HEPATITIS B IMMUNE STATUS IN CHILDREN TREATED FOR ACUTE LYMPHOBLASTIC LEUKEMIA
(Abstract release date: 05/19/16)
EHA Library. El Chazli Y. 06/09/16; 132729; E1180
Dr. Yasmine El Chazli
Contributions
Contributions
Abstract
Abstract: E1180
Type: Eposter Presentation
Background
Hepatitis B virus (HBV) infection occurs worldwide, with the highest HBsAg carrier rates found in developing countries, where infection is expected to occur in infancy and childhood. Immunization with hepatitis B vaccine is the most effective way of preventing HBV infection and its consequences, especially in endemic areas. Hepatitis B vaccines are highly immunogenic, inducing a protective anti-HBs antibody titer (≥10 mIU/mL), in more than 95% of healthy children and young adult. Partial or complete loss of protective antibody titers against vaccine preventable diseases makes leukemic children more susceptible to infections. Hemato-oncological patients are considered at risk for either acute acquired HBV infection or HBV reactivation.
Aims
evaluate the immune status to HB vaccine in children treated for acute lymphoblastic leukemia (ALL) after completion of chemotherapy and determine factors affecting anti-HBs titer in those children.
Methods
We evaluated HBV immune status among 76 children who have been treated for ALL, 43 males and 33 females, their age ranged from 4.9 to 16.3 years with a mean of 11.19 years. They were consecutively recruited from the hematology oncology clinic at Alexandria University Children’s Hospital. One hundred healthy children were also included as controls, 51 males and 49 females, age ranged from two to 12 years with a mean of 7 years. All have been previously vaccinated with 3 doses of hepatitis B vaccine at 2, 4 and 6 months of age. Anti-HBs titer was assessed in all leukemic children and controls by ELISA, and concentrations <10.0 mIU/mL were considered negative for anti-HBs (non-immune).
Results
Significantly more leukemic children were non-immune (51.3%) compared to only (15%) in the control group, (p<.0001). Moreover, mean anti-HBs titer in normal children was significantly higher than in leukemic children, (61.57 vs 42.79 mIU/mL, p=.038). When comparing immune and non-immune leukemic children according to age at diagnosis of leukemia, it was significantly higher in non-immune than in immune ones, (6±2.9 vs 4.6±1.9 respectively, p=.017). Using logistic regression analysis, both previous chemotherapy and age were identified as independent variables affecting immunity to HB vaccine, (p=.032, p=.001 respectively). An equation resulted from this analysis to predict the probability of non-immune status: Y=-3.589+[0.928×disease status]+[0.243×age (years)], where disease status is entered as “0” if normal child and as “1” if child has been previously treated for leukemia. The diagnostic performance of the new equation using Receiver Operating Characteristic (ROC) curve analysis was fair to good tool in discrimination between immune and non-immune children, (AUC=0.782, 95% CI 0.713-0.851, p<.0001). Children with value of ≤0.286 will be considered immune with negative predictive value of 86%. On the other hand, children having a value >0.656, are considered to be non-immune with a positive predictive value of 78.9%.
Conclusion
Several variables affect immunity of children to HB vaccine. Chemotherapy affects immunity to HB vaccine in children treated for ALL regardless the type of leukemia, the intensity of the protocol used for treatment, and the post chemotherapy interval. A novel equation was developed to predict non-immune state to HBV in children using both his age and his disease status thus help taking a decision concerning revaccination of these patients with minimal costs and time consumption.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Children, Hepatitis B virus, Vaccination
Type: Eposter Presentation
Background
Hepatitis B virus (HBV) infection occurs worldwide, with the highest HBsAg carrier rates found in developing countries, where infection is expected to occur in infancy and childhood. Immunization with hepatitis B vaccine is the most effective way of preventing HBV infection and its consequences, especially in endemic areas. Hepatitis B vaccines are highly immunogenic, inducing a protective anti-HBs antibody titer (≥10 mIU/mL), in more than 95% of healthy children and young adult. Partial or complete loss of protective antibody titers against vaccine preventable diseases makes leukemic children more susceptible to infections. Hemato-oncological patients are considered at risk for either acute acquired HBV infection or HBV reactivation.
Aims
evaluate the immune status to HB vaccine in children treated for acute lymphoblastic leukemia (ALL) after completion of chemotherapy and determine factors affecting anti-HBs titer in those children.
