Significant disparities in allergy prevalence and microbiota between the young people in Finnish and Russian Karelia

BACKGROUND

Atopic allergy has been more common among schoolchildren in Finland, as compared to Russian Karelia. These adjacent regions show one of the most contrasting socio-economical differences in the world.

OBJECTIVE

We explored changes in allergy from school age to young adulthood from 2003 to 2010/2012 in these two areas. The skin and nasal microbiota were also compared.

METHODS

Randomly selected children from Finnish (n = 98) and Russian Karelia (n = 82) were examined in 2003, when the children were 7-11 years of age, and again in 2010 (Finnish Karelia) and 2012 (Russian Karelia). We analysed self-reported allergy symptoms and sensitization to common allergens by serum sIgE values. The skin (volar forearm) and nasal mucosa microbiota, collected in 2012 (aged 15-20 years), identified from DNA samples, were compared with multivariate methods.

RESULTS

Asthma, hay fever, atopic eczema, self-reported rhinitis, as well as atopic sensitization, were threefold to 10-fold more common in Finland, as compared to Russian Karelia. Hay fever and peanut sensitization were almost non-existent in Russia. These patterns remained throughout the 10-year follow-up. Skin microbiota, as well as bacterial and fungal communities in nasal mucosa, was contrastingly different between the populations, best characterized by the diversity and abundance of genus Acinetobacter; more abundant and diverse in Russia. Overall, diversity was significantly higher among Russian subjects (P_skin < 0.0001, P_{nasal-bacteria} < 0.0001 and P_nasal-fungi < 0.01). Allergic diseases were not associated with microbial diversity in Finnish subjects.

CONCLUSIONS AND CLINICAL RELEVANCE

Differences in allergic phenotype, developed in early life, remain between populations. A parallel difference in the composition of skin and nasal microbiota suggests a potential underlying mechanism. Our results also suggest that high abundance and diversity of Acinetobacter might contribute to the low allergy prevalence in Russia. Implications of early-life exposure to Acinetobacter should be further investigated.

Are allergic multimorbidities and IgE polysensitization associated with the persistence or re-occurrence of foetal type 2 signalling? The MeDALL hypothesis

Allergic diseases [asthma, rhinitis and atopic dermatitis (AD)] are complex. They are associated with allergen-specific IgE and nonallergic mechanisms that may coexist in the same patient. In addition, these diseases tend to cluster and patients present concomitant or consecutive diseases (multimorbidity). IgE sensitization should be considered as a quantitative trait. Important clinical and immunological differences exist between mono- and polysensitized subjects. Multimorbidities of allergic diseases share common causal mechanisms that are only partly IgE-mediated. Persistence of allergic diseases over time is associated with multimorbidity and/or IgE polysensitization. The importance of the family history of allergy may decrease with age. This review puts forward the hypothesis that allergic multimorbidities and IgE polysensitization are associated and related to the persistence or re-occurrence of foetal type 2 signalling. Asthma, rhinitis and AD are manifestations of a common systemic immune imbalance (mesodermal origin) with specific patterns of remodelling (ectodermal or endodermal origin). This study proposes a new classification of IgE-mediated allergic diseases that allows the definition of novel phenotypes to (i) better understand genetic and epigenetic mechanisms, (ii) better stratify allergic preschool children for prognosis and (iii) propose novel strategies of treatment and prevention.

Allergy gap between Finnish and Russian Karelia on increase

BACKGROUND

Multinational time-trend analyses of atopic disease have shown that the East-West gradients in prevalence are shrinking. We set out to clarify whether the disparities in the occurrence of atopy and atopic diseases in Finnish and Russian Karelia during the past 10 years have diminished and how the prevalence of atopy has evolved with successive years of birth.

METHODS

Two surveys with identical methodology were performed in 1997/1998 and 2007. The study population comprised randomly selected adults, aged 25-54 years, from Finnish and Russian Karelia. Serum samples were collected for total and specific IgE measurements. Clinical data were obtained by questionnaires.

