Herrera Guillermo A, Turbat-Herrera Elba A
Nephrocor-Bostwick Laboratories, Tempe, Arizona, USA.
Ultrastruct Pathol. 2010 May;34(3):161-73. doi: 10.3109/01913121003672873.
Renal dysfunction is often seen in patients with plasma cell dyscrasias. The abnormal light and heavy chains that are produced by the neoplastic plasma cells in these patients are responsible for the renal abnormalities that occur. The renal manifestations are heterogeneous and include alterations in all three renal compartments; sometimes more than one compartment is affected in a given case. It must be demonstrated that the renal abnormalities are directly related to the underlying plasma cell dyscrasia to make a definitive diagnosis of an associated lesion. Therefore, it becomes crucial to link the renal findings with the circulating nephrotoxic light or heavy chains. Immunofluorescence is very helpful and diagnostic in the majority of the cases, as it can localize the light or heavy chains to the various renal compartments showing alterations, and frequently confirm monoclonality. However, the antibodies that are used routinely do not necessarily label the abnormal light and heavy chains; the corollary of this is that a negative immunofluorescence workup does not rule out a light- or heavy-chain-related renal disorder. Electron microscopy is also important as it can depict crucial morphologic correlates to provide unique evidence or to simply confirm and clarify diagnostic findings. Ultrastructural immunolabeling combines the information obtained from immunofluorescence and electron microscopy by highlighting specific structures associated with the deposition of the pathogenic monotypical light and heavy chains.
肾功能不全在浆细胞异常增殖性疾病患者中较为常见。这些患者体内肿瘤性浆细胞产生的异常轻链和重链是导致肾脏异常的原因。肾脏表现具有异质性，包括肾的三个部分均出现改变；在特定病例中，有时不止一个部分会受到影响。必须证明肾脏异常与潜在的浆细胞异常增殖性疾病直接相关，才能明确诊断相关病变。因此，将肾脏检查结果与循环中的肾毒性轻链或重链联系起来至关重要。免疫荧光在大多数病例中非常有用且具有诊断价值，因为它可以将轻链或重链定位到显示有改变的各个肾部分，并常常证实其单克隆性。然而，常规使用的抗体不一定能标记出异常轻链和重链；由此推断，免疫荧光检查结果为阴性并不能排除轻链或重链相关的肾脏疾病。电子显微镜检查也很重要，因为它可以描绘关键的形态学关联，以提供独特的证据或仅仅是确认和阐明诊断结果。超微结构免疫标记通过突出与致病性单型轻链和重链沉积相关的特定结构，将从免疫荧光和电子显微镜检查中获得的信息结合起来。
