Cutaneous lymphocyte-associated antigen expression in children with atopicdermatitis and non-atopic healthy children

Cutaneous lymphocyte-associated antigen (CLA) is a cell surface glycoprotei n which has been implicated in the homing of lymphocytes to cutaneous sites , It is postulated to play an important role in T-cell migration to skin in atopic dermatitis; however, the expression of CLA in both normal children and children with atopic dermatitis has not been extensively studied. If CL A expression on T cells were important in the traffic of lymphocytes to ato pic dermatitis skin lesions, it might be expected that the proportion of CL A(+) T cells in unstimulated peripheral blood from children with atopic der matitis would be elevated. We have examined the proportion of CLA(+) T cell s in children with atopic dermatitis and non-atopic age-matched controls. T he proportion of CLA(+) T cells in non-atopic children was highly associate d with and increased with increasing age (r = 0,88, p < 0.001). There was n o difference between the proportion of T cells expressing CLA in the unstim ulated peripheral blood mononuclear cells from children with severe (p = 0. 18) or with mild/moderate (p = 0.3) atopic dermatitis and age-matched non-a topic controls. Despite this, children with atopic dermatitis did show evid ence of perturbation of CLA expression, as unlike the non-atopic children t he proportion of CLA(+) T cells in the atopic children did not correlate wi th age. These findings suggest that while CLA expression may play a role in atopic dermatitis, other as yet undefined surface markers are likely to pr incipally determine the migration of T cells to skin in atopic dermatitis.