The Association of Chlamydia pneumonia and Helicobacter pylori IgG Seropositivity With Omentin-1, Visfatin and Adiponectin Levels in Postmenopausal Women

Some adipocytokines are cardioprotective or pro-inflammatory for cardiovascular system. Chronic infection with Chlamydia pneumoniae and Helicobacter pylori has been also considered as novel risk factors for atherosclerosis. The main aim of the current population-based study is to investigate the potential link between circulating adipocytokines and Chlamydia pneumoniae or Helicobacter pylori IgG seropositivities. A total of 250 healthy postmenopausal women who participated in a prospective cohort study were evaluated for IgG antibodies directed against C.pneumoniae and H. pylori. Omentin-1, visfatin, adiponectin, and high sensitivity C-reactive protein were measured by highly specific enzyme-linked immunosorbent assay methods. The prevalence of IgG antibodies against C. pneumoniae and H. pylori among the studied population was 20.4% (51 women) and 57.2% (143 women), respectively. There were no significant differences in adipocytokine levels between H. pylori IgG seropositive and H. pylori seronegative subjects. Similar results for visfatin and omentin-1 were found when C. pneumoniae IgG seropositive were compared with C. pneumoniae IgG seronegative subjects. However, in general linear model adjusted for age, body mass index and hs-CRP levels revealed significant difference between C. pneumoniae seropositive and C. pneumoniae seronegative subjects for circulating adiponectin. In conclusion, Chlamydia pneumoniae IgG seropositivity was associated with higher adiponectin levels in postmenopausal women. The elucidation of interaction mechanism of Chlamydia pneumoniae and a cardioprotective adipocytokine (adiponectin) will be useful in future therapeutic strategies.

Chlamydia pneumoniae and Helicobacter pylori IgG seropositivities are not predictors of osteoporosis-associated bone loss: a prospective cohort study

The potential link between infection with Chlamydia pneumoniae or Helicobacter pylori and osteoporosis has not been investigated in population-based longitudinal studies. A total of 250 healthy postmenopausal women who participated in a prospective cohort study were evaluated for IgG antibodies directed against C. pneumoniae and H. p ylori, osteoprotegerin (OPG), the receptor activator of nuclear factor kappa B ligand (RANKL), CrossLaps, and osteocalcin. Bone mineral density (BMD) was measured at the femoral neck and lumbar spine at baseline and at follow-up 5.8 years later. There were no significant differences in age-adjusted bone turnover markers, OPG, RANKL, the RANKL/OPG ratio, and BMD between the C. p neumoniae and H. p ylori IgG seropositive and seronegative subjects (P > 0.05). Neither C. p neumoniae nor H. p ylori IgG seropositivity was associated with age-and body mass index-adjusted BMD at the femoral neck and lumbar spine or bone loss at the 5.8-year follow-up. In logistic regression analysis, neither C. p neumoniae nor H. p ylori IgG seropositivities predicted incident lumbar or spine osteoporosis 5.8 years later. In conclusion, neither C. p neumoniae nor H. p ylori IgG seropositivity was associated with bone turnover markers, the RANKL/OPG ratio, BMD, or bone loss in postmenopausal women. In addition, chronic infection with C. p neumoniae or H. p ylori did not predict incident osteoporosis among this group of women.

Is Chlamydia Pneumoniae a Risk Factor for Peripheral Atherosclerosis?

Seroepidemiological studies have shown a relationship between Chlamydia pneumoniae and coronary atherosclerosis. It is not clear whether Chlamydia pneumoniae is also a risk factor for peripheral atherosclerosis. Chlamydia pneumoniae antibodies were measured by a microimmunofluorescence method in 75 patients who underwent surgery for peripheral atherosclerosis, and the seroprevalence was compared with that in the normal population. Chlamydia pneumoniae immunoglobulin-G seroprevalence was 80% in the study group vs. 40% in controls. More foam cells were noted on light microscopy in atherosclerotic plaques from the infected patients. The 60 infected patients were divided into: group A ( n = 35) given both anti-chlamydial and antiplatelet agents for 1 year; and group B ( n = 25) given antiplatelet therapy only. The groups were compared on the basis of clinical findings, ankle-brachial index, and antibody titers. Decreasing Chlamydia pneumoniae immunoglobulin-G seroprevalence in group A correlated significantly with increasing ankle-brachial index and improvement in clinical findings. It was concluded that Chlamydia pneumoniae may be a risk factor for peripheral atherosclerosis.

