Riispere Živile, Kuudeberg Anne, Seppet Elviira, Sepp Kristin, Ilmoja Madis, Luman Merike, Kõlvald Külli, Auerbach Asta, Ots-Rosenberg Mai
Department of Internal Medicine, Tartu University and Tartu University Hospital, 8 Puusepa Str, Tartu, Estonia.
Department of Pathology, Tartu University Hospital, Tartu, Estonia.
BMC Nephrol. 2017 Mar 14;18(1):89. doi: 10.1186/s12882-017-0499-4.
IgA nephropathy (IgAN) is the most frequent glomerulonephritis in many countries including Estonia. There is no specific treatment for IgAN but renoprotection is indicated when proteinuria is >1 g/day. We aimed to assess the clinicopathological correlations of IgAN and to compare the follow-up outcome of the IgAN patients receiving renoprotection with the patients with other antihypertensive regimen treatments.
A retrospective kidney biopsy cohort study was carried out in consecutive 73 IgAN cases, using the new Oxford classification. The baseline and follow-up (FU, 4.1 years) clinical data were collected. The patients were divided into two main study groups according to their drug-treatment: the drug-treated and untreated patients' groups. Two subgroups among patients receiving two different antihypertensive drugs were formed and statistically analysed: Renin-angiotensin system (RASb, renoprotection) - and calcium-channel blockers (CCB)-receiving patients. Also, patient' subgroups with and without the presence of clinical and morphological risk factors were used for statistical analysis.
The patients' mean age was 33.7 years (range 16-76). Proteinuria decreased at the end of FU (0.91 g/24 h to 0.79 g/24 h). Mean arterial pressure remained at the end of FU almost at the same level. Drug treatment was prescribed to the patients who had lower eGFR, higher proteinuria and more severe histological lesions (S1, T1/2), while the patients with minimal clinical symptoms and the ones with near-normal kidney function remained without drug treatment. The kidney function remained almost at the same normal level in untreated patients irrespective of the risk factors whereas in both treated patient' subgroups eGFR declined. The following statistically significant correlations in the IgAN cohort were found: correlations in patients with lower kidney function (eGFR <60 ml/min/1.73 m), higher blood pressure (p = 0.00006) and proteinuria were found irrespectively of the fact whether the patients received (p = 0.006) or did not receive renoprotection (p = 0.001). The biggest significant eGFR change by Wilcoxon rank sum test was found among the patients who had clinical and morphological risk factors and received treatment. The result was confirmed by post hoc analysis and did not depend on the presence of treatment. In the investigation of the subgroups receiving RASb we found that the lowering of eGFR did depend on the presence of clinical and morphological risk factors.
Renoprotection is only effective in preventing the progression of IgAN when clinical and morphological risk factors are modest or missing.
在包括爱沙尼亚在内的许多国家，IgA肾病（IgAN）是最常见的肾小球肾炎。IgAN尚无特效治疗方法，但当蛋白尿>1g/天时，需进行肾脏保护治疗。我们旨在评估IgAN的临床病理相关性，并比较接受肾脏保护治疗的IgAN患者与接受其他降压治疗方案患者的随访结果。
采用新牛津分类法，对连续73例IgAN病例进行回顾性肾活检队列研究。收集基线和随访（FU，4.1年）临床数据。根据药物治疗情况将患者分为两个主要研究组：药物治疗组和未治疗组。在接受两种不同降压药物治疗的患者中形成两个亚组并进行统计学分析：接受肾素-血管紧张素系统（RASb，肾脏保护）治疗的患者和接受钙通道阻滞剂（CCB）治疗的患者。此外，将有和无临床及形态学危险因素的患者亚组用于统计分析。
患者平均年龄为33.7岁（范围16 - 76岁）。随访结束时蛋白尿减少（从0.91g/24小时降至0.79g/24小时）。随访结束时平均动脉压几乎保持在同一水平。对估算肾小球滤过率（eGFR）较低、蛋白尿较高且组织学病变较严重（S1，T1/2）的患者进行药物治疗，而临床症状轻微和肾功能接近正常的患者未接受药物治疗。无论有无危险因素，未治疗患者的肾功能几乎保持在相同的正常水平，而在两个治疗患者亚组中，eGFR均下降。在IgAN队列中发现以下具有统计学意义的相关性：无论患者是否接受肾脏保护治疗（接受治疗组p = 0.006，未接受治疗组p = 0.001），肾功能较低（eGFR <60ml/min/1.73m²）、血压较高（p = 0.00006）和蛋白尿之间均存在相关性。通过Wilcoxon秩和检验发现，在有临床和形态学危险因素并接受治疗的患者中，eGFR变化最为显著。事后分析证实了该结果，且不依赖于治疗的存在。在对接受RASb治疗的亚组进行研究时，我们发现eGFR的降低确实取决于临床和形态学危险因素的存在。
只有当临床和形态学危险因素较少或不存在时，肾脏保护治疗才对预防IgAN进展有效。
