Immunogenicity and safety of BPZE1, an intranasal live attenuated pertussis vaccine, versus tetanus-diphtheria-acellular pertussis vaccine: a randomised, double-blind, phase 2b trial.

BACKGROUND: Bordetella pertussis epidemics persist as transmission remains unabated despite high acellular pertussis vaccination rates. BPZE1, a live attenuated intranasal pertussis vaccine, was designed to prevent B pertussis infection and disease. We aimed to assess the immunogenicity and safety of BPZE1 compared with the tetanus-diphtheria-acellular pertussis vaccine (Tdap). METHODS: In this double-blind, phase 2b trial at three research centres in the USA, healthy adults aged 18-50 years were randomly assigned (2:2:1:1) via a permuted block randomisation schedule to receive BPZE1 vaccination followed by BPZE1 attenuated challenge, BPZE1 vaccination followed by placebo challenge, Tdap followed by BPZE1 attenuated challenge, or Tdap followed by placebo challenge. On day 1, lyophilised BPZE1 was reconstituted with sterile water and given intranasally (0·4 mL delivered to each nostril), whereas Tdap was given intramuscularly. To maintain masking, participants in the BPZE1 groups received an intramuscular saline injection, and those in the Tdap groups received intranasal lyophilised placebo buffer. The attenuated challenge took place on day 85. The primary immunogenicity endpoint was the proportion of participants achieving nasal secretory IgA seroconversion against at least one B pertussis antigen on day 29 or day 113. Reactogenicity was assessed up to 7 days after vaccination and challenge, and adverse events were recorded for 28 days after vaccination and challenge. Serious adverse events were monitored throughout the study. This trial is registered with ClinicalTrials.gov, NCT03942406. FINDINGS: Between June 17 and Oct 3, 2019, 458 participants were screened and 280 were randomly assigned to the main cohort: 92 to the BPZE1-BPZE1 group, 92 to the BPZE1-placebo group, 46 to the Tdap-BPZE1 group, and 50 to the Tdap-placebo group. Seroconversion of at least one B pertussis-specific nasal secretory IgA was recorded in 79 (94% [95% CI 87-98]) of 84 participants in the BPZE1-BPZE1 group, 89 (95% [88-98]) of 94 in the BPZE1-placebo group, 38 (90% [77-97]) of 42 in the Tdap-BPZE1 group, and 42 (93% [82-99]) of 45 in the Tdap-placebo group. BPZE1 induced broad and consistent B pertussis-specific mucosal secretory IgA responses, whereas Tdap did not induce consistent mucosal secretory IgA responses. Both vaccines were well tolerated, with mild reactogenicity and no serious adverse events related to study vaccination. INTERPRETATION: BPZE1 induced nasal mucosal immunity and produced functional serum responses. BPZE1 has the potential to avert B pertussis infections, which ultimately could lead to reduced transmission and diminished epidemic cycles. These results should be confirmed in large phase 3 trials. FUNDING: ILiAD Biotechnologies.

Genetic polymorphisms of TLR1, TLR2, TLR3 and TLR4 in patients with recurrent or severe infections.

Toll-like receptors (TLRs) play an important role in innate immunity. Previous studies have shown that single nucleotide polymorphisms (SNPs) in the genes coding for these innate immune molecules can affect susceptibility to and the outcome of certain diseases. The aim of the present study was to examine the clinical relevance of well-studied TLR1-4 SNPs in individuals who are prone to infections. Four functional SNPs, TLR1 rs5743618 (1805C > A, Ser602Ile), TLR2 rs5743708 (2258G > A, Arg753Gln), TLR3 rs3775291 (1234C > T, Leu412Phe) and TLR4 rs4986790 (896A > G, Asp299Gly), were analysed in 155 patients with recurrent respiratory infections (n = 84), severe infections (n = 15) or common variable immunodeficiency (n = 56), and in 262 healthy controls, using the High Resolution Melting Analysis method. Polymorphisms of TLR2 rs5743708 (odds ratio [OR] 3.16; 95% confidence interval [CI] 1.45-6.83, p = .004, ap = .016) and TLR4 rs4986790 (OR 1.8; 95% CI 1.05-3.12, p = .028, ap = .112) were more frequent in patients with recurrent or severe infections than in controls. Interestingly, seven patients were found to carry both variant genotypes of TLR2 and TLR4, whereas none of the control group carried such genotypes (p  ≤ .0001). Moreover, TLR2 polymorphism was associated with increased risk for acute otitis media episodes (OR, 3.02; 95% CI 1.41-6.47; p = .012). This study indicates that children and adults who are more prone to recurrent or severe respiratory infections carry one or both variant types of TLR2 and TLR4 more often than control subjects. Genetic variations of TLRs help explain why some children are more susceptible to respiratory infections.

