In vivo dynamics of intraepidermal CD8+ T cells and CD4+ T cells during the evolution of fixed drug eruption.
ABSTRACT Although a severe form of fixed drug eruption (FDE) clinically and histologically mimics toxic epidermal necrolysis (TEN), subsequent evolution of the two conditions is quite different. It remains unknown, however, which factors determine whether these lesions resolve spontaneously or subsequently progress to TEN.
Because epidermal injury in TEN can be locally reproduced in the evolving FDE lesions, we sought to investigate how epidermal damage can be induced in the evolving FDE lesions and how disease progression to TEN can be prevented, by analysing the FDE lesions induced by clinical challenge with the causative drug.
We immunohistochemically investigated in vivo dynamics of T-cell trafficking and activation that occur in the evolving FDE lesions using sequential biopsy specimens obtained at multiple time points from the FDE lesions.
Intraepidermal CD8+ T cells, which are resident in the lesional epidermis as a stable homogeneous population of memory T cells, transiently acquire a natural killer-like phenotype and express cytotoxic granules upon activation. The influx into the epidermis of CD4+ T cells including Foxp3+ regulatory T cells (Tregs) during the evolution serves to ameliorate epidermal damage induced by activation of the intraepidermal CD8+ T cells. Interleukin-15 derived from the lesional epidermis could maintain the survival of the intraepidermal CD8+ T cells even in the absence of antigenic stimulus over a prolonged period of time (> 4 years).
Whether Tregs could migrate to the lesions upon activation of intraepidermal CD8+ T cells would determine whether the inflammation becomes resolved spontaneously or progresses to TEN.
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ABSTRACT: Generalized bullous fixed drug eruption (GBFDE), a particular form of fixed drug eruption (FDE), is characterized by widespread blisters and erosions and can be confused with Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN). We sought to analyze specific features of GBFDE and differentiate it from SJS/TEN. We retrospectively studied patients with GBFDE and SJS/TEN during a period of 10 years. GBFDE was defined as typical FDE lesions with blisters involving at least 10% body surface area on at least 3 of 6 different anatomic sites. Clinical presentations; histopathological features; immunohistochemical patterns of cluster-of-differentiation (CD)3, CD4, CD8, CD56, Fas, Fas ligand, granzyme B, perforin, granulysin, and forkhead box P3 (Foxp3); and serum granulysin levels were compared. Twenty-three cases of GBFDE were collected. Patients with GBFDE had shorter latent periods, less mucosal involvement, more eosinophil infiltration, and dermal melanophages. Lesional infiltrates in GBFDE had more dermal CD4(+) cells including Foxp3(+) regulatory T cells, fewer intraepidermal CD56(+) cells, and fewer intraepidermal granulysin(+) cells. The serum level of granulysin in GBFDE was also significantly lower than in SJS/TEN. The number of cases in this study is small. GBFDE is a distinct disease distinguishable from SJS/TEN by particular features such as granulysin, CD56, and Foxp3 expressions.Journal of the American Academy of Dermatology 01/2014; · 4.91 Impact Factor
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ABSTRACT: A growing number of cells, mediators, and pathways have been implicated in severe drug eruptions. Fifteen years ago, we published landmark studies that sparked the current advances in our understanding of the role of viral reactivations in severe drug eruptions. Viral reactivations then became critically important as diagnostic tools, but how precisely they participated in the pathogenesis remained less well-defined. The question of whether viral reactivations are pathogenic or are instead as epiphenomenon of severe tissue damage has plagued the field of drug allergy for some decades. Recent evidence points to a crucial role for tissue-resident memory T (TRM) cells in immune protection against viral infections. Yet immune protection against viral infections is but one side of a coin, the other side of which comprises effector cells capable of mediating severe immunopathology: Once drug antigen is cross-recognized by these T cells, they could be activated to kill surrounding epidermal cells, resulting in drug-induced tissue damage. Such TRM cells could persistently reside in the skin lesions of fixed drug eruptions (FDE) and are most likely a major cell type responsible for the development of FDE. We also discuss the role of regulatory T (Treg) cells in the setting of drug allergy, in which herpesviruses are reactivated in sequence. Although many details of the complicated interactions among viruses, anti-viral immune responses, TRM cells, and Treg cells remain to be elucidated, we review the current status of this rapidly advancing field.Clinical Reviews in Allergy & Immunology 04/2014; · 5.59 Impact Factor
Article: FRT – Fondation Rene TouraineExperimental Dermatology 10/2014; 23(10). · 3.58 Impact Factor