Ecological succession in the vaginal microbiota during pregnancy and birth

The mother's vaginal microbiota represents the first microbes to which a child is exposed when delivered vaginally. However, little is known about the composition and development of the vaginal microbiota during pregnancy and birth. Here, we analyzed the vaginal microbiota of 57 women in pregnancy week 24, 36 and at birth after rupture of membranes but before delivery, and further compared the composition with that of the gut and airways of the 1-week-old child. The vaginal community structure had dramatic changes in bacterial diversity and taxonomic distribution, yet carried an individual-specific signature. The relative abundance of most bacterial taxa increased stepwise from week 24 of pregnancy until birth, with a gradual decline of Lactobacillus. Mother-to-child vertical transfer, as suggested by sharing, was modest, with the strongest transfer being for Clostridiales followed by Lactobacillales and Enterobacteriales. In conclusion, late gestation is associated with an increase in maternal vaginal microbiota diversity, and vaginal bacteria at birth only modestly predict the composition of the neonatal microbiota.

Neonates colonized with pathogenic bacteria in the airways have a low-grade systemic inflammation

BACKGROUND AND OBJECTIVES

The development of childhood asthma is associated with neonatal colonization with pathogenic bacteria in hypopharynx. Furthermore, established asthma is associated with systemic low-grade inflammation. We here report on the association between neonatal colonization with pathogenic bacteria in hypopharynx and the development of systemic low-grade inflammation.

METHODS

Bacterial colonization of the hypopharynx with Moraxella catharralis, Haemophilus influenzae, and/or Streptococcus pneumoniae was assessed in asymptomatic children from the Copenhagen Prospective Studies on Asthma in Childhood₂₀₀₀ (COPSAC₂₀₀₀ ) cohort at age 1 month by culturing technique (N = 238) and by quantitative polymerase chain reaction (qPCR) technique (N = 249) and in the COPSAC₂₀₁₀ cohort by culturing at age 1 month (N = 622) and again at age 3 months (N = 613). Systemic low-grade inflammation was determined in both cohorts at age 6 months by measuring plasma levels of high-sensitivity C-reactive protein (hs-CRP), tumor necrosis factor-α (TNF-α), and interleukin-6 (lL-6).

RESULTS

In both cohorts, bacterial colonization was associated with increased levels of hs-CRP: COPSAC₂₀₀₀ , 1 month culturing (geometric mean ratio of colonized/noncolonized [95% CI]), 1.39 [0.97-2.01], P = .08; 1 month qPCR, 1.55 [1.14-2.10], P < .01; COPSAC₂₀₁₀ , 1 month, 1.52 [1.23-1.87], P < .01; and 3 month, 1.57 [1.30-1.90], P < .01. A multiparametric principal component analysis incorporating hs-CRP, TNF-α, and IL-6 confirmed a systemic inflammatory profile in children colonized with M. catharralis, H. influenzae. and/or S. pneumoniae in the hypopharynx compared to noncolonized children (P-values < .05).

CONCLUSION

The composition of the upper airway microbiome in early life may cause systemic low-grade inflammation.

Allergic sensitization at school age is a systemic low-grade inflammatory disorder

BACKGROUND

Systemic low-grade inflammation has been demonstrated in a range of the frequent noncommunicable diseases (NCDs) proposing a shared mechanism, but is largely unexplored in relation to allergic sensitization. We therefore aimed to investigate the possible association with childhood allergic sensitization.

METHODS

High-sensitivity C-reactive protein (hs-CRP), interleukin-1β (IL-1β), IL-6, tumor necrosis factor-α (TNF-α), and chemokine (C-X-C motif) ligand 8 (CXCL8) were measured in plasma at age 6 months (N = 214) and 7 years (N = 277) in children from the Copenhagen Prospective Studies on Asthma in Childhood₂₀₀₀ (COPSAC₂₀₀₀ ) birth cohort. Allergic sensitization against common inhalant and food allergens was determined longitudinally at ages ½, 1½, 4 and 6 years by specific IgE assessments and skin prick tests. Associations between inflammatory biomarkers and sensitization phenotypes were tested with logistic regression and principal component analyses (PCAs).

