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Influence of nutrition on postvaccinial tuberculin sensitivity
Insights
BCG vaccination elicits a strong immune response in most children, even with mild malnutrition. However, severe malnutrition like kwashiorkor may impair skin test responses, suggesting leukocyte migration inhibition is a more reliable indicator.
Area of Science:
- Immunology
- Pediatrics
- Nutritional Science
Background:
- Bacille Calmette-Guérin (BCG) vaccination is crucial for preventing tuberculosis.
- Malnutrition can impact immune responses, potentially affecting vaccine efficacy.
- Assessing BCG vaccine response in vulnerable populations is essential.
Purpose of the Study:
- To evaluate the immune response to BCG vaccination in preschool children with varying nutritional statuses.
- To compare tuberculin sensitivity and leukocyte migration inhibition test (LMIT) results in malnourished children.
- To determine if malnutrition affects the immune response to BCG vaccination.
Main Methods:
- Studied 261 preschool children classified by weight-for-age deficits and 9 children with kwashiorkor.
- Administered BCG vaccine and assessed tuberculin sensitivity (5 U PPD) after 6 months.
- Determined leukocyte migration inhibition (LMI) using PPD in 84 subjects.
Main Results:
- Over 80% of children showed positive tuberculin tests, unaffected by mild malnutrition.
- Children with kwashiorkor predominantly had negative skin tests.
- LMIT showed positive results in children with kwashiorkor, similar to well-nourished groups, indicating intact lymphocyte sensitization.
Conclusions:
- Mild malnutrition does not significantly impair immune response to BCG vaccination.
- Severe malnutrition (kwashiorkor) may lead to negative tuberculin skin tests.
- Leukocyte migration inhibition test may be a more sensitive marker for BCG vaccination response in severely malnourished children.
Abstract:
Response to BCG vaccination was studied in 261 apparently normal preschool children in a community. They were classified into different nutritional groups based on deficit in weight for age. In addition, nine children who had kwashiorkor and were admitted to the hospital were investigated. They were given 0.1 ml of BCG vaccine, and 6 months later, tuberculin sensitivity was assessed using 5 U of PPD. Blood samples were collected from 84 subjects and leukocyte migration inhibition was determined using the same antigen. After BCG vaccination, over 80% of children in the community showed positive tuberculin test, irrespective of the extent of growth retardation. There were no significant differences in the size of induration or the percentage of reactors between the various groups, indicating that the immune response to BCG vaccination is not affected by milder grades of malnutrition. However, the skin test was negative in most of the children who had had kwashiorkor. Leukocyte migration inhibition was similar in all the groups of children including those with kwashiorkor indicating that sensitisation of lymphocytes was not influenced by the nutritional status. In children with kwashiorkor, the leukocyte migration inhibition test was positive though the skin test was negative, suggesting that the former may be a better measure of assessing the response to BCG vaccination.