BK virus immunity in patients undergoing hematopoietic stem cell transplant.

• Main Author: Teo, Ai Ling.
• Other Authors: School of Biological Sciences
• Format: Final Year Project
• Language: English
• Published: 2011
• Subjects: DRNTU::Science::Biological sciences
• Online Access: http://hdl.handle.net/10356/44855
• Institution: Nanyang Technological University

Hematopoietic stem cell transplant (HSCT) is an important modality of treatment for hematological diseases and cancers. Latent BK virus (BKV) infection is found in more than 90% of the world’s population. A challenging complication associated with BKV reactivation in HSCT patients is hemorrhagic cystitis (HC). There is currently little data about the reconstitution of BKV-specific immunity after HSCT and its relationship to HC. Peripheral blood mononuclear cells (PBMCs) were stimulated with BKV antigens large T and VP1 and the number of BKV-specific T cells were analysed by flow cytometry. Higher levels of CD4+IL-17+ (p<0.01) and CD8+IL-17+ (p=0.05) BKV-specific cells were observed in post engraftment HSCT patients that developed HC compared to those that did not. Furthermore, peak levels of these BKV-specific T cells were observed just before or after the onset of HC and this coincided with high levels of BKV detected in the urine. These preliminary results suggest that BK associated HC is an immunopathology caused by IL-17 secreting BK-specific T cells. Our study will need to be confirmed in a larger cohort of patients.