SPECIFIC SERUM IMMUNOGLOBULIN G AGAINST CHLAMYDIA PNEUMONIAE IN HEALTHY CHILDREN AND ADULTS IN SOUTH-EAST OF IRAN

BACKGROUND

Chlamydia pneumoniae (C. pneumonia) is an obligate intracellular bacterium and recognized as a risk factor for several diseases such as asthma, atherosclerosis and arthritis. The aim of this study was to determine the seroprevalence of C. pneumonia in healthy subjects in different age groups.

METHODS

The serum levels of anti C. pneumonia IgG were measured by using of ELISA.

RESULTS

Totally, 630 subjects (164 children and 466 adults) were included into study. The seroprevalence and the mean titer of anti C. pneumonia antibody were 11.3% and 14.48?2.18 RU/mL; at age 510 years, 15% and 17.47 +/- 2.40 RU/mL at age 11-20 years, 21% and 25.15 +/- 4.56 RU/mL at age 21-30 years group, 40% and 53.77 +/- 6.40 RU/mL at age 31-40 years, 94% and 146.41 +/- 8.95 RU/mL at age 41-50 years, 98% and 153.59 +/- 10.38 RU/mL at age 51-60 years, 96% and 138.80 +/- 12.78 RU/mL at age 61-70 years, respectively. The differences of the seroprevalence and the mean titer of anti C. pneumonia antibody between age groups were significant (p<0.0001). The sero-prevalence and the mean titer of anti C. pneumonia antibody were 11.6% and 14.33 +/- 1.49 RU/mL in children and 65.5% and 97.40 +/- 4.46 RU/mL in adults. The seroprevalence and the mean titer of anti C. pneumonia antibody were significantly higher in adults in comparison with those in children (p<0.0001).

CONCLUSION

These findings showed that the sero- prevalence and titer of anti C. pneumonia IgG were increased with advanced ages and were higher in adults as compared to children.

[Chlamydia pneumoniae persistent infection is associated with primary IgA nephropathy]

OBJECTIVE

To explore the correlations between Chlamydia pneumoniae (CP) infection and IgA nephropathy (IgAN).

METHODS

Seventy patients with primary IgAN were enrolled in the study. Seventy serum specimens from healthy blood donors and twelve renal autopsy specimens from accidental death bodies were regarded as control groups. Serum CP IgG and CP IgA antibody titers were detected by indirect immunofluorescence. CP DNA of renal tissue was measured by fluorescent quantitative PCR. Finally, using statistical methods, we analyzed the correlations of CP infection and CP DNA of renal tissue with clinical manifestations and kidney pathological changes of IgAN patients.

RESULTS

The rate of CP persistent infection in IgAN group was higher than that of healthy blood donor group (P<0.01). The rate was not significantly different within the IgAN group, such as among acute infection, previous infection and no infection subgroups (P>0.05). It was higher in the patients with gross proteinuria and/or durative renal insufficiency than in non-gross proteinuria patients (P<0.05). The scores of glomerular patholopical and tubulointerstitial injury of CP persistent infection patients were higher than those of non-persistent infection ones (P<0.05). The renal injury of CP persistent infection patients was more severe than that of non-persistent infection ones. The positive rate of CP DNA in gross proteinuria and/or renal insufficiency patients was higher than that of non-gross proteinuria patients (P<0.05). The scores of glomerular pathological and tubulointerstitial injury of positive CP DNA patients were respectively higher than those of negative CP DNA ones (P<0.05, P<0.01). The renal injury of patients with positive CP DNA was more severe than that of negative CP DNA ones. CP persistent infection was obviously correlated with renal CP DNA (P<0.01).

CONCLUSION

Primary IgAN is associated with CP persistent infection, but not with CP previous infection or CP acute infection.

Chlamydia pneumoniaeRespiratory Infections in Taiwan

To understand the epidemiology of Chlamydia pneumoniae acute infections in Taiwan, we collected 116 paired and 244 single sera from patients suspected of C. pneumoniae infection and conducted microimmunofluorescence test. Eighty-three patients (83/360, 23%) met the diagnostic criteria of current C. pneumoniae infection. The C. pneumoniae infections were significantly higher in men than in women (P< or =0.0001) and were most frequent in the group of 40-49 year-olds, and the people older than 70 years old. C. pneumoniae infection often occurred in the late autumn lasting to the cold winter and in the transition period between the spring and summer.

