CD8A and toxic epidermal necrolysis: Late reactions may also be related to models involving non-covalent binding, such as the pharmacological interaction model or modification in specificity of the peptide bound to human leukocyte antigens (HLA).(32) These new models are often associated with severe skin reactions with systemic involvement, including SJS, TEN, DRESS, and AGEP.(14) Drug reaction with eosinophilia and systemic symptoms is associated with infiltration of the skin and internal organs by TCD4+, CD8+, and eosinophils.