RESULTS

Adjusted for gender, recent infections, and a CRP genetic risk score, hs-CRP at 7 years was associated with concurrent elevated specific IgE against any allergen [adjusted OR (aOR) = 1.40; 95% CI, 1.14-1.72; P = 0.001], aeroallergens (aOR, 1.43; 1.15-1.77; P = 0.001), food allergens (aOR, 1.31; 95% CI, 1.02-1.67; P = 0.04), sensitization without any clinical allergy symptoms (aOR = 1.40; 1.06-1.85; P = 0.02), and with similar findings for skin prick tests. The other inflammatory markers were not univariately associated with sensitization, but multiparametric PCA suggested a specific inflammatory response among sensitized children. Inflammatory markers at age 6 months were not associated with subsequent development of sensitization phenotypes.

CONCLUSIONS

Elevated hs-CRP is associated with allergic sensitization in school-aged children suggesting systemic low-grade inflammation as a phenotypic characteristic of this early-onset NCD.

Domestic dog exposure at birth reduces the incidence of atopic dermatitis

BACKGROUND

While the etiopathogenesis of atopic dermatitis is complex and poorly understood, neonatal exposures are important for disease occurrence. However, the effect of dog exposure on the risk of atopic dermatitis is unresolved.

OBJECTIVE

We investigated whether domestic dog exposure affected the risk of atopic dermatitis in children during the first 3 years of life.

METHODS

Copenhagen Prospective Studies on Asthma in Childhood (COPSAC) are ongoing prospective clinical birth cohort studies. Data from 411 children born to mothers with asthma (COPSAC₂₀₀₀ ) and 700 unselected children (COPSAC₂₀₁₀ ) were analyzed following the same protocols at the same research site. Atopic dermatitis was diagnosed prospectively according to the Hanifin-Rajka criteria. Parental history of asthma, eczema, or rhinitis was defined by self-reported physician diagnosis. In the COPSAC₂₀₀₀ , maternal specific serum IgE against eight inhalant allergens was sampled after the children's birth and at pregnancy week 24 in the COPSAC₂₀₁₀ cohort. Associations between dog exposure and atopic dermatitis were analyzed by Cox proportional hazard regression models and adjusted for lifestyle confounders.

RESULTS

In the COPSAC₂₀₀₀ and COPSAC₂₀₁₀ cohorts, the risk of atopic dermatitis was significantly lower in children with domestic dog exposure (_adjusted HR = 0.46 [0.25-0.87], P = 0.02; and _adjusted HR = 0.58 [0.36-0.93], P = 0.03, respectively). The risk of atopic dermatitis decreased in a dose-dependent manner with increasing number of dogs (_adjusted HR = 0.58 [0.38-0.89], P = 0.01) in the COPSAC₂₀₁₀ . The protective effect was restricted to children born to mothers with atopic disease in the unselected COPSAC₂₀₁₀ cohort (_adjusted HR = 0.39 [0.19-0.82], P = 0.01), as no effect was observed in children born to mothers without atopic disease (_adjusted HR = 0.92 [0.49-1.73], P = 0.79). Paternal atopic status did not affect the risk of atopic dermatitis. We found no significant interaction between the CD14 T/T genotype and domestic dog exposure in either cohort (COPSAC₂₀₀₀ , P = 0.36; and COPSAC₂₀₁₀ cohort, P = 0.42).

CONCLUSION

Neonatal domestic dog exposure was associated with a strongly reduced risk of atopic dermatitis in two independent birth cohorts and in a dose-dependent manner. While the mechanisms involved are unclear, our findings raise the question of whether in utero exposures may affect the risk of atopic dermatitis and emphasize the importance of the early environment for disease trajectory.

Immune-mediated diseases and microbial exposure in early life

The non-communicable disease pandemic includes immune-mediated diseases such as asthma and allergy, which are likely originating in early life where the immature immune system is prone to alterations caused by the exposome. The timing of exposure seems critical for the developing immune system, and certain exposures may have detrimental effects in the earliest life, but no or even beneficial effects later. The human microbiome and infections are candidates as intermediary in the interaction between the host and the environment. The evidence seems inconsistent as infections as well as particular colonization patterns in neonates drive both short-term and long-term asthma symptoms, while, on the other hand, the composition of the microbiome in early life may protect against asthma and allergy in later life. This apparent contradiction may be explained by a deeper disease heterogeneity than we are currently able to discriminate, and in particular, the indiscriminate lumping together of different diseases into one atopic disease category. Also, the microbiome needs a differentiated understanding, considering balance between microbial groups, diversity and microbial genetic capability. Furthermore, the effects of the microbial exposure may only affect individuals with certain susceptibility genes. Few of the observations have been replicated, and publication bias is likely. Therefore, we are still far from understanding, or having proved, causal effects of the human microbiome. Still, the microbiome-gene interaction is a fascinating paradigm that fosters exiting research and promises a breakthrough in the understanding of the mechanisms driving asthma, allergy and eczema, and potentially also other immune-mediated non-communicable diseases.