Chlamydia pneumoniae and osteoporosis-associated bone loss: a new risk factor?

We found an association between the presence of Chlamydia pneumoniae DNA both in osteoporotic bone tissue and peripheral blood mononuclear cells (PBMCs) and the increase in circulating resorptive cytokines.

INTRODUCTION

Our study was designed to determine whether C. pneumoniae infection may be involved in osteoporosis-associated bone loss.

METHODS

The study included 59 women undergoing hip joint replacement surgery for femoral neck fracture: 32 with osteoporosis and 27 with osteoarthritis. A total of 118 tissue specimens (59 bone tissues, 59 PBMCs) were examined for C. pneumoniae DNA by real-time polymerase chain reaction (PCR). Serum levels of soluble receptor activator of nuclear factor kappa B ligand (sRANKL), osteoprotegerin (OPG), interleukin (IL)-1β, tumor necrosis factor-α, and IL-6 were also measured.

RESULTS

C. pneumoniae DNA was detected in osteoporotic bone tissue whereas it was not found in non-osteoporotic bone tissue (p < 0.05). A significantly higher rate of C. pneumoniae DNA (p < 0.05) was found in PBMCs of osteoporotic patients than in those of osteoarthritis patients. Among osteoporotic patients, serum sRANKL, IL-1, and IL-6 concentrations as well as sRANKL/OPG ratio significantly differ between patients with bone tissue and PBMCs positive to C. pneumoniae and C. pneumoniae-negative patients.

CONCLUSION

The association between the presence of C. pneumoniae DNA, both in bone tissue and PBMCs, and the increase in sRANKL/OPG ratio as well as in IL-1β and IL-6 levels observed in osteoporotic patients suggests C. pneumoniae infection as a new risk factor for osteoporosis.

[The dynamics of detection of antibodies class G against Chlamydia pneumoniae and Chlamydia psittaci in blood serum of patients of different age groups]

The detection of antibodies class G in blood serum of patients of different age groups was carried out in 2005-2010. The analysis permitted to establish the peak of activity of chlamydiae infection in 2006 and increase of activity of morbidity in 2010.

[Chlamydophila pneumoniae infections in younger children. Experience of one centre. Preliminary report]

BACKGROUND

Very few recent Polish data are available on the epidemiology of Chlamydophil pneumoniae (C. pneumoniae) as causative agent among paediatric patients, hospitalized with respiratory tract disorders. Extending these data would serve as rationale for empirical antimicrobial therapy. The aim of the study was to evaluate the frequency of C. pneumoniae infections in younger children hospitalized with prolonged cough and/or prolonged pneumonia.

MATERIAL AND METHODS

110 children, aged 0.3-7.0 yrs., hospitalized from January 1st to March 3 1st 2009 for the above reasons were retrospectively enrolled in the study. Diagnosis of C. pneumoniae was based on ELISA IgM antibodies positive test. Patients with ambiguous IgM titre were excluded from further study (n=12).

RESULTS

Of 98 finally investigated children, C. pneumoniae infection was found in 28 patients (28.5%) with the highest frequency in February 2009 (15 cases). It was diagnosed more frequentlyin toddlers (over 1.73 yrs. of age) than in infants and youngest children (p=0,014; OR=4,10 95%C1=1,4-12,0). In patients with active C pneumoniae infection WBC were significantly lower (p=0,001), but within normal range (8647/mm3, +/- SD: 3247/mm3). Other factors such as sex, clinical symptoms and some chosen laboratory markers did not differ significantly between subgroups of sero-positive/sero-negative patients.

CONCLUSIONS

Performed analysis suggests a significant role of C. pneumoniae etiology in younger children with prolonged respiratory tract symptoms and can be a useful tool in empirical antibacterial treatment. Further studies for a longer period, larger groups of patients and additional confirmation of sero-positive cases are needed.

The relationship between seropositivity against Chlamydia pneumoniae and stroke and its subtypes in a Latvian population

BACKGROUND AND OBJECTIVE

Serological evidence of infection with Chlamydia pneumoniae has been associated with cardiovascular diseases, but the relationship with stroke and its risk factors remains not completely understood. The aim of this study was to determine whether serological evidence of infection with Chlamydia pneumoniae was associated with the risk of ischemic stroke and any of investigated stroke subtypes.

