Date: Tuesday, May 5, 2015
Session Name: Concurrent Session: Glomerulonephritis/Recurrent Disease
Session Time: 2:15pm-3:45pm
Presentation Time: 3:27pm-3:39pm
Location: Room 121-AB
Backgound: IMN is frequently associated with autoantibodies to the podocyte antigen, PLA2R. Anti-PLA2R associated IMN is diagnosed by detecting PLA2R antigen within glomerular immune complexes in renal biopsies (Bx) and/or elevated anti-PLA2R IgG in blood. Secondary MN is usually negative(-) for PLA2R. Here we measured blood anti-PLA2R levels using ELISA in pre- and post-kidney transplant patients (Tx pts) to assess the utility of this non-invasive test in predicting post-Tx IMN.
Methods: Archived serum or plasma samples from 76 normal individuals and 98 pre-Tx pts with ESRD due to various causes including 4 with IMN were submitted for anti-PLA2R ELISA. Additionally, available pre- and post-Tx samples were analyzed in 15 pts with post-Tx MN and 21 pts without. Anti-PLA2R levels >14 RU/ml were considered positive(+). PLA2R immunohistochemistry was performed on post-Tx renal Bx with MN.
Results: All samples from normal individuals were anti-PLA2R(-) (1.3±1.0 RU/ml). Of 98 ESRD pts, 1 lupus pt and 1/4 IMN pt were anti-PLA2R(+). The remaining 96 pts were anti-PLA2R(-) (0.8±1.2 RU/mL, p=0.06 vs. normals). The anti-PLA2R(+) sample (230 RU/ml) from the IMN pt was obtained close to diagnosis, while (-) samples from the other 3 IMN pts were from years after diagnosis. Of 4 post-Tx pts who had Tx renal Bx with PLA2R(+) IMN, 3 were anti-PLA2R(-) in post-Tx samples. The fourth patient was strongly anti-PLA2R(+) (66 RU/mL), 6 weeks before Bx. Follow-up sera were (-) and the MN resolved. The remaining 11 pts with post-Tx MN were PLA2R(-) in Bx and anti-PLA2R(-) in post-Tx sera tested, except for 1 anti-PLA2R(+) (15 RU/ml) sample at CMV infection. The 21 post-Tx pts without MN were anti-PLA2R(-) at all post-Tx time points, except for 1 lupus pt with consistently high (+) anti-PLA2R (46±24 RU/mL) and even higher levels at cellular rejection (84 RU/mL) and CMV infection (64 RU/mL). Post-Tx anti-PLA2R(-) levels were similar to pre-Tx. We found a modest rise (up to 3RU/mL) in anti-PLA2R within 1 month after IVIG infusion.
Conclusion: Anti-PLA2R was only (+) in rare pts without IMN. Viral infection, IVIG infusion and rejection may cause modest elevations in anti-PLA2R. A rise in anti-PLA2R can precede development of PLA2R(+) MN in Bx, but the antibody may soon disappear. Frequent monitoring may be required to predict IMN post-Tx.
To cite this abstract in AMA style:VanBeek C, Thomas D, Jimenez A, Vo A, Jordan S, Toyoda M. Utility of Anti-Phospholipase A2 Receptor (Anti-PLA2R) ELISA Testing in Predicting Post-Transplant Idiopathic Membranous Nephropathy (IMN) [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/utility-of-anti-phospholipase-a2-receptor-anti-pla2r-elisa-testing-in-predicting-post-transplant-idiopathic-membranous-nephropathy-imn/. Accessed April 20, 2021.
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