou Hospital Affiliated to Anhui Medical University and Jinling Hospital of the Medical School of Nanjing University from June 2015 to June 2020. Based on serum 25-(OH)D level, the patients were divided into a normal group and a lower group. The clinicopathological characteristics and follow-up data of the two groups were collected and compared.

Results: A total of 359 children with IgAVN were included. Compared to the normal group (62 cases), the lower group (297 cases) exhibited higher incidences of hematochezia and gross hematuria, higher levels of serum creatinine, blood urea nitrogen, urinary retinol protein, urinary N-acetyl-β-D-glucosaminidase, and quantitative urinary protein, and a longer duration from renal biopsy to urinary protein becoming negative, as well as lower estimated glomerular filtration rate and albumin level (<0.05). Renal pathology in the lower group showed a higher occurrence of tubular interstitial injury, crescent formation, segmental sclerosis in glomeruli, and inflammatory cell infiltration in the renal interstitium compared to the normal group (<0.05). Survival analysis indicated that the cumulative renal survival rate was lower in the lower group (<0.05). Multivariate Cox regression analysis revealed that low serum 25-(OH)D level is an independent risk factor for poor prognosis in children with IgAVN.

Conclusions: Children with IgAVN and low serum 25-(OH)D level have relatively severe clinicopathological manifestations. Low serum 25-(OH)D level is an independent risk factor for poor prognosis in children with IgAVN.