MATERIAL AND METHODS

Confirmed stroke cases (n=102) were compared with gender- and age-matched control patients (n=48). The patients with stroke were divided into 3 groups according to the TOAST criteria: atherothrombotic (n=36), cardioembolic (n=47), and of undetermined etiology (n=19). Plasma levels of IgG antibodies to Chlamydia pneumoniae were measured by enzyme-linked immunosorbent assay.

RESULTS

There was a significant association between seropositivity to Chlamydia pneumoniae and stroke. Anti-Chlamydia pneumoniae IgG antibodies were detected in 64 case patients (62.7%) and 17 control patients (35.4%) (χ(2)=9.8; df=1; P=0.002). IgG seropositivity to Chlamydia pneumoniae was linked to all the analyzed etiological subtypes of stroke.

CONCLUSION

This study showed that IgG seropositivity to Chlamydia pneumoniae was associated with stroke and all the analyzed etiological subtypes of stroke.

Increased expression of CD11a and CD45 on leukocytes and decreased serum TNF-alpha levels in patients with isolated coronary artery ectasia

BACKGROUND

Aneurysm and ectasia have similar pathological pathways. TH2-associated cytokines are stimulated by aneurismal tissue and correspondingly lack mediators associated with TH1 response. In this study, we measured serum TNF-alpha and IL-18 levels which are strong TH1 stimulating cytokines and also investigated the expression of CD11a, CD11b, CD18 adhesion molecules and CD45 on leukocytes in patients with coronary artery ectasia (CAE) and controls with normal coronary arteries (NCA).

METHODS

A total of 51 isolated CAE patients free of atherosclerosis and 37 NCA controls were included in the study. Cell counts and cell surface adhesion molecules were detected by flow cytometry using fluorescence conjugated monoclonal antibodies. Serum TNF-alpha, IL-18 levels, and Chlamydophila pneumoniae IgG and IgM and Helicobacter pylori IgG levels were detected by ELISA methods.

RESULTS

The mean fluorescence intensities of CD11a on granulocytes, monocytes and lymphocytes and CD45 on granulocytes and monocytes were significantly higher in CAE patients when compared with the NCA group (10.01 +/- 8.2 vs. 6.79 +/- 3.49, p = 0.04; 15.84 +/- 8.64 vs. 11.56 +/- 5.27, p = 0.016; 29.58 +/- 9.98 vs. 20.02 +/- 9.66, p < 0.001; 7.58 +/- 5.03 vs. 4.57 +/- 3.05, p = 0.003; 18.73 +/- 1238 vs. 10.74 +/- 738, p = 0.004; respectively) detected by flow cytometry. TNF-alpha levels were significantly lower in the patient group (18.76 +/- 7.07 vs. 24.29 +/- 8.46; p < 0.001) when compared with controls. The percentage of granulocytes was higher in the CAE group when compared with the NCA group (65.52 +/- 14.91 vs. 52.28 +/- 1537; p = 0.002). Contrarily, the percentage of monocytes was higher in the control group when compared with the CAE group (18.12 +/- 15.69 vs. 934 +/- 733 p = 0.008). Among the infection markers studied, only C. pneumoniae IgG levels were significantly higher in patients when compared with controls (81.62 +/- 48.53 RU/mL vs. 63.79 +/- 33.83 RU/mL; p = 0.045). In CAE patients, TNF-alpha levels significantly correlated with mean fluorescence intensity levels of CD45+ granulocyte (0.525, p < 0.001), monocyte (0.469, p = 0.001) and lymphocytes (0376, p = 0.013).

CONCLUSIONS

The decreased levels of TNF-alpha may indicate predominance of TH2 and lack of TH1 type immunity in CAE patients, similar to patients with aortic aneurysms. Increased levels of cell surface adhesion molecules in CAE are an indicator of activation of leukocytes for adherence and transmigration through the vessels for the initiation of inflammation.

