Aino Rantala

Mannose-binding lectin concentrations, MBL2 polymorphisms, and susceptibility to respiratory tract infections in young men.

BACKGROUND Mannose-binding lectin (MBL) is an important component of innate immunity, and its deficiency is associated with susceptibility to recurrent infections. METHODS This exploratory study investigated the association of serum MBL concentrations and MBL2 gene polymorphisms with respiratory tract infections in young men. We genotyped 6 single-nucleotide polymorphisms (SNPs) in the promoter region (alleles H/L, X/Y, and P/Q) and exon 1 (variant alleles B, C, and D and wild-type allele A) of the MBL2 gene by real-time polymerase chain reaction and measured serum MBL concentrations in 111 Finnish military recruits with asthma and 362 without. RESULTS An MBL level below the median concentration was a significant risk factor for infections (asthma status-adjusted odds ratio [OR], 2.5 [95% confidence interval {CI}, 1.4-4.5]). Among the 6 SNPs, there was a significant association between the promoter Y/Y genotype and infections (OR, 2.3 [95% CI, 1.2-4.4]) and a borderline significant association between exon 1 variant alleles and infections (OR, 1.7 [95% CI, 0.9-3.1]), after adjustment for asthma status. CONCLUSION These preliminary results suggest, for the first time, an association between MBL level and respiratory tract infections in young men and a possible association between infections and MBL2 polymorphisms.

Central Aortic Blood Pressure of Hypertensive Men During Short-Term Cold Exposure

BACKGROUND Short- and long-term exposures to cold increase blood pressure and may explain the higher wintertime cardiovascular morbidity and mortality. Hypertensive subjects may be more susceptible to adverse cold-related cardiovascular health effects. The aim of our study was to assess the effect of short-term cold exposure on central aortic blood pressure among untreated hypertensive men. METHODS We conducted a population-based recruitment of 41 hypertensive men and a control group of 20 men without hypertension (aged 55-65 years) who underwent whole-body cold exposure (15-minute exposure to temperature -10 °C, wind 3 m/s, winter clothes). Central aortic blood pressure, augmentation index, and subendocardial viability ratio were measured by radial artery applanation tonometry. RESULTS Short-term cold exposure increased the central aortic blood pressure similarly both in both hypertensive men, from 130/93 to 162/107 mm Hg (P < 0.001) and men in the control group, from 114/81 to 142/91 mmHg (P < 0.001). Augmentation index increased by 12% (from 10% to 22%, P < 0.001; and from 16% to 28%, P < 0.001, respectively), whereas subendocardial viability ratio decreased 10% (from 188% to 177%, P = 0.001; and from 203% to 193%, P = 0.01, respectively) during cold exposure in both hypertensive men and control subjects. CONCLUSIONS Short-term cold exposure increases central aortic blood pressure and cardiac workload, and myocardial oxygen demand slightly increases in relation to blood supply in untreated hypertensive middle-aged men. Because of the higher baseline blood pressure among hypertensive subjects, the cold-induced rise in central aortic blood pressure may increase the risk of adverse cardiovascular health effects.

Respiratory Infections in Adults with Atopic Disease and IgE Antibodies to Common Aeroallergens

Background Atopic diseases, including allergic rhinitis, allergic dermatitis and asthma, are common diseases with a prevalence of 30–40% worldwide and are thus of great global public health importance. Allergic inflammation may influence the immunity against infections, so atopic individuals could be susceptible to respiratory infections. No previous population-based study has addressed the relation between atopy and respiratory infections in adulthood. We assessed the relation between atopic disease, specific IgE antibodies and the occurrence of upper and lower respiratory infections in the past 12 months among working-aged adults. Methods and Findings A population-based cross-sectional study of 1008 atopic and non-atopic adults 21–63 years old was conducted. Information on atopic diseases, allergy tests and respiratory infections was collected by a questionnaire. Specific IgE antibodies to common aeroallergens were measured in serum. Adults with atopic disease had a significantly increased risk of lower respiratory tract infections (LRTI; including acute bronchitis and pneumonia) with an adjusted risk ratio (RR) 2.24 (95% confidence interval [CI] 1.43, 3.52) and upper respiratory tract infections (URTI; including common cold, sinusitis, tonsillitis, and otitis media) with an adjusted RR 1.55 (1.14, 2.10). The risk of LRTIs increased with increasing level of specific IgE (linear trend P = 0.059). Conclusions This study provides new evidence that working-aged adults with atopic disease experience significantly more LRTIs and URTIs than non-atopics. The occurrence of respiratory infections increased with increasing levels of specific IgE antibodies to common aeroallergens, showing a dose-response pattern with LRTIs. From the clinical point of view it is important to recognize that those with atopies are a risk group for respiratory infections, including more severe LRTIs.

