O. Bock et al., Expression of dipeptidyl-peptidase IV (CD26) on CD8(+) T cells is significantly decreased in patients with psoriasis vulgaris and atopic dermatitis, EXP DERMATO, 10(6), 2001, pp. 414-419
T cells play a major role in inflammatory skin disorders such as psoriasis
vulgaris and atopic dermatitis. They are both active on the level of cell-t
o-cell interaction and by the secretion of pro-inflammatory mediators. CD26
is a lymphocyte membrane-associated dipeptidyl peptidase IV (DPP IV), whic
h is able to inactivate chemokines such as RANTES or eotaxin by cleaving di
peptides from the NH2-terminus of proteins. We investigated the expression
of CD26 on CD4(+) and CD8(+) peripheral blood T cells in patients with psor
iasis and atopic dermatitis. In addition PASI and SCORAD as a measure of di
sease severity were determined in each patient at the time of blood drawing
. Thirty patients with psoriasis, 15 with atopic dermatitis and 17 age- and
sex-matched healthy persons were investigated by two-colour flow cytometry
using epitope-specific monoclonal antibodies. Our results revealed, that t
here is a significant decrease (P <0.05) of CD26 expression on CD8(+) T cel
ls in both psoriasis (7.7%+/-3.3, mean and SD, n=30) and atopic dermatitis
patients (7.9%+/-3.7, mean and SD, n=15) compared to the control population
(11.58%+/-5.0, mean and SD, n=17). However, there was no correlation to di
sease severity as determined by PASI and SCORAD, respectively. Since CD26 c
an be regarded as an anti-inflammatory principle the decreased expression i
n psoriasis and atopic dermatitis patients may lead to a dysbalance in favo
ur of pro-inflammatory mediators in both clinical conditions.