Peripheral T Lymphocyte Responses in Idiopathic Acquired Aplastic Anemia Patients Treated with Immunosuppressive Therapy

Abstract

Introduction: Idiopathic acquired aplastic anemia is an immune-mediated disorder that manifests as pancytopenia. Raised CD4+ and CD8+ T cell counts and altered ratios play an important role in its pathogenesis. Hematopoietic stem cell transplant is the treatment of choice but not readily available or expensive. In developing countries, the majority of the patients are treated with immunosuppressive drugs. In this study, we aimed to evaluate the effect of immunosuppressive drugs on the absolute CD4+ and CD8+ T cell counts and their ratios. Methodology:In this study, 60 patients and 35 healthy controls were included. CD4+ and CD8+ T cell counts were measured using flow cytometry and Ham’s test for Paroxysmal Nocturnal Haemoglobinuria exclusion. Cyclosporine levels of patients receiving the drug were also performed. Results: A high frequency of acquired aplastic anemia in patients of younger age groups with a slight male preponderance was observed. CD4+ and CD8+ cell counts were lower in younger patients while no significant difference was seen in adult patients.  Patients receiving immunosuppressive drugs had a trend toward reduction in raised cell counts particularly in CD4+ T cells. This effect was more pronounced in patients receiving the immunosuppressive drug for more than 6 months. Conclusion: Immunosuppressive drugs play a key role in restoring immune imbalance by decreasing CD4+, CD8+ T cell counts and their ratios, especially in young patients.