Increased CD8+CD27+perforin+ T cells and decreased CD8+CD70+ T cells may be immune biomarkers for aplastic anemia severity.

OBJECTIVES: Aplastic anemia (AA) is T cell immune-mediated autoimmune disease. Aberrant T cell activation involves an imbalance in T cell homeostasis in AA. However, whether the T cell activation molecule CD27 and its ligand CD70 participate in the immune pathogenesis of AA remains ill defined. METHODS: The frequencies of CD27/CD70 and perforin/granzyme B in different T cell subsets were detected in AA patients and healthy individuals by flow cytometry. RESULTS: We first time demonstrate a significantly elevated proportion of CD27+ and significantly decreased CD70+ T cells from AA. Changed frequency of CD27+ and CD70+ in different T cell subsets appeared to be associated with AA severity. In very severe aplastic anemia (VSAA) and severe aplastic anemia (SAA), increased CD8+CD27+ T cells present with a cytotoxic effector phenotype by elevating perforin proportion. CONCLUSIONS: Elevated proportion of CD27 in T cells may contribute to distinct immune pathogenesis for different severities of AA. The CD8+CD27+perforin+ T cells combined with CD8+CD70+ T cells may serve as an immune biomarker for AA severity estimation.