ALTERED EXPRESSION OF A NEW ANTIGEN OF THE DERMAL-EPIDERMAL JUNCTION (NU-T2 DEJ AG) IN JUNCTIONAL EPIDERMOLYSIS-BULLOSA

NU-T2 antigen (Ag) is a new and recently described antigen of the derm al-epidermal junction, recognized by an anti-CD1b monoclonal antibody denominated NU-T2. We studied NU-T2 Ag expression injunctional epiderm olysis bullosa (13 patients) and in other forms of hereditary epidermo lysis bullosa (23 patients), comparing the results with nicein express ion. In junctional epidermolysis bullosa gravis type no differences we re found between the expression of NU-T2 and nicein, both being negati ve in bullous as well as in non-bullous skin. Interestingly, in mitis type junctional epidermolysis bullosa, NU-T2 Ag was found to be absent or reduced in five of six patients both in lesional and in uncleaved skin. When compared with nicein expression, clearcut differences were found, further suggesting that these two antigens are different. These data confirm that NU-T2 Ag is a novel epitope of the dermal-epidermal junction, probably relevant in dermal-epidermal cohesion, and it coul d be responsible, together with nicein, 19-DEJ-1 and other adhesion mo lecules, for the different subtypes of junctional epidermolysis bullos a. Finally, NU-T2 monoclonal antibody is a new relevant tool for the d iagnosis, classification, and prenatal diagnosis of junctional epiderm olysis bullosa.