Salivary IL-33 and sST2 levels in relation to TLR2 rs111200466 polymorphism and periodontitis.

OBJECTIVES: Toll-like receptor-2 (TLR2) signalling pathway is involved in the regulation of interleukin (IL)-33 and its receptor suppression of tumorigenicity-2 (ST2). This study aimed to compare salivary IL-33 and soluble ST2 (sST2) levels of periodontitis patients with those of periodontally healthy individuals in relation to their TLR2 rs111200466 23-bp insertion/deletion polymorphism within the promoter region. MATERIALS AND METHODS: Unstimulated saliva samples were collected, and periodontal parameters were recorded from 35 periodontally healthy individuals and 44 periodontitis patients. Non-surgical treatments were applied to periodontitis patients, and sample collections and clinical measurements were repeated 3 months following therapy. Salivary IL-33 and sST2 levels were measured with enzyme-linked immunosorbent assay kits, and TLR2 rs111200466 polymorphism was detected by polymerase chain reaction. RESULTS: Elevated salivary IL-33 (p = 0.007) and sST2 (p = 0.020) levels were observed in periodontitis patients, in comparison to controls. sST2 levels declined 3-months following treatment (p < 0.001). Increased salivary IL-33 and sST2 levels were found to be associated with periodontitis, with no significant relation to the TLR2 polymorphism. CONCLUSION: Periodontitis, but not TLR2 rs111200466 polymorphism, is associated with elevated salivary sST2 and possibly IL-33 levels, and periodontal treatment is effective in reducing salivary sST2 levels.

Toll-like receptor-1, -2, and -6 genotypes in relation to salivary human beta-defensin-1, -2, -3 and human neutrophilic peptide-1.

AIM: To examine whether functional gene polymorphisms of toll-like receptor (TLR)1, TLR2, and TLR6 are related to the salivary concentrations of human beta-defensins (hBDs)-1, -2, -3, and human neutrophilic peptide (HNP)-1. MATERIALS AND METHODS: Polymorphisms of TLR1 (rs5743618), TLR2 (rs5743708), and TLR6 (rs5743810) were genotyped by PCR-based pyrosequencing from the salivary samples of 230 adults. Salivary hBD-1, -2, -3, and HNP-1 concentrations were measured using enzyme-linked immunosorbent assay. General and periodontal health examinations, including panoramic radiography, were available for all participants. RESULTS: The genotype frequencies for wild types and variant types were as follows: 66.5% and 33.5% for TLR1, 95.5% and 4.5% for TLR2, and 25.1% and 74.9% for TLR6, respectively. The TLR2 heterozygote variant group exhibited higher salivary hBD-2 concentrations than the TLR2 wild-type group (p = .038). On the contrary, elevated hBD-2 concentrations were detected in the TLR6 wild-type group compared with the TLR6 heterozygote and homozygote variant group (p = .028). The associations between TLR6 genotypes and salivary hBD-2 concentrations remained significant after adjusting them for periodontal status, age, and smoking. CONCLUSION: hBD-2 concentrations in saliva are related to TLR2 and TLR6 polymorphisms, but only the TLR6 genotype seems to exhibit an independent association with the salivary hBD-2 concentrations.

Interleukin 1 receptor-like 1 rs13408661/13431828 polymorphism is associated with persistent post-bronchiolitis asthma at school age.

AIM: Interleukin (IL) 1 receptor-like 1, encoded by the IL1RL1 gene, is a receptor for IL-33. In European birth cohorts, IL1RL1 rs102082293, rs10204137 (rs4988955), rs13424006 and rs13431828 (rs13048661) variations were associated with asthma at school age. In a Dutch multi-centre study, IL1RL1 rs1921622 variation was associated with severe bronchiolitis. We evaluated the associations of these five IL1RL1 variations with asthma and lung function at school age after hospitalisation for bronchiolitis in infancy. METHODS: Follow-up data, including impulse oscillometry at age 5-7 and flow-volume spirometry at age 11-13 years, and the IL1RL1 genotype data were available for 141 children followed until 5-7 and for 125 children followed until 11-13 age years after bronchiolitis in infancy. The IL1RL1 rs10204137 and rs4988955, and the IL1RL1 rs13048661 and rs13431828, are 100% co-segregating in the Finnish population. RESULTS: The variant IL1RL1 rs13048661/13431828 genotype was constantly associated with increased asthma risk by various definitions at 5-7 and 11-13 years of ages. The result was confirmed with analyses adjusted for current confounders and early-life environment-related factors. Statistical significances were lost, when maternal asthma and atopic dermatitis in infancy were included in the model. CONCLUSION: IL1RL1 rs13048661/13431828 variation was associated with post-bronchiolitis asthma outcomes at school age.