RESULTS

Sensitization rates to birch pollen increased from 7.8% to 14.8% (P < 0.001) and to cat from 6.1% to 10.8% (P < 0.001) in Finland. In Russia, no significant increase was found. Contrary to this, total IgE remained stable in Finland but decreased significantly (P < 0.001) in Russia. Analyses based on years of birth revealed that the prevalence of sensitization to allergens increased with successive birth years in Finland, but remained stable in Russia. Over the 10 years, self-reported physician-diagnosed asthma increased from 5.5% to 8.1% (P = 0.05) and hay fever from 8.1% to 13.2% (P < 0.001) in Finland.

CONCLUSIONS

Disparities in the prevalence of atopy and atopic disease between Finnish and Russian Karelia have further grown. The 'allergy epidemic' continues in Finland and is mainly attributable to the years of birth effect shown in atopy prevalence. In Russia, no signs of the epidemic are discernible, although the decrease in total IgE may indicate a change in environmental exposure.

MeDALL (Mechanisms of the Development of ALLergy): an integrated approach from phenotypes to systems medicine

The origin of the epidemic of IgE-associated (allergic) diseases is unclear. MeDALL (Mechanisms of the Development of ALLergy), an FP7 European Union project (No. 264357), aims to generate novel knowledge on the mechanisms of initiation of allergy and to propose early diagnosis, prevention, and targets for therapy. A novel phenotype definition and an integrative translational approach are needed to understand how a network of molecular and environmental factors can lead to complex allergic diseases. A novel, stepwise, large-scale, and integrative approach will be led by a network of complementary experts in allergy, epidemiology, allergen biochemistry, immunology, molecular biology, epigenetics, functional genomics, bioinformatics, computational and systems biology. The following steps are proposed: (i) Identification of 'classical' and 'novel' phenotypes in existing birth cohorts; (ii) Building discovery of the relevant mechanisms in IgE-associated allergic diseases in existing longitudinal birth cohorts and Karelian children; (iii) Validation and redefinition of classical and novel phenotypes of IgE-associated allergic diseases; and (iv) Translational integration of systems biology outcomes into health care, including societal aspects. MeDALL will lead to: (i) A better understanding of allergic phenotypes, thus expanding current knowledge of the genomic and environmental determinants of allergic diseases in an integrative way; (ii) Novel diagnostic tools for the early diagnosis of allergy, targets for the development of novel treatment modalities, and prevention of allergic diseases; (iii) Improving the health of European citizens as well as increasing the competitiveness and boosting the innovative capacity of Europe, while addressing global health issues and ethical issues.

Opposite gene by environment interactions in Karelia for CD14 and CC16 single nucleotide polymorphisms and allergy

BACKGROUND

Finnish Karelians have a higher prevalence of allergic disease than Russian Karelians. As both populations are generally from the same ethnic group, the Karelian population offers a unique opportunity to analyse genetic and allergic disease interactions between 'Western' and 'Eastern' environments.

OBJECTIVES

We investigated associations between allergic diseases and CD14 and CC16 polymorphisms in Finnish vs Russian Karelian women.

METHODS

Adult female Karelians (330 Finnish and 274 Russian) were recruited, examined for a range of symptoms and conditions including rhinitis, itchy rash, asthma and atopy and genotyped for CD14 C-159T and CC16 A38G.

RESULTS

For both CD14 C-159T and CC16 A38G, the risk allele for atopic phenotypes in Finnish Karelia was the protective allele in Russian Karelia. For CD14 C-159T, an interactive effect on ever itchy rash (P(interaction) = 0.004), itchy rash <12 mo (P(interaction) = 0.001) and dry cough at night in the past 12 months (<12 months) (P(interaction) = 0.011) was found; the risk allele was C in Russians and T in Finns. For CC16 A38G, an interaction was significant for ever rhinitis (P(interaction) = 0.006), rhinitis <12 mo (P(interaction) = 0.004), and marginally significant for ever hayfever (P(interaction) = 0.07), allergic eye symptoms <12 mo (P(interaction) = 0.09); their risk allele was G in Russians and A in Finns.