Deep phenotyping of the unselected COPSAC2010 birth cohort study

Background

We hypothesize that perinatal exposures, in particular the human microbiome and maternal nutrition during pregnancy, interact with the genetic predisposition to cause an abnormal immune modulation in early life towards a trajectory to chronic inflammatory diseases such as asthma and others.

Objective

The aim of this study is to explore these interactions by conducting a longitudinal study in an unselected cohort of pregnant women and their offspring with emphasis on deep clinical phenotyping, exposure assessment, and biobanking. Exposure assessments focus on the human microbiome. Nutritional intervention during pregnancy in randomized controlled trials are included in the study to prevent disease and to be able to establish causal relationships.

Methods

Pregnant women from eastern Denmark were invited during 2008–2010 to a novel unselected ‘COPSAC₂₀₁₀’ cohort. The women visited the clinic during pregnancy weeks 24 and 36. Their children were followed at the clinic with deep phenotyping and collection of biological samples at nine regular visits until the age of 3 and at acute symptoms. Randomized controlled trials of high‐dose vitamin D and fish oil supplements were conducted during pregnancy, and a trial of azithromycin for acute lung symptoms was conducted in the children with recurrent wheeze.

Results

Seven hundred and thirty‐eight mothers were recruited from week 24 of gestation, and 700 of their children were included in the birth cohort. The cohort has an over‐representation of atopic parents. The participant satisfaction was high and the adherence equally high with 685 children (98%) attending the 1 year clinic visit and 667 children (95%) attending the 2 year clinic visit.

Conclusions

The COPSAC₂₀₁₀ birth cohort study provides longitudinal clinical follow‐up with highly specific end‐points, exposure assessments, and biobanking. The cohort has a high adherence rate promising strong data to elucidate the interaction between genomics and the exposome in perinatal life leading to lifestyle‐related chronic inflammatory disorders such as asthma.

Antibiotic use during pregnancy alters the commensal vaginal microbiota

Antibiotics may induce alterations in the commensal microbiota of the birth canal in pregnant women. Therefore, we studied the effect of antibiotic administration during pregnancy on commensal vaginal bacterial colonization at gestational week 36. Six hundred and sixty-eight pregnant women from the novel unselected Copenhagen Prospective Studies on Asthma in Childhood (COPSAC2010 ) pregnancy cohort participated in this analysis. Detailed information on oral antibiotic prescriptions during pregnancy filled at the pharmacy was obtained and verified prospectively. Vaginal samples were obtained at pregnancy week 36 and cultured for bacteria. Women who received oral antibiotics during any pregnancy trimester had an increased rate of colonization by Staphylococcus species in the vaginal samples as compared with samples obtained from women without any antibiotic treatment during pregnancy (adjusted OR 1.63, 95% CI 1.06-2.52, p 0.028). Oral antibiotic administration in the third trimester were also associated with increased colonization by Staphylococcus species (adjusted OR 1.98, 95% CI 1.04-3.76, p 0.037). These bacteriological changes were associated with urinary tract infection antibiotics. Women treated in the third trimester of pregnancy were more often colonized by Escherichia coli than women without antibiotic treatment in the third trimester (adjusted OR 1.91, 95% CI 1.04-3.52, p 0.038). This change was associated with respiratory tract infection (RTI) antibiotics. We did not observe any significant changes in vaginal Streptococcus agalactiae (group B streptoccocus) or Staphylococcus aureus colonization following antibiotic treatment in pregnancy. Antibiotic administration during pregnancy leads to alterations in the vaginal microbiological ecology prior to birth, with potential morbidity, and long-term effects on the early microbial colonization of the neonate.

Overdiagnosis of dementia in young patients - a nationwide register-based study

BACKGROUND

Little is known about the quality of the diagnostic evaluation and the validity of dementia diagnoses in young patients established in routine clinical practice. The aim of this study was to investigate the validity of the diagnosis of dementia registered in the Danish nationwide hospital registers in young patients.

METHODS

Two hundred patients were randomly selected from 891 patients <65 years registered with a dementia diagnosis for the first time in 2008. The patients' medical records were reviewed to evaluate if they fulfilled ICD-10 and/or DSM-IV criteria for dementia and current clinical criteria for specific dementia subtypes.

RESULTS

A registered diagnosis was found to be correct in only 59%. A misdiagnosis of dementia occurred primarily in patients with depression or alcohol abuse.