Toll-like receptor 10 rs10004195 variation may be protective against Bacillus Calmette-Guérin osteitis after newborn vaccination.

AIM: Toll-like receptor 1 (TLR1), TLR2, TLR6 and TLR10 form the TLR2 subfamily. In our previous controlled studies in 132 subjects with osteitis after newborn Bacillus Calmette-Guérin (BCG) vaccination, TLR1, TLR2 and TLR6 variations were associated with the risk of BCG osteitis. Now, we evaluated the role of ten single nucleotide polymorphisms (SNP) of the TLR10 gene in this cohort. METHODS: Five synonymous TLR10 SNPs (rs10004195, rs10856837, rs10856838, rs1109695 and rs11466652), and five missense TLR10 SNPs (rs11096955, rs11096957, rs11466649, rs11466653 and rs11466658) were determined by polymerase chain reaction (PCR)-based sequencing in 132 former BCG osteitis patients. RESULTS: TLR10 rs10004195 polymorphism was associated with the risk of BCG osteitis, compared to Finnish population controls. The variant genotype (AT/AA) was present in 13.6% of cases versus 26.2% of controls (p = 0.024). Correspondingly, the minor allele frequency (MAF) was lower (0.075) in cases than in controls (0.152; p = 0.009). There were no significant differences in the genotypes of the other nine studied TLR10 SNPs or in the corresponding MAFs between cases and controls. CONCLUSION: Among ten studied TLR10 gene polymorphisms, the variation only in the TLR10 rs10004195 was associated with the BCG osteitis risk after newborn BCG vaccination.

Interleukin-1 receptor-associated kinase-4 gene variation may increase post-bronchiolitis asthma risk.

AIM: Evidence based on studies of the encoding genes suggests that interleukin-1 receptor-associated kinase-4 (IRAK4) plays a role in childhood asthma and allergy. Our aim was to evaluate the associations of six IRAK4 gene polymorphisms with presence of asthma and allergic rhinitis and use of inhaled corticosteroids (ICSs) for asthma at 5-7 and 11-13 years of ages after hospitalisation for bronchiolitis at younger than 6 months of age. METHODS: IRAK4 rs4251513, rs4251520, rs4251522, rs4251578, rs79154645 and rs13852554 polymorphisms were determined in 141 former bronchiolitis patients prospectively followed up until 5-7 and in 125 children until 11-13 years of age. RESULTS: The homozygous variant IRAK4 rs4251513 genotype was associated with the presence of asthma and allergic rhinitis and use of ICSs at 5-7 and 11-13 years of ages in univariate analyses. Statistical significance remained for the presence of asthma and use of ICSs but was lost in the case of allergic rhinitis in multivariate analyses. The adjusted odds ratios were 3.48 and 4.16 for asthma and 5.22 and 14.00 for ICS use at these two ages. CONCLUSION: The homozygous variant IRAK4 rs4251513 genotype was constantly associated with post-bronchiolitis asthma and asthma medication in school-aged children.

IL17F rs763780 single nucleotide polymorphism is associated with asthma after bronchiolitis in infancy.

