Histological features and immune cell changes in skin lesions of engraftment syndrome of children undergoing hematopoietic stem cell transplantation

Various skin eruptions are encountered during hematopoietic stem cell transplantation (HSCT) of children with hematologic malignancies. Engraftment syndrome (ES) is a disease characterized by fever, weight gain, maculopapular skin rash and noncardiogenic pulmonary edema. ES occurs during neutrophil recovery without identifiable causes of infection. Early detection of ES is critical to reduce mortality and morbidity, but identical morphologic changes found in skin lesions from ES and graft-versushost disease (GVHD) are a challenging problem for histology-based diagnosis. To resolve this issue, immunopathologic changes in skin lesions of ES were studied. Five skin biopsies from patients with symptoms clinically compatible with ES were retrieved and compared to 15 age- and sex-matched cases of acute GVHD with antibodies to CD3, CD4, CD8 and CD1a. Mean numbers of epidermal CD8 ⁺ cells and CD1a ⁺ cells were lower in ES than in GVHD. However, there were no significant differences in mean score of GVHD grade, mean numbers of lymphoid cells, CD3 ⁺ cells, or CD4 ⁺ cells. In the setting of HSCT in children, the dominance of CD4 ⁺ cells and a decreased number of CD1a ⁺ cells in the epidermis are specific features for the skin lesions of ES.