Analysis of differential gene expression of PBMC for the in vitro detection of drug sensitization

The detection of drug-specific activation of T cells in the lymphocyte transformation test (LTT) is mainly based on cell proliferation or cytokine secretion. However, the LTT presents with a varying sensitivity and specificity. The aim of our study was to analyse the genome wide gene expression of PBMC to identify drug allergy-specific gene regulation patterns. Additionally, gene expression differences related to the allergy-inducing drug or the type of allergy (immediate/delayed) were investigated.

Blood samples from 40 patients with allergy to different drugs and from 40 non-drug-allergic controls were recruited. PBMC were isolated and stimulated with the culprit drug ("LTT-platform"). Transcriptome analyses of PBMC were conducted after 3.5 days. The concentration of IFN-γ and IL-5 in the culture supernatants was measured by ELISA after 6 days.

The transcriptome analyses revealed an allergy type and drug-specific gene regulation in PBMC from patients. Importantly, in the corresponding control groups these genes were barely or even opposingly regulated. It was also shown that in particular cefuroxime exerted a strong effect on the gene regulation in PBMC. Quantitative RT-PCR of selected genes identified by the transcriptome analyses revealed that CCL17, CISH and CD25 were specifically upregulated in patients. Notably, a strong upregulation of CCL17, CISH or CD25 did not necessarily correlate with the ELISA outcome of the patients and controls.

Our results could be helpful for the identification of one or a panel of regulated genes considering patient specific parameters like the type of the allergy-inducing drug.