AIM: Interleukin-17F (IL-17F) is involved with asthma. The aim of this study was to evaluate the association of IL17F polymorphisms with childhood asthma after bronchiolitis in infancy. METHODS: We invited 166 children who were hospitalised for bronchiolitis at younger than 6 months of age to follow-up visits at 5-7 years and 11-13 years of ages. Asthma and allergy diagnoses, asthma-presumptive symptoms and use of inhaled corticosteroids (ICSs) were registered. Blood samples were available for IL17F rs763780 (T/C), rs11465553 (C/T) and rs7741835 (C/T) determinations in 165 cases. RESULTS: The presence of IL17F rs11465553 and rs7741835 variations showed no significant associations with any asthma or allergy outcome at either 5-7 years or 11-13 years of ages. Instead, children with the variant IL17F rs763780 genotype had used more often ICSs between the follow-up visits from 5-7 to 11-13 years (adjusted OR 3.58) than those with the wild genotype. Children with the variant IL17F rs763780 genotype reported more often doctor-diagnosed atopic dermatitis (adjusted OR 2.71) at 11-13 years of age than those with the wild genotype. CONCLUSION: This prospective long-term follow-up study provided preliminary evidence on the association of the IL17F rs763780 polymorphism with asthma at school age after bronchiolitis in infancy.

Interleukin 17F gene variations showed no association with BCG osteitis risk after newborn vaccination.

AIM: Interleukin-17 (IL-17) family cytokines promote the host defence against mycobacterial infections. We have previously shown an association between IL17A variations and Bacillus Calmette-Guérin (BCG) osteitis. This paper evaluates the association of three IL17F polymorphisms with BCG osteitis after newborn vaccination. METHODS: IL17F rs763780, rs11465553 and rs7741835 single nucleotide polymorphisms (SNPs) were studied in 132 adults, who presented with BCG osteitis in infancy. The genotypes and minor allele frequencies (MAFs) were compared between cases and Finnish population-based controls (N = 99) from the 1000 Genomes Project, and MAFs were compared between cases and allele data of Finnish subjects from the large Genome Aggregation Database. RESULTS: There were no significant differences between former BCG osteitis patients and population-based controls in the IL17F rs763780 (wild 84.4% vs 84.8%), rs11465553 (86.4% vs 91.9%) or rs7741835 (65.7% vs 67.7%) genotypes. Homozygous variant genotypes were only present in 1.5%, 0.8% and 3.8% of cases, respectively. Likewise, MAFs of the three IL17F SNPs did not substantially differ from those of 11 252, 11 939 and 1371 Finnish subjects, respectively, from the available Genome Aggregation Database. CONCLUSION: IL17F rs763780, rs11465553 and rs7741835 variations showed no association with the risk of BCG osteitis after newborn vaccination.

IL17RA variations showed no associations with post-bronchiolitis asthma or lung function.

BACKGROUND: Interleukin-17A (IL-17A) and IL-17F are involved in the pathogenesis of asthma and allergy. Interleukin-17 receptor A (IL-17RA), encoded by the IL17RA gene, is a common receptor for IL-17A and IL-17F. The aim of the present study was to evaluate the association of IL17RA gene variations with asthma, allergy, and lung function at school age in children prospectively followed up after hospitalization for bronchiolitis in early infancy. METHODS: Data on IL17RA rs4819553, rs4819554, and rs4819558 polymorphisms and clinical outcomes, including asthma and allergic rhinitis, were available for 145 former bronchiolitis patients at 5-7 years and for 125 at 11-13 years of age. One hundred children underwent impulse oscillometry at 5-7 years and 84 underwent flow-volume spirometry at 11-13 years of age. The IL17RA rs4819553, rs4819554 and rs4819558 were completely co-segregating in Finnish children in our previous studies. RESULTS: The distributions of the studied IL17RA wild versus variant genotypes and major versus minor allele frequencies did not differ between bronchiolitis cases and population controls. These variations showed no significant association with asthma or allergic rhinitis nor with lung function reduction at 5-7 or 11-13 years of ages. Only 5.6% to 6.4% of the variations were homozygous. CONCLUSIONS: The IL17RA gene variations that were studied showed no association with susceptibility to severe bronchiolitis in infancy, nor with post-bronchiolitis asthma or lung function at school age. Future studies should evaluate other IL17RA polymorphisms and include more cases, and especially cases with homozygous variations.

Toll-interacting protein polymorphisms in viral bronchiolitis outcomes.

