CD8+ Lymphocytes in the Blister Fluid of Severe Acute Cutaneous Graft-versus-Host Disease: Further Similarities with Toxic Epidermal Necrolysis

Abstract
Background: Graft-versus-host disease (GvHD) remains the major toxicity of allogeneic bone marrow transplantation (BMT). In the acute form of the disease, the differential diagnosis includes viral rash and drug eruptions. Methods: We report two patients with chronic myeloid leukemia submitted to allogeneic BMT who developed a severe form of acute cutaneous GvHD, with clinical and histological pictures mimicking toxic epidermal necrolysis (TEN). Results: We found a predominance of peripheral CD8+ T lymphocytes and, at the same time, studying the cellular profile of the blister fluid, just in the beginning of blister eruption, we also found a high proportion of CD8+ T lymphocytes, mainly CD8+CD57–. Conclusion: These data are in agreement with previous reports of the presence of CD8+ T cells in the blister fluid of patients with TEN, further emphasizing similar immunoinflammatory pathways in both diseases.