CONCLUSION

An Eastern vs Western environment appears to exert an effect via opposite alleles on risk of allergic diseases in adult women.

Finnish Allergy Programme 2008-2018--time to act and change the course

BACKGROUND

The prevalence of allergic diseases has grown in Finland, similarly to many other western countries. Although the origin of allergy remains unresolved, increasing body of evidence indicates that the modern man living in urban built environment is deprived from environmental protective factors (e.g. soil microorganisms) that are fundamental for normal tolerance development. The current dogma of allergen avoidance has not proved effective in halting the 'epidemic', and it is the Finnish consensus that restoring and strengthening tolerance should more be in focus.

AIM

The national 10-year programme is aimed to reduce burden of allergies. The main goals are to (i) prevent the development of allergic symptoms; (ii) increase tolerance against allergens; (iii) improve the diagnostics; (iv) decrease work-related allergies; (v) allocate resources to manage and prevent exacerbations of severe allergies and (vi) decrease costs caused by allergic diseases.

METHODS

For each goal, specific tasks, tools and evaluation methods are defined. Nationwide implementation acts through the network of local co-ordinators (primary care physicians, nurses, pharmacists). In addition, three nongovernmental organizations (NGOs) take care of the programme implementation. The 21 central hospital districts carry out a three step educational process: (i) healthcare personnel; (ii) representatives and educators of NGOs and (iii) patients and the general population. For outcome evaluation, repeated surveys are performed and healthcare registers employed at the beginning, at 5 years, and at the end of the programme. The process will be evaluated by an independent external body.

CONCLUSION

The Finnish initiative is a comprehensive plan to reduce burden of allergies. The aim is to increase immunological tolerance and change attitudes to support health instead of medicalizing common and mild allergy symptoms. It is time to act, when allergic individuals are becoming a majority of western populations and their numbers are in rapid increase worldwide. The Programme is associated with the Global Alliance of Chronic Respiratory Diseases (GARD), WHO.

Microbial content of drinking water in Finnish and Russian Karelia - implications for atopy prevalence

BACKGROUND AND AIM

The influence of microbial quality of drinking water from different sources on the occurrence of atopy has been poorly examined. This study was undertaken to clarify the association between the overall microbial content in drinking water and the occurrence of atopy among schoolchildren from two neighbouring areas with profound differences in living conditions and lifestyles.

METHODS

Drinking water samples were obtained from kitchens of nine schools in North Karelia, Finland and of nine schools from Pitkäranta, the Republic of Karelia, Russia. The pupils of these schools were participants of the Karelian Allergy Study. Occurrence of atopy, determined by skin prick test positivity (one or more) to 14 common airborne and food allergens, was measured in all 563 children, aged 7-16 years, from these 18 schools. Water samples were analysed using standard methods for drinking water analyses including viable counts for Escherichia coli, intestinal enterococci, coliform bacteria and heterotrophic bacteria. In addition, total cell counts including both viable and nonviable bacteria, algae and protozoans were assessed using epifluorescence microscope with 4'-6-diamidino-2-phenylindole (DAPI) staining.

RESULTS

In Finland, 29% of the children were sensitized to birch when compared with 2% of the Russian children (P < 0.0001). Overall, sensitization rates for any of the pollens were 39% and 8% (P < 0.0001), and for any of the allergens 48% and 16%, respectively (P < 0.0001). Because of substantial differences in raw water sources and treatment practices, the total numbers of microbial cells in drinking water were many-fold higher in Russia than in Finland. A dose-response relationship was found for occurrence of atopy and the DAPI value indicative of microbial cell content in the water (P < 0.0001). Further, multivariate logistic regression analysis revealed that high (>10(6) cells/ml) and intermediate (10(5)-10(6) cells/ml) DAPI values were associated with reduced risk of atopy (odds ratio 0.34, 95% confidence interval 0.20-0.57 and 0.39, 0.23-0.69, respectively), independently from other factors.