CONCLUSION

Our results suggest that dementia is overregistered and overdiagnosed in young patients. This may be due to a different symptom profile of dementia in young patients, lack of knowledge among clinical physicians and the wide range of conditions which may be misinterpreted as dementia.

A novel presenilin 2 mutation (V393M) in early-onset dementia with profound language impairment

BACKGROUND

Mutations in the Presenilin 2 gene (PSEN2) are rare causes of Alzheimer's disease (AD). Pathogenic mutations in the genes associated with autosomal dominant inherited AD have been shown to alter processing of the amyloid precursor protein (APP) resulting in a relative increase of the amount of Abeta42 peptide.

METHODS AND RESULTS

We present a patient with neuropathologically confirmed early-onset AD characterized by profound language impairment. The patient was heterozygous for a novel missense mutation in exon 11 of the PSEN2 gene leading to a predicted amino acid substitution from valine to methionine in position 393, a conserved residue. However, in vitro expression of PSEN2 V393M cDNA did not result in detectable increase of the secreted Abeta42/40 peptide ratio. The mutation was not found in 384 control individuals tested.

CONCLUSIONS

The possible pathogenic nature of the mutation is not clarified. We discuss the limitations of functional PSEN2 studies and the challenges associated with genetic counselling of family members at risk.

Alzheimer disease-like clinical phenotype in a family with FTDP-17 caused by a MAPT R406W mutation

We report clinical, molecular, neuroimaging and neuropathological features of a Danish family with autosomal dominant inherited dementia, a clinical phenotype resembling Alzheimer's disease and a pathogenic mutation (R406W) in the microtubule associated protein tau (MAPT) gene. Pre-symptomatic and affected family members underwent multidisciplinary (clinical, molecular, neuroimaging and neuropathological) examinations. Treatment with memantine in a family member with early symptoms, based on the clinical phenotype and the lack of specific treatment, appears to stabilize the disease course and increase the glucose metabolism in cortical and subcortical areas, as determined by serial [F(18)]FDG-PET scanning before and after initiation of treatment. Neuropathological examination of a second affected and mutation-positive family member showed moderate atrophy of the temporal lobes including the hippocampi. Microscopy revealed abundant numbers of tau-positive neurofibrillary tangles in all cortical areas and in some brainstem nuclei corresponding to a diagnosis of frontotemporal lobe degeneration on the basis of a MAPT mutation. The clinical and genetic heterogeneity of autosomal dominant inherited dementia must be taken into account in the genetic counselling and genetic testing of families with autosomal dominantly inherited dementia in general.

[Barotrauma in children and adults after flying. Prevalence and treatment with Otovent]

To prevent barotitis during descent in aviation, the ears have to be cleared several times by performing the Valsalva's manoeuvre. The manoeuvre is difficult for children to perform, and they are therefore at high risk of developing barotitis. The treatment of barotitis is either inflation by a Politzer balloon or myringotomy. An alternative treatment is autoinflation using the Otovent. This prophylaxis/treatment can be performed by the child with assistance from its parents as soon as or preferably before the descent has started. The prevalence of barotitis amongst 45 children and 49 adults in transit was found to be highest in children, 28%, compared with adults, 10%. Only 6% of the children with negative middle ear pressure after flight managed a successful Valsalva manoeuvre, whereas 33% could normalise the middle ear pressure by inflating the Otovent. In conclusion we recommend autoinflation using the Otovent set by children and adults who have problems clearing their ears during flight.

Point prevalence of barotitis in children and adults after flight, and effect of autoinflation

The most common cause of barotitis is pressure changes during descent in aviation. Equilibration is normally achieved by swallowing, jaw movements, yawning, or chewing, but some have to perform a Valsalva maneuver several times during descent and even by these means some fail. The aim of the study was to estimate the point prevalence of barotrauma in children and adults after flight, and to test the effect of an autoinflation device (Otovent), in improving negative middle ear pressure after flight. Questionnaires and Otovent, were distributed to all air passengers in eight incoming flights. The questionnaires inquired about nasal allergy, nasal congestion, previous and actual ear pain, use of decongestants and experience of inflating the Otovent set during descent. After flight, the passengers were offered an ear examination including otoscopy and tympanometry both before and after a Valsalva maneuver, as well as after Otovent inflation. Otoscopic signs of barotitis were found in 10% of the adults and in 22% of the children. Negative middle ear pressure of more than 10 hPa after landing was found in 20% of the adults and in 40% of the children. The Valsalva maneuver normalized the pressure in 46% of the adults and in 33% of the children. Of the adults, 73%, and of the children, 69% with an unsuccessful Valsalva maneuver could improve or normalize the middle ear pressure by inflating the Otovent set. In conclusion, we recommend autoinflation using the Otovent set to air passengers with problems clearing the ears during flight.

