Use of DPB1 T‐cell epitope algorithm among italian transplant centers: A survey on behalf of Associazione Italiana di Immunogenetica e Biologia dei Trapianti

Abstract

The HLA‐DPB1 locus has been demonstrated to have a significant role on patients' outcome after allogeneic HSCT, and the so‐called T‐cell epitope (TCE) algorithm has been incorporated in international guidelines for the selection of unrelated donors. The purpose of the present study is to measure, through a national survey conducted on behalf of the Associazione Italiana di Immunogenetica e Biologia dei Trapianti (AIBT), the extent of awareness and use of HLA‐DPB1 TCE‐based algorithms during the donor search. 89% of the HLA laboratories answered to a short questionnaire and the results showed a progressive increase of the laboratories typing DPB1 in patients and their potential donors during the search (from 44% to 79% during the 2010–2019 period) as well as the application of a TCE‐based algorithm for the donor choice whenever possible (from 24% to 65% during the same period). The DP‐permissiveness status is detailed in the official HLA typing report by 12%, 32% and 50% of laboratories in 2010, 2015 and 2019, respectively. The present data indicate an encouraging raise in the awareness of the HLA‐DPB1 role in unrelated donor selection; noteworthy, mentioning the TCE‐based permissiveness status in the HLA typing report of each potential unrelated donor represents a notable mean to raise awareness among transplant physicians and to support them in their task of choosing the best donor. Nonetheless, despite the compelling evidence of the predictive ability of TCE‐based algorithms, further efforts are still needed to extend its application to all transplant centers in Italy.

Human Leucocyte Antigen System and Selection of Unrelated Hematopoietic Stem Cell Donors: Impact of Patient–Donor (Mis)matching and New Challenges with the Current Technologies

“…Consistent evidence, accumulated over years and by different groups, supports the inclusion of DPB1 in the selection process [ 45 ], taking into account the permissiveness of mismatches at DPB1 according to the T-cell epitope or the expression model [ 46 ]. The last CIBMTR guidelines [ 19 ] include the algorithm based on the T-cell epitope model in order to avoid a non-permissive unrelated donor, currently avoidable in at least 71% of cases [ 47 ], although a higher fraction is expected whenever HLA-DPB1 is typed upfront for all potential unrelated donors, as it is the case with NGS typing.…”

Allojeneik Hematopoietik Kök Hücre Donörü Seçiminde Dpb1 T-Hücre Epitop Algoritmaları

“…Bu karşılaştırmada hasta ve donörün HLA-DPB1 allellerinin ait olduğu TCE grupları ve birbirlerine karşı immünijenite durumları belirlenir. (Fleischhauer, 2012;Crocchiolo, 2021;Kantarcıoglu, 2017).…”