The basal cell adhesion molecule (B-CAM) is a 90-kD cell surface glycoprote
in with a characteristic immunoglobulin domain structure. The pattern of B-
CAM expression in cultured cells suggests that the molecule is associated w
ith a substrate-adherent growth pattern in some lineages. We investigated t
he expression of B-CAM in normal and diseased human epidermis by means of i
mmunohistochemistry employing a single batch of high-titer mouse monoclonal
antibody G253. Snap-frozen biopsy material from normal skin (n=8), psolias
is (n=5), contact dermatitis (n=6). basal cell carcinoma (n=5) and fetal sk
in (n=6) was studied. In normal human skin. B-CAM was found in varying degr
ees throughout the epidermis with a preference for suprabasal expression, h
air follicles were regularly of a B-CAM-positive phenotype. There were no q
ualitative differences with regard to the B-CAM expression pattern in norma
l skin ill comparison to psoriasis and contact dermatitis. In contrast, fet
al skin (15th to 18th week of gestation) was characterized by B-CAM-positiv
e cells in the basal layer of the epidermis as well as in the outer root sh
eath of hair follicles. Basal cell carcinomas also regularly expressed high
levels of B-CAM. A strong B-CAM-positive phenotype can be found in the out
er root sheath of air follicles of adult and fetal human skin as well as in
fetal basal kerarinocytes.