Graft versus host reaction. An ultrastructural study.

Graft versus host reaction (GvH) following leukocytic transfusions occurred in a 34-year-old man with a generalized lymphosarcoma. Histologic and ultrastructural studies were performed, with special reference to dyskeratotic cells scattered in the epidermis. These cells are usually considered to be a constant and important feature of GvH reaction. Dense aggregation of tonofilaments, including cytoplasmic organelles and loss of desmosomes, were seen in dyskeratotic cells. Several intracellular desmosomes with tonofilaments bound to their attachment plaque were observed. Some of these cells were able to reach the horny layer; some others were phagocytosed by neighboring keratinocytes. These cells could be the result of a toxic damage to the epidermis, provoked by the immunologic phenomenon implicated in GvH reaction. Later in the clinical course, bullae formations occurred, showing some features of toxic epidermal necrolysis (TEN), as well as features of GvH reaction.