CONCLUSION

High overall content of micro-organisms in drinking water may be associated with reduced risk of atopy, independently from other determinants.

A disparity in the association of asthma, rhinitis, and eczema with allergen-specific IgE between Finnish and Russian Karelia

BACKGROUND

A substantial variation in the association of asthma, rhinitis and eczema with elevated serum allergen-specific immunoglobulin E (sIgE) levels between different populations has been reported. Here, we wanted to clarify whether these proportions are different in Finnish and Russian Karelia, and compared the ability of questionnaires, skin prick tests (SPT) and sIgE measurements to detect atopic conditions in these adjacent areas with different living conditions.

METHODS

Randomly selected schoolchildren, aged 6-16 years, and their mothers from Finland (n = 344 children, 344 mothers) and Russia (427 and 284 respectively) participated. SPTs and sIgE measurements to common inhalant and food allergens were performed. The occurrence of asthma, rhinitis, eczema and related symptoms was assessed with an International Study of Asthma and Allergies in Childhood-based questionnaire. Correlation between SPT and sIgE was estimated using the Spearman correlation coefficient.

RESULTS

The rate of positive sIgE results was significantly higher in Finland among both mothers and children. Seventy-seven per cent of Finnish children and 43% of Russian children with asthma were sIgE positive. The respective figures for hay fever were 94% and 67%, and for eczema 68% and 41%. This discrepancy was similar but of lower magnitude among mothers. The overall occurrence of asthma, rhinitis and eczema was very low in Russian Karelia. The correlation between SPT and sIgE results was generally good.

CONCLUSION

Asthma, rhinitis and eczema in Russian Karelia are not only rare but also, to a large extent, have no sIgE component. Therefore, the ability of questionnaires to detect sIgE-mediated atopic conditions in this area of Russia is poor.

Signs of reversing trends in prevalence of asthma

Several recent reports have provided evidence that the burden of asthma may have levelled off, after increasing for decades. Implementation of the national and global asthma prevention and management guidelines that have led to earlier detection and improved treatment of asthmatics, is considered to be involved in this apparent change for the better. In addition, environmental influences associated with the modern life may have reached the maximum in inducing symptoms and disease in genetically susceptible individuals in some areas. Available data obtained from Canada and non-English-speaking countries in Europe show that the peak in asthma prevalence has been reached at the level of 8-12%. This review outlines the most recent literature on time trends in asthma prevalence and considers the possible causes of the current trends. Problems and pitfalls in appraising studies on time trends are also discussed.

Highly elevated serum phyto-oestrogen concentrations in patients with diabetic nephropathy

BACKGROUND AND OBJECTIVES

Phyto-oestrogens, naturally occurring phenolic, hormone-like compounds, have raised considerable interest due to their anticarcinogenic, antiatherogenic and antioxidative potential. Oxidative stress may be one of the key factors in the development of vascular complications in patients with type 1 diabetes. Here, we tested the hypothesis that high concentrations of phyto-oestrogens in serum may be associated with lower occurrence of vascular complications in these patients.

SUBJECTS

A total of 400 patients, recruited consecutively from the participant register of the nationwide FinnDiane study of type 1 diabetes and divided into four parallel groups according to the severity of their renal disease with 100 patients to each group: (i) normoalbuminuric patients, (ii) microalbuminuric patients, (iii) macroalbuminuric patients, and (iv) patients with end-stage renal disease (ESRD).

MAIN OUTCOME MEASURES

Phyto-oestrogen concentrations in serum (enterolactone, daidzein, genistein and equol) and urine (enterolactone), assessed by time-resolved fluoroimmunoassay.

