Trends in the incidence, rate and treatment of miscarriage-nationwide register-study in Finland, 1998-2016

STUDY QUESTION

What changes have occurred in the incidence of miscarriage, its treatment options, and the profile of the women having miscarriages in Finland between 1998 and 2016?

SUMMARY ANSWER

The annual incidence of registry-identified miscarriage has declined significantly between 1998 and 2016, and non-surgical management has become the dominant treatment.

WHAT IS KNOWN ALREADY

Miscarriage occurs in 8-15% of clinically recognized pregnancies and in ~30% of all pregnancies. Increasing maternal age is associated with an increasing risk of miscarriage. The treatment of miscarriage has evolved significantly in recent years: previously, surgical evacuation of the uterus was the standard of care, but nowadays medical and expectant management are increasingly used.

STUDY DESIGN, SIZE, DURATION

We conducted a nationwide retrospective cohort study of 128 381 women that had experienced a miscarriage that was managed in public healthcare between 1998 and 2016 in Finland.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We used the National Hospital Discharge Registry for the data. Women aged 15-49 years that had experienced their first miscarriage during the follow-up period and had miscarriage-related diagnoses during their admission to public hospital were included in the study. Miscarriages were defined by the 10th Revision of the International Statistical Classification of Diseases and related Medical Problems (ICD-10) diagnostic codes O02*, O03* and O08*. Women with ectopic, molar and continuing pregnancies and induced abortions were excluded. Treatment was divided into surgical and non-surgical treatment using the surgical procedure codes.

MAIN RESULTS AND THE ROLE OF CHANCE

The annual incidence of registry-identified miscarriage has declined from 6.8/1000 15-49-year-old women in 1998 to 5.0/1000 in 2016 (P < 0.001). Also, the incidence rate of registry-identified miscarriage (i.e. the proportion of miscarriages of registry-identified pregnancies [i.e. deliveries, induced abortions, and miscarriages]) has declined from 112/1000 15-49-year-old pregnant women in 1998 to 83/1000 in 2016 (P < 0.001). The largest decrease in this proportion occurred among women over 40 years of age, among whom 26.5% of registry-identified pregnancies in 1998 ended in miscarriage compared to that of 16.4% in 2016. The proportion of missed abortion has increased (30.3 to 38.8%, P < 0.001) whereas that of blighted ovum has decreased (25.4 to 12.8%, P < 0.001). The proportion of registry-identified miscarriages seen among nulliparous women has increased from 43.7 to 49.6% (P < 0.001). Mean age at the time of miscarriage remained at 31 years throughout the study. Altogether, 29% of all miscarriages were treated surgically and 71% underwent medical or expectant management. The proportion of surgical management has decreased from 38.0 to 1.6% for spontaneous abortion, from 60.7 to 9.4% for blighted ovum and 70.9 to 11.2% for missed abortion between 1998 and 2016.

LIMITATIONS, REASONS FOR CAUTION

This study includes only women with registry-identified pregnancies, i.e. women who were treated in public hospitals. However, the number of women treated elsewhere is presumed to be small. Neither can this study estimate the number of women having spontaneous miscarriage with no hospital contact.

WIDER IMPLICATIONS OF THE FINDINGS

Both the annual incidence and incidence rate of miscarriage of all registry-identified pregnancies has decreased, and non-surgical management has become the standard of care. These findings are of value when planning allocation of healthcare resources and at individual level considering fertility and miscarriage questions. We speculate that improving ultrasound diagnostics explains the increasing proportion of missed abortion relative to other types of miscarriage. More investigation is needed to examine potential risk factors, complications and morbidity associated with miscarriages.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by the research funds of the Helsinki and Uusimaa hospital system, by a personal grant from Viipurin Tuberkuloosisäätiö to R.L. and by a personal grant from The Finnish Cultural Foundation to N.H. The authors have no conflicts of interest to declare.

Changes in objectively measured smoking in pregnancy by time and legislative changes in Finland: a retrospective cohort study

OBJECTIVES

To study the changes in prevalence, characteristics and outcomes of pregnant smokers over time and legislative changes.

DESIGN AND SETTING

Retrospective nationwide cohort.

PARTICIPANTS

Our study consisted of 9627 randomly selected pregnancies from the Finnish Maternity Cohort (1987-2011), with demographic characteristics and pregnancy and perinatal data obtained from the Medical Birth Registry and early pregnancy serum samples analysed for cotinine levels. Women were categorised based on their self-reported smoking status and measured cotinine levels (with ≥4.73 ng/mL deemed high). Data were stratified to three time periods based on legislative changes in the Tobacco Act.

PRIMARY AND SECONDARY OUTCOME MEASURES

Prevalence of pregnant smokers and demographics, and perinatal and pregnancy outcomes of pregnant smokers over time.

RESULTS

Overall, 71.6% of women were non-smokers, 16.2% were active cigarette smokers, 7.7% undisclosed smoking but had high cotinine levels and 4.5% were inactive cigarette smokers. The prevalence of active cigarette smokers decreased from mid-1990s onwards among women aged ≥30 years, probably due to the ban of cigarette smoking in most workplaces. We observed no changes in the prevalence of inactive smokers or women who undisclosed smoking by time or legislative changes.Women who undisclosed smoking had similar characteristics and perinatal outcomes as inactive and active smokers. Compared with non-smokers, women who undisclosed smoking were more likely to be young, unmarried, have a socioeconomic status lower than white-collar worker and have a preterm birth.

CONCLUSIONS

Women who undisclosed smoking were very similar to pregnant cigarette smokers. We observed a reduction in the prevalence of active pregnant cigarette smokers after the ban of indoor smoking in workplaces and restaurants, mostly among women aged ≥30 years.

Irregular menstruation and hyperandrogenaemia in adolescence are associated with polycystic ovary syndrome and infertility in later life: Northern Finland Birth Cohort 1986 study

STUDY QUESTION

Do teenage girls with a history of menstrual irregularity and/or elevated androgen levels in adolescence exhibit an increased risk of polycystic ovary syndrome (PCOS) and/or infertility later on in adulthood?

SUMMARY ANSWER

Our results suggest that menstrual irregularity and/or elevated androgen levels at 16 years are still associated with symptoms of PCOS at 26 years as well as infertility problems at 26 years but not with decreased pregnancy or delivery rates at 26 years.

WHAT IS KNOWN ALREADY

Hyperandrogenaemia is associated with menstrual irregularity, hirsutism, acne and potentially higher risk for PCOS, but there are few follow-up studies investigating whether adolescent hyperandrogenaemia and/or menstrual irregularity are an early sign of PCOS.

STUDY DESIGN, SIZE, DURATION

A prospective population-based cohort study was conducted using two postal questionnaires targeting girls in the Northern Finland Birth Cohort 1986 (NFBC1986, n = 4567). The NFBC1986 comprises all expected births from the year 1986 in the two northernmost provinces of Finland. Collection of the database was performed at the age of 16 and 26. The 16-year and 26-year questionnaires included one question about the regularity and length of the menstrual cycle. The 26-year questionnaire also included questions about symptoms of PCOS, reproduction and infertility problems.

PARTICIPANTS, SETTING, METHODS

The response rates for the questionnaires were 80% (n = 3669) at 16 years and 50% (n = 2270) at 26 years. At 15-16 years, of 2448 girls, 709 (29%) girls reported menstrual irregularity (symptomatic girls) and 1739 (71%) had regular periods (non-symptomatic girls). After combining data from the two questionnaires a total of 2033 girls were included in the analyses. The χ(2) and Student's t-test was used to compare reproductive outcome and prevalence of clinical hyperandrogenaemia, PCOS and infertility at 26 years between the study groups. Univariate and multivariate logistic regression models were employed to estimate the association of menstrual irregularity at 16 years with clinical hyperandrogenaemia, PCOS and infertility at 26 years.

