Drug Specific Cytotoxic T-Cells in the Skin Lesions of a Patient with Toxic Epidermal Necrolysis

Abstract

Toxic epidermal necrolysis is an extremely severe drug reaction, manifesting itself by widespread apoptosis of keratinocytes, generally considered to result from Fas/CD95-FasLigand interaction, but of unknown primary mechanism. We looked at the role of cells present in the skin blisters as probable effectors of this immune reaction. In a patient suffering from cotrimoxazole-induced toxic epidermal necrolysis, blister fluid cells were phenotyped by FACS and tested without prior restimulation for cytotoxicity on autologous and allogeneic cells in the presence of the drug. Blister fluid lymphocytes were predominantly CD8+, DR+, CLA+, CD56+ T lymphocytes, perforin positive and expressing preferentially two Vbeta chains of the T cell receptor repertoire. These lymphocytes were cytotoxic only in the presence of the drug towards autologous EBV transformed lymphocytes and towards allogeneic cells sharing HLA-Cw4. Cytotoxicity occurred in the presence of either cotrimoxazole, sulfamethoxazole, or the nitroso metabolite of sulfamethoxazole, but not with the hydroxylamine metabolite of sulfamethoxazole. The lysis was blocked by an anti-MHC class I monoclonal antibody. It was abolished by EGTA and CMA, but neither by anti-fas, brefeldin A, nor by anti-TRAIL receptor monoclonal antibodies, strongly suggesting perforin/granzyme-mediated cytotoxicity, without implication of Fas or TRAIL at this stage. This is direct evidence that T lymphocytes present within the lesions of toxic epidermal necrolysis may exhibit, without any re-stimulation, a drug-specific cytotoxicity against autologous cells. Harboring the markers of classical CTL and MHC class I restriction these lymphocytes reacted against the parent drug and one of its reactive metabolites. These results challenge several current concepts and could support new therapeutic approaches.

Bioactivation, protein haptenation, and toxicity of sulfamethoxazole and dapsone in normal human dermal fibroblasts☆

“…While much remains to be learned about the mechanisms of the varied reactions that can occur in the skin after systemic drug administration, many of these reactions are consistent with delayed-type hypersensitivity -implicating the involvement of the immune system in their provocation (Cribb et al, 1996a;Svensson et al, 2001;Pichler et al, 2002;Pichler, 2003). The observation that patients with a history of such reactions may possess drug-reactive T-cells suggests that these responses are T-cell mediated (Mauri-Hellweg et al, 1995;Schnyder et al, 2000;Nassif et al, 2002). As drugs noted to provoke these reactions are small molecules, it has been proposed that bioactivation of drugs to reactive metabolites is an essential prerequisite to the initiation of CDRs (Park and Kitteringham, 1990;Park et al, 1998;Park et al, 2000;Svensson, 2003).…”

An update on diagnosis and treatment of toxic epidermal necrolysis / Novine u dijagnostici i lečenju toksične epidermalne nekrolize

“…The existence of drug-specific cytotoxic CD8+ lymphocytes was reported in two studies (13,14). Presence of CD8+ T-lymphocytes expressing cutaneous lymphocyte antigen (CLA), responsible for skin homing, is already evident in the early stages of TEN (13,14). It has been demonstrated that cytotoxicity of T-cells in TEN is mediated by TEN: sulfonamides, allopurinol, carbamazepine, phenobarbitone, phenytoin and oxycam group of nonsteroidal anti-inflammatory drugs, as well as new drugs nevirapine and lamotrigine (8).…”

“…The pathogenic substrate of toxic epidermal necrolysis is a massive, drug-induced apoptosis of keratinocytes, activated by drug-specific CD8+ cytotoxic lymphocytes (not by its metabolites, as previously assumed). The existence of drug-specific cytotoxic CD8+ lymphocytes was reported in two studies (13,14). Presence of CD8+ T-lymphocytes expressing cutaneous lymphocyte antigen (CLA), responsible for skin homing, is already evident in the early stages of TEN (13,14).…”

Update on Advances in Research on Idiosyncratic Drug-Induced Liver Injury

“…This concept, referred to as the "pharmacological interaction of drugs with immune receptors (p-i concept), " states that drugs by themselves act as antigens interacting in a reversible fashion with immunological receptors. 49 By characterizing T-cell clones from patients with immunological drug reactions, the pharmacophore of several drugs, including sulfamethoxazole, 30,34,50 carbamazepine, 51,52 abacavir, 53 and penicillin, 54 have been shown to interact with MHC molecules directly and provide a sufficiently strong signal to stimulate T cells.…”