The effect of methotrexate on the expression of cell adhesion molecules and activation molecule CD69 in psoriasis.
BACKGROUND
The mechanism of the action of methotrexate (MTX) in the treatment of psoriasis has not been completely elucidated.


OBJECTIVE
To assess the effect of MTX on the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, activation molecule CD69 and T-cell phenotype in skin specimens from patients with psoriasis.


METHODS
We performed an immunohistochemical analysis of the expression of T-cell phenotype and cell adhesion/activation molecules in skin biopsies from patients with psoriasis treated with a fixed dose of MTX (12.5 mg/week). To determine data on the epidermal/dermal T-cell infiltration we carried out a manual quantification.


RESULTS
Skin samples prior to therapy showed a moderate to severe inflammatory infiltrate, mainly due to T lymphocytes with a helper/inducer (CD4) phenotype. Most of these cells also expressed ICAM-1 and VCAM-1. Blood vessels showed expression of E-selectin and VCAM-1, and keratinocytes were positive for ICAM-1 staining. The cell infiltrate was reduced after therapy, as well as the expression of cell adhesion molecules. However, we also noted the persistence of the T lymphocyte phenotype CD8(+), expressing the CD69 activation molecule, after the MTX treatment.


CONCLUSIONS
MTX downregulates the expression of some adhesion molecules, a phenomenon that may contribute to its anti-inflammatory therapeutic effect in psoriasis. The infiltrating T cells post-treatment have an activated cytotoxic phenotype, which may suggest a pathogenic role in the continuation and/or recurrence of psoriasis.
Torres-Alvarez
B
B
Department of Dermatology, Hospital Central, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, Av. Venustiano Carranza 2395, CP 78240 San Luis Potosí, Mexico. torresmab@yahoo.com.mx
Castanedo-Cazares
J P
JP
Fuentes-Ahumada
C
C
Moncada
B
B
D000328:Adult; D015703:Antigens, CD / Q000096:biosynthesis*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000096:biosynthesis*; D001706:Biopsy; D015815:Cell Adhesion Molecules / Q000096:biosynthesis*; D003879:Dermatologic Agents / Q000494:pharmacology*; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D037181:Lectins, C-Type; D008297:Male; D008727:Methotrexate / Q000494:pharmacology*; D008875:Middle Aged; D010641:Phenotype; D011565:Psoriasis / Q000188:drug therapy* / Q000378:metabolism*; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D015815:Cell Adhesion Molecules; D003879:Dermatologic Agents; D037181:Lectins, C-Type; D008727:Methotrexate; D000099192:CD69 Antigens