Drugs
can activate different cells of the immune system and initiate
an immune response that can lead to life-threatening diseases collectively
known as severe cutaneous adverse reactions (SCARs). Antibiotics,
anticonvulsants, and antiretrovirals are involved in the development
of SCARs by the activation of αβ naïve T-cells.
However, other subsets of lymphocytes known as nonconventional T-cells
with a limited T-cell receptor repertoire and innate and adaptative
functions also recognize drugs and drug-like molecules, but their
role in the pathogenesis of SCARs has only just begun to be explored.
Despite 30 years of advances in our understanding of the mechanisms
in which drugs interact with T-cells and the pathways for tissue injury
seen during T-cell activation, at present, the development of useful
clinical biomarkers for SCARs or predictive preclinical in
vitro assays that could identify immunogenic moieties during
drug discovery is an unmet goal. Therefore, the present review focuses
on (i) advances in the understanding of the pathogenesis of SCARs
reactions, (ii) a description of the interaction of drugs with conventional
and nonconventional T-cells, and (iii) the current state of soluble
blood circulating biomarker candidates for SCARs.