BACKGROUND The management of IgA vasculitis with nephritis (IgAVN) remains controversial because of the difficulty to identify prognostic factors. This study reports the prognosis of children with IgAVN in relation to histological parameters. METHODS All children with IgAVN diagnosed between 2000 and 2015 in three pediatric nephrology centers were included. The following histological parameters were analyzed: mesangial proliferation (MP), endocapillary proliferation (EP), crescents, active, or chronic tubular and interstitial lesions (TIa lesions/TIc lesions), and segmental glomerulosclerosis (GS). Clinical and biological data were collected at the time of renal biopsy. The primary endpoint was IgAVN remission defined as a proteinuria < 200 mg/l without renal failure. RESULTS One hundred fifty-nine children were included with a median age of 7.6 years. Acute glomerular or TI lesions including MP, EP, crescents, and TIa lesions were observed, respectively, in 81%, 86%, 49%, and 21% of patients. Chronic glomerular lesions including GS and TIc lesions were observed in 6 and 7% of patients. Median initial proteinuria was 330 mg/mmol, albuminemia 32 g/l, and eGFR 110 ml/min/1.73 m2. One hundred twelve (70%) patients were in remission at the end of a median follow-up of 37.4 months. Chronic lesions were significantly associated with the absence of remission in multivariate analysis, whereas EP, crescents and TIa were not associated with a poor prognosis. CONCLUSIONS Of children with IgAVN, 30% present a persistent renal disease at the end of a 3-year follow-up. Chronic histological lesions, but not EP or crescents, are associated with a bad prognosis and must be evaluated in IgAVN histological classification.

中文翻译：

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过敏性紫癜性肾炎患儿的组织学预后因素。

背景技术由于难以确定预后因素，因此对患有肾炎的IgA血管炎（IgAVN）的治疗仍存在争议。这项研究报告了与组织学参数有关的IgAVN儿童的预后。方法纳入2000年至2015年在三个儿科肾脏病中心诊断出的所有IgAVN患儿。分析了以下组织学参数：系膜增生（MP），毛细血管内增生（EP），新月形，活动性或慢性肾小管和间质病变（TIa病变/ TIc病变）和节段性肾小球硬化（GS）。在肾活检时收集临床和生物学数据。主要终点是IgAVN缓解，定义为蛋白尿<200 mg / l，无肾功能衰竭。结果纳入159名儿童，中位年龄为7.6岁。分别在81％，86％，49％和21％的患者中观察到了急性肾小球或TI病变，包括MP，EP，新月形和TIa病变。在6和7％的患者中观察到了包括GS和TIc病变在内的慢性肾小球病变。初始蛋白尿中位数为330 mg / mmol，白蛋白血症为32 g / l，eGFR为110 ml / min / 1.73 m2。中位随访37.4个月结束时，有112名（70％）患者缓解。在多变量分析中，慢性病变与无缓解显着相关，而EP，新月和TIa与不良预后无关。结论IgAVN儿童中，有3％在3年随访期末表现出持续性肾脏疾病。慢性组织学病变，但不是EP或新月形病变，