Barotitis in children after aviation; prevalence and treatment with Otovent

Barotitis is an acute or chronic inflammation caused by environmental pressure changes. The most common cause is the pressure change during descent in civil aviation. To prevent barotitis the middle ear pressure has to be equalised several times during descent. This can be achieved by performing the Valsalva manoeuvre, but for children, many of whom have a dysfunction of the Eustachian tube, this is difficult to perform and they are therefore at high risk of developing barotitis during flight. The traditional treatment modalities of barotitis are inflation by a Politzer balloon, myringotomy or prophylactic grommet insertion. An alternative treatment or prophylactic measure is autoinflation using the Otovent treatment set. This prophylaxis/treatment can be performed by the child with assistance from its parents as soon as possible or rather before the descent has started. The prevalence of barotitis amongst transit passengers was found to be highest in young children, 25 per cent, compared with adults, five per cent. Only 21 per cent of the youngest children with negative middle ear pressure after flight managed a successful Valsalva's manoeuvre, whereas 82 per cent could increase the middle ear pressure inflating the Otovent set. In conclusion we recommend autoinflation using the Otovent set by children and adults with problems clearing the ears during flight.

Human platelet 5-hydroxytryptamine concentration as a tool in prediction of solvent induced neurotoxic effects

Many organic solvents are lipophilic and concentrate in lipid rich tissues e.g. nervous tissue, where they are known to induce toxic effects in humans, especially in the central nervous system. Changes in the presynaptic neurotransmitter metabolism may play a role in these effects. The platelet is proposed as an alternative human model for this complex in the investigation of such changes, especially regarding 5-hydroxytryptamine (5-HT). The platelet 5-HT concentration was measured in platelets isolated from exposed persons with diagnosed neurointoxication caused by exposure to organic solvents and compared to controls. No difference in the concentration was found. Instead of using the platelet 5-HT concentration in the prediction of neurotoxic effects, the platelet 5-HT uptake rate may be an alternative parameter. A specific and sensitive double isotope derivative technique for 5-HT measurements is described. A solvent induced reduction in the number of platelets/ml platelet rich plasma was found and is discussed.

Ophthamologic effects of man-made mineral fibers

The effect of man-made mineral fibers on the human eye was investigated in a cross-sectional study of 15 workers exposed to Rockwool and a matched reference group of 15 people. Eye symptoms, changes in the cellular and mucous content of the conjunctival fluid, break-up time of the precorneal film, the number of microepithelial defects, and the number of dead and degenerated cells on the cornea and bulbar conjunctiva were used as measures of effect. The number of fibers accumulated in the eye and conventional dust sampling methods were used as measures of dose. A significantly higher frequency of eye symptoms related to work conditions (p less than 0.001) was found among exposed workers. Similarly, the number of microepithelial defects on the medial bulbar conjunctiva increased significantly (p = 0.009) after 4 d of exposure. Six exposed workers had a pathological increase in the neutrophil count of the conjunctival fluid after 4 d of exposure, and an increase was seen in only one worker after a weekend free from exposure. Significant correlation was found between microepithelial defects on the medial bulbar conjunctiva and measures of dose (p less than 0.01). The symptoms and cellular changes can be explained by the assumption that man-made mineral fibers have the same mechanical and reversible effect on the eye as on the skin. The described dose-effect relationship suggests that a much lower hygienic standard is needed for man-made mineral fibers than what has been recommended by the American Conference of Governmental Industrial Hygienists.

Accumulation of fibers in the eyes of workers handling man-made mineral fiber products

The external eye can be considered a passive dust sampler. Foreign material deposited in the conjunctival cul-de-sac becomes enclosed by mucous fibrils. The fibrils adhere to the conjunctival mucous thread. Hence, by removing the mucus, one can study, eg, man-made mineral fibers deposited in the eye. In this study a simple method for this purpose has been developed, and the sampling characteristics of the eye for nonrespirable fibers is described. The numbers of nonrespirable fibers accumulated in the eyes correlated with the total dust exposure dose (correlation coefficient r = 0.92) and with the nonrespirable fiber exposure dose (r = 0.82). There was no correlation between the airborne fiber concentration and the number of fibers in the mucous thread alone.