[Detection of Mycoplasma pneumoniae, Chlamydia trachomatis and common respiratory viruses in children with acute respiratory infection in Nanjing].

OBJECTIVE: To investigate the nonbacterial pathogens in children with acute respiratory infection (ARI) in Nanjing. METHODS: The presence of Mycoplasma pneumoniae (MP) and Chlamydia trachomatis (CT) was determined by quantitative PCR in the nasopharyngeal samples from 1 592 hospitalized children with ARI. Common respiratory viruses, including respiratory syncytial virus (RSV), adenovirus (ADV), influenza virus types A and B (IVA and IVB), parainfluenza virus types 1, 2, 3(PIV-1, 2, 3) and human metapneumovirus (hMPV), were detected using direct immunofluorescence assay. RESULTS: MP and CT were detected in 25.7% and 2.4% of the 1 592 samples respectively. The overall positive rate of respiratory viruses was 40.9%. Among the viruses, the top detected virus was RSV (61.3%), followed by PIV-3 (6.7%) and hMPV (4.9%). Mixed infection among MP, CT and viruses was observed in 107 cases (6.7%). The infants under 1 year old were susceptible to mix-infection (68/107, 63.6%). CONCLUSIONS: Respiratory virus is the main pathogen responsible for ARI in children from Nanjing. RSV is the most commonly identified virus. MP is also the frequently identified pathogen for ARI in children. Mixed infection is common in infants under 1 year old.

Effect of variation in RANTES promoter on serum RANTES levels and risk of recurrent wheezing after RSV bronchiolitis in children from Han, Southern China.

To investigate the association among RANTES (regulated on activation normal T cell expressed and secreted) gene promoter polymorphism, serum RANTES levels, and recurrent wheezing after RSV (respiratory syncytial virus) bronchiolitis in children (1-12 months of age) from Han, Southern china. Three hundred twenty children with RSV bronchiolitis and 272 controls were enrolled in the 3-year follow-up study. The polymerase chain reaction-restriction fragment length polymorphism (PCR-RELP), enzyme-linked immunosorbent assay (ELISA) kit and luciferase analysis were the mainly used methods, which were used to genotype the RANTES (-403 G/A), assess the serum RANTES levels and the RANTES promoter activity. As the results showed, the RANTES (-403 G/A) in the promoter region was associated with recurrent wheezing after RSV bronchiolitis (p < 0.05) and serum RANTES levels (RANTES genotype G/G: 26.03 +/- 7.46 ng/ml G/A: 28.22 +/- 6.44 ng/ml A/A: 30.12 +/- 5.88 ng/ml). Functional analyses of RANTES promoter activity indicated that the RANTES (-403 G to A) mutation increases the transcriptional activity of the RANTES promoter. In conclusion, the RANTES (-403 G/A) polymorphism increases RANTES transcriptional activity resulted in a high serum RANTES levels, thus increased the risk of recurrent wheezing after RSV bronchiolitis.

Low level of galacto-oligosaccharide in infant formula stimulates growth of intestinal Bifidobacteria and Lactobacilli.

AIM: To investigate the effect of a new infant formula supplemented with a low level (0.24 g/100 mL) of galacto-oligosaccharide (GOS) on intestinal micro-flora (Bifidobacteria, Lactobacilli and E. coli) and fermentation characteristics in term infants, compared with human milk and a standard infant formula without GOS. METHODS: Term infants (n = 371) were approached in this study in three hospitals of China. All infants started breast-feeding. Those who changed to formula-feeding within 4 wk after birth were randomly assigned to one of the two formula groups. Growth and stool characteristics, and side effects that occurred in recruited infants were recorded in a 3-mo follow-up period. Fecal samples were collected from a subpopulation of recruited infants for analysis of intestinal bacteria (culture technique), acetic acid (gas chromatography) and pH (indicator strip). RESULTS: After 3 mo, the intestinal Bifidobacteria, Lactobacilli, acetic acid and stool frequency were significantly increased, and fecal pH was decreased in infants fed with the GOS-formula or human milk, compared with those fed with the formula without GOS. No significant differences were observed between the GOS formula and human milk groups. Supplementation with GOS did not influence the incidence of crying, regurgitation and vomiting. CONCLUSION: A low level of GOS (0.24 g/100 mL) in infant formula can improve stool frequency, decrease fecal pH, and stimulate intestinal Bifidobacteria and Lactobacilli as in those fed with human milk.

[The correlation factor about respiratory syncytial virus bronchiolitis and post-bronchiolitis wheezing in infant].

OBJECTIVE: To observe the correlation factor about early-life RSV bronchiolitis and sequential recurrent wheezing for two years. METHODS: Follow up the RSV bronchiolitis patients for two years in order to analyze the occurrence of wheezing post-bronchiolitis. Single and multiple logistic regression analysis were used to determined the risk factors such as individual atopy history and familial atopy history, pet feeding, breast milk, secondhand smoke for RSV bronchiolitis and subsequent wheezing. RESULTS: (1) Not breast feeding, exposure to cigarette smoke and the deficiency of VitA, D were the significant risk factors contributed to the RSV branchiolitis. (2) Exposure to cigarette smoke, the deficiency of VitA, D, the personal history of atopy and the family history of atopy were the significant risk factors contributed to the post-bronchiolitis wheezing in children. (3) Those patients who eosinophilia, high serum IgE, RANTES and decreased TH1 to TH2 Ratio were more likely to have wheezing after RSV bronchiolitis. CONCLUSION: (1) Not breast feeding, exposure to cigarette smoke and the deficiency of VitA, D were the significant risk factors contributed to the RSV bronchiolitis. (2) Exposure to cigarette smoke, the deficiency of VitA, D, the personal history of atopy and the family history of atopy were the significant risk factors contributed to the post-bronchiolitis wheezing in children.