Methods
We evaluated HBV immune status among 76 children who have been treated for ALL, 43 males and 33 females, their age ranged from 4.9 to 16.3 years with a mean of 11.19 years. They were consecutively recruited from the hematology oncology clinic at Alexandria University Children’s Hospital. One hundred healthy children were also included as controls, 51 males and 49 females, age ranged from two to 12 years with a mean of 7 years. All have been previously vaccinated with 3 doses of hepatitis B vaccine at 2, 4 and 6 months of age. Anti-HBs titer was assessed in all leukemic children and controls by ELISA, and concentrations <10.0 mIU/mL were considered negative for anti-HBs (non-immune).
Results
Significantly more leukemic children were non-immune (51.3%) compared to only (15%) in the control group, (p<.0001). Moreover, mean anti-HBs titer in normal children was significantly higher than in leukemic children, (61.57 vs 42.79 mIU/mL, p=.038). When comparing immune and non-immune leukemic children according to age at diagnosis of leukemia, it was significantly higher in non-immune than in immune ones, (6±2.9 vs 4.6±1.9 respectively, p=.017). Using logistic regression analysis, both previous chemotherapy and age were identified as independent variables affecting immunity to HB vaccine, (p=.032, p=.001 respectively). An equation resulted from this analysis to predict the probability of non-immune status: Y=-3.589+[0.928×disease status]+[0.243×age (years)], where disease status is entered as “0” if normal child and as “1” if child has been previously treated for leukemia. The diagnostic performance of the new equation using Receiver Operating Characteristic (ROC) curve analysis was fair to good tool in discrimination between immune and non-immune children, (AUC=0.782, 95% CI 0.713-0.851, p<.0001). Children with value of ≤0.286 will be considered immune with negative predictive value of 86%. On the other hand, children having a value >0.656, are considered to be non-immune with a positive predictive value of 78.9%.
Conclusion
Several variables affect immunity of children to HB vaccine. Chemotherapy affects immunity to HB vaccine in children treated for ALL regardless the type of leukemia, the intensity of the protocol used for treatment, and the post chemotherapy interval. A novel equation was developed to predict non-immune state to HBV in children using both his age and his disease status thus help taking a decision concerning revaccination of these patients with minimal costs and time consumption.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Children, Hepatitis B virus, Vaccination
Abstract: E1180
Type: Eposter Presentation
Background
Hepatitis B virus (HBV) infection occurs worldwide, with the highest HBsAg carrier rates found in developing countries, where infection is expected to occur in infancy and childhood. Immunization with hepatitis B vaccine is the most effective way of preventing HBV infection and its consequences, especially in endemic areas. Hepatitis B vaccines are highly immunogenic, inducing a protective anti-HBs antibody titer (≥10 mIU/mL), in more than 95% of healthy children and young adult. Partial or complete loss of protective antibody titers against vaccine preventable diseases makes leukemic children more susceptible to infections. Hemato-oncological patients are considered at risk for either acute acquired HBV infection or HBV reactivation.
Aims
evaluate the immune status to HB vaccine in children treated for acute lymphoblastic leukemia (ALL) after completion of chemotherapy and determine factors affecting anti-HBs titer in those children.
Methods
We evaluated HBV immune status among 76 children who have been treated for ALL, 43 males and 33 females, their age ranged from 4.9 to 16.3 years with a mean of 11.19 years. They were consecutively recruited from the hematology oncology clinic at Alexandria University Children’s Hospital. One hundred healthy children were also included as controls, 51 males and 49 females, age ranged from two to 12 years with a mean of 7 years. All have been previously vaccinated with 3 doses of hepatitis B vaccine at 2, 4 and 6 months of age. Anti-HBs titer was assessed in all leukemic children and controls by ELISA, and concentrations <10.0 mIU/mL were considered negative for anti-HBs (non-immune).