RESULTS

Highly elevated serum concentrations of phyto-oestrogens were measured amongst patients with diabetic nephropathy, and low concentrations amongst patients without diabetic complications. The pattern was similar for all phyto-oestrogens measured, although the increase in mean serum concentrations along with the increasing severity of renal disease was steepest for enterolactone, ranging from 13 nmol L(-1) amongst women and 18 nmol L(-1) amongst men in normoalbuminuric patients to 181 and 206 nmol L(-1) in women and men, respectively, in patients with ESRD (P < 0.001 for both genders between the groups). A strong correlation between serum enterolactone and creatinine concentration was found (r = 0.60, P < 0.001).

CONCLUSIONS

The serum concentration of phyto-oestrogens and the severity of diabetic renal disease showed a close positive association, suggesting that phyto-oestrogens are unable to provide any major protective effect, through antioxidative or other mechanisms, on the development of diabetic renal and cardiovascular complications.

Smoking and atopy as determinants of sputum eosinophilia and bronchial hyper-responsiveness in adults with normal lung function

Data concerning the determinants of sputum eosinophilia and bronchial hyper-responsiveness (BHR) in large cohorts of individuals with normal lung function are limited. Here, we assessed the occurrence of sputum eosinophilia and BHR and identified the risk factors for these variables in two populations living in North Karelia, Finland, and in Pitkäranta, the Republic of Karelia, Russia. These areas are geographically adjacent, but differ, however, fundamentally in major cultural, socioeconomical and lifestyle aspects. The study population comprised 790 Finns and 387 Russian, aged 25-54 years, who were randomly enrolled from the population registers. A methacholine challenge test to measure BHR was successfully performed in 581 (74%) Finns and 307 (79%) Russians with virtually normal lung function (FEV1 > 70% of predicted). Of these, induced sputum samples were obtained from 41% of the Finns and from 67% of the Russians. The proportion of current smokers was 27% among the former and 42% among the latter. Sputum eosinophilia was assessed using a semi-quantitative method, and total concentrations of sputum eosinophilic cationic protein (ECP) and myeloperoxidase (MPO) were measured using an immunoassay. Risk factors for BHR and sputum eosinophilia were identified with a regression analysis. The prevalence of sputum eosinophilia was 22% among the Finns and 19% among the Russians, and the respective figures for BHR were 14% and 13%. The median ECP concentration in sputum was significantly higher among the Russians as compared with the Finns (P<0.001), whereas for MPO, the difference did not achieve significance. Current smoking was significantly associated with both sputum eosinophilia and BHR in Russia (OR 3.1, 95% CI 1.2-7.6 for sputum eosinophilia, 2.8, 1.3-6.1 for BHR) and with BHR in Finland (2.1, 1.3-3.7). Atopy showed a tendency to be another risk factor for BHR in Finland (1.6, 0.98-2.6). In conclusion, sputum eosinophilia and BHR occurred commonly among the Finns and the Russians with normal lung function. Current smoking was significantly associated with BHR in both countries and additionally with sputum eosinophilia in Russia. Atopy was identified as a risk factor, albeit of borderline significance, for BHR in Finland only, suggesting that there may be differences in the aetiology and nature of BHR between the two countries.

Airway obstruction in relation to symptoms in chronic respiratory disease--a nationally representative population study

