ABSTRACT
Children in remission from acute lymphoblastic leukemia [ALL] have a high prevalence of immune system defects; one of them is the decrease of vaccine-induced antibody seropositivity rates. This antibody deficiency may place children with ALL at risk for the development of vaccine- preventable diseases, even after completion of chemotherapy, and they could function as a reservoir for additional spread of these diseases in the population. The aim of the present study was the assessment of the levels of vaccine- induced antibodies against measles and rubella viruses n ALL children following chemotherapy. Antibody levels against measles and rubella vaccine viruses were evaluated by ELISA technique in 96 children with ALL after completion of chemotherapy, in addition to 30 healthy children [non cancer controls of matched age and sex]. All healthy children were seropositive for measles and rubella antibodies. On the other hand, out of 96 children who received chemotherapy, only 19 [19.8%] were seropositive for measles antibodies, while 70 [72.9%] were seropositive for rubella antibodies. Most of measles seropositive cases [57.9%] had low levels of measles antibodies while among control group most children [56.7%] had high levels of measles antibodies, Similarly among children who received chemotherapy, most of the seropositive cases [45.7%] had low levels of rubella antibodies, while among control group, most of children [36.6%] had high levels of rubella antibodies. Seropositivity rate of measles was found to be related to the age at diagnosis and disease duration, while that of rubella was found to be related to the disease duration only. Most of children who have been treated with chemotherapy for ALL had lost measles antibodies and to less extent rubella antibodies. Among seropositive cases, levels of measles and rubella antibodies are low following treatment with chemotherapy compared to levels among normal controls. Therefore, revaccination of children with ALL following completion of chemotherapeutic treatment against measles and rubella is recommended