Immunohistological study of involucrin expression in Darier's disease skin.
BACKGROUND
Darier's disease (DD) is an autosomal dominant skin disorder characterized by acantholysis and abnormal keratinization. The gene responsible for DD, ATP2A2 encodes for the sarco/endoplasmic reticulum (ER) Ca2+-ATPase isoform 2 protein. Involucrin, considered as a marker of terminal epidermal differentiation, could be altered in some keratinization disorders including DD.


METHODS
An immunohistochemical staining using anti-involucrin antibody was carried out on 16 DD patients epidermis. Involucrin staining was compared with biopsies from cutaneous lesions of three healthy individuals and of patients with Hailey-Hailey disease (five cases) and Mal de Meleda (four cases). A semi-quantitative analysis was performed in order to evaluate involucrin immunostaining on the basis of intensity, extension and epidermal distribution. The involucrin expression was examined afterward with confocal laser scanning microscopy.


RESULTS
In contrast to normal skin, all DD cases showed premature expression of involucrin in the lower epidermal layers in four cases with a strong labeling in both keratinocytes cell membrane and cytoplasm. Other keratinization disorders share premature expression of involucrin but displayed differences in cytoplasm/cell membrane labeling.


CONCLUSIONS
DD skin displayed a constant immunohistochemical involucrin pattern characterized by both premature expression and a particular cytoplasmic/cell membrane localization distribution.
Kassar
Selma
S
Department of Pathology, Institut Pasteur de Tunis, Belvédère, Tunisia.
Charfeddine
Cherine
C
Zribi
Hela
H
Tounsi-Kettiti
Haifa
H
Bchetnia
Mbarka
M
Jerbi
Emna
E
Cassio
Doris
D
Mokni
Mourad
M
Abdelhak
Sonia
S
Ben Osman
Amel
A
Boubaker
Samir
S
D000051:Acantholysis / Q000378:metabolism / Q000473:pathology; D000704:Analysis of Variance; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D007644:Darier Disease / Q000378:metabolism* / Q000473:pathology; D004817:Epidermis / Q000378:metabolism* / Q000473:pathology; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007150:Immunohistochemistry; D007645:Keratoderma, Palmoplantar / Q000378:metabolism / Q000473:pathology; D018613:Microscopy, Confocal; D016506:Pemphigus, Benign Familial / Q000378:metabolism / Q000473:pathology; D011498:Protein Precursors / Q000378:metabolism*
D011498:Protein Precursors; C032253:involucrin