We examined the severity of airway obstruction and the occurrence of respiratory symptoms in a large, nationally representative population sample and in a subgroup of subjects with chronic bronchitis and/or emphysema to obtain information for developing national prevention and treatment strategies for these diseases. The study population comprised of 7217 randomly selected subjects (aged 30 years and older) who participated in a comprehensive health examination survey. The 'cases' were subjects diagnosed as having chronic bronchitis and/or emphysema. The survey methods comprised of questionnaires, interviews, physical measurements, including spirometry, and clinical examinations. In the whole study population, the age-adjusted prevalence of chronic bronchitis and/or emphysema was 22% among men and 7% among women, whilst clinically relevant airways obstruction (FEV1/FVC%< or = 69) was present in 11% of men and in 5% of women. The occurrence of chronic cough and phlegm production was lowest among the 'cases' with pronounced obstruction (in 68% of men with severe and in 60% of women with moderate obstruction), whereas cold air-associated dyspnoea aggravation showed an inverse relationship, occurring most commonly in men (80%) with severe obstruction. Unexpectedly, half of the bronchitic women had never smoked. We conclude that the occurrence of certain bronchitic symptoms, such as chronic cough and phlegm production and cold air-associated dyspnoea aggravation, may to some degree indicate different stages of the disease. Smoking was not closely associated with airflow limitation in women here.

Mycobacterium tuberculosis infection and the subsequent development of asthma and allergic conditions

BACKGROUND

Epidemiologic studies have suggested that certain viral infections, as well as exposure to Mycobacterium tuberculosis in early life, could, at least to some extent, prevent the subsequent development of atopic disease.

OBJECTIVE

We investigated whether M tuberculosis infection in childhood or adolescence has any effect on the development of asthma and allergic conditions in later life.

METHODS

The study subjects (n = 1162) were individuals notified to the National Tuberculosis Registry between January 1, 1966, and December 31, 1969, who were 20 years of age or younger and had verified or justifiably probable new active tuberculosis of respiratory or other organs. The control subjects were age-matched, sex-matched, and geographically matched control pairs from the Population Registry of the Social Insurance Institution in Finland. The subjects were followed for 28 to 32 years. The prevalence of persistent asthma and allergic conditions among men and women at the end of 1997 were calculated on the basis of the Drug Reimbursement Registry of the Social Insurance Institution in the whole study population and in the subgroup of subjects aged 16 years or younger at the time of M tuberculosis infection.

RESULTS

In women a significantly lower prevalence of persistent asthma was found among those aged 16 years or younger at the time of M tuberculosis infection than among the control subjects (3.7% vs 8.3%, respectively; P =.035). The women with a history of tuberculosis also showed a significantly lower prevalence of allergic conditions than the control subjects (8.3% vs 14.0%, respectively; P =.003) when the whole study population of women was considered. In men, however, the only significant difference between the cases and control subjects was found for persistent asthma, with the cases showing a significantly higher prevalence than the control subjects (4.4% and 1.8%, respectively; P =.008).

CONCLUSION

M tuberculosis infection in childhood significantly reduced the occurrence of subsequent asthma in women. Moreover, this infection was also found to reduce the occurrence of allergic conditions in later life in women. By contrast, no suppressive effect of M tuberculosis infection in childhood or adolescence on the later development of asthma or allergic conditions could be observed in men. The differences in the natural history of atopic disease between the sexes and the occurrence of tuberculosis mostly in later childhood and adolescence may largely explain our findings.

Humoral immune response to Chlamydia pneumoniae in twin discordant for smoking

OBJECTIVES

The aim of this study was to investigate whether there is a relationship between smoking and Chlamydia pneumoniae specific antibody levels in generally healthy subjects, and whether this possible relationship is dose-dependent.

DESIGN

Match pair study.

SUBJECTS

The study population comprised of 111 same-gender twin pairs from the Finnish Twin Cohort who in a previous study reported the highest discordance between smoking assessed as pack-years.

MAIN OUTCOME MEASURES

Smoking and background data were obtained by a questionnaire, and C. pneumoniae specific serum IgG and IgA antibodies were measured by the micro-immunofluorescence (mIF) test.

