Cutaneous T-cell recruitment in toxic epidermal necrolysis. Further evidence of CD8+ lymphocyte involvement.

BACKGROUND: Toxic epidermal necrolysis (TEN) is a life-threatening disease with severe mucocutaneous shedding. Although it is widely accepted that immune mechanisms are at play, the pathophysiology of TEN is still unknown. We studied the blister fluid inflammatory cells in three drug-related cases to further define the suspected T-cell involvement in TEN. OBSERVATIONS: A peripheral blood lymphopenia, especially of CD4+ T lymphocytes, was associated with a high lymphocytic cellularity of the blister fluid. In two cases, immunophenotyping of blister fluid lymphocytes showed a predominance of the CD8 phenotype. Furthermore, using two-color flow cytometry in one patient, we could show the predominance of CD8+ CD29+ lymphocytes and CD45RA- negative cells.
CONCLUSIONS: Our findings point to a cutaneous recruitment of antigen-primed and cytotoxic T cells in TEN, further supporting the involvement of CD8+ lymphocytes in TEN pathogenesis and its immune mediation.