Chlamydia pneumoniae DNA in Peripheral Blood Mononuclear Cells in Healthy Control Subjects and Patients with Diabetes mellitus, Acute Coronary Syndrome, Stroke, and Arterial Hypertension

Infection with Chlamydia pneumoniae has been suggested to play a role in the development and maintenance of atherosclerosis based on differences in the prevalence of antibodies against Chlamydia pneumoniae in patients with and without atherosclerotic lesions. We evaluated the prevalence of Chlamydia pneumoniae DNA in the white cells of the peripheral blood in 194 patients with diabetes mellitus, 50 patients with acute coronary syndrome, 102 hypertensive patients, 193 patients having suffered a stroke and in 368 healthy subjects with a nested polymerase chain reaction (nPCR). Overall the prevalence of Chlamydia pneumoniae DNA in peripheral blood cells was: diabetes mellitus (11.9%), stroke (10.4%), hypertension (6.9%), acute coronary syndrome (4.0%) and healthy subjects (7.9%). The prevalence of Chlamydia pneumoniae DNA in the patients was not significantly different from prevalence in the healthy subjects. However, a significant association was found between high levels of triglycerides and presence of C. pneumoniae DNA (OR = 3.27, p < 0.04). The prevalence of C. pneumoniae DNA was not associated with age, gender, smoking, BMI, HDL, CRP, plasma creatinine and symptoms or signs of ischaemic heart disease. The association between high levels of triglycerides and C. pneumoniae DNA suggests that infection by C. pneumoniae affects lipid metabolism.

[Intervention of Huanglian Jiedu decoction on haemorheology and cholesterol-supplemented diet]

OBJECTIVE

To study the influence of Chlamydia pneumonia (Cpn) infection on haemorheology and atherosclerosis and the intervention of Huanglian Jiedu decoction (HJT).

METHOD

At the beginning of the experiment, all the sixty New-Zealand rabbits were token blood to test Cpn IgG and all the results were negative. Eight New-Zealand rabbits were randomized into normal group F, and all other rabbits were fed with forage containing 2.5 g x kg(-1) cholesterol and infected with Cpn via nasophrynx for three times during 6 weeks. At the end of the sixth week, forty-four rabbits with serum Cpn IgG positive were randomized into four groups: Group A treat with HJD 2 g x kg(-1) d(-1) by gastric gavage, group B with HJT 1 g x kg(-1) x d(-1), group C with azithromycin 20 mg x kg(-1) x d(-1), model group D with normal saline for six weeks. Group E was set up in eight rabbits with serum Cpn IgG negative and served as the control. At the end of 18th week, blood was token from middle ear artery to test haemorheology such as whole blood viscosity, plasma viscosity, haematocrit, erythrocyte aggregation index (EAI), erythrocyte rigidity index (IRI), and erythrocyte deformability index (EDI). After that, all the rabbits were executed and the pathological features of aorta tissue were observe under microscope.

RESULT

Haemorheological disorder and atherosclerotic changes were obvious in both group D and E. while maximum intimal thickness (MIT) (23.65 +/- 8.19 vs 12.76 +/- 4.06), atherosclerotic damage percentage (P(LCI)) (41.08 +/- 12.51 vs 22.43 +/- 9.45), plaque area index (I(PA)) (9.57 +/- 1.82 vs 2.84 +/- 0.25) in group D was much higher than that in group E (all P < 0.01). Compare with group D, haemorphological disorder and atherosclerotic changes were much improved in group A, B and C. MIT (6.45 +/- 1.27 vs 23.65 +/- 8.19), (P < 0.01), P(LCI) (22.39 +/- 6.74 vs 41.08 +/- 12.51), (P < 0.05) and I(PA) (1.44 +/- 0.33 vs 9.57 +/- 1.82), (P < 0.01) in group A was much lower than that in group D. And MIT (12.65 +/- 3.63 vs 23.65 +/- 8.19), (P < 0.01) and I(PA) (4.43 +/- 1.17 vs 9.57 +/- 1.82), (P < 0.05) in gruoup B was much lower than that in group D too.

CONCLUSION

Cpn infection could aggravate the haemorheology disorder in cholesterol-supplemented-diet rabbits, and both antidotal decoction of Coptis and azithromycin can alleviate it.

Prognostic value of infection and inflammation markers for late cardiac events in an Iranian sample

We evaluated the serum levels of IgG antibodies to Helicobacter pylori, Chlamydia pneumoniae and cytomegalovirus and the level of the inflammatory markers C-reactive protein and fibrinogen in 57 patients with acute coronary syndrome, 65 with unstable angina, 60 with stable angina and 44 healthy controls, and whether these markers were associated with cardiac instability 6 months after admission. acute There was a significant increased risk of late coronary events (cardiac death or readmission with coronary events) associated with seropositivity to C. pneumoniae (adjusted odds ratio 2.12; 95% confidence interval: 1.16-4.08). Other parameters were not significantly associated with late cardiac events after adjustment for age, sex, diabetes mellitus, hypertension, hyperlipidaemia and smoking behaviour.