[Association of RANTES gene promoter -28C/G polymorphism with respiratory syncytial virus bronchiolitis].

OBJECTIVE: Respiratory syncytial virus (RSV) infects nearly all children under two years of age. It is poorly understood why a few children who were infected with RSV develop bronchiolitis that require hospital admission while most have a relatively minor illness. Several recent studies have obtained some indications for the involvement of genetic heterogeneity in RSV bronchiolitis, implying that the clinical outcome of RSV infection perhaps is determined by genetic factors. Regulated on activation, normal T cell expressed and secreted RANTES plays a key role in the pathophysiology of RSV bronchiolitis. The purpose of this study was to explore the genetic association between the RANTES gene promoter -28C/G polymorphism and RSV bronchiolitis in Chinese Han ethnic group population. METHODS: The study recruited 238 hospitalized patients (186 male and 52 female) under 12 months of age, with a clinical diagnosis of bronchiolitis due to RSV, the sex, age, hospital stay, SaO2 at the time of admission, personal and family history of atopy were recorded. The 288 healthy control subjects (206 male and 82 female), who had no evidence of personal or familial history of atopy and no history of wheezing, were chosen at the same time. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to identify the polymorphism at position -28C/G of the RANTES promoter. The total IgE concentrations in serum samples were measured by enzyme-linked immunosorbent assay (ELISA). The absolute peripheral blood eosinophil counts were measured by using an automated hematology analyzer. RESULTS: The distribution of RANTES -28C/G gene polymorphism was in accordance with Hardy-Weinberg equilibrium. Compared to control subjects, significant difference was demonstrated for genotypes and allele frequencies of the RANTES -28C/G polymorphism in patients with RSV bronchiolitis (G = 10.22, P < 0.01; chi2 = 9.708, P < 0.01). Compared with the wild type CC, the -28G allele carriers demonstrated a 2.09-fold increased risk of RSV bronchiolitis (OR = 2.09, 95% CI = 1.32 - 3.30, P < 0.01). Interestingly, both the percentage of personal history of atopy and the percentage of family history of atopy for the -28G allele carriers were significantly higher (P < 0.05) than that for those CC homozygotes carriers in RSV bronchiolitis. Compared with the wild type CC, the -28G allele carriers demonstrated a 1.85-fold increased risk of the personal history of atopy (OR = 1.85, 95% CI = 1.01 - 3.38, P = 0.045) and a 1.91-fold increased risk of the family history of atopy (OR = 1.91, 95% CI = 1.03 - 3.54, P = 0.037), and the absolute peripheral blood eosinophil counts for the -28G allele carriers were significantly higher (P < 0.05). CONCLUSION: The RANTES gene promoter -28C/G polymorphism is associated with the susceptibility to RSV bronchiolitis, and the -28G allele is an important predisposing factor for the personal history of atopy and the family history of atopy in RSV bronchiolitis.

[Association between interleukin-8 gene-251 locus polymorphism and respiratory syncytial virus bronchiolitis and post-bronchiolitis wheezing in infants].

OBJECTIVE: Respiratory syncytial virus (RSV) infects nearly all children under two years of age. It is not understood why some develop serious bronchiolitis. Whether there is a genetic component is not known. The nature of the association between RSV bronchiolitis and subsequent wheezing remains unknown. interleukin-8 (IL-8) is a potent neutrophil chemokine and activator, which plays a role in virus-induced wheezing diseases. The purpose of this study was to assess the genetic association between the IL-8 gene promoter -251A/T polymorphism and RSV bronchiolitis and post-bronchiolitis wheezing in children. METHODS: Totally 320 children who were hospitalized for bronchiolitis together with positive immunofluorescence for RSV were recruited in this study from Jan. 2002 to Jan. 2004. A group of 272 healthy children were enrolled as controls. The age of these children ranged from 1 to 12 months. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to identify the polymorphism at position-251 of the IL-8 promoter in RSV bronchiolitis and control groups. The total IL-8 and IgE concentrations in serum samples were measured by enzyme-linked immunosorbent assay (ELISA). The patients with RSV bronchiolitis were followed up in order to analyze the occurrence of wheezing post-bronchiolitis. RESULTS: (1) Both A allele and T allele were detected at -251 of the IL-8 promoter; the prevalence of the A allele in RSV bronchiolitis group was 45.6%, as compared with 37.7% in normal group. The prevalence of IL-8-251A allele was significantly different between the two groups (P < 0.05). (2) For genotypes T/T, A/T, A/A in RSV bronchiolitis, level of serum IL-8 were (17 +/- 6) ng/L, (21 +/- 7) ng/L, (24 +/- 9) ng/L, respectively, the difference was significant among the three genotypes (P < 0.01). (3) The prevalence of the A allele in the group who wheezed after the episode of RSV bronchiolitis was 54.6%, as compared with 35.8% in the group who had bronchiolitis but did not go on to wheeze. The prevalence of IL-8-251A allele was significantly different between the two groups (P < 0.05). CONCLUSION: Polymorphism of IL-8 promoter-251A/T was associated with susceptibility to RSV bronchiolitis in children. The association of IL-8-251A with severe RSV bronchiolitis is most marked in the children who go on to wheeze.