Endo M, Ohi H, Ohsawa I, Fujita T, Matsushita M
Second Department of Internal Medicine, Nihon University School of Medicine, Tokyo.
Am J Kidney Dis. 2000 Mar;35(3):401-7. doi: 10.1016/s0272-6386(00)70192-2.
Henoch-Schönlein purpura nephritis (HSPN) is considered a form of systemic vasculitis of the small blood vessels with immune pathogenesis. In this disorder, the complement system is recognized as an important mechanism of glomerular injury. The aim of this study is to determine whether the lectin pathway, a novel pathway of complement activation, is related to the pathogenesis of HSPN. Renal biopsy material from 10 patients with HSPN was studied immunohistochemically and examined for a clinicopathologic correlation. Serum levels of complement components, including mannose-binding lectin (MBL), and plasma levels of complement activation products were also evaluated in these patients and compared with levels in patients with immunoglobulin A (IgA) nephropathy or mesangial proliferative glomerulonephritis (GN) without IgA deposition (non-IgA GN). Glomerular deposition of components of the pathway, MBL and MBL-associated serine protease (MASP-1), as well as C3b/C3c, C5b-9, and C4-binding protein (C4-bp), was detected in 8 of 10 patients. Although no significant correlation was found between glomerular deposition of MBL/MASP-1 and histological or clinical findings, the biopsies on all patients with MBL/MASP-1 deposits were performed within 20 weeks from the onset of disease. Levels of plasma C4d, the activation fragment of C4, and C4-bp, a soluble regulatory protein of the pathway, were greater in patients with HSPN than in those with non-IgA GN. However, there was no difference in serum MBL levels between the three groups of patients (HSPN, IgA nephropathy, and non-IgA GN). These results suggest that complement activation through the lectin pathway was involved at the onset of HSPN, and this mechanism might be important in the disease pathogenesis.
过敏性紫癜性肾炎（HSPN）被认为是一种具有免疫发病机制的小血管系统性血管炎。在这种疾病中，补体系统被认为是肾小球损伤的重要机制。本研究的目的是确定凝集素途径（一种新的补体激活途径）是否与HSPN的发病机制有关。对10例HSPN患者的肾活检材料进行免疫组织化学研究，并检查其临床病理相关性。还评估了这些患者的补体成分血清水平，包括甘露糖结合凝集素（MBL），以及补体激活产物的血浆水平，并与免疫球蛋白A（IgA）肾病或无IgA沉积的系膜增生性肾小球肾炎（GN）（非IgA GN）患者的水平进行比较。在10例患者中的8例中检测到该途径成分、MBL和MBL相关丝氨酸蛋白酶（MASP-1）以及C3b/C3c、C5b-9和C4结合蛋白（C4-bp）的肾小球沉积。虽然未发现MBL/MASP-1的肾小球沉积与组织学或临床发现之间存在显著相关性，但所有有MBL/MASP-1沉积患者的活检均在疾病发作后20周内进行。HSPN患者的血浆C4d（C4的激活片段）和该途径的可溶性调节蛋白C4-bp水平高于非IgA GN患者。然而，三组患者（HSPN、IgA肾病和非IgA GN）的血清MBL水平没有差异。这些结果表明，通过凝集素途径的补体激活在HSPN发病时就已参与，并且这种机制可能在疾病发病机制中起重要作用。
