Associations between lipid metabolism and Henoch-Schönlein purpura nephritis in children: a systematic review and meta-analysis.

BACKGROUND: Henoch-Schönlein purpura (HSP)is the most common childhood vasculitis, and renal involvement (HSPN) significantly worsens its prognosis. Noninvasive correlates of renal involvement are therefore of interest. Dyslipidemia often coexists with renal inflammation. Clarifying this association is essential to understand the metabolic perturbations in HSPN. However, although dyslipidemia has been associated with HSPN, its exact mechanism remains unclear from an evidence-based. METHODS: A comprehensive search was performed using PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang, China Science and Technology Journal (VIP), and the Chinese Medical Journal full-text databases from their inception to December 25, 2024. Primary outcomes compared levels of total cholesterol (TC), total triglycerides (TG), low-density lipoprotein (LDL), and high-density lipoprotein (HDL) between the HSPN group and the HSP group; secondary outcomes included study methodology, publication date, sample size, and quality assessment scores. Study quality was assessed using modified NOS scales, with inter-rater reliability measured by Cohen's kappa. Statistical analysis was performed using Stata 16.0 to calculate standardized mean differences (SMDs) with 95% confidence intervals (CIs). Subgroup analyses were limited by the paucity of data regarding the timing of blood sampling relative to corticosteroid initiation and renal onset. RESULTS: Eighteen studies were included. Meta-analysis revealed that patients with HSPN had significantly higher levels of TC, TG, and LDL compared with patients with HSP without nephritis. The pooled estimates were TC (SMD = 0.55, 95% CI = 0.36 to 0.75; I2 = 89.9%, P < 0.001), TG (SMD = 0.47, 95% CI = 0.29 to 0.65; I2 = 69.8%, P = 0.001), and LDL (SMD = 0.37, 95% CI = 0.12 to 0.61; I2 = 76.1%, P < 0.001). No significant difference was observed for HDL (SMD = - 0.87, 95% CI = - 1.89 to 0.14; I2 = 97.9%, P < 0.001). CONCLUSION: Elevated levels of TC, TG, and LDL are observed in patients with HSPN, underscoring a robust association between lipid dysregulation and renal involvement. However, significant heterogeneity, coupled with the lack of pretreatment baseline data, precludes causal inference and precludes utility in early prediction. Prospective studies measuring pretreatment baseline lipids prior to renal onset are warranted to validate these findings.