BACKGROUND: Toll-interacting protein is a key factor in regulating innate immunity responses via gatekeeping Toll-like receptors. Genetic variance in innate immunity has been linked with susceptibility to infections. Children with viral bronchiolitis in infancy are at increased risk of later asthma. The aim was to evaluate the role of toll-interacting protein gene point mutations in severity of bronchiolitis and subsequent risk of asthma. METHODS: Infants less than 6 months old were recruited during hospitalization due to bronchiolitis. In all, 166 children were prospectively followed up to age of 1.5, 6, and 11 years. Clinical data on viral etiology and severity markers, and further post-bronchiolitis asthma and lung function outcomes were compared with genetic differences in two single-nucleotide point mutations rs116938768 and rs5743854 in the toll-interacting protein gene. RESULTS: Toll-interacting protein rs116938768 or rs5743854 did not show significant associations with severity markers or viral etiology of bronchiolitis. Follow-up data on current asthma or lung function at 6 or 11 years of age after bronchiolitis were not associated with the investigated mutations. CONCLUSION: Toll-interacting protein gene point mutations in rs116938768 or rs5743854 were not involved with the clinical course of viral bronchiolitis in early infancy, and did not predict post-bronchiolitis asthma or lung function reduction by the age of 11 years.

Airway microbiome, host immune response and recurrent wheezing in infants with severe respiratory syncytial virus bronchiolitis.

BACKGROUND: Early interactions between respiratory viruses and microbiota might modulate host immune responses and subsequently contribute to later development of recurrent wheezing and asthma in childhood. We aimed to study the possible association between respiratory microbiome, host immune response, and the development of recurrent wheezing in infants with severe respiratory syncytial virus (RSV) bronchiolitis. METHODS: Seventy-four infants who were hospitalized at Beijing Children's Hospital during an initial episode of severe RSV bronchiolitis at 6 months of age or less were included and followed up until the age of 3 years. Sputum samples were collected, and their microbiota profiles, LPS, and cytokines were analyzed by 16S rRNA-based sequencing, ELISA, and multiplex immunoassay, respectively. RESULTS: Twenty-six (35.1%) infants developed recurrent wheezing by the age of 3 years, and 48 (64.9%) did not. The relative abundance of Haemophilus, Moraxella, and Klebsiella was higher in infants who later developed recurrent wheezing than in those who did not (LDA score >3.5). Airway levels of LPS (P = .003), CXCL8 (P = .004), CCL5 (P = .029), IL-6 (P = .004), and IL-13 (P < .001) were significantly higher in infants who later developed recurrent wheezing than in those who did not. Moreover, high airway abundance of Haemophilus was associated with CXCL8 (r = 0.246, P = .037) level, and that of Moraxella was associated with IL-6 level (r = 0.236, P = .046) and IL-10 level (r = 0.266, P = .024). CONCLUSION: Our study suggests that higher abundance of Haemophilus and Moraxella in airway microbiome might modulate airway inflammation during severe RSV bronchiolitis in infancy, potentially contributing to the development of subsequent recurrent wheezing in later childhood.

Toll-like receptor 4 polymorphisms were associated with low serum pro-inflammatory cytokines in BCG osteitis survivors.

AIM: The aim of the study was to evaluate the association of Toll-like receptor 4 (TLR4) gene variations with osteitis risk after Bacillus Calmette-Guérin (BCG) vaccination given at birth and with serum cytokine levels measured in adulthood. METHODS: We determined the TLR4 rs4986790 single-nucleotide polymorphism (SNP) in 132 study subjects with BCG osteitis in infancy and compared the genotype distributions and allele frequencies between them and population controls. Serum concentrations of 11 cytokines measured in adulthood were compared between study subjects with the wild vs variant TLR4 rs4986790 genotype. RESULTS: The genotypes and allele frequencies of the TLR4 rs4986790 SNP did not differ between BCG osteitis cases and population controls. Instead, subjects with the variant genotype presented with lower serum interleukin (IL) concentrations of the pro-inflammatory IL-6, IL-17A and IL-12 cytokines and with marginally lower interferon-γ concentrations, but with higher serum anti-inflammatory IL-4 concentration. The results concern also the TLR4 rs4986791, since these two SNPs are co-segregating in the Finnish population. CONCLUSION: The findings suggest that TLR4 has no significant role in the emergence of osteitis after newborn BCG vaccination, but the variant genotypes of the TLR4 rs4986790 and rs4986791 may impair the production of pro-inflammatory cytokines.

IL33 rs1342326 gene variation is associated with allergic rhinitis at school age after infant bronchiolitis.

