Immunity to herpes simplex virus in children receiving treatment for acute lymphoblastic leukaemia (ALL)

Children receiving anti-leukaemic therapy often become susceptible to severe herpesvirus infection. To investigate specific immunity to herpes simplex virus (HSV) in patients with acute lymphoblastic leukaemia (ALL), in first remission and receiving maintenance chemotherapy, we measured their HSV specific T responder cell frequency (RCF) and their in vitro anti-HSV antibody production. Concurrently, we determined their serum anti-HSV antibody titres and their lymphocyte response to phytohaemagglutinin (PHA). Neither the presence of anti-HSV antibody in serum, nor the HSV-RCF correlated with the in vitro anti-HSV antibody response or the PHA response. This suggests that antigen-specific immune responses in patients being treated for ALL may be impaired independently of mitogen-induced proliferative responses.