Results
Significantly more leukemic children were non-immune (51.3%) compared to only (15%) in the control group, (p<.0001). Moreover, mean anti-HBs titer in normal children was significantly higher than in leukemic children, (61.57 vs 42.79 mIU/mL, p=.038). When comparing immune and non-immune leukemic children according to age at diagnosis of leukemia, it was significantly higher in non-immune than in immune ones, (6±2.9 vs 4.6±1.9 respectively, p=.017). Using logistic regression analysis, both previous chemotherapy and age were identified as independent variables affecting immunity to HB vaccine, (p=.032, p=.001 respectively). An equation resulted from this analysis to predict the probability of non-immune status: Y=-3.589+[0.928×disease status]+[0.243×age (years)], where disease status is entered as “0” if normal child and as “1” if child has been previously treated for leukemia. The diagnostic performance of the new equation using Receiver Operating Characteristic (ROC) curve analysis was fair to good tool in discrimination between immune and non-immune children, (AUC=0.782, 95% CI 0.713-0.851, p<.0001). Children with value of ≤0.286 will be considered immune with negative predictive value of 86%. On the other hand, children having a value >0.656, are considered to be non-immune with a positive predictive value of 78.9%.
Conclusion
Several variables affect immunity of children to HB vaccine. Chemotherapy affects immunity to HB vaccine in children treated for ALL regardless the type of leukemia, the intensity of the protocol used for treatment, and the post chemotherapy interval. A novel equation was developed to predict non-immune state to HBV in children using both his age and his disease status thus help taking a decision concerning revaccination of these patients with minimal costs and time consumption.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Children, Hepatitis B virus, Vaccination
Type: Eposter Presentation
Background
Hepatitis B virus (HBV) infection occurs worldwide, with the highest HBsAg carrier rates found in developing countries, where infection is expected to occur in infancy and childhood. Immunization with hepatitis B vaccine is the most effective way of preventing HBV infection and its consequences, especially in endemic areas. Hepatitis B vaccines are highly immunogenic, inducing a protective anti-HBs antibody titer (≥10 mIU/mL), in more than 95% of healthy children and young adult. Partial or complete loss of protective antibody titers against vaccine preventable diseases makes leukemic children more susceptible to infections. Hemato-oncological patients are considered at risk for either acute acquired HBV infection or HBV reactivation.
Aims
evaluate the immune status to HB vaccine in children treated for acute lymphoblastic leukemia (ALL) after completion of chemotherapy and determine factors affecting anti-HBs titer in those children.
Methods
We evaluated HBV immune status among 76 children who have been treated for ALL, 43 males and 33 females, their age ranged from 4.9 to 16.3 years with a mean of 11.19 years. They were consecutively recruited from the hematology oncology clinic at Alexandria University Children’s Hospital. One hundred healthy children were also included as controls, 51 males and 49 females, age ranged from two to 12 years with a mean of 7 years. All have been previously vaccinated with 3 doses of hepatitis B vaccine at 2, 4 and 6 months of age. Anti-HBs titer was assessed in all leukemic children and controls by ELISA, and concentrations <10.0 mIU/mL were considered negative for anti-HBs (non-immune).
Results
Significantly more leukemic children were non-immune (51.3%) compared to only (15%) in the control group, (p<.0001). Moreover, mean anti-HBs titer in normal children was significantly higher than in leukemic children, (61.57 vs 42.79 mIU/mL, p=.038). When comparing immune and non-immune leukemic children according to age at diagnosis of leukemia, it was significantly higher in non-immune than in immune ones, (6±2.9 vs 4.6±1.9 respectively, p=.017). Using logistic regression analysis, both previous chemotherapy and age were identified as independent variables affecting immunity to HB vaccine, (p=.032, p=.001 respectively). An equation resulted from this analysis to predict the probability of non-immune status: Y=-3.589+[0.928×disease status]+[0.243×age (years)], where disease status is entered as “0” if normal child and as “1” if child has been previously treated for leukemia. The diagnostic performance of the new equation using Receiver Operating Characteristic (ROC) curve analysis was fair to good tool in discrimination between immune and non-immune children, (AUC=0.782, 95% CI 0.713-0.851, p<.0001). Children with value of ≤0.286 will be considered immune with negative predictive value of 86%. On the other hand, children having a value >0.656, are considered to be non-immune with a positive predictive value of 78.9%.
Conclusion
Several variables affect immunity of children to HB vaccine. Chemotherapy affects immunity to HB vaccine in children treated for ALL regardless the type of leukemia, the intensity of the protocol used for treatment, and the post chemotherapy interval. A novel equation was developed to predict non-immune state to HBV in children using both his age and his disease status thus help taking a decision concerning revaccination of these patients with minimal costs and time consumption.
Session topic: E-poster
Keyword(s): Acute lymphoblastic leukemia, Children, Hepatitis B virus, Vaccination
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