BACKGROUND: An inverse association between tuberculin responses and atopy has been observed in Japanese children, indicating that BCG immunisation, subclinical exposure to Mycobacterium tuberculosis without clinical disease, or host characteristics may influence the T helper (Th) lymphocyte balance with decreased atopy as a result. This study was undertaken to determine whether tuberculin reactivity is inversely related to atopy in young adults vaccinated with BCG at the age of 14. METHODS: Men and women aged 20-44 years were tested using the adrenaline-Pirquet test with Norwegian produced synthetic medium tuberculin (n = 891). In addition, their serum total and specific IgE antibodies against mite, cat, timothy grass, mould and birch were measured. RESULTS: Of the 574 subjects with complete examinations, 64% had a positive adrenaline-Pirquet tuberculin test (> or =4 mm) and 27% exhibited IgE antibodies (> or =0.35 kU/l) to one or more of the five specific allergens. The geometric mean of total serum IgE in the population was 30.2 kU/l. Tuberculin reactivity and log IgE were not correlated (r = 0.043, p = 0.30). The mean tuberculin reactivity was 4.6 mm, 4.9 mm, and 5.0 mm in the lower, middle and upper tertile of IgE distribution (61 kU/l). The prevalence of atopy, as assessed by either the presence of any of the five specific IgE antibodies or by each specific IgE antibody separately, did not differ between subjects with a positive and those with a negative tuberculin test. These results persisted after adjustment for age, sex, and smoking status in multivariate logistic regression analyses. CONCLUSIONS: In this young adult population, BCG vaccinated at the age of 14, no significant relationship between a positive tuberculin reaction and atopy was observed. If a true relationship had been found, our study suggests that it may be limited to populations immunised in early childhood when a substantial modulation of the immune system can occur.
The genotype was studied according to the 8 polymorphic genetic systems (Gm, Hp, Tf, Gc, ESD, PGM, ACP and ADA) in 73 children suffering from tuberculosis and 251 healthy children of the Tuvinian nationality. Analysis of the data obtained showed that a positive association was found in the allotype G1m (2), phenotype G1m (+1, +2, +4) and the genetic variant ESD 2-2 with tuberculosis in subjects of the Tuvinian nationality, and a negative association with the genotype ESD 1-1. It has been suggested that these genetic markers play a definite role in susceptibility to tuberculosis.
Interpretation of tuberculin reactions in revaccinated children is somewhat controversial among paediatricians. In this study, the effect of the number of BCG vaccines on tuberculin reactivity is evaluated. In 2810 healthy children aged 7 to 14 years with purified protein derivative (PPD) testing. Children were grouped according to the concordance of the number of the reported/documented vaccinations to the number of scars. Group 1 and 2 comprised of children 7 to 10 years of age and 11 to 14 years of age respectively, who had non-concordant scar numbers, and Group 3 and 4 included 7 to 10 and 11 to 14 years old children with concordant scar numbers. Mean tuberculin induration sizes were 8.0 +/- 5.7 mm for Group 1, 10.6 +/- 4.9 mm for Group 2, 9.8 +/- 4.9 mm for Group 3 and 10.9 +/- 4 mm for Group 4. As the time interval after the last dose of vaccination increased, mean induration sizes decreased in Group 1 and Group 3. In contrast, the mean reaction sizes of Group 2 and Group 4 showed a positive correlation with the period after the last dose of vaccine. It seems advisable that an induration size > or = 15 mm should not be attributed to BCG vaccination in countries with a high tuberculosis infection prevalence and routine BCG revaccination policies. A detailed investigation for tuberculosis infection and disease should be performed in those cases.
Bacille Calmette-Guérin (BCG) vaccination generally leads to scar formation and tuberculin skin test (TST) reactivity. This study aimed at analysing these 2 parameters and their correlation in a setting with a low prevalence of tuberculosis. Retrospectively, we analysed 314 children and 390 adults living in Sweden and known from records or individual recall to have undergone BCG vaccination. A BCG scar was present in 161 (51%) of the children and in 340 (87%) of the adults. Among children with a scar, 94 (58%) were TST-positive (>or=6 mm) compared to 23 (15%) of 154 children lacking a visible scar. Among adults with a scar, 258 (76%) were TST- positive compared to 23 (46%) of 50 with no scar. Out of 152 non-vaccinated adults, 142 (94.4%) were TST-negative. When 175 TST-negative health care students were BCG-vaccinated in a prospective part of the study, 174 (99%) were found to develop a scar. In essence, the study showed a positive correlation between scar presence and TST reactivity. Furthermore, BCG vaccination of adults in the present setting resulted in consistent scar formation, while scar prevalence in previously vaccinated children was low.