RESULTS

A significantly higher proportion of men with a history of smoking had elevated levels (a titre of > or=40) of serum IgA antibodies (P=0.003), whereas in women, a significant difference between the pairs was found in the proportion of IgG seropositive (a titre of > or=128) subjects (P=0.03). Conditional logistic regression analysis revealed that the risk for elevated IgA antibodies suggestive of chronic infection was significantly increased in current or former smokers in men (odds ratio 5.0 with 95% confidence intervals of 1.45-17.3). No dose-response effect was found between smoking and IgG or IgA titres, neither even if men and women were analysed separately.

CONCLUSION

Smoking was significantly associated with elevated IgA antibody levels in men, supporting indirectly the hypothesis that smoking is a contributory factor in the establishment of chronic C. pneumoniae infection.

Immune responses to Chlamydia pneumoniae in twins in relation to gender and smoking

This study investigated whether gender or smoking has an impact on immune responses to Chlamydia pneumoniae in generally healthy adults. A total of 129 twins (46 twin pairs and 37 single twins) from the Finnish Twin Cohort who had previously reported the highest discordance for smoking with their co-twins participated. C. pneumoniae-specific serum IgA and IgG antibody levels were measured by the micro-immunofluorescence test (micro-IF) at admission and 3 months later if the IgA level in the first sample was elevated. Cell-mediated immune (CMI) responses to C. pneumoniae and control antigens from heparinised blood samples were assessed by the lymphoproliferation (LP) assay. When all the subjects were pooled and analysed by gender and smoking status, marked differences in the humoral immune response between the genders were observed, irrespective of smoking status. When twin pairs solely were analysed, significantly elevated IgA antibody levels suggestive of persistent infection were found among the currently or formerly smoking men compared to their non-smoking co-twins. The CMI response showed a reciprocal trend with respect to humoral immunity. In conclusion, specific antibody levels were found to be higher in men than in women irrespective of smoking status, although smoking may further enhance the humoral response and depress the CMI response in men.

Chlamydia pneumoniae-specific cell-mediated and humoral immunity in healthy people

In this work, cell-mediated immunity to Chlamydia pneumoniae was studied in 157 healthy individuals using lymphoproliferative assay and serum antibodies were analysed by microimmunofluorescence techniques. The C. pneumoniae-specific IgG antibodies were elevated more frequently and the geometric mean titres for IgG (67.5 versus 44.1; P = 0.05) and IgA (14.9 versus 11.3; P = 0.025) antibodies were significantly higher in males than in females. However, no gender-dependent differences were observed in cellular reactivity to C. pneumoniae, since the median cellular responses were similar (stimulation indices 7.5) in men and women. Although the cell-mediated and humoral responses to C. pneumoniae did not correlate clearly, elevated IgG antibodies were associated with slightly higher lymphocyte proliferation in comparison to all subjects (15.5 versus 7.5) and significantly stronger in comparison to those with persistently elevated IgA (> 80) antibodies (15.5 versus 3.5; P = 0.023). Further studies are needed to evaluate a possible role of reduced cellular reactivity in the cause of chronic C. pneumoniae infection.

Influence of age, gender and smoking on Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis antibody titres in an elderly population

The purpose of this study was to investigate the association of serum antibody levels to Streptococcus pneumoniae, Haemophilus influenzae and Moraxella (Branhamella) catarrhalis with age, gender and smoking in an elderly population. The study population comprised all the inhabitants aged 65 years or over in a rural municipality in south-western Finland. Serum samples were obtained from 1,174 out of a total of 1,360 subjects. Bacterial antibodies were measured by enzyme immunoassay (EIA) using pneumolysin and whole bacterial cells of H. influenzae and M. catarrhalis (mixture of 10 different strains for both) as antigens. The main findings were as follows: (i) antibody levels generally decreased with increasing age both in men and in women; (ii) antibody titres against H. influenzae and M. catarrhalis were higher in men than in women; and (iii) antibody titres to H. influenzae and M. catarrhalis, but not to S. pneumoniae, were significantly higher in smokers than in non-smokers. These data suggest that antibody-mediated protection against respiratory pathogens may be impaired in the elderly, leading to a higher susceptibility to respiratory tract infections, that the exposure to H. influenzae and M. catarrhalis may be higher in men than in women, and that smokers have more respiratory infections or colonization due to these 2 bacteria than do non-smokers.