MAIN RESULTS AND THE ROLE OF CHANCE

At follow-up, the proportion of symptomatic girls who had conceived at least once (68.0 versus 67.9%) and had delivered at least one child (25.7 versus 28.1%) was similar to the non-symptomatic women and the groups had similar miscarriage rates (11.6 versus 12.1%). Logistic regression analyses indicated that menstrual irregularity at 16 years was associated with an increased risk of menstrual irregularity [adjusted odds ratio (OR) 1.37, 95% confidence interval (CI) 1.00-1.88, P = 0.050], PCOS (adjusted OR 2.91, 95% CI 1.74-4.84, P < 0.001) and infertility problems (adjusted OR 2.07, 95% CI 1.16-3.76, P = 0.013) at 26 years. At 26 years, women with PCOS (P = 0.013), hirsutism (P = 0.001) and acne (P < 0.001) exhibited significantly higher values of free androgen index (FAI) at 16 years than control women. There was a significant linear trend in the higher FAI quartiles at 16 years towards higher prevalence of PCOS (P = 0.005), hirsutism (P < 0.001) and acne (P < 0.001) at 26 years. Only 10.5% of the girls with menstrual irregularity at 16 years had PCOS at 26 years.

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of menstrual irregularity was based on a self-reported questionnaire, thus introducing a risk of information bias in reporting the symptoms. Moreover, ovarian ultrasonography was not available to aid the diagnosis of PCOS and there was no clinical evaluation of hyperandrogenism. The relatively low rate of participation to the questionnaire at 26 years may also have biased the results.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings confirm that menstrual irregularity and/or elevated androgen levels are already present in adolescence in women with PCOS and infertility in later life, which strengthens the importance of early identification of menstrual irregularity.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, the Sigrid Juselius Foundation, University Hospital Oulu and University of Oulu, the European Commission and the Medical Research Council, UK, Welcome Trust (089549/Z/09/Z). None of the authors have any conflict of interest.

Anti-Müllerian hormone: correlation with testosterone and oligo- or amenorrhoea in female adolescence in a population-based cohort study

STUDY QUESTIONS

Can serum anti-Müllerian hormone (AMH) levels measured in female adolescents predict polycystic ovary syndrome (PCOS)-associated features in adolescence and early adulthood?

SUMMARY ANSWER

AMH levels associated well with PCOS-associated features (such as testosterone levels and oligoamenorrhoea) in adolescence, but was not an ideal marker to predict PCOS-associated features in early adulthood.

WHAT IS KNOWN ALREADY

Several studies have reported that there is a strong correlation between antral follicle count and serum AMH levels and that women with PCOS/PCO have significantly higher serum AMH levels than women with normal ovaries. Other studies have reported an association between AMH serum levels and hyperandrogenism in adolescence, but none has prospectively assessed AMH as a risk predictor for developing features of PCOS during adulthood.

STUDY DESIGN, SIZE, DURATION

A subset of 400 girls was selected from the prospective population-based Northern Finland Birth Cohort 1986 (n = 4567 at age 16 and n = 4503 at age 26). The population has been followed from 1986 to the present.

PARTICIPANTS/MATERIAL, SETTING, METHODS

At age 16, 400 girls (100 from each testosterone quartile: 50 with oligo- or amenorrhoea and 50 with a normal menstrual cycle) were selected at random from the cohort for AMH measurement. Metabolic parameters were also assessed at age 16 in all participants. Postal questionnaires enquired about oligo- or amenorrhoea, hirsutism, contraceptive use and reproductive health at ages 16 and 26.

MAIN RESULTS AND ROLE OF CHANCE

There was a significant correlation between AMH and testosterone at age 16 (r = 0.36, P < 0.001). AMH levels at age 16 were significantly higher among girls with oligo- or amenorrhoea compared with girls with normal menstrual cycles (35.9 pmol/l [95% CI: 33.2;38.6] versus 27.7 pmol/l [95% CI: 25.0;30.4], P < 0.001). AMH at age 16 was higher in girls who developed hirsutism at age 26 compared with the non-hirsute group (31.4 pmol/l [95% CI 27.1;36.5] versus 25.8 pmol/l [95% CI 23.3;28.6], P = 0.036). AMH at age 16 was also higher in women with PCOS at age 26 compared with the non-PCOS subjects (38.1 pmol/l [95% CI 29.1;48.4] versus 30.2 pmol/l [95% CI 27.9;32.4], P = 0.044). The sensitivity and specificity of the AMH (cut-off 22.5 pmol/l) for predicting PCOS at age 26 was 85.7 and 37.5%, respectively. The addition of testosterone did not significantly improve the accuracy of the test. There was no significant correlation between AMH levels and metabolic indices at age 16.

IMPLICATIONS, REASONS FOR CAUTION

AMH is related to oligo- or amenorrhoea in adolescence, but it is not a good marker for metabolic factors. The relatively low rate of participation in the questionnaire at age 26 may also have affected the results. AMH was measured in a subset of the whole cohort. AMH measurement is lacking international standardization and therefore the concentrations and cut-off points are method dependent.

WIDER IMPLICATIONS FOR THE FINDINGS

Using a high enough cut-off value of AMH to predict which adolescents are likely to develop PCOS in adulthood could help to manage the condition from an early age due to a good sensitivity. However, because of its low specificity, it is not an ideal diagnostic marker, and its routine use in clinical practice cannot, at present, be recommended.

STUDY FUNDINGS AND COMPETING INTERESTS

The study was funded by a grant from Wellcome Trust (089549/Z/09/Z) to H.L., S.F. and M.-R.J. Study funding was also received from Oulu University Hospital Research Funds, Sigrid Juselius Foundation and the Academy of Finland. None of the authors have any competing interest to declare.

The impact of self-reported oligo-amenorrhea and hirsutism on fertility and lifetime reproductive success: results from the Northern Finland Birth Cohort 1966

STUDY QUESTION

To what extent do self-reported oligo-amenorrhea and hirsutism affect reproductive performance (childlessness, age at first delivery, family size and miscarriage rates)?

SUMMARY ANSWER

At the age of 44, among women with both self-reported oligo-amenorrhea and hirsutism the prevalence of childlessness was not significantly different from non-symptomatic women but they had a smaller family size than non-symptomatic women.

WHAT IS KNOWN ALREADY

Polycystic ovary syndrome (PCOS) is a common endocrine disorder characterized by oligo-amenorrhea or amenorrhea, hyperandrogenism and hirsutism and it is the most frequent cause of anovulatory infertility, but there are few studies on the reproductive capacity of women with PCOS. In our previous population-based cohort study the women with self-reported oligo-amenorrhea and hirsutism were found to have more infertility problems and smaller family size than non-symptomatic women at the age of 31.

STUDY DESIGN, SIZE, DURATION

A prospective population-based cohort study. The population of the study is derived from the prospective Northern Finland Birth Cohort 1966 (NFBC1966), comprising all expected births from the year 1966 in the two northernmost provinces of Finland (n = 12 058). Of them, 5889 were females. Enrollment in this database begun at the 24th gestational week and so far data have been collected from the subjects at the ages of 1, 14 and 31 years.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A postal questionnaire including questions about oligo-amenorrhea and hirsutism was sent to all women at the age of 31 (n = 5608, response rate 81%, n = 4535) and a clinical examination was performed (attendance rate 76.5%). Those who reported both hirsutism and oligo-amenorrhea were defined as women with both symptoms (n = 153). Data on pregnancies/deliveries were obtained from the Finnish Medical Birth Register (FMBR) in 2010 when the women were 44 years old.

MAIN RESULTS AND THE ROLE OF CHANCE

Women with both symptoms had delivered at least one child as often as non-symptomatic women [75.2 versus 79.0%, adjusted odds ratio (OR) 0.86, 95% confidence intervals (CI) 0.57-1.30], were of similar age [mean (SD)] at first delivery [27.7 (4.81) versus 27.3 (4.71)] and had similar incidence of miscarriages. However, non-symptomatic women had more often ≥2 deliveries (61.6 versus 52.9%, adjusted OR 0.70, 95% CI 0.49-1.00, P = 0.048) and had larger family size [mean (SD)] [2.4 (1.4) versus 1.9 (0.8), P < 0.001]. Women with both symptoms had been treated more often for infertility than non-symptomatic women (6.1 versus 2.4%, adjusted OR 2.74, 95% CI 1.14-6.60, P = 0.024).

