儿童过敏性紫癜性肾炎与IgA肾病的临床和病理的对比研究

A clinico-pathological study comparing Henoch-Schonlein purpura nephritis with IgA nephropathy in children

目的 对比研究过敏性紫癜性肾炎 (HSPN)和IgA肾病在临床、实验室检查及肾脏病理改变上的异同 ,探讨两者的关系。方法 对经肾活检证实的 31例IgA肾病及 12 0例过敏性紫癜性肾炎患儿进行详细的临床及病理对比分析。结果 2 5 8%的IgA肾病发病年龄在 12岁以上 ,而HSPN中仅占 10 .0 % ,差异有显著意义 (P <0 0 5 )。二组患儿临床表现类型分布上相似 ,但HSPN肾外症状多 ,均有皮肤紫癜 ,5 9 2 %有胃肠症状 ,4 6 7%有关节痛 ,而IgA肾病仅 3 2 %有腹痛。在肾脏病理改变上 ,IgA肾病 35 5 %出现球性硬化、4 1 9%系膜硬化 ,HSPN分别为 3 1%及 6 3% ,但HSPN有 6 5 6 %出现内皮增生 ,IgA肾病仅 2 9 0 % ,差异均有非常显著意义 (P <0 0 1)。IgA肾病中 6 5 %合并有薄基底膜病变 ,HSPN未见薄基底膜病变。电镜下HSPN电子致密物稀疏、松散 ,沉积部位分布较为广泛 ,位于肾小球系膜、内皮下甚至基底膜内 ,而IgA肾病电子致密物成密集团块状 ,主要局限于系膜区及旁系膜区。HSPN患儿中 2 3例 (71 9% )肾小球免疫沉积物中含有IgG ,其中 6例以IgG为主 (4例 )或毛细血管壁有IgG线样沉积 (2例 ) ,而IgA肾病肾小球免疫沉积物中有IgG沉积的仅为 19 4 % ,其多为IgA伴IgM和 (或 )C3 沉积 ,未见以IgG沉积为主以及线样IgG沉积?

Objective Henoch-Schonlein purpura nephritis (HSPN) and IgA nephropathy are very similar in immunopathological changes, and therefore some nephrologists considered that they are substantially one disease entity caused by IgA immune abnormalities, and IgA nephropathy is, in fact, a kind of HSPN without rashes. The present study aimed to characterize their relationship through clinico-pathological comparison between IgA nephropathy and HSPN. Methods Thirty-one children with IgA nephropathy aged from 3 to 15 years and 120 children with HSPN aged between 4 to 15 years were enrolled in this study. Their clinical manifestations, blood biochemical test, serum immunology and follow-up data were collected and analyzed. Renal pathological findings in light microscopy, immunofluorescence and electron microscopy were analyzed and also compared between 31 children with IgA nephropathy and 32 children with HSPN.Results The age of onset was over 12 years in 25.8% children with IgA nephropathy, but only in 10 % with HSPN, and the difference was significant (P<0.05). The clinical patterns of IgA nephropathy and HSPN were similar, but extra-renal manifestations were seen more often in HSPN, all of them had skin purpura, 59% had gastrointestinal symptoms and 47% suffered from arthralgia. While the abdominal pain occurred only in 3.2% children with IgA nephropathy. The renal pathological investigation showed global sclerosis in 35.5% of IgA nephropathy and 3.1% of HSPN, mesangial sclerosis in 41.9% of IgA nephropathy and 6.3% of HSPN, but endothelial proliferation in 65.6% of HSPN and 29% of IgA nephropathy. The differences were extremely significant (P<0.01). Thin basement membrane nephropathy were only found in 6.5% children with IgA nephropathy, but in none with HSPN. The electronic dense deposits in HSPN were sparse, loose and widely spread in glomerular mesangium, subendothelial area and even intra basement membrane. While the deposits were dense, lumpy and mostly limited in mesangium and paramesangium in IgA nephropathy. IgG was found in glomerular immune deposits in 71.9% of HSPN, but only 19.4% of IgA nephropathy. No IgG deposit was observed in 81.6% of IgA nephropathy, among them most showed IgA and IgM and/or C 3 deposit. Predominant IgG deposits were found in 12.5% of HSPN with relatively weak IgA deposit, moreover 6.3% of HSPN showed linear IgG deposits in glomerular capillary wall, which couldn′t be found in IgA nephropathy. The follow-up data of average 20 months showed complete remission in 72.5% of HSPN and 19.4% in IgA nephropathy after 34 months follow-up. Moreover, 64.5% of IgA nephropathy had consistent hematuria and proteinuria, 16.1% had active nephritides, the difference was significant (P<0.05).Conclusion Significant clinico-pathological differences were found between HSPN and IgA nephropathy, which does not support the one disease entity hypothesis. HSPN and IgA nephropathy are probably two diseases with similar immune abnormalities.