الفهرس | Only 14 pages are availabe for public view |
Abstract HBV infection is a well recognized and a major health problem world wide, especially in developing countries leading to significant morbidity and mortality. In Egypt HB vaccine was introduced as integral part of the existing childhood immunization programe. It is given at 2,4,6 months in conjunction with DPT and oral poliovaccines schedule. It was reported that immunogenicity of HB vaccine ranges from (83%-99%). However, the efficacy of HB vaccine decay with time and there are certain population fail to mount an adequate protective immune response, such as patients with chronic renal failure, HIV, cancer, diabetes mellitus and other immunocompromised conditions. In Egypt, there is shortage in numbers of studies for evaluating efficacy of HBvaccine after 10 years from primary vaccination, especially in diabetic children. Therefore the present study was conducted in Alexandria aiming to estimate the state of HB immunity among diabetic students vs. non diabetics and to study the different factors affecting their immune response. The study population comprised 130 diabetic children with age ranging 10-<18 years and 130 normal children selected from outpatient clinics of EL-Shatby Pediatrics University Hospital and Insurance Sporting student’s hospitals. A predesigned questionnaire sheet was filled for all children which included inquires about different socio-demographic data, history of hepatitis risk factors and of HB vaccine as well as details about diabetes e.g age of onset, treatment, glycemic state, complications etc. Sera of all studied population was tested for immunogenicity of HB vaccine measured by anti-HBs titre in mIU/ml as well as for anti-HCV seropositivity. Sera found to be anti-HBs titre <10m IU/ ml, were further tested for reactivity to HBsAg and anti- HBc. Data were collected, statistically analyzed and the following results, were obtained: 1. Higher percentage of the studied groups were males and of urban residence. 2. Significantly higher percentage of diabetics gave positive history of frequent hospitalization and injections as compared to non diabetics. In contrast, positive history of dental manipulation, accidents, going to local barber and household contact with HCV were more abundant among non diabetics. 3. Among the 260 studied children, 92 (70.8%) of diabetic children vs.78 (60%) of the normal were non responders (negative for anti-HBs). The median value of anti- HBs titre was significantly lower (3.0 m IU/mL) among diabetics as compared to non diabetics (6.8 mIU/mL). 4. All children with anti-HBs titre <10 mIU/ml were negative for HBsAg. HBV exposure measured by anti-HBc seropositivity revealed no significant difference between both groups. Receiving IV injections and hospitalization significantly prevailed among anti-HBc positive diabetic cases, while going to local barber was the significant risk factor among anti-HBc positive non diabetics. Summary and Conclusions 49 5. Among the factors affecting the immune response to HB vaccine, the results revealed that the percentage of children with anti-HBs titre <10mIU/ml was found to increase with the increase in age. However the difference was statistically significant only in the diabetic group. The stepwise logistic regression analysis of risk factors for poor response indicted that increasing age by 1 year increased the risk for being <10 mIU/ml by about 30%. 6. Gender and BMI categories had no significant effect on HBV vaccine response in both groups. 7. The stepwise logistic regression analysis of risk factors for poor response indicated that diabetic children have 60% more risk for being <10 m IU/ml than non diabetics. The percentage of children with poor response to HBV vaccine was higher among children having diabetic disease for more than 10 years (75%) as compared to those with disease duration <10 years (70.3% ). The frequency of poor vaccine responders was higher among those who had poor metabolic control (31.7% vs. 25%, p=0.066). 8. Diabetic cases had higher frequency of anti-HCV seropositivity as compared to non diabetics (4.6% vs. 0.8% ) respectively. The difference was border line significant. The results revealed that 33.3% of anti-HCV positive diabetic cases had anti-HBs titre <10 mIU/ml vs. 72.6% of anti-HCV negative diabetics. CONCLUSIONS from the previous results it can be concluded that although HB vaccine appears to be protective after 10-18 years of its compulsory inclusion in EPI, there are a considerable proportion of evidence of exposure. The long term immune response to HB vaccine is significantly better in healthy versus diabetic children. Being diabetic and time lapse since immunization were the significant independent risk factors beyond poor response. |