Date: Saturday, May 2, 2015
Session Name: Poster Session A: Kidney Antibody Mediated Rejection
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Exhibit Hall E
Background: Immune responses to tissue restricted self antigens have been proposed to play a role in transplant glomerulopathy (TG). The goal of this study is to determine the role of one of these self antigens, vimentin, through characterization of anti-vimentin antibody isotypes found pre and post transplant in the development of TG following renal transplantation.
Methods: Pre and Post-transplant sera were collected from 25 biopsy proven TG patients and time matched stable KTx recipients for measuring serum vimentin Abs concentrations. Using ELISA method, IgG and IgM isotypes were measured using isotype specific antibodies conjugated with horse Horseradish peroxidase (HRP). Samples were considered positive to vimentin isotype antibodies if values are above Mean+2X standard deviations of healthy controls.
Results: In pre-transplant 6/25 (24%) of biopsy proven TG patients had antibodies of IgG isotype (521±58ng/ml) and 10/25 (40%) had IgM isotype (654±71ng/ml) also in stable patients 7/25 (28%) had antibodies of IgG isotype (541±63ng/ml) and 9/25 (36%) had antibodies of IgM subtype (763±80ng/ml). In post-transplant serum sample 15/25 (60%) of biopsy proven TG patients developed antibodies of IgG isotype (741±142ng/ml) and 3/25 (12%) to IgM isotype (436±87ng/ml) while in stable patients 4/25 (16%) developed IgG isotype (315±68ng/ml) and 2/25 (8%) developed IgM isotype antibody (198±42ng/ml) to vimentin. TG patients showed increased antibody concentration to vimentin compared to the stable KTx (p=0.01). Similarly, IgM antibody concentration were significantly reduced in post-transplant serum samples (p=0.03) compared with pre-transplant serum samples of TG. In contrast the concentration of IgG isotype was markedly increased in post-transplant serum samples than pre-transplant sera of TG (0.04).
Conclusions:Development of antibodies to vimentin was associated with the development of transplant glomerulopathy in KTx recipients. Isotype switch from IgM to IgG following transplantation was significantly associated with TG development.
To cite this abstract in AMA style:Gunasekaran M, Maw T, Santos R, Wellen J, Shenoy S, Mohanakumar T. Isotype Switching of Antibodies to Vimentin Following Transplantation Is Associated With Development of Transplant Glomerulopathy Following Renal Transplantation [abstract]. Am J Transplant. 2015; 15 (suppl 3). https://atcmeetingabstracts.com/abstract/isotype-switching-of-antibodies-to-vimentin-following-transplantation-is-associated-with-development-of-transplant-glomerulopathy-following-renal-transplantation/. Accessed March 23, 2019.
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