LIMITATIONS, REASONS FOR CAUTION

The diagnosis of oligo-amenorrhea and hirsutism was based on a questionnaire, suggesting a risk of information bias in reporting the symptoms. However, we have previously shown that self-reported oligo-amenorrhea and hirsutism can distinguish most women with the typical profile of PCOS. Only the women who had delivered at least once were recorded in the FMBR, thus excluding from the study those who had experienced miscarriages and/or infertility treatments but did not have a live birth. This feature could potentially decrease the differences in incidence of miscarriages and/or infertility treatment between symptomatic and non-symptomatic subjects.

WIDER IMPLICATIONS OF THE FINDINGS

This is one of the few studies, in which the impact of self-reported oligo-amenorrhea and hirsutism on lifetime reproductive success can be measured. Our results suggest that even at more advanced age, women with both symptoms do not quite match the parity of healthy non-symptomatic women, and that infertility treatment does not always restore normal reproductive capacity in these women. Obese women with both symptoms had the worst prognostic as regards reproduction, which emphasizes the importance of life intervention and preventive politics against obesity in this group of women.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland, University Hospital Oulu, Biocenter, University of Oulu, Finland, the European Commission and the Medical Research Council, UK, the National Institute for Health Research (NIHR). None of the authors has any conflict of interest to declare.

Menstrual disorders in adolescence: a marker for hyperandrogenaemia and increased metabolic risks in later life? Finnish general population-based birth cohort study

STUDY QUESTION

Are self-reported menstrual disorders associated with hyperandrogenaemia and metabolic disturbances as early as in adolescence?

SUMMARY ANSWER

Menstrual disorders at the age 16 are a good marker of hyperandrogenaemia, and an adverse lipid profile was associated with higher androgen levels.

WHAT IS KNOWN AND WHAT THIS PAPER ADDS

Hyperandrogenism per se has been suggested to be a significant metabolic risk factor in women and a cause of physical and psychological morbidity in adolescent girls. A weak positive correlation has been described between hyperandrogenaemia and obesity in adolescent girls, but the clinical consequences are still poorly understood. Hyperandrogenism and insulin resistance are also key features of polycystic ovary syndrome (PCOS), and women with PCOS are consequently at an increased risk of developing type 2 diabetes mellitus and/or metabolic syndrome, and may have increased cardiovascular morbidity. Our findings confirm that the association between menstrual disorders, hyperandrogenism, obesity and metabolic risks is already evident in adolescence.

STUDY DESIGN

This population-based, cross-sectional study used postal questionnaires to targeting 15-16-year-old girls in the Northern Finland Birth Cohort 1986 (n= 4567).

PARTICIPANTS AND SETTING

There were 3669 girls who answered the postal questionnaire and out of 3373 girls who also underwent clinical examinations and blood tests, 2448 were included in the analyses. The questionnaire included one question about the regularity and length of the menstrual cycle: 'Is your menstrual cycle (the interval from the beginning of one menstrual period to the beginning of the next period) often (more than twice a year) longer than 35 days?' The girls who answered 'yes' to this question were considered to be suffering from menstrual disorders and were classified as 'symptomatic'. The girls who answered 'no' were defined as 'non-symptomatic'.

MAIN RESULTS AND THE ROLE OF CHANCE

There were 709 (29%) girls who reported menstrual disorders (symptomatic girls) and 1739 who had regular periods (non-symptomatic girls). In the whole population and in both study groups, there were significant correlations between body mass index (BMI) (and waist-to-hip ratio), hyperandrogenaemia and metabolic parameters. Symptomatic girls exhibited significantly higher serum concentrations of testosterone (P= 0.010), lower levels of sex hormone-binding globulin (P =0.042) and higher free androgen indices [FAIs; geometric mean 3.38 (interquartile range (IQR): 2.27, 5.18) versus 3.08 (IQR: 2.15, 4.74), P= 0.002]. The two groups had comparable BMI and insulin sensitivity, and serum levels of glucose, insulin and lipids. There was a significant linear trend towards higher FAI values in the higher BMI quartiles in both symptomatic and non-symptomatic girls. In the whole population, there was a statistically significant linear decrease in high-density lipoprotein concentrations (P < 0.001) and higher triglyceride concentrations (P =0.004) in the upper FAI quartile.

IMPLICATIONS

Information regarding menstrual disorders in adolescence is a good marker of hyperandrogenaemia and may be an early risk factor for the development of PCOS in adulthood. The association between obesity, hyperandrogenism and metabolic risks is already evident in adolescence, which strengthens the importance of noting menstrual disorders at an early stage. BIAS, LIMITATIONS, GENERALIZABILITY: The cross-sectional nature of the study does not allow us to draw conclusions concerning the metabolic risks of this population in later life. The diagnosis of menstrual disorders was based on a questionnaire, suggesting a risk of information bias in reporting the symptoms. This study was not designed to diagnose PCOS, as ultrasonography was not available and there was no clinical evaluation of hyperandrogenism (i.e. hirsutism). However, we were able to take into account potential confounding factors in the analyses.

STUDY FUNDING/COMPETING INTERESTS

This work was supported by grants from the Finnish Medical Society Duodecim, the North Ostrobothnia Regional Fund, the Academy of Finland (project grants 104781, 120315, 129269, 1114194, SALVE), University Hospital Oulu, Biocenter, University of Oulu, Finland (75617), the European Commission (EURO-BLCS, Framework 5 award QLG1-CT-2000-01643) and the Medical Research Council, UK (PrevMetSyn/SALVE). None of the authors have any conflict of interest to declare.

Prevalence of metabolic syndrome at age 16 using the International Diabetes Federation paediatric definition

OBJECTIVE

We estimated the prevalence of metabolic syndrome (MS) in adolescents, using the new International Diabetes Federation (IDF) paediatric definition and compared this with prevalence estimated using the IDF adult definition and five other previously published definitions.

DESIGN

Cross-sectional survey in the prospective general population-based Northern Finland Birth Cohort 1986 (NFBC 1986) at age 16 years.

SETTING

Birth cohort in Finland.

PARTICIPANTS

5665 adolescents (2862 males and 2803 females) clinically examined in 2001-2002.

MAIN OUTCOME MEASURES

The prevalence of MS using different definitions.

RESULTS

The overall prevalence of MS using the IDF paediatric definition was 2.4% (95% CI 2.0 to 2.8%) at the age of 16 years. Using the IDF adult definition the overall prevalence was lower, 1.7% (CI 1.3 to 2.0%, European cut-offs for waist circumference) and 1.0% (CI 0.7 to 1.3%, North American cut-offs).

CONCLUSION

In 16-year-old adolescents, the paediatric IDF definition rendered a higher prevalence estimate than the adult definition.

Acute Chlamydia pneumoniae infections in asthmatic and non-asthmatic military conscripts during a non-epidemic period

Chlamydia pneumoniae respiratory tract infections were studied in 512 male military conscripts (123 asthmatic and 389 non-asthmatic) taking part in 180-day service between July 2004 and July 2005 in Kajaani, Finland. Respiratory tract infections requiring a medical consultation were analysed prospectively. At baseline, at end of service, and during each episode of respiratory infection, blood samples were obtained for measurement of C. pneumoniae antibodies. Data concerning the clinical features of each infection episode were collected. Serological evidence of acute C. pneumoniae infection was found in 34 of the 512 conscripts with antibody data available, including 9.8% of the asthmatic subjects and 5.7% of the non-asthmatic subjects (p 0.111). A serological diagnosis could be made for 25 clinical episodes in 24 conscripts. The spectrum of respiratory tract infections included 13 episodes of mild upper respiratory tract infection and seven episodes of sinusitis, with five episodes involving asthma exacerbation. Two of three pneumonias were primary infections. Primary infections were diagnosed in five subjects, and re-infection/reactivation in 19 subjects, with the latter comprising 12 non-asthmatic subjects and seven asthmatic subjects (p 0.180). Prolonged infections were present in six asthmatic subjects and one non-asthmatic subject (p 0.001). A wide variety of respiratory tract infections, ranging from common cold to pneumonia, were associated with serologically confirmed C. pneumoniae infections. Infections were often mild, with common cold and sinusitis being the most common manifestations. Acute, rapidly resolved C. pneumoniae infections were equally common among asthmatic subjects and non-asthmatic subjects, whereas prolonged infections were more common among subjects with asthma.

