A reliable clinical test for detection of membranous nephropathy antigens using laser microdissection and mass spectrometry.

Autor: Vrana JA; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Theis JD; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Wegwerth PJ; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Dasari S; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Madden B; Mayo Clinic Proteomics Core, Mayo Clinic, Rochester, Minnesota, USA., Nasr SH; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Fidler ME; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., McPhail ED; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA., Fervenza FC; Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota, USA., Sethi S; Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: sethi.sanjeev@mayo.edu.
Jazyk: angličtina
Zdroj: Kidney international [Kidney Int] 2024 Nov; Vol. 106 (5), pp. 907-912. Date of Electronic Publication: 2024 Aug 26.
DOI: 10.1016/j.kint.2024.07.031
Abstrakt: Membranous nephropathy (MN) results from accumulation of antigen-antibody immune complexes along the subepithelial region of the glomerular basement membranes. Over the last years, 13 target antigens have been discovered and include PLA2R, THSD7A, EXT1 and EXT2, NELL1, SEMA3B, NCAM1, CNTN1, HTRA1, FAT1, PCDH7, NTNG1, PCSK6 and NDNF, accounting for 80-90% of MN antigens. MN associated with many of these antigens have distinctive clinicopathologic findings. It is important to accurately identify the antigen in MN. Immunohistochemical (IHC) and/or immunofluorescence (IF) methods are currently used to detect PLA2R, THSD7A, NELL1, SEMA3B and EXT1/EXT2. However, for the remaining antigens, IHC/IF methods do not exist and are not practical for detection. Here, we developed laser microdissection-based mass spectrometry methodology (LMD/MS) as a one-stop clinical test for the detection of MN antigens using paraffin-embedded kidney biopsy tissue. The LMD/MS test was validated in two steps. LMD/MS was used to detect the antigen in 75 cases of MN with known antigens and correctly identified the antigen in all these cases. Next, LMD/MS was used to identify the antigen in 61 MN cases where the antigen was unknown and identified one of the known antigens in 40 of 61 cases including many of the less common antigens. This lower-than-expected detection rate is explained by intentional enrichment of the cohort with PLA2R-negative MN. Overall, PLA2R was identified in 16.4%, one of the other antigens detected in 49.1%, and in the remaining 34.5% of cases, none of the above antigens was detected. Thus, LMD/MS is an extremely useful and reliable method for the detection of known MN antigens and possibly indicating an unknown MN antigen for eventual discovery.
(Copyright © 2024 International Society of Nephrology. Published by Elsevier Inc. All rights reserved.)
Databáze: MEDLINE