Department of Pathology and Cell Biology, Columbia University Medical Center, New York, New York.
Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota.
Curr Opin Nephrol Hypertens. 2022 May 1;31(3):221-227. doi: 10.1097/MNH.0000000000000783. Epub 2022 Mar 7.
Immunofluorescence on frozen tissue (IF-F) utilizing antibodies against immunoglobulin (Ig) heavy and light chains (IgA, IgG and IgM, kappa and lambda) and components of classical and alternative complement pathways (C1q, C3c and C4) is the standard of renal pathology. However, conventional IF-F has limitations, particularly in nephropathies associated with organized and/or monoclonal Ig deposits. This review will discuss new applications of established methods beyond conventional IF-F and recent novel immunohistochemical methods.
The combined application of paraffin immunofluorescence (IF-P) and IgG subtype staining excluded monotypic deposits in 62-66% of DNA J homolog subfamily B member 9-associated fibrillary glomerulonephritis (FGN) with apparent monotypic deposits by IF-F, whereas IF-P unmasks IgG deposits in a subset of cases of immunotactoid glomerulopathy. A novel IF technique targeting epitopes at the junction of the Ig heavy and light chains was introduced and unmasked polytypic deposits in a subset of glomerulonephritis with apparent monotypic deposits on IF-F. A recent study described the successful application of co-detection by indexing (CODEX) multiplexed IF to visualize more than a dozen target antigens within a single kidney tissue section. Finally, immunohistochemical protocols for detection of the novel antigens in membranous nephropathy have already entered the clinical practice of renal pathology.
Novel ancillary techniques in renal pathology have the potential to significantly enhance our ability to evaluate renal biopsies.
利用针对免疫球蛋白（Ig）重链和轻链（IgA、IgG 和 IgM、kappa 和 lambda）以及经典和替代补体途径成分（C1q、C3c 和 C4）的抗体进行冰冻组织免疫荧光（IF-F）是肾脏病理学的标准。然而，常规 IF-F 存在局限性，特别是在与有组织的和/或单克隆 Ig 沉积相关的肾病中。这篇综述将讨论超出常规 IF-F 的既定方法的新应用以及最近的新型免疫组织化学方法。
石蜡免疫荧光（IF-P）与 IgG 亚型染色的联合应用排除了 DNA J 同源物亚家族 B 成员 9 相关纤维状肾小球肾炎（FGN）中 62-66%的单克隆沉积，而 IF-F 表现出明显的单克隆沉积，而 IF-P 则揭示了免疫触须状肾小球病的一部分病例中的 IgG 沉积。引入了一种针对 Ig 重链和轻链交界处表位的新型 IF 技术，在一组表现为常规 IF-F 上明显单克隆沉积的肾小球肾炎中揭示了多克隆沉积。最近的一项研究描述了索引共检测（CODEX）多重 IF 成功应用于在单个肾组织切片中可视化十多种目标抗原。最后，检测膜性肾病新型抗原的免疫组织化学方案已经进入肾脏病理的临床实践。
肾脏病理学中的新型辅助技术有可能显著增强我们评估肾活检的能力。