Pathogenic bacteria and viruses in induced sputum or pharyngeal secretions of adults with stable asthma

BACKGROUND

Respiratory infections are well known triggers of asthma exacerbations, but their role in stable adult asthma remains unclear.

METHODS

103 asthmatics and 30 control subjects were enrolled in the study. Sputum was induced by inhalation of 3% NaCl solution. Oropharyngeal swab specimens were obtained from the posterior wall of the oropharynx. Respiratory specimens were analysed by RT-PCR for rhinovirus, enterovirus and respiratory syncytial virus and by PCR for adenovirus, Chlamydia pneumoniae, Mycoplasma pneumoniae and Bordetella pertussis.

RESULTS

Sputum samples from two of the 30 healthy controls (6.7%), five of 53 patients with mild asthma (9.4%), and eight of 50 with moderate asthma (16.0%) were positive for rhinovirus. Rhinovirus positive asthmatic subjects had more asthma symptoms and lower forced expiratory volume in 1 second (FEV(1)) (79% predicted) than rhinovirus negative cases (93.5% predicted; p = 0.020). Chlamydia pneumoniae PCR was positive in 11 healthy controls (36.6%), 11 mild asthmatics (20.8%), and 11 moderate asthmatics (22%), and PCR positive asthmatics had lower FEV(1)/FVC than negative cases (78.2% v 80.8%, p = 0.023). Bordetella pertussis PCR was positive in 30 cases: five healthy controls (16.7%), 15 mild asthmatics (28.3%), and 10 moderate asthmatics (20%). Bordetella pertussis positive individuals had lower FEV(1)/FVC (77.1% v 80.7%, p = 0.012) and more asthma symptoms than B pertussis negative cases.

CONCLUSIONS

Rhinovirus, C pneumoniae, and B pertussis are found in the sputum or pharyngeal swab specimens of asthmatic subjects without concurrent symptoms of infection or asthma exacerbation, as well as in some healthy controls. Positivity is associated with lower lung function and more frequent asthma symptoms.

Chlamydia trachomatis and chlamydial heat shock protein 60-specific antibody and cell-mediated responses predict tubal factor infertility

BACKGROUND

To evaluate the role of Chlamydia trachomatis-induced humoral and cell-mediated immune (CMI) responses in predicting tubal factor infertility (TFI).

METHODS

Blood samples were taken from 88 women with TFI and 163 control women. C. trachomatis and chlamydial heat shock protein 60 (CHSP60)-specific immunoglobulin G (IgG) antibodies were analysed using enzyme-linked immunosorbent assay (ELISA) kits. Proliferative reactivity of peripheral blood mononuclear cells was studied in vitro against Chlamydia elementary body (EB) and recombinant CHSP60 antigens.

RESULTS

C. trachomatis-specific IgG antibodies were found more frequently (43.2 versus 13.5%), and the antibody levels were higher in the TFI cases than in the controls (P < 0.001). C. trachomatis EB-induced lymphocyte responses were positive in 81.8% of the TFI cases and 58.9% of the controls (P < 0.001). Similarly, CHSP60-induced lymphocyte responses were found in 45.5% of the TFI cases and 30.7% of the controls (P < 0.001). CHSP60 antibody test was the best single test predicting TFI. Compared to cases with all four markers negative, the estimated risk for TFI was 4.1 (95% CI 1.4-11.9) among those with one positive marker and 19.9 (95% CI 6.9-57.4) among those with three to four positive markers.

CONCLUSION

Our results show that TFI prediction model can be improved by combining tests for humoral and CMI response to chlamydial antigens.

Antibodies to Chlamydia trachomatis heat shock proteins Hsp60 and Hsp10 and subfertility in general population at age 31

PROBLEM

To assess the association between antibodies to Chlamydia trachomatis heat shock proteins 60 and 10 (Hsp60 and Hsp10) and subfertility in a general population sample.

METHOD OF STUDY

A nested case (n = 146)-control (n = 278) study in a population-based birth cohort. Serum immunoglobulin (Ig)G and IgA antibodies against C. trachomatis Hsp60 and Hsp10, explanatory factors, were measured by enzyme immunoassay, using recombinant proteins as antigens. The main outcome variable was subfertility (time to pregnancy > or =12 months).

RESULTS

The prevalence and medians of serum IgA antibodies to Hsp60 and Hsp10 were significantly higher in the female partners of subfertile couple than in their fertile controls. On the contrary, among male partners of subfertile couple, especially among smokers serum antibody levels to Hsp antigens were lower than in the controls.

CONCLUSION

The results indicate a serological association of antibodies to chlamydial Hsp antigens with female subfertility in a population-based sample.

Association between Chlamydia trachomatis antibodies and subfertility in the Northern Finland Birth Cohort 1966 (NFBC 1966), at the age of 31 years

The objective of this study was to assess the serological association between previous Chlamydia trachomatis infection and subfertility in a general population sample. A nested case (n = 493)-control (n = 986) study in a population-based birth cohort consisting of 12,058 live births from the year 1966 was conducted. The analysis was restricted to those 6007 cohort members who replied to a postal inquiry and participated in a health examination including blood samples at the age of 31 years. The presence of C. trachomatis-specific serum IgG antibodies was screened by a synthetic peptide-based enzyme-linked immunosorbent assay. All the positive sera were further tested by the microimmunofluorescence method using immunotype pools and individual immunotypes of C. trachomatis as antigens. An association was found between the detection of immunotype-specific C. trachomatis antibodies and subfertility both in men and women. The results of the present study confirm the serological association between past C. trachomatis infections and subfertility in male or female partners of the couple in the population-based sample.

Chlamydia pneumoniae infection and inflammation in adults with asthma

BACKGROUND

Chlamydia pneumoniae infection and immune response to the C. pneumoniae heat shock protein 60 (CpHsp60) have been suggested to be associated with asthma.

OBJECTIVES

To study whether a slightly elevated C-reactive protein (CRP) level as a marker of low-grade systemic inflammation has a role in this association, we collected serum and sputum samples from 103 asthma patients with disease severity ranging from mild to moderate and from 30 healthy volunteers.

METHODS

IgA and IgG antibodies to C. pneumoniae elementary bodies (CpEB) and CpHsp60 were measured by enzyme immunoassay. Serum CRP levels were measured with a rapid two-site ultra-sensitive assay based on time-resolved immunofluorometry.

RESULTS

The asthma patients, especially those with moderate asthma, had higher serum IgA antibody levels to CpHsp60 than the healthy controls (test for trend, p = 0.05), whereas antibody levels to CpEB antigen did not differ between the study groups. CRP levels were higher in both asthma groups compared to the control group and moreover, the patients with moderate asthma had higher CRP levels than those with mild asthma (test for trend, p < 0.01). The subjects with a slightly elevated CRP level, defined as > or =1.8 mg/l, had higher CpEB IgA (p = 0.001), CpEB IgG (p = 0.008) and CpHsp60 IgA (p = 0.023) antibody levels in serum compared to the subjects with lower CRP levels.

CONCLUSIONS

Slightly elevated CRP levels as a marker of low-grade systemic inflammation may be associated with C. pneumoniae infection in asthma patients.

Effect of acute Chlamydia pneumoniae infection on lipoprotein metabolism in NIH/S mice

Chlamydia pneumoniae is a well-known cause of respiratory infections, globally. Chronic C. pneumoniae infection has been associated with atherosclerosis. The aim of the present study was to investigate the effects of acute C. pneumoniae infection on serum lipid levels and some regulatory proteins/enzymes in NIH/S mice. Female mice (n=30) were intranasally infected with 5.3*10(5) inclusion forming units (IFU) of C. pneumoniae and control mice (n = 30) were inoculated with buffer. Six uninoculated mice at day 0 and then six mice from each group 3, 6, 9, 14 and 20 days post-inoculation were killed and serum samples were collected for analysis. Successful infection was confirmed by IgG response to C. pneumoniae and positive Chlamydia cultivation from the lungs. Serum triglycerides and total cholesterol, as well as the activities of hepatic lipase (HL), lecithin-cholesterol acyltransferase (LCAT) and phospholipid transfer protein (PLTP) and the concentration of lipopolysaccharide-binding protein (LBP) were analyzed. In C. pneumoniae infected mice, a minor change in triglyceride (corrected p-value 0.020) levels was observed 9 days post-infection (p.i.). LCAT activity declined remarkably, and the lowest activities were measured on day 9 p.i. (67% from the baseline value). HL and PLTP activities did not differ from those in the control group during the whole experimental period. There was a 2.5-fold increase in the serum LBP concentration owing to the C. pneumoniae infection 9 days p.i. The data indicate that acute C. pneumoniae infection, although clinically almost asymptomatic, causes small, transient changes in serum total lipids and some key proteins involved in lipoprotein metabolism in mice.