CONTEXT: It has been suggested that BCG vaccination may protect against development of allergic diseases, particularly when given just after birth. BCG vaccination was given routinely to all infants in Greenland until 1990, when it was withdrawn from the vaccination program. Whether this resulted in an increased prevalence of atopy in children born after the stop of BCG vaccination is unknown. OBJECTIVE: To determine whether BCG vaccination and age at BCG vaccination are associated with development of atopy. DESIGN, SETTING, AND PARTICIPANTS: Cross-sectional study among schoolchildren aged 8 to 16 years in 4 towns on the northwest coast of Greenland. Participants had a blood sample drawn and information on BCG vaccination was obtained during 2 periods, November 1998 and November 2001. A total of 1686 children (79% of available children) participated, 1575 of whom had complete information on vaccination status. Atopy was defined as a positive test result in an assay that tests for IgE specific against the most common inhalant allergens in serum. MAIN OUTCOME MEASURES: Odds ratio (OR) of atopy in BCG-vaccinated compared with unvaccinated children and OR according to age at vaccination. RESULTS: The risk of atopy was the same in BCG-vaccinated compared with unvaccinated children after adjustment for confounders (OR, 1.03; 95% confidence interval, 0.72-1.48). The risk of atopy in BCG-vaccinated children was not associated with age at vaccination (P =.17). CONCLUSIONS: BCG vaccination administered to infants is not associated with reduced risk of development of atopy.
Beta-Lactoglobulin (BLG) is a clinically important antigen in cow's milk and one of the major allergens causing cow's milk allergy. Bacillus Calmette-Guerin (BCG) vaccination has been suggested to modify immune response possibly decreasing the risk of allergy to some antigens in both human and experimental animals. In the present study, we have analyzed whether the early BCG vaccination has any effect on the markers of systemic and gastrointestinal (GI) sensitization to BLG. We immunized two groups of Hooded-Lister rat puppets with intraperitoneal injections of native BLG at 43 and 62 days with pertussis vaccine as adjuvant, one group receiving additionally BCG. The animals were then fed native and denatured milk products twice weekly from 73 to 131 days of age, when they were killed. Control group was not vaccinated and received normal rat forage. Total immunoglobulin E (IgE) levels and BLG-specific IgG(1) and IgG(2a) concentrations were determined in serum samples. Spontaneous interleukin (IL)-4 and interferon (IFN)-gamma production from duodenal specimens were measured, and the inflammatory cells were quantitated in specimens from different sections of the GI tract. Administration of BCG simultaneously with BLG resulted in reduced IgE concentration in serum, while the specific IgG(1) and IgG(2a) antibody responses and the spontaneous secretion of IL-4 and IFN-gamma were not affected. Furthermore, BCG-induced eosinophilic infiltration and increase of intraepithelial lymphocytes (IEL) in the GI mucosa, and a trend toward increased number of lamina propria mononuclear inflammatory cells in the colon (BCG compared with BLG, p = 0.09; BCG compared with controls, p = 0.02). Controls showed increment of IgG(1) response in comparison with the BLG group (p = 0.04) and increase of mucosal eosinophilic infiltration. The BCG modified the response to BLG both at the systemic level as shown by decrease of total IgE and at GI mucosa where increase of eosinophilic infiltration and increased number of IEL were seen. Increment of IgG(1) level and eosinophils in the controls might be related with the lack of modulatory effect of pertussis vaccination. A shift of response toward the lower GI tract after BCG immunization as shown by a trend for increase of mononuclear inflammatory cells in colon lamina propria mimics disease development in some cases of clinical food allergy, and emphasizes the need for evaluation of the changes in the whole GI tract in food allergy models.
Tuberculosis (TB) in children is an endemic and sometimes life-threatening disease in Taiwan. This study analyzed the clinical characteristics of a total of 112 children with TB managed in a referral children's hospital in the north of Taiwan between 1998 and 2002. The diagnosis of TB was made by either a positive result of culture, acid-fast stain, histopathology, or polymerase chain reaction (PCR). Tuberculin skin test was positive (indurations > or =10 mm) in 73% of 63 patients tested. The male-to-female ratio was 0.93 (54/58), and the mean age was 10.7 years. Thirty one percent of children were younger than 6 years of age, 12% were 6 to 12 years old, and 57% were older than 12 years. Fifty percent (50/100) of these children had household members with TB; 29.2% (31/106) were aboriginal; 93% had received Bacille Calmette-Guerin (BCG) vaccine. Isolated pulmonary TB was diagnosed in 65 cases (58%), extrapulmonary TB in 25 (22%), and combined intra- and extrapulmonary TB in 22 (20%). Fever was not a presenting symptom in 30.4% of children, was low grade ( or =38.5 degrees C) in 46.4%. The mean duration of fever was 13.9 days. Patients with combined intra- and extrapulmonary TB had a significantly longer hospital stay (p