Early Respiratory Infections and the Development of Asthma in the First 27 Years of Life

Previous studies have provided contradictory evidence on the role of early childhood respiratory infections in the development of asthma and other allergic diseases during childhood. We investigated early-life respiratory infections as predictors of the development of asthma in a 20-year prospective cohort study (the Espoo Cohort Study, 1991-2011). Information on upper respiratory tract infections (URTIs) and lower respiratory tract infections (LRTIs) was collected with a parent-administered baseline questionnaire covering the preceding 12 months (part 1; n = 2,228), and information on LRTIs leading to hospitalization was obtained from the National Hospital Discharge Registry (part 2; n = 2,568). The incidence of asthma was assessed on the basis of 6-year and 20-year follow-up questionnaires. Adjusted hazard ratios were estimated using Cox proportional hazards models. Both URTIs (adjusted hazard ratio (HR) = 1.64, 95% confidence interval (CI): 1.22, 2.19) and LRTIs (adjusted HR = 2.11, 95% CI: 1.48, 3.00) in early childhood were strong predictors of asthma incidence up to young adulthood (ages 20-27 years). A declining age trend was present for both URTIs (P-trend < 0.01) and LRTIs (P-trend < 0.001). In part 2 of our analysis, a significant risk of asthma was found in relation to LRTIs requiring hospitalization (adjusted HR = 1.93, 95% CI: 1.10, 3.38). The results provide new evidence that respiratory tract infections in early life predict the development of asthma through childhood to young adulthood.

Erratum: Allergic diseases and asthma in the family predict the persistence and onset-age of asthma: a prospective cohort study

Author details Center for Environmental and Respiratory Health Research, University of Oulu, Oulu, Finland. Respiratory Medicine Unit, Department of Medicine, Oulu University Hospital, Oulu, Finland. Respiratory Medicine Unit, Institute of Clinical Medicine, University of Oulu, Oulu, Finland. Public Health, Institute of Health Sciences, University of Oulu, Oulu, Finland. Medical Research Center Oulu, University of Oulu, Oulu, Finland.

Comparison of polymerase chain reaction methods, in situ hybridization, and enzyme immunoassay for detection of Chlamydia pneumoniae in atherosclerotic carotid plaques

Chlamydia pneumoniae has been associated with cardiovascular diseases and has been shown by different methods to be present in atherosclerotic lesions. However, not all studies have found C. pneumoniae in atherosclerotic tissues. We compared polymerase chain reaction (PCR) methods, in situ hybridization (ISH), and measurement of chlamydial lipopolysaccharide (cLPS) by enzyme immunoassay (EIA) from homogenized atherosclerotic tissue in the detection of C. pneumoniae. In a study population of 110 patients with carotid artery disease, cLPS was found in 22.2%, and DNA by PCR was found in 34.3% and by ISH in 39.4% of the samples. Poor repeatability was shown to complicate PCR, and the technical problems inherent in ISH were not insignificant. In contrast, the cLPS EIA test was fast and easy to perform. If the sensitivity could be increased, for example, by testing multiple tissue pieces, cLPS EIA might provide a standardized commercial method for the detection of chlamydia in tissue samples, and it, thus, merits further characterization and validation in different patient populations.

Interleukin‐6 −174 G/C Promoter Polymorphism is Associated with Persistence of Chlamydia pneumoniae Antibodies in Young Men

A promoter polymorphism −174 G/C in the inflammatory cytokine interleukin‐6 (IL‐6) gene has been associated with differences in serum IL‐6 levels and a risk for inflammatory conditions, such as cardiovascular diseases. We investigated whether this polymorphism is associated with Chlamydia pneumoniae, a common causative agent of respiratory infection with tendency for persistent infections, in 867 Finnish military recruits. IgG seropositivity in arrival and departure serum samples during 6–12 months of military service was considered as persistence of antibodies and a possible prolonged or chronic infection. The −174C allele was significantly associated with IgG seropositivity (P = 0.0002) and the persistence of IgG antibodies (P = 0.0002) as well as with slightly elevated C‐reactive protein (CRP) levels (P = 0.003). In addition, the association was stronger when persistent C. pneumoniae antibodies were present together with elevated CRP than when either of them was positive alone (OR; 95% CI: 3.45; 2.00–5.98 and 1.41; 1.00–1.99, respectively). Our data suggest that IL‐6 −174 G/C polymorphism is associated with persistence of C. pneumoniae antibodies and may be linked to the chronic or prolonged infection with systemic low‐grade inflammation.

Early Respiratory Infections and Dental Caries in the First 27 Years of Life: A Population-Based Cohort Study.

Early-life respiratory tract infections (RTIs) and dental caries are among the most common infectious diseases worldwide. The relations between early RTIs and development of caries in permanent teeth have not been studied earlier. We assessed childhood RTIs as potential predictors of caries in young adulthood in a 20-year prospective population-based cohort study (The Espoo Cohort Study). Information on lower respiratory tract infections (LRTIs) that had required hospitalization was retrieved from the National Hospital Discharge Registry (n = 1623). Additional information on LRTIs and upper RTIs (URTIs) was assessed based on the questionnaire reports that covered the preceding 12 months. Caries was measured as the number of teeth with fillings (i.e. filled teeth, FT) reported in the 20-year follow-up questionnaire. The absolute and relative excess numbers of FT were estimated applying negative binomial regression. The mean number of FT in young adulthood was 1.4 greater among subjects who had experienced LRTIs requiring hospitalization before the age of 2 years (SD 4.8) compared to those without any such infections (SD 3.4), and the adjusted relative excess number of FT was 1.5 (95% CI 1.0–2.2). LRTIs up to 7 years were associated with an absolute increase of 0.9 in the mean FT number, the adjusted relative excess being 1.3 (1.0–1.8). Also the questionnaire-based LRTIs (adjusted relative excess 1.3; 95% CI 0.9–1.8) and URTIs (adjusted relative excess 1.4, 1.0–1.8) before the age of 2 years predicted higher occurrence of FT. Findings suggest that early RTIs have a role in the development of dental caries in permanent teeth.