HLA DQ alleles and interleukin-10 polymorphism associated with Chlamydia trachomatis-related tubal factor infertility: a case-control study

BACKGROUND

The relationship between Chlamydia trachomatis tubal factor infertility (TFI) and the host's immunoregulatory genes was studied.

METHODS

Cell-mediated immune responses to C. trachomatis and chlamydial heat shock protein (CHSP60) were determined by lymphocyte proliferation assay. HLA-DQ alleles and interleukin-10 (IL-10) promoter polymorphism (-1082 A/G) were analysed in 52 TFI cases and in 61 controls by PCR.

RESULTS

HLA-DQB1 or DQA1 alleles did not significantly differ between the TFI group and the control group. However, DQA1*0102 and DQB1*0602 alleles together with IL-10 -1082AA genotype were found significantly more frequently in the TFI patients than in the controls (0.18 and 0.02 respectively; P = 0.005). Five (22%) of the 23 patients who had a positive lymphocyte proliferative response to CHSP60 were positive also for IL-10 -1082AA and for the HLA-DQA1*0102 and HLA-DQB1*0602 alleles.

CONCLUSIONS

Our results reveal an association of a cellular immune response to CHSP60, HLA class II alleles and IL-10 promoter genotypes in patients with chlamydial TFI.

Severity assessment of lower respiratory tract infection in elderly patients in primary care

BACKGROUND

Simple markers for evaluating the severity of lower respiratory tract infections (LRTI) in primary care are lacking. It is of value to examine whether the information available to the primary care physician during a patient's initial visit can be used to assess the severity of LRTI.

METHODS

The associations between different baseline variables and outcomes (survival within or more than 30 days) were investigated prospectively in a series of 950 home-living patients 65 years or older with severe LRTI that their primary care physicians suspected to be pneumonia.

RESULTS

Twenty-one men and 17 women died (4.1%) within 30 days. According to univariate analysis, the following parameters differed (P < .01) between the fatalities and survivors: acute aggravation of a coexisting illness, age, respiratory rate, white blood cell count, and C-reactive protein (CRP) level. According to Cox forward stepwise regression analysis (P = .01 for entry and.05 for removal), acute aggravation of a concurrent illness, respiratory rate (> or = 25/min), and CRP concentration (> or = 100 mg/L) were independently associated with death. The mortality rate was 2.2% if the patients had none or only 1 of the independent risk factors and 20% if they had all 3 risk factors.

CONCLUSIONS

Preceding aggravation of a concurrent illness and respiratory rate of 25/min or higher, together with an elevated serum CRP level (> or = 100 mg/L), can be used as simple markers for identifying patients with the highest risk for LRTI and improve management decisions among elderly people in primary care.

Neutrophil adhesion molecules in colorectal surgery: effect of filgrastim given perioperatively

OBJECTIVE

To assess whether the postoperative expression of neutrophil adhesion molecules CD11b/CD18 (Mac-1) and CD62L (L-selectin) would differ in peripheral blood, peritoneal fluid and wound fluid in patients operated on for colorectal conditions, and to analyse the effect of perioperative filgrastim on their expression.

DESIGN

Prospective randomised double-blind placebo-controlled clinical study.

SETTING

University hospital, Finland.

SUBJECTS

Thirty consecutive patients undergoing elective colorectal operations (15 in each group).

INTERVENTIONS

The patients were prospectively randomised to receive either filgrastim or placebo. Expression of neutrophil adhesion molecules was measured 48 hours postoperatively in peripheral blood, peritoneal fluid, and wound fluid by flow cytometry.

RESULTS

Postoperative neutrophil CD11b/CD18 expression was higher in both wound fluid and peritoneal fluid than in peripheral blood in the placebo group. Simultaneously, the expression of neutrophil CD62L was higher in peripheral blood than in peritoneal fluid or wound fluid in both groups. Filgrastim caused increased postoperative expression of neutrophil CD11b/CD18 in peripheral blood but not in peritoneal fluid or wound fluid.

CONCLUSIONS

Postoperative expression of neutrophil adhesion molecules differs at the local operation site from that in peripheral blood. Filgrastim increases only blood neutrophil CD11b/CD18 expression.

Balance between interleukin-10 and interleukin-12 in adult cancer patients with or without infections

Reliable markers for identifying infections in cancer patients on admission are lacking. The utility of the balance between interleukin (IL)-10 and IL-12 was analysed in this respect. The infection group (n=56) had higher median serum levels of IL-10 (3.8 pg/ml; interquartile range (IQR) 1.7-11.4 pg/ml versus 1.8 pg/ml; IQR 0.6-4.6 pg/ml; P=0.005) and IL-10 to IL-12 ratio (0.4; IQR 0.06-4.23pg/ml versus 0.05; IQR 0.02-0.31pg/ml; P<0.001) than the non-infection group (n=36). IL-10 and the ratio had the following figures of sensitivity (79%; 95% confidence interval (CI) 66-88 versus 39%; 95% CI 27-53), specificity (40%; 95% CI 12-74 versus 90%; 95% CI 56-100) and positive predictive value (88%; 95% CI 76-96 versus 96%; 95% CI 78-100) for identifying infections (56 cases with infection and 10 with neoplastic fever), and the corresponding area under curve (AUC) values for IL-10 and the ratio in identifying infections in general were 0.58; 95% CI 0.39-0.78 versus 0.64; 95% CI 0.46-0.82 and in bacteraemia 0.71; 95% CI 0.50-0.92 versus 0.75; 95% CI 0.58-0.93, respectively. Thus, IL-10 can be used as a screening method for identifying infections in cancer patients and the ratio of IL-10 to IL-12 for confirming the diagnosis.

Activation of cell-mediated immunity following immunization with pneumococcal conjugate or polysaccharide vaccine

The immunogenicity of pneumococcal polysaccharide (PS) vaccines can be improved by conjugating PS to a polypeptide carrier that alters the immune response from T-cell independent to T-cell dependent. In order to study the influence of PS or protein antigens as inducers of cell-mediated responses, 30 adults were immunized with a 23-valent pneumococcal PS vaccine (PS-group) or an 11-valent, tetanus and diphtheria mixed carrier conjugate vaccine with (adjuvant group) or without aluminium adjuvant (nonadjuvant group). Cell-mediated responses were analyzed on days 0, 14 and 28 after vaccination by measuring lymphocyte proliferation and production of interferon (IFN)-gamma (Th1 marker) or interleukin (IL)-4 and IL-5 (Th2 markers) cytokines after in vitro stimulation with the PS and protein components of the vaccines. Tetanus and diphtheria proteins were the main inducers of lymphocyte proliferative and cytokine responses. Conjugate vaccines induced increased proliferative responses to the tetanus or diphtheria protein, but not to the PS components. In the PS-group, a lymphocyte proliferative response to protein antigens was not observed. The number of antigen-specific and nonspecific IFN-gamma-secreting cells detected by ELISPOT tended to increase in all three groups in response to protein or to PS antigen. No major differences were detected in the number of IL-4-secreting cells measured 14 and 28 days after vaccination. The conjugate vaccine with adjuvant was associated with Th2 type of activation indicated by an enhanced IL-5 secretion in response to the tetanus and diphtheria protein antigens.