AIM: Interleukin (IL)-33, encoded by the IL33 gene, is associated with allergy and asthma. We evaluated IL33 rs1342326 polymorphism in relation to asthma, asthma medication and allergic rhinitis after infant bronchiolitis. METHODS: IL33 rs1342326 polymorphism was studied in children, who were hospitalised for bronchiolitis at age younger than 6 months and who were prospectively followed until 5-7 years (N = 141) and 11-13 years (N = 125) of ages. RESULTS: The presence of the wild AA vs variant AC or CC genotypes of the IL33 rs1342326 showed no significant associations with previous or current asthma at the mean ages of 6.4 or 11.7 years. However, 22.5% of children with the variant genotype used inhaled corticosteroids at the 5-7 years of visit (adjusted OR: 2.94, 95% CI: 1.04-8.33 vs those 8.9% with the wild genotype). The variant IL33 rs1342326 genotype was associated with allergic rhinitis at 6.4 years (adjusted OR: 2.17, 95% CI: 1.01-4.76) and 11.7 years (3.23, 1.18-9.09) of ages. CONCLUSION: The frequent use of asthma control medication in 6.4-year-old children with IL33 rs1342326 polymorphism suggests that this variation may increase susceptibility to severe asthma at preschool age. The IL33 rs1342326 variant genotype was associated with a 3-fold risk of allergic rhinitis at school age.

Toll-like receptor 10 rs4129009 gene polymorphism is associated with post-bronchiolitis lung function in adolescence.

AIM: The aim was to evaluate the association of polymorphisms in the Toll-like receptor (TLR) 2 subfamily encoding genes with lung function by spirometry at 10-13 years of age in children who had been hospitalised for bronchiolitis at <6 months of age. METHODS: In a prospective cohort of 166 former bronchiolitis patients, 138 returned a structured questionnaire and 89 attended a clinical follow-up visit including spirometry before and after bronchodilation at 10-13 years of age. Data on polymorphisms of the TLR1, TLR2, TLR6 and TLR10 genes were available from 81-82 children. RESULTS: In the TLR10 rs4129009, the wild (AA) genotype was associated with lower FEV1/FVC before (92.4 vs 97.4, P = .002) and after (95.5 vs 98.6, P = .011) bronchodilator administration, compared to those with the variant genotype. When the TLR10 rs4129009 and TLR2 rs5743708 genotypes, and the TLR10 rs4129009 and TLR1 rs5743618 genotypes, respectively, were analysed as combined, both baseline and post-bronchodilator FEV1/FVC were lowest in the subjects with the wild (AA) genotype of the TLR10 rs4129009. CONCLUSION: In this post-bronchiolitis follow-up, lung function in children with the variant TLR10 rs4129009 genotype with potentially altered TLR10 function was superior to lung function in those with the wild genotype.

Interleukin-10 gene polymorphism rs1800896 is associated with post-bronchiolitis asthma at 11-13 years of age.

AIM: Interleukin-10 (IL-10) is an anti-inflammatory cytokine that is involved with bronchiolitis and asthma. We evaluated associations between four IL-10 polymorphisms, namely rs1800871, rs1800872, rs1800890 and rs1800896, and post-bronchiolitis asthma in young adolescents. METHODS: The cohort consisted of 125 children hospitalised for bronchiolitis at Tampere University Hospital, Finland, in 2000-2004, at less than six months of age. At 11-13 years, asthma diagnoses and asthma-presumptive symptoms, allergic rhinitis and use of inhaled corticosteroids (ICS) were registered. Data on the four polymorphisms and their genotypes, haplotypes and allele frequencies were analysed in relation to asthma, allergic rhinitis and asthma medication. RESULTS: The variant IL-10 rs1800896 genotype was associated with less persistent asthma at five to seven and 11-13 years of age (4.3 versus 15.2%, p = 0.04) than the wild genotype and less ICS use during the previous 12 months (5.4 versus 18.2%, p = 0.03), as was the variant allele G. Allele A was associated with more persistent asthma and ICS use. The significant differences between the variant and wild genotypes were lost in adjusted logistic regression, but the direction of the association remained. CONCLUSION: IL-10 rs1800896 gene polymorphism was associated with post-bronchiolitis asthma at 11-13 years of age in children hospitalised for bronchiolitis at less than six months of age.

Molecular Epidemiology of Bordetella pertussis.

