Date: Saturday, June 2, 2018
Session Time: 5:30pm-7:30pm
Presentation Time: 5:30pm-7:30pm
Location: Hall 4EF
DSA occurrence after kidney transplant is a main risk factor for humoral rejection and graft loss, however graft outcomes after DSA detection is very heterogeneous. DSAs are mainly IgG, composed of different subclasses whose distribution could have a major impact on their pathogenicity. Impact of DSA subclasses analyzed by cytometry, adapting the Luminex single Ag (SAB) test used routinely, shown that IgG3 detection was associated with a poorer prognosis, however, this result was contrasted. In addition, this test does not analyze IgG subclass distribution.
Material and method:
In our center, DSA were screened by SAB at Month 3, 1 year and every year after transplantation and allograft biopsy was performed in all patients who developed de novo DSA. Sera was systematically collected for DSA IgG subclass analysis. We have developed a test to analyze the repartition of DSA IgG subclasses by mass spectrometry after isolation of DSA on Luminex beads.
Three patients groups were analyzed according to positive antibody mediated rejection (ABMR): patients with DSA without (w/o) ABMR, patients with DSA and sub-clinical ABMR (sABMR) and those with DSA with clinical ABMR.
Between January 2014 and June 2017, 29 patients developed dnDSA after transplantation, 10 without ABMR, 9 with sABMR and 10 with clinical ABMR. For each immunodominant DSA isolated, we had detected the four IgG subclasses : IgG1 represented 61.8%, IgG2 23.4%, IgG3 8.5% and IgG4 6.1% of total DSA respectively. Percentage of IgG3 was 11.8% in ABMR group, significantly higher than in sABMR group (7.4%, p=0.05) and group w/o ABMR (6.2%, p=0.006). High percentage of IgG3 were associated with C4d deposition on biopsy. Mean percentage of IgG3 were 10.7% for patients with C4d score at 2 or 3 compared to 6.9% for patients with C4d score at 0 or 1 (p=0.028).
We demonstrated for the first time by isolating DSA that distribution of DSA IgG subclass impact on ABMR occurrence. High percentage of IgG3 was associated with clinical humoral rejection and complement deposition on kidney biopsy.
CITATION INFORMATION: Pernin V., Bec N., Larroque C., Duperray C., Mourad G., Lequintrec M. Subclass Distribution of DSA Analyzed by Mass Spectrometry Predicts the Risk of Humoral Rejection Am J Transplant. 2017;17 (suppl 3).
To cite this abstract in AMA style:Pernin V, Bec N, Larroque C, Duperray C, Mourad G, Lequintrec M. Subclass Distribution of DSA Analyzed by Mass Spectrometry Predicts the Risk of Humoral Rejection [abstract]. https://atcmeetingabstracts.com/abstract/subclass-distribution-of-dsa-analyzed-by-mass-spectrometry-predicts-the-risk-of-humoral-rejection/. Accessed April 19, 2019.
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