Admission neopterin and interleukin 12 concentrations in identifying infections in adult cancer patients

Differential diagnosis between infections and neoplastic fever is a common diagnostic problem. The utility of admission serum concentrations of neopterin and interleukin 12 (IL-12) was prospectively evaluated in this respect. The infection group (n=56) had a higher median neopterin value (12.8 nmol/l vs 4.0 nmol/l, P<0.001) and neopterin-to-IL-12 ratio (1.74 vs 0.11, P<0.001) than the non-infection group (n=36); the median IL-12 values were higher in the latter group (10.6 pg/ml vs 71.6 pg/ml, P=0.007). According to the area under the operating characteristics curves (AUC), especially neopterin (0.90), but also the neopterin-to-IL-12 ratio (0.79), was good at identifying bacteremia. However, in differentiating infections in general from neoplastic fever (n=10), the neopterin-to-IL-12 ratio was less powerful (0.64), though still better than neopterin (0.58) and clearly better than IL-12 (0.42). The present results show that the neopterin-to-IL-12 ratio, which reflects simultaneously both the ongoing infection and the tumour load, may have promising clinical implications for differential diagnosis between infections and neoplastic fever.

C-reactive protein and erythrocyte sedimentation rate in differential diagnosis between infections and neoplastic fever in patients with solid tumours and lymphomas

The goals of our work were to study prospectively the possibility of differentiating between infections and neoplastic fever in adult cancer patients on admission, by means of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) or of follow-up CRP values. Patients and methods were as follows: the final infection group consisted of 56 patients and the noninfection group of 10 patients with neoplastic fever; CRP was measured on days 0, 3 and 5 and ESR at entry. The main results showed that the median CRP did not differ between the groups (91 mg/l vs 102 mg/l) on entry, while the ESR level was higher in the neoplastic fever group (50 mm/H vs 89 mm/H, P = 0.023). On admission, both markers had low area under receiver operating characteristic curves for the demonstration of infection (CRP 0.42; ESR 0.27). The CRP level dropped significantly in the infection group within 5 days (P = 0.009). We conclude that neither of the markers was useful in differentiating between infections and neoplastic fever on admission, but that the follow-up CRP values were advantageous in this respect.

Serotypes of Chlamydia trachomatis and risk for development of cervical squamous cell carcinoma

CONTEXT

Human papillomavirus (HPV) infection has been established as a cause of cervical cancer. Epidemiologic studies suggest that Chlamydia trachomatis infection also confers increased risk for cervical squamous cell carcinoma (SCC). Whether this risk is serotype-specific is unknown.

OBJECTIVE

To study the association between exposure to different C trachomatis serotypes and subsequent development of cervical SCC.

DESIGN AND SETTING

Longitudinal, nested case-control study within a cohort of 530 000 women who provided samples to serum banks in Finland, Norway, and Sweden. The data files were linked to respective national cancer registries.

SUBJECTS

One hundred twenty-eight women who had developed invasive cervical SCC at least 12 months following serum donation. Each case had 3 matched controls.

MAIN OUTCOME MEASURE

Risk for the development of cervical SCC by IgG antibodies to 10 different C trachomatis serotypes, adjusted for antibodies to HPV types 16, 18, and 33 and for serum cotinine levels.

RESULTS

Of specific C trachomatis serotypes, serotype G was most strongly associated with SCC (adjusted odds ratio [OR], 6.6; 95% confidence interval [CI], 1. 6-27.0). Other serotypes associated with SCC were I (OR, 3.8; 95% CI, 1.3-11.0) and D (OR, 2.7; 95% CI, 1.3-5.6). Presence of serum IgG antibodies to more than 1 serotype increased the adjusted ORs for SCC (P<.001 for trend).

CONCLUSIONS

Chlamydia trachomatis serotype G is most strongly associated with subsequent development of cervical SCC. Increasing numbers of exposures to different C trachomatis serotypes also increases risk. Our results strengthen the evidence that there is a link between past C trachomatis infection and cervical SCC.

C-reactive protein, procalcitonin and interleukin-8 in the primary diagnosis of infections in cancer patients

The diagnostic utility of C-reactive protein (CRP), procalcitonin (PCT) and interleukin-8 (IL-8) were studied in 66 cancer patients with suspected infection (39 with definite foci of infection, 17 with antibiotic responses without foci and 10 with neoplastic fever without infection) and 26 patients scheduled for chemotherapy. The infection group (n=56) had higher median CRP (91 versus 19 mg/l, P<0. 001), PCT (0.28 versus 0.12 ng/ml, P<0.001) and IL-8 values (27.7 versus 16.9 pg/ml, P=0.032) than the non-infection group (n=36). In patients with suspected infection, only PCT was a good marker to discriminate bacteraemia with an area under the receiver operating characteristics curve of 0.92 (95% confidence interval (CI), 0.77-1. 0), but even PCT was less well able to differentiate between non-bacteraemic infections and neoplastic fever (0.56; 95% CI, 0. 35-0.77). In conclusion, PCT was a good indicator for bacteraemia, but none of the three markers were reliable indicators for minor infections in non-neutropenic cancer patients.

The resistance of human monocyte-derived macrophages to Chlamydia pneumoniae infection is enhanced by interferon-gamma

Chlamydia pneumoniae is an intracellular bacterium which commonly causes respiratory infections. Chronic infections have been associated with atherosclerosis and the organism has been detected in macrophages in the disease lesions. Growth of chlamydiae in different epithelial cell lines is restricted by interferon-gamma (IFN-gamma), a monocyte activator produced by T cells. We have studied the influence of IFN-gamma on the growth and infectivity of C. pneumoniae in HL-cells and human monocyte-derived macrophages. Low concentrations of the cytokine significantly restricted the growth and productivity of C. pneumoniae in epithelial cells in vitro. In macrophages, however, no effect on the growth of the bacteria in infected cells was found, but high doses clearly restricted the production of infectious progeny. The results suggest that IFN-gamma participates in the resistance to C. pneumoniae. The bacterium is, however, still capable of infecting macrophages that are important in the pathogenesis of atherosclerosis and it may thus participate in the inflammatory process associated with the disease.

Asthma, atopy and Chlamydia pneumoniae antibodies in adults

BACKGROUND

Factors involved in the development of inflammation and asthma in nonatopic subjects have remained largely obscure, although there is some evidence to suggest that certain infections may play a role.

OBJECTIVE

We investigated the association between serological evidence of Chlamydia pneumoniae infection and asthma in adults, and the possible modifying effect of the patients' atopic status on this association.

METHODS

Four hundred and thirty consecutive patients who attended the hospital between 1992 and 1993 with symptoms suggestive of asthma, rhinitis or allergy were enrolled. Diagnostic procedures including lung function measurements and skin-prick tests were performed in all patients. The patients with established asthma (n = 332) were divided into those with recent asthma (n = 224, onset 1985 onward) and longstanding asthma (n = 108, onset before 1985). The controls (n = 98) comprised all subjects who did not meet the criteria of asthma. Serum immunoglobulin (Ig)G, IgA and IgM antibodies to C. pneumoniae were measured by the microimmunofluorescence test.

RESULTS

In women, the prevalences of elevated IgG (a titre of >/= 128) and IgA (>/= 32) antibody levels and the age-adjusted geometric mean titres (GMT) of IgG and IgA antibodies were invariably highest among subjects with nonatopic longstanding asthma. Elevated IgG titres in women occurred in 11% of controls, in 28% of nonatopic recent onset asthmatics, and in 43% of asthmatics with nonatopic longstanding disease; for men the respective figures were 33, 50 and 64%. Logistic regression analysis controlling for age, sex and smoking showed that asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae (odds ratio 3.3, 1.6-6.8 for longstanding asthma, 2.3, 1. 2-4.4 for recent asthma, and among women only 4.2, 1.6-10.9 for longstanding asthma, and 3.0, 1.3-7.2 for recent asthma). When the atopics and nonatopics were analysed separately, an even stronger relationship in the nonatopics was obtained for longstanding asthma (6.0,2.1-17.1). In contrast, the relationship between atopic asthma, either recent or longstanding, and elevated IgG titres was not significant, indicating that asthma per se does not predispose to C. pneumoniae infection.

CONCLUSIONS

Asthma was significantly associated with elevated IgG antibody levels to C. pneumoniae, and this association was strongest for nonatopic longstanding asthma.

