Membranoproliferative glomerulonephritis with masked monotypic immunoglobulin deposits.
Membranoproliferative glomerulonephritis with masked monotypic immunoglobulin deposits.
复制标题
膜增生性肾小球肾炎，具有掩盖的单型免疫球蛋白沉积物。
DOI：
10.1038/ki.2015.195
复制
发表时间：
2015-10
影响因子：
19.6
通讯作者：
Nasr SH
中科院分区：
文献类型：
--
作者：
Larsen CP;Messias NC;Walker PD;Fidler ME;Cornell LD;Hernandez LH;Alexander MP;Sethi S;Nasr SH
膜增生性肾小球肾炎（MPGN）的诊断最近已从基于电子显微镜的分类方案转变为主要基于免疫荧光结果的分类方案。这一变化是由于认识到许多此类病例是由替代补体级联异常引起的，从而产生了 C3 肾小球病的概念。在这里，我们回顾了我们的病例档案，以识别那些具有 MPGN 模式的患者，这些模式通过常规免疫荧光显示单克隆免疫球蛋白的假阴性染色。蛋白酶消化后，通过对福尔马林固定的石蜡包埋组织进行免疫荧光，揭示单克隆免疫球蛋白沉积物。随后确定了 16 例平均血清肌酐为 2.7mg/dl、平均 24 小时蛋白尿为 7.1g 的病例的临床病理学细节。三分之二的患者存在低补体血症。 14 名患者的血清免疫固定有副蛋白，所有这些都与活检免疫荧光染色模式相匹配。 13 名患者的骨髓活检显示浆细胞恶液质或 B 细胞淋巴增殖性疾病。在进行石蜡免疫荧光检查之前，其中 10 名患者的活检结果与 C3 肾小球肾炎最为一致。因此，必须高度警惕以避免这些病例的误诊，因为如果不进行石蜡免疫荧光检查，许多病例可能会被误诊为 C3 肾小球病或未分类的 MPGN。
The diagnosis of membranoproliferative glomerulonephritis (MPGN) has recently undergone change from an electron microscopy-based classification scheme to one based largely on immunofluorescence findings. This change is due to the recognition that many of these cases are driven by abnormalities of the alternative complement cascade, resulting in the concept of C3 glomerulopathy. Here we reviewed our case files to identify those with an MPGN pattern that show false negative staining for monoclonal immunoglobulins by routine immunofluorescence. Monoclonal immunoglobulin deposits were unmasked by performing immunofluorescence on formalin-fixed paraffin embedded tissue after protease digestion. Clinico-pathological details of 16 such cases with a mean serum creatinine of 2.7 mg/dl and mean 24 h proteinuria of 7.1 g were then determined. Hypocomplementemia was present in two-thirds of patients. Fourteen patients had a paraprotein on serum immunofixation, all of which matched the biopsy immunofluorescence staining pattern. Bone marrow biopsy showed plasma cell dyscrasia or B-cell lymphoproliferative disorder in 13 patients. Ten of these patients had findings on biopsy most consistent with C3 glomerulonephritis prior to performing paraffin immunofluorescence. Thus a high index of suspicion is necessary to avoid misdiagnosis in these cases, as many would have been mistakenly diagnosed as C3 glomerulopathy or unclassified MPGN if paraffin immunofluorescence was not performed.