Efficacy of ultraviolet A1 phototherapy on the expression of bcl-2 in atopic dermatitis and cutaneous T-cell lymphoma in vivo: a comparison study.
OBJECTIVE
Atopic dermatitis (AD) is characterized immunohistochemically by a high number of skin infiltrating T-helper cells (CD4 +). In most cases cutaneous T-cell lymphoma (CTCL) is characterized by a malignant proliferation of CD4+ T-helper lymphocytes. The purpose of our study was to evaluate the extent of anti-apoptotic effects in patients suffering from AD or CTCL, respectively, which may contribute to the prolonged inflammation. Furthermore, we investigated whether medium-dose ultraviolet A1 (UVA1) phototherapy is able to modulate the expression of bcl-2 within the dermal inflammatory infiltrate.


METHODS
In order to enumerate bcl-2+ cells pre- and post-therapeutic punch skin biopsies of ten patients with AD and five patients with CTCL were stained immunohistochemically for features of apoptosis using a monoclonal antibody detecting bcl-2.


RESULTS
Both AD and CTCL sections revealed a high percentage of bcl-2+ cells within the dermal perivascular infiltrate before therapy. After the successful treatment using medium-dose UVA1 phototherapy this percentage could be decreased significantly.


CONCLUSIONS
Both T-cell-derived skin diseases exhibit an increased pre-therapeutic number of bcl-2+ cells. After medium-dose UVA1 phototherapy the substantial improvement of the skin condition was linked to a significant decrease of the dermal bcl-2+ cell count. Moreover, we could demonstrate a remarkable correlation referring to the decrease and staining pattern of bcl-2 between these two groups as well as within each group. Because the bcl-2 protein is known to act as an apoptosis inhibitor, its pre-therapeutic increase may provide the persistent cutaneous inflammatory reaction in T-cell-derived skin diseases. Additionally, the post-therapeutic reduction of bcl-2+ cells might represent a key mechanism of medium-dose UVA1 phototherapy.
Breuckmann
F
F
Department of Dermatology, Clinical and Experimental Photodermatology, Ruhr-University Bochum, Gudrunstrasse 56, D-44791 Bochum, Germany. Frank.Breuckmann@ruhr-uni-bochum.de
von Kobyletzki
G
G
Avermaete
A
A
Kreuter
A
A
Altmeyer
P
P
D017209:Apoptosis; D001706:Biopsy; D018791:CD4 Lymphocyte Count; D003876:Dermatitis, Atopic / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D006801:Humans; D016014:Linear Models; D016410:Lymphoma, T-Cell, Cutaneous / Q000378:metabolism* / Q000473:pathology / Q000532:radiotherapy*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*; D012867:Skin / Q000378:metabolism / Q000528:radiation effects; D016896:Treatment Outcome; D014467:Ultraviolet Therapy
D019253:Proto-Oncogene Proteins c-bcl-2