Chlamydia pneumoniae antibodies associated with altered serum lipid profile

Chronic Chlamydia pneumoniae infection has been associated with atherosclerosis by seroepidemiological studies. Further, acute bacterial infections are known to influence lipid metabolism. To clarify the possible pathogenetic mechanisms of this association, we studied serum lipids and the C. pneumoniae IgG antibody titers of 1,053 males who participated in the reindeer herders health survey in Northern Finland in 1986-1989. The mean age of the study group was 47 years (range 20-87). When comparing nonsmoking C. pneumoniae antibody-positive (IgG > or = 32) subjects to those with no antibodies, the age-adjusted mean concentration of triglycerides was increased (1.34 vs. 1.04 mmol/l; p = 0.03) and high-density lipoprotein (HDL) was decreased (1.24 vs. 1.35 mmol/l; p < 0.001). HDL:total cholesterol ratio was also decreased (0.20 vs. 0.23; p = 0.01). In smokers changes were very similar, but not statistically significant. Thus, C. pneumoniae antibodies seem to correlate with an altered serum lipid profile considered to increase the risk of atherosclerosis. This finding supports the proposal that infections, in this case C. pneumoniae infection, may play a role in the pathogenesis of atherosclerosis.

Association of Helicobacter pylori infection with elevated serum lipids

Helicobacter pylori causes a chronic gastric infection, which has been associated with coronary heart disease. To evaluate the mechanisms of this association, we studied whether the infection affects serum lipid levels as previously shown in acute infections. We analysed the serum samples of 880 males who participated in a reindeer herders' health survey in Northern Finland in 1989. H. pylori IgG and IgA antibodies were measured by enzyme-linked immunosorbent assay and triglyceride, total cholesterol and high-density lipoprotein cholesterol concentrations by routine enzymatic methods. A total of 52% of the subjects were positive for both H. pylori specific IgG and IgA and 31% were antibody-negative. The serum triglyceride and total cholesterol concentrations were significantly higher in the males with positive IgG and IgA antibody titres for H. pylori than in the males with no signs of infection (1.20 vs. 1.03 mmol/l, P < 0.001 and 6.59 vs. 6.11 mmol/l, P < 0.001, respectively). The associations remained statistically significant in non-smokers after the adjustment for age, body mass index (BMI) and social class. The finding supports the hypothesis that chronic infections may modify the serum lipid profile in a way that increases the risk of atherosclerosis.

IgG subclass-specific antibodies in Chlamydia pneumoniae infections

IgG subclass-specific antibodies to Chlamydia pneumoniae and chlamydial lipopolysaccharide (LPS) were analysed in paired sera obtained from 15 patients with primary C. pneumoniae pneumonia and from 16 pneumonia patients with reinfection, as well as in single sera of 40 subjects with possible chronic C. pneumoniae infection and 40 healthy controls. The microimmunofluorescence (MIF) method was used to measure total IgG, IgM and IgG subclass-specific antibodies to C. pneumoniae protein antigens and enzyme immunoassay (EIA) to measure antibodies against the LPS antigen. By MIF, IgG1 antibodies to C. pneumoniae were demonstrated in all individuals of the 3 patient groups and also in all healthy controls. IgG2 subclass antibodies were not found by MIF. IgG3 antibodies were detected in 40% of patients with primary infection, in 31% of patients with reinfection, in 25% of those with chronic infection and in 8% of the controls. IgG4 antibodies were associated with acute C. pneumoniae infection and were found in 13% of primary infections and 31% of reinfections. The subclass pattern of LPS antibodies resembled that of protein antibodies measured by MIF: IgG1 was the most common subclass among the antibodies to LPS.

Serological evidence of an association between chlamydial infections and malignant lymphomas

Chronic infections may predispose to malignant growth. Recently, serological markers of chronic Chlamydia pneumoniae infection have been associated with lung cancer. Our aim was to study the possible association between chronic chlamydial infections and malignant lymphomas. The present case-control study involved 72 patients with lymphoma (31 females and 41 males) and matched controls. 53 patients had non-Hodgkin's lymphoma (NHL) and 19 had Hodgkin's disease. The sera, collected at the time of diagnosis, were tested for IgG antibodies and immune complexes to C. pneumoniae and C. trachomatis by a microimmunofluorescence method and ELISA and for IgG antibodies and immune complexes to Helicobacter pylori by ELISA. The serological markers suggesting chronic chlamydial infection were associated with malignant lymphoma. The association was most evident for the presence of C. pneumoniae-specific immune complexes in NHL (OR = 7.3, 95% CI 2.2-25) and appeared to be limited to men. No association between H. pylori antibodies or immune complexes and malignant lymphomas could be demonstrated. Our study provides seroepidemiological evidence of an association between chronic chlamydial infections and lymphomas.

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.

Elevated circulating levels of inflammatory cytokines in patients with abdominal aortic aneurysm

The basic feature in the pathogenesis of abdominal aortic aneurysm (AAA) is the degradation of extracellular matrix components. This process is induced partly by cytokines secreted from inflammatory and mesenchymal cells. Circulating levels of inflammatory cytokines were studied in AAA patients and compared with subjects suffering from atherosclerotic disease only. Furthermore, the predictive value of cytokine concentrations was evaluated for aneurysm expansion rate. Circulating levels of interleukin 1 beta (IL-1 beta), interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interferon-gamma (IFN-gamma) were measured in 50 AAA patients (40 men, 10 women), 42 patients with coronary heart disease (CHD) (23 men, 19 women), and 38 controls whose angiogram was normal (17 men, 21 women). No differences in cytokine concentrations were found between the CHD patients and the controls. AAA disease was found to be associated with significantly higher IL-1 beta and IL-6 concentrations in both male patients (median concentrations of 19.40 pmol/L and 6.45 pmol/L, respectively) and female patients (19.26 pmol/L and 7.99 pmol/L) than in either the CHD patients or the controls (P < .005). TNF-alpha levels were slightly higher in the AAA patients (1.64 pmol/L in the males and 1.59 pmol/L in the females) than in the other groups (P < .05). IFN-gamma levels were elevated significantly in the female AAA patients (3.75 pmol/L) compared with levels found in the other female (P < .05) or male (P < .01) patient groups. The measured cytokine concentrations were not related to the size of the aneurysm or the maximal thickness of the thrombus within the aneurysm. IFN-gamma concentration showed a significant positive correlation to the aneurysm expansion (R = .37, P < .02) and negative correlation to the concentration of aminoterminal propeptide of type III procollagen during 6-month follow up (R = -.42, P < .005). The results show that circulating levels of inflammatory cytokines are elevated in patients with AAA disease, suggesting that the production of these cytokines is increased in these patients compared with CHD patients and controls. Elevated INF-gamma concentrations seem to predict an increased rate of expansion in AAA.

Chronic Chlamydia pneumoniae infection is associated with a serum lipid profile known to be a risk factor for atherosclerosis

Chlamydia pneumoniae infection has been associated with coronary heart disease. To evaluate the mechanisms of this association, we studied whether chronic C. pneumoniae infection affects serum lipid values similarly to acute infections. Triglyceride, total and HDL cholesterol concentrations, and C. pneumoniae antibodies were measured from paired serum samples of 415 Finnish males taken 3 years apart. Chronic infection, defined as persistent IgG and IgA antibodies, was found in 20%, and the antibodies were negative (IgG < 32 and IgA < 16 in both samples) in 15% of the cases studied. The serum triglyceride and total cholesterol concentrations were higher in the subjects with a chronic C. pneumoniae infection than in the subjects with no antibodies (1.23 versus 1.03 mmol/L and 6.41 versus 6.31 mmol/L, respectively). The HDL cholesterol concentrations and the ratios of HDL cholesterol to total cholesterol were significantly decreased in the subjects with chronic infection (1.24 versus 1.36 mmol/L, P = .026; and 0.19 versus 0.22, P = .018, respectively). Chronic C. pneumoniae infection seems to be associated with a serum lipid profile considered to increase the risk of atherosclerosis. This finding supports the hypothesis that infections play a role in the pathogenesis of atherosclerosis.

Persistence of antibodies to pneumococcal capsular polysaccharide vaccine in the elderly

Persistence of antibodies to 23-valent pneumococcal vaccine was assessed among 62 subjects aged 65-88 years. IgG antibodies were measured by standardized EIA to serotypes 4, 6B, 9V, 14, 19F, and 23F before and 1 month, 1 year, and 3 years after vaccination. After satisfactory antibody responses (fold increases from 2.6 to 5.3), 3-year geometric mean concentrations (GMCs) had waned to close (for types 4, 9V, and 23F) or similar (for types 6B and 19F) to their prevaccination values. Type 14 was exceptional: 1-month GMC was 7.7-fold and 3-year GMC was 3.0-fold in comparison to the prevaccination GMC. Antibody concentrations decreased at an equal rate irrespective of serotype and age or sex of the vaccinee. The major factor predicting the persistence of antibodies above the prevaccination level was the magnitude of the original antibody response. Present results suggest that pneumococcal revaccination of the elderly may be needed as early as 3-4 years after the initial vaccination.

