Possible involvement of gelatinase A (MMP2) and gelatinase B (MMP9) in toxic epidermal necrolysis or Stevens-Johnson syndrome.

Toxic epidermal necrolysis (TEN) and Stevens-Johnson syndrome (SJS) are considered to be drug-induced diseases, and are characterized by extensive mucocutaneous disorder and epidermal necrosis which result in the detachment of the epidermis. Inactive and active forms of metalloproteinases (MMP2 and MMP9) secreted by skin explants maintained in organ culture for 72 h and in blister fluid from two TEN and three SJS patients were investigated. Interestingly, lesional skin from both the TEN and the SJS patients cultured for 3 days in conditioned medium showed high levels of both 72 kDa progelatinase A and 66 kDa activated gelatinase A, and the 66 kDa activated form was not observed in cultures of skin from control individuals. Furthermore, indirect immunodetection showed the presence of MMP2 and MMP9 in TEN and SJS patients' skin. Increased gelatinase activity in the culture medium of TEN and SJS skin maintained in organ culture and in blister fluid indicates that these gelatinases may be responsible for the detachment of the epidermis in these drug-induced necrolyses.