Chlamydia pneumoniae antibodies in chronic obstructive pulmonary disease

BACKGROUND

The significance of persistent or recurrent respiratory infections in adult life for the development of chronic obstructive pulmonary disease (COPD) is still to a large extent unknown. A few clinical and experimental animal studies suggest that peripheral airways diseases may be due to the cumulative effects of recurrent respiratory infections over an extended period.

METHODS

C. pneumoniae-specific IgG and IgA antibody levels were determined in two elderly groups of male patients with COPD and in control subjects without the disease. The first group (N = 36) consisted of patients who were hospitalized due to an acute exacerbation of COPD. The second group of patients (N = 54) and the controls (N = 321) were participants in a community survey on respiratory diseases in the elderly. The criteria for seropositivity were defined as an IgG titre of >=16.

RESULTS

89% of the hospitalized patients (group I) and 66% of the non-hospitalized patients (Group II) were IgA seropositive as compared to 55% of the controls. Derived from the logistic regression analysis, the odds ratio (OR) WAS 7.4 (95% CI : 2.1-25.7) between group I and the controls and 1.5 (0.7-2.9) between group II and controls. Furthermore, the difference in the age-adjusted geometric mean titres (GMT) of lgA antibodies between the group I and the controls was significant (53.0 for the patients versus 19.1 for the controls). On the contrary, no significant differences between the patients and the controls were found either in the proportion of IgG-seropositive or in the GMT of IgG antibodies. Two of the 29 patients with an exacerbation of COPD, for whom paired sera were available, showed an antibody response suggesting a current acute or reactivated chlamydial infection.

CONCLUSIONS

The results showed that C. pneumoniae lgA antibodies are found more frequently and in higher concentrations in COPD patients than in disease-free controls. The finding may indicate a chronic C. pneumoniae infection in these patients. The association persisted after controlling for the potential confounding effect of smoking.

Measurement of sputum antibodies in the diagnosis of acute and chronic respiratory infections associated with Chlamydia pneumoniae

The aim of this study was to develop methods for the measurement of sputum antibodies in the laboratory diagnosis of acute and chronic lower respiratory tract infections caused by Chlamydia pneumoniae. Paired serum specimens, sputum specimens, and pharyngeal or nasopharyngeal swabs were obtained from 97 patients; 51 of them had community-acquired pneumonia, and 46 had chronic obstructive pulmonary disease (COPD). C. pneumoniae-specific serum immunoglobulin G (IgG), IgA, and IgM antibodies were measured by the microimmunofluorescence (micro-IF) test. For sputa, specific IgA and IgG antibodies were measured by the micro-IF test and secretory IgA (sIgA) was measured by enzyme immune assay (EIA) with C. pneumoniae elementary bodies as the antigen. Sputum IgA and sIgA antibodies to C. pneumoniae were found, respectively, in 52 and 51% of the COPD patients. Elevated levels of stable serum IgG and IgA antibodies (IgG titer of > or = 128 and IgA titer of > or = 40), suggesting chronic infection, were found in 54% of the COPD patients. The sensitivity for the sputum IgA micro-IF test compared with elevated serum antibody levels was 87.5%, and that for the sputum sIgA EIA was 88%; the respective specificities were 90 and 95%. Acute C. pneumoniae infection was diagnosed in seven pneumonia patients, and two (29%) of these patients were positive by sputum EIA antibody measurements. Two pneumonia patients without acute infection had stable elevated IgG and IgA levels in their sera, and both of them were sputum antibody positive. We conclude that the measurement of IgA antibodies to C. pneumonia in sputum is a useful additional diagnostic tool for chronic C. pneumoniae infections.