Tan Min, Li Wenge, Zou Guming, Zhang Cong, Fang Jing
Center of Nephrology, China-Japan Friendship Hospital, Health Ministry of China, Beijing, China.
Kidney Blood Press Res. 2015;40(2):200-6. doi: 10.1159/000368495. Epub 2015 Apr 6.
BACKGROUND/AIMS: Information regarding the clinical and histological prognostic factors of IgA nephropathy (IgAN) is mostly derived from patients in whom diagnostic renal biopsies were performed because their proteinuria levels were higher than 1-2 g/d. The clinicopathological features and outcomes of IgAN patients presenting with normal blood pressure, normal renal function, hematuria and minimal or no proteinuria are not well described. We therefore conducted a study of the clinicopathological features and outcomes in IgAN patients with these characteristics.
The clinical, laboratory, and pathological manifestations and long-term outcomes of all IgAN patients with the above-mentioned characteristics were collected. The relationships between renal pathology, injury, long-term outcomes and clinical factors were studied, and the risk factors of IgAN were analyzed using multivariate logistic regression.
Of all of the renal biopsy cases, IgAN with the above features accounted for 8.9%. Among these patients, 67.2% (253) showed simultaneous hematuria and proteinuria, 23.1% (87) showed only hematuria, and 9.7% (36) showed only proteinuria. Additionally, 33.8% (127) patients showed macroscopic hematuria and 65.1% (245) had a prodromal infection. Regarding renal pathological changes, 45.5% (171) of the patients were unexpectedly classified as Grade II to IV (Hass classification). Proteinuria at the time of renal biopsy was an independent predictor of more severe renal pathological injury. After a median follow-up of 75 months, 61 (16.2%) patients experienced adverse events. Among these patients, 28 (7.45%) exhibited hypertension, 22 (5.85%) presented proteinuria levels >1 g/24 h, and 11 (2.9%) developed impaired renal function.
Severe renal histological injury may be observed in some IgAN patients with benign clinical characteristics. Proteinuria is an independent predictor of severe renal pathological injury in IgAN patients with mild proteinuria. More severe pathological injury (> Grade II, Hass classification) are predictors of poor prognosis.
背景/目的：关于IgA肾病（IgAN）临床和组织学预后因素的信息大多来自因蛋白尿水平高于1 - 2g/d而进行诊断性肾活检的患者。血压正常、肾功能正常、血尿且蛋白尿极少或无蛋白尿的IgAN患者的临床病理特征和预后情况描述较少。因此，我们对具有这些特征的IgAN患者的临床病理特征和预后进行了研究。
收集所有具有上述特征的IgAN患者的临床、实验室和病理表现及长期预后情况。研究肾脏病理、损伤、长期预后与临床因素之间的关系，并采用多因素逻辑回归分析IgAN的危险因素。
在所有肾活检病例中，具有上述特征的IgAN占8.9%。在这些患者中，67.2%（253例）同时出现血尿和蛋白尿，23.1%（87例）仅表现为血尿，9.7%（36例）仅表现为蛋白尿。此外，33.8%（127例）患者出现肉眼血尿，65.1%（245例）有前驱感染。关于肾脏病理变化，45.5%（171例）患者意外被归类为Ⅱ至Ⅳ级（Hass分级）。肾活检时的蛋白尿是更严重肾脏病理损伤的独立预测因素。中位随访75个月后，61例（16.2%）患者发生不良事件。在这些患者中，28例（7.45%）出现高血压，22例（5.85%）蛋白尿水平>1g/24h，11例（2.9%）出现肾功能损害。
一些具有良性临床特征的IgAN患者可能存在严重的肾脏组织学损伤。蛋白尿是轻度蛋白尿的IgAN患者严重肾脏病理损伤的独立预测因素。更严重的病理损伤（>Ⅱ级，Hass分级）是预后不良的预测因素。