Although vaccination has been effective, Bordetella pertussis is increasingly causing epidemics, especially in industrialized countries using acellular vaccines (aPs). One factor behind the increased circulation is the molecular changes on the pathogen level. After pertussis vaccinations were introduced, changes in the fimbrial (Fim) serotype of the circulating strains was observed. When bacterial typing methods improved, further changes between the vaccine and circulating strains, especially among the common virulence genes including pertussis toxin (PT) and pertactin (PRN) were noticed. Moreover, development of genome based techniques including pulsed-field gel electrophoresis (PFGE), multiple-locus variable number tandem repeat analysis (MLVA) and whole-genome sequencing (WGS) have offered a better resolution to monitor B. pertussis strains. After the introduction of aP vaccines, B. pertussis strains that are deficient to vaccine antigens, especially PRN, have appeared widely. On the other hand, antimicrobial resistance to first line drugs (macrolides) against B. pertussis is still low in many countries and therefore no globally evaluated antimicrobial susceptibility test values have been recommended. In this review, we focus on the molecular changes in the bacteria, which have or may have affected the past and current epidemiology of pertussis.

Interferon-γ and interleukin-12 production in relation to gene polymorphisms in bacillus Calmette-Guérin osteitis.

BACKGROUND: Interferon-γ (IFN-γ) and interleukin-12 (IL-12) play a crucial role in the defense against mycobacteria, and in the response to bacillus Calmette-Guérin (BCG) vaccination. We have previously reported clinical and outcome data of 222 BCG osteitis cases diagnosed in 1960-1988 in Finland. The immunological and genetic reports have been based on 132 blood samples obtained in 2007-2008. METHODS: We compared IFNγ rs2430561 and rs35314021, IL12A rs568408 and rs2243115, and IL12B rs3212227 single-nucleotide polymorphisms (SNP) between 132 BCG osteitis patients and 99 population-based controls. In addition, stimulated production of IFN-γ and IL-12 in cell culture was evaluated in relation to the presence of IFNγ and IL12 wild versus variant genotypes, respectively. RESULTS: The distributions of IFNγ rs2430561, IFNγ rs35314021, IL12A rs568408, IL12A rs2243115 and IL12B rs3212227 SNP did not differ between BCG osteitis patients and Finnish population-based controls. For IFNγ rs2430561, IFNγ rs35314021 and IL12A rs2243115, the negative result was confirmed by comparing the minor allele frequencies (MAF) in BCG osteitis cases with those in the publicly available genome aggregation database, including data for 3,472 Finnish persons. Instead, for IL12A rs568408 and IL12B rs3212227, the comparison of MAF in BCG osteitis cases with those in population-based and in aggregation-based controls gave conflicting results. The presence of the wild versus variant genotype had no significant association with IL-12 or IFN-γ production in BCG-stimulated cell cultures. CONCLUSION: IFNγ gene polymorphisms did not show any association with BCG osteitis after newborn vaccination.

Pertactin-deficient Bordetella pertussis isolates: evidence of increased circulation in Europe, 1998 to 2015.

IntroductionPertussis outbreaks have occurred in several industrialised countries using acellular pertussis vaccines (ACVs) since the 1990s. High prevalence of pertactin (PRN)-deficient Bordetella pertussis isolates has been found in these countries.AimsTo evaluate in Europe: (i) whether proportions of PRN-deficient strains increased in consecutive collections of B. pertussis clinical isolates; (ii) if the frequency of PRN-deficient strains in countries correlated with the time since ACV introduction; (iii) the presence of pertussis toxin (PT)-, filamentous haemagglutinin (FHA)- or fimbriae (Fim)-deficient isolates.MethodsB. pertussis clinical isolates were obtained from different European countries during four periods (EUpert I-IV studies): 1998 to 2001 (n = 102), 2004 to 2005 (n = 154), 2007 to 2009 (n = 140) and 2012 to 2015 (n = 265). The isolates' selection criteria remained unchanged in all periods. PRN, PT, FHA and Fim2 and Fim3 expression were assessed by ELISA.ResultsIn each period 1.0% (1/102), 1.9% (3/154), 6.4% (9/140) and 24.9% (66/265) of isolates were PRN-deficient. In EUpert IV, PRN-deficient isolates occurred in all countries sampled and in six countries their frequency was higher than in EUpert III (for Sweden and the United Kingdom, p < 0.0001 and p = 0.0155, respectively). Sweden and Italy which used ACVs since the mid 1990s had the highest frequencies (69%; 20/29 and 55%; 11/20, respectively) while Finland, where primary immunisations with ACV containing PRN dated from 2009 had the lowest (3.6%). Throughout the study, no PT- or FHA-deficient isolate and one Fim2/3-deficient was detected.ConclusionResults suggest that the longer the period since the introduction of ACVs containing PRN, the higher the frequency of circulating PRN-deficient isolates.