Effect of BCG vaccination on cytokine mRNA expression in atopic children with asthma.

BACKGROUND: To investigate whether a preexisting T(H2)-type immune response could be suppressed by BCG immunization in atopic children with asthma. METHODS AND RESULTS: We have used PCR to amplify reverse transcribed (RT) IFN-gamma and IL-5 mRNA expressed by peripheral blood mononuclear cells (PBMCs) in response to in vitro phytohemagglutinin A, purified protein derivative and Dermatophagoides pteronyssinus II stimulation from nine atopic children, both before and 8 weeks after BCG vaccination. We have demonstrated that IFN-gamma expression was induced in response to all stimulants (IFN-gamma/beta-actin) after the vaccination, whereas there was no expression before (P<0.001). Although there was a tendency to diminish in the expression of IL-5 mRNA in response to the stimulants, only PHA rendered a statistically significant decrease after the vaccination. CONCLUSIONS: These results provide some evidence of TH1 dominance after BCG administration in atopic children.

The impact of in vivo Calmette-Guérin Bacillus administration on in vitro IgE secretion in atopic children.

To investigate whether a preexisting T helper (T(H)) 2 type immune response could be suppressed by Calmette-Guérin Bacillus (BCG) immunization in atopic children with asthma, we determined interferon (IFN)-gamma, interleukin (IL)-2, IL-4, and IL-5 and total IgE level in the supernatant of peripheral blood mononuclear cells (PBMC) of six atopic and five nonatopic children in response to phytohemagglutinin A (PHA), purified protein derivate (PPD), and Dermatophagoides pteronyssinus II allergen (Der p II) both before and after BCG vaccination. IL-5 level in response to Der p II was significantly higher in the atopic group than in the nonatopic group both before and after BCG vaccination (p = 0.004, p = 0.009, respectively). In the atopic group, IgE levels determined in PPD and Der p II stimulated and unstimulated culture supernatants decreased significantly after BCG vaccination (p = 0.028, p = 0.026, p = 0.046, respectively), whereas in the nonatopic group (p = 0.041) BCG vaccination resulted in a significant decrease in IgE level only in response to Der p II stimulation. We concluded that in vivo BCG administration can downregulate both spontaneous and stimulated in vitro IgE secretion from PBMC of atopic children.

Pharyngeal colonization with Haemophilus influenzae type b among healthy Turkish infants and children.

BACKGROUND: An absence of Haemophilus influenzae type b (Hib) disease surveillance and epidemiological data on the pharyngeal carriage of Turkish children causes delay in the introduction of conjugated Hib vaccination into proposed national vaccination programs. METHODS: Oropharyngeal cultures were obtained from 1404 healthy infants and children. Six healthy child clinic (HCC), 11 day-care centers (DCC) and seven elementary schools (ES) were randomly selected in seven different counties at the Anatolian side of Istanbul between January and April 2000. RESULTS: Haemophilus influenzae was isolated from 315 (22.8%) of all participants and 98 (31%) isolates were serotype b. The carriage rate for Hib was higher in children at DCC (43 out of 448, 9.6%) and ES (46 out of 504, 9.1%) compared to infants 0-24 months of age (nine out of 430, 2.1%) presented to HCC. All Hib isolates were susceptible to azithromycin, chloramphenicol and cefotaxime. Beta-lactamase production was detected in only one isolate. Trimethoprim-sulfamethoxazole resistance was found in 8.5% of Hib isolates. Multivariate analysis showed that DCC and ES attendance were independent predictors of Hib carriage. CONCLUSION: A significant proportion of healthy Turkish children was shown to be colonized with Hib. The burden of invasive Hib infections should be determined in order to evaluate the Hib conjugated vaccine as a part of a routine immunization program in Turkey.

Which factors predict success after discontinuation of inhaled budesonide therapy in children with asthma?

Urinary eosinophil protein X (UEPX) concentration, lung function, and nonspecific bronchial hyperreactivity were determined in 40 asthmatic children (asymptomatic for 6.4 +/- 3.0 months) (mean age 9.8 +/- 2.9 years) receiving inhaled budesonide, in order to establish whether measurement of these parameters is useful in determining discontinuation of inhaled corticosteroid therapy. After the discontinuation of therapy, patients were asked to come to the Outpatient Clinic if symptoms recurred and did not respond to beta2 mimetic usage in 24 hr. Otherwise they were to be seen 2-3 months later for a follow-up visit. UEPX concentration was determined and spirometry was performed on this visit. While UEPX concentrations had increased (p < 0.0001), FEV1, FEF 25-75 and PEF had decreased significantly 2.3 +/- 0.53 months after the cessation of inhaled budesonide therapy in all children (p = 0.004, p = 0.02, p = 0.02, respectively). Due to clinical deterioration, inhaled corticosteroid therapy had to be restarted in 19 (48%) of the children (Group I), while the remaining 21 (52%) (Group II) continued to be asymptomatic during the 2.3 +/- 0.5 months follow-up period. Although the initial UEPX concentrations, spirometer variables, and methacholine PC20 values of these two groups were not statistically different, the duration of clinical remission before discontinuation of budesonide prophylaxis was significantly longer in group II (p = 0.0037). We concluded that, in determining discontinuation of inhaled corticosteroid prophylaxis, duration of clinical remission seems to be a more useful criterion than measurement of UEPX levels, lung function test, and assessment of bronchial hyperreactivity.

Inhaled corticosteroids and bone density of children with asthma.

In this cross-sectional study, we aimed to compare anteroposterior (AP) spine and total body bone mineral density (BMD) measurements of children with asthma treated with long-term inhaled budesonide (n = 52, mean age 6.4+/-2.2yr, M/F = 22/30) (Group I) with those of asthmatic children who had never received treatment with inhaled corticosteroids (Group II) (n = 22, mean age 6.8+/-2.2, M/F = 10/12). Boys and girls were comparable for age, weight, height, cumulative corticosteroid (CS) dosage, duration of disease and inhaled corticosteroid (ICS) treatment within each group. The mean total accumulated dosage of budesonide for children in Group I was 154.0+/-135.3mg (mean daily dosage = 419+/-154 microg) and the mean treatment duration was 13.0+/-9.8 months. The two groups were comparable with respect to age, gender, weight, height, Tanner's stage and duration of disease. There was no significant difference between subjects in the two groups for total (p = 0.214) and (AP) spine BMD results (p = 0.661), respectively. Our results provide additional support for the safety of ICS therapy on bone density of asthmatic children.