Kim Chankyung, Brealey John, Jobert Anjelo, Nolan James
Department of Anatomical Pathology, SA Pathology, Adelaide, Australia.
Central and Northern Adelaide Renal Transplantation Services, Royal Adelaide Hospital, Adelaide, Australia.
J Pathol Transl Med. 2020 Nov;54(6):504-507. doi: 10.4132/jptm.2020.09.18. Epub 2020 Nov 9.
Monoclonal gammopathy of renal significance is defined as any B cell or plasma cell clonal lymphoproliferation which neither causes tumor complications nor meets any current hematological criteria for specific therapy, with one or more kidney lesions related to the produced monoclonal immunoglobulin, such as amyloidosis. A 50-year-old male presented with heavy proteinuria and blood tests showing IgA and Lambda paraproteinemia. Light microscopy showed mesangial eosinophilic ground substance extending into the capillary loops, and positive staining within the glomeruli and vessel walls for amyloid P immunohistochemistry was also noted. Immunofluorescence showed positive staining for IgA and Lambda in the mesangia and capillary loops. Electron microscopy exhibited organized fibrils measuring 4-5 nm in diameter in the mesangia, glomerular basement membranes and vessel walls. We interpreted the overall findings as atypical renal amyloidosis with IgA and Lambda deposition on immunofluorescence. Further amyloid typing using laser microdissection-liquid chromatography and mass spectrometry will be useful.
具有肾脏意义的单克隆丙种球蛋白病被定义为任何既不引起肿瘤并发症也不符合当前特定治疗血液学标准的B细胞或浆细胞克隆性淋巴增殖，伴有一个或多个与所产生的单克隆免疫球蛋白相关的肾脏病变，如淀粉样变性。一名50岁男性出现大量蛋白尿，血液检查显示IgA和λ副蛋白血症。光镜检查显示系膜嗜酸性基质延伸至毛细血管袢，肾小球和血管壁内淀粉样蛋白P免疫组化染色阳性。免疫荧光显示系膜和毛细血管袢中IgA和λ染色阳性。电子显微镜显示系膜、肾小球基底膜和血管壁中有直径为4-5nm的有组织的纤维。我们将总体发现解释为免疫荧光显示IgA和λ沉积的非典型肾淀粉样变性。使用激光显微切割-液相色谱和质谱进行进一步的淀粉样蛋白分型将很有用。
