Contributions
Abstract: EP821
Type: E-Poster Presentation
Session title: Infections in hematology (incl. supportive care/therapy)
Background
Children treated for acute lymphoblastic leukemia are at increased risk of severe infection with varicella zoster virus (VZV) that causes significant morbidity and mortality. Previous studies have reported the risk of disseminated infection in these patients, in the absence of prophylaxis to be approximately 50%. Hence the importance of identifying patients who have unprotective serum levels of Varicella antibodies as candidates for vaccine after completing their chemotherapy protocol.
Aims
Determine the level of varicella IgG antibody in children treated for acute lymphoblastic leukemia and assess the need for their vaccination after end of therapy.
Methods
A prospective study conducted on 2 groups, each consisting of 44 children treated for acute leukemia at the Pediatric Hematology and Oncology Unit of Alexandria University Children’s Hospital. Children in group 1 were on maintenance chemotherapy and in remission ≥ 1 year, while group 2 have completed chemotherapy ≥ 6 months. The level of varicella IgG antibody was assessed by VZV IgG ELISA, it was considered positive (protective) above 0.77 u/ml.
Results
In group 1 (patients on maintenance chemotherapy) males were slightly more represented than females (61.4% vs 38.6%). The median age at the time of the study was 6 years. Most of the studied patients were B-ALL (86.4%) while only (13.6%) were T-ALL. Only 5 (11.4%) were varicella IgG positive, while the remaining 39 (88.6%) were negative with a median IgG titer of 0.07 u/ml. In group 2 (off-therapy patients), 56.8% of patients were males versus 43.2% females. The median age at the time of the study was 10 years, and the median duration since completion of chemotherapy was 24.5 months. Most of the studied patients were B-ALL (93.2%) while only 6.8% were T-ALL. Only 9 (20.5%) were Varicella IgG positive while the remaining 35 (79.5%) were negative with a median IgG titer of 0.12u/ml. In both groups, age of diagnosis, the gender, duration of chemotherapy, type of ALL, and intensity of the treatment protocol did not significantly affect the varicella antibody titer.
Conclusion
Varicella zoster vaccine should be given to all leukemic patients after completion of chemotherapy as the varicella IgG level was unprotective in the majority of children.
Keyword(s): Children, Immunity, Immunoglobulin, Vaccination
Abstract: EP821
Type: E-Poster Presentation
Session title: Infections in hematology (incl. supportive care/therapy)
Background
Children treated for acute lymphoblastic leukemia are at increased risk of severe infection with varicella zoster virus (VZV) that causes significant morbidity and mortality. Previous studies have reported the risk of disseminated infection in these patients, in the absence of prophylaxis to be approximately 50%. Hence the importance of identifying patients who have unprotective serum levels of Varicella antibodies as candidates for vaccine after completing their chemotherapy protocol.
Aims
Determine the level of varicella IgG antibody in children treated for acute lymphoblastic leukemia and assess the need for their vaccination after end of therapy.
Methods
A prospective study conducted on 2 groups, each consisting of 44 children treated for acute leukemia at the Pediatric Hematology and Oncology Unit of Alexandria University Children’s Hospital. Children in group 1 were on maintenance chemotherapy and in remission ≥ 1 year, while group 2 have completed chemotherapy ≥ 6 months. The level of varicella IgG antibody was assessed by VZV IgG ELISA, it was considered positive (protective) above 0.77 u/ml.
Results
In group 1 (patients on maintenance chemotherapy) males were slightly more represented than females (61.4% vs 38.6%). The median age at the time of the study was 6 years. Most of the studied patients were B-ALL (86.4%) while only (13.6%) were T-ALL. Only 5 (11.4%) were varicella IgG positive, while the remaining 39 (88.6%) were negative with a median IgG titer of 0.07 u/ml. In group 2 (off-therapy patients), 56.8% of patients were males versus 43.2% females. The median age at the time of the study was 10 years, and the median duration since completion of chemotherapy was 24.5 months. Most of the studied patients were B-ALL (93.2%) while only 6.8% were T-ALL. Only 9 (20.5%) were Varicella IgG positive while the remaining 35 (79.5%) were negative with a median IgG titer of 0.12u/ml. In both groups, age of diagnosis, the gender, duration of chemotherapy, type of ALL, and intensity of the treatment protocol did not significantly affect the varicella antibody titer.
Conclusion
Varicella zoster vaccine should be given to all leukemic patients after completion of chemotherapy as the varicella IgG level was unprotective in the majority of children.
Keyword(s): Children, Immunity, Immunoglobulin, Vaccination