Usefulness of myeloid dendritic cells in cellular in vitro assays for evaluating immediate hypersensitivity reactions to betalactams.

Abstract

Introduction Dendritic cells (DCs) are the most potent antigen presenting cells (APCs) with an important role detecting, processing, and presenting antigens to T cells. The analysis of maturation after in vitro stimulation with the culprit drug, and their ability to trigger the proliferation of specific T cell populations in patients with immediate drug hypersensitivity reactions (IDHRs) could serve to prove the sensitization to a drug. Most approaches used monocyte-derived DCs (moDCs), although their sensitivity is not optimal. The different nature of moDCs and myeloid DCs (mDCs), main DC population involved during the in vivo development of IDHRs, could influence the sensitivity of these in vitro tests. Therefore, we evaluated the effect of two betalactams (BLs), amoxicillin (AX) and clavulanic acid (CLV) in moDCs and mDCs from selective-allergic patients (AP) to each BL, as well as to assess their capacity to stimulate different T cell populations. Methods mDCs and moDCs were obtained from 14 AX-AP, 14 CLV-AP and 10 Healthy controls (HC). After stimulating with the culprit BL, maturation and their capacity to stimulate different T cell populations was assessed by flow cytometry. Results Higher maturation was observed in both AX- and CLV-AP compared with HC when using BL-stimulated-mDCs, whereas with moDCs, only higher was observed in AX-AP, but not in CLV-AP. The % of positive maturation cases was higher with mDCs than moDCs, with higher % with AX compared to CLV. The most relevant T cell population proliferative response was obtained in CD4+Th2 cells, reaching to 67% of positivity when using mDCs, followed by 50% with the traditional LTT, and only of 22% with moDCs from AX-AP. The specificity was higher than 80% in all cases. Conclusions mDCs from selective AP efficiently recognised the culprit drug and triggered the proliferation of T-cells, mainly those with a Th2 cytokine pattern, although these responses depended on the drug.