Chlamydia pneumoniae and Helicobacter pylori infections in Sámi and Finnish reindeer herders

The Sámi people in northernmost Finland have lower mortality from cardiovascular diseases than the main population of Finland. Chronic infections caused by Chlamydia pneumoniae and Helicobacter pylori, both quite recently discovered gram-negative bacteria, have been associated with atherosclerosis. We studied the prevalence of these infections in Sámi and Finnish men by analysing the C. pneumoniae and H. pylori specific serum IgG and IgA antibodies using microimmune fluorescence and enzyme linked immunosorbent assay methods, respectively. The frequency of C. pneumoniae IgG antibodies and the age adjusted geometric mean titres differed significantly between these groups. The Finns were more often sero-positive than the Sámi (76% vs. 67%, respectively), the age adjusted geometric mean titre being 71.6 in the Finns and 38.3 in the Sámi; p = 0.001. No significant difference was found in the H. pylori IgG and IgA antibody prevalences, nor in the geometric mean titres between these groups. The difference in cardiovascular mortality between the Sámi and Finns may be partly explained by the lower incidence of chlamydial infections in the Sámi.

Lymphocyte responses to Chlamydia antigens in patients with coronary heart disease

AIMS

To clarify the relationship of Chlamydia pneumoniae infection and coronary atherosclerosis we studied cell-mediated and humoral immune responses to Chlamydia in 93 patients with angiographically confirmed coronary heart disease and in 115 controls without angiographically demonstrable lesions.

METHODS AND RESULTS

Cell-mediated responses were analysed by measuring lymphocyte proliferative reactivity to whole elementary body antigens of C. pneumoniae. Control antigens included C. trachomatis and purified protein derivative of tuberculin. Chlamydia-specific antibodies were measured using microimmunofluorescence assay. Marked C. pneumoniae-specific immune reactivity, demonstrated by the high incidence of elevated IgG and IgA antibodies and strong lymphocyte proliferative response, was associated with coronary heart disease in male but not in female patients or controls. In male patients, the cell-mediated responses were strong to C. pneumoniae (median stimulation index 9,6) and to C. trachomatis (stimulation index 6,9). The females with coronary heart disease showed significantly stronger cell-mediated responses to C. pneumoniae (stimulation index 6,5) than to C. trachomatis (3,8; P < 0.001) and were comparable to the controls.

CONCLUSION

Marked cell-mediated and humoral immunity to C. pneumoniae in males with coronary heart disease suggest that the immune mechanisms triggered by Chlamydia are a possible contributing factor in the disease pathogenesis of coronary atherosclerosis in males. The Chlamydia-specific cell-mediated responses seem to be predominantly induced by antigenic structures that are similar among different Chlamydia-species.

Effect of age, sex and smoking habits on pneumococcal antibodies in an elderly population

BACKGROUND

Pneumococcal infections are a common cause of morbidity and mortality among elderly people. Protection against pneumococcal infections is mediated by serotype-specific antibodies to capsular polysaccharides. To obtain an estimate of anti-pneumococcal immunity, prevalence and levels of pneumococcal antibodies were studied in an unvaccinated elderly population.

METHODS

IgG antibodies to pneumococcal serotypes 3, 6A, and B and to cell wall polysaccharide (C-PS, a common antigen to all pneumococci) were measured by enzyme immuno-assay in 480 subjects aged 64-97 years (206 men, 274 women) who were a random sample (41%) of elderly inhabitants in a semirural community in Finland.

RESULTS

An average of 10% of the elderly lacked antibodies to serotypes 3, 6A, and 8, and 62% of the elderly had them in low titres only. Anti-C-PS antibodies were found in 99% of the elderly, and in significantly higher titres than anti-capsular antibodies. Antibody titres to C-PS and to type 6A decreased with age. Elderly women had significantly lower antibody levels than men. Among the men, current smokers had higher antibody titres than non-smokers; in the women, this analysis was not possible because of infrequent history of smoking. The effect of smoking on antibody titres was reversible after cessation of smoking.

CONCLUSIONS

A considerable proportion of the elderly lacked protective antibodies to commonly infecting pneumococcal serotypes 3, 6A, and 8. Smoking increased the prevalence and levels of pneumococcal antibodies probably as a consequence of numerous respiratory infections. These observations emphasize the importance of administration of the pneumococcal vaccine among the elderly.

Serological evidence of an association between Chlamydia pneumoniae infection and lung cancer

Epidemiological evidence suggests that airway obstruction is an independent risk factor for lung cancer and that this cannot be explained by active or passive smoking alone. Chlamydia pneumoniae infection has been associated with chronic bronchitis and its exacerbates. Our aim was to evaluate the association between chronic C. pneumoniae infection and risk of lung cancer among male smokers. Smoking males with lung cancer (n = 230) and their age- and locality-matched controls were selected among participants of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. The presence of C. pneumoniae infection was assessed by analyzing specific antibodies and immune complexes in 2 serum samples collected with a 3-year interval before the lung cancer diagnosis. The diagnosis of chronic infection was based on stable levels of positive specific IgA antibody (titer > or = 16) and immune complex (titer > or = 4). Relative risks were estimated by odds ratios (OR) adjusted for age, locality and smoking history by a conditional logistic regression model. Markers suggesting chronic C. pneumoniae infection were present in 52% of cases and 45% of controls and hence were positively associated with the incidence of lung cancer (OR 1.6; 95% confidence interval [CI] 1.0-2.3). The incidence was especially increased in men younger than 60 years (OR 2.9; 95% CI 1.5-5.4) but not in the older age group (OR 0.9; 95% CI 0.5-1.6). Before concluding that C. pneumoniae infection is a new independent risk factor for lung cancer, corroboration from other studies with larger number of cases and longer follow-up is needed.

Antibody response to pneumococcal capsular polysaccharide vaccine in the elderly

Antibody response to 23-valent pneumococcal vaccine was assessed in 350 subjects (131 men, 219 women) aged 65-91 years. IgG antibodies to pneumococcal serotypes 4, 6B, 9V, 14, 19F, and 23F were measured by EIA after blocking of antibodies to cell wall polysaccharide. Antibody concentrations in both pre- and postvaccination sera (mean interval, 35 days) were higher in elderly men than women; in the women, the concentrations decreased significantly with increasing age, but not in the men. Antibody fold increases were good in the elderly, including those > or = 85 years old. The overall percentage of the elderly with antibody concentrations > 1 microgram/mL to the 6 antigens increased by vaccination from 61% to 87%, but in the women > or = 85 years old, only to 75%. Antibody response to 23-valent pneumococcal vaccine was satisfactory in the elderly.

Chilodonella spp. at four fish farms in northern Finland

A total of 4.1% infestation with Chilodonella spp. was found among fish studied in 144 tanks in 1987-1989, representing 14.0% of the tanks in which fish are reared at four salmonid farms in northern Finland. Two species were found, C. hexasticha and C. piscicola, and both occurred on salmon (Salmo salar L.), sea trout [S. trutta m. trutta (L.)] and brown trout [S. t. m. lacustris (L.)]. Variability was observed in the length and width of the C. piscicola specimens and the number of ciliary rows or kineties. Large specimens which had more kineties than average for C. piscicola were found mainly on the skin of salmon aged 1-2 years. The number of kineties in the right ciliary band was found in stepwise logistic regression analysis to be of importance when typing C. piscicola specimens. Fingerlings were found to be more susceptible to Chilodonella infestation than older fish, and mortality varied in the range 2-10% in the course of the epizootics in the three fish species. Most mortality cases were caused by C. hexasticha, occurring mainly on the gills of the fish. Chilodonella piscicola was most often found in salmon and occurred at lower water temperatures than C. hexasticha (mean water temperature when found for the first time being 13 degrees C and 16 degrees C, respectively).