Chlamydia pneumoniae IgA and elevated level of IL-6 may synergize to accelerate coronary artery disease

OBJECTIVES

A strong association of cytokines [interleukin (IL)-6, IL-2 and tumor necrosis factor (TNF)-alpha] with atherosclerosis is well documented. However, their role in Chlamydia pneumoniae (Cp)-associated progression of coronary artery disease (CAD) is not well studied. Hence we evaluated the presence of these cytokines in CAD patients positive for Cp immunoglobulin (Ig) A (low, medium, and high levels) CAD and compared with controls. Also the physiological and baseline characteristics in IL-6 positive CAD patients were studied.

METHODS

During the period from March 2005 to June 2007, 192 CAD patients and controls attending the cardiology clinic of Safdarjung Hospital, New Delhi, India were enrolled. ELISA was performed for the estimation of Cp IgA, high sensitive C-reactive protein (hsCRP), and cytokines IL-6, IL-2, and TNF-alpha in CAD patients and controls.

RESULTS

IL-6 was significantly higher in CAD patents with medium and higher Cp IgA levels (35 vs. 10 and 32 vs. 4) compared to controls. Physiological features and baseline characteristics of CAD were significantly higher in IL-6 positive CAD patients. Additionally, in CAD patients IL-6 was significantly correlated with hsCRP (p<0.001, r=0.42).

CONCLUSIONS

Our results lead us to hypothesize the role of IL-6 in the pathogenesis of CAD, which may subsequently get accelerated through Cp infection.

Lack of association between Chlamydophila pneumoniae seropositivity and abdominal aortic aneurysm

Chronic Chlamydophila pneumoniae infection has been suggested as a possible contributing factor for the development and expansion of abdominal aortic aneurysm (AAA). The relevance of C pneumoniae involved in the processes underlying aneurysmal rupture is unknown. The aim of this study was to examine the relationship between C pneumoniae seropositivity and AAA rupture. In a case-control study, 119 patients with AAA and 36 matched controls were prospectively investigated with C pneumoniae serology. Patients with ruptured AAA have similar levels of IgG antibodies against C pneumoniae as patients with an electively operated AAA, a small AAA, and controls. In conclusion, this study fails to demonstrate a connection between C pneumoniae seropositivity and AAA rupture.

Impact of latent infections with Chlamydophila species in young cattle

To assess long-term effects of naturally occurring infection with Chlamydophila spp. on animal health, 25 calves were grouped according to their chlamydial carrier status and checked for health parameters from 2 to 7 months of age. Monthly PCR testing revealed persistent or frequently recurring infections with Chlamydophila pecorum and Chlamydophila abortus in Group 2 (Chl+, n=13), but not in Group 1 (Chl-, n=12). Despite the absence of any clinical illness, calves in Group 2 showed significantly higher body temperatures (subfebrile), lower bodyweights, reduced serum iron concentrations, lower total haemoglobin and haematocrit values. Counting and flow cytometric differentiation of peripheral white blood cells revealed a general decrease in leukocytes in Group 2. At necropsy, follicular bronchiolitis was found in 10/13 calves in Group 2 but in none of Group 1, and the weight of pharyngeal tonsils was significantly higher in Group 2. In conclusion, naturally occurring infections with Chlamydophila species in calves were found to be associated with chronic effects on animal health at a subclinical level.

Serology of Chlamydia pneumoniae in patients with chronic cough

OBJECTIVE AND BACKGROUND

Chronic cough is one of the more common respiratory symptoms. Controversy exists as to whether Chlamydia infection is associated with chronic cough. As such, the association of chronic cough with serological evidence of Chlamydia pneumoniae (C. P) infection and a systemic inflammatory marker was assessed.

METHODS

Thirty-seven patients who visited Kangwon National University Hospital for chronic cough between September 2003 and August 2004 and 37 age-matched healthy controls were evaluated for C. P. antibodies and C-reactive protein. Chronic infection was defined as an IgG or IgA titre between 1:64 and 1:512, and acute infection was defined as IgM=1:16 or IgG titre of=1:512 or IgA=1:512. A nasopharyngeal swab was evaluated for C. P. DNA using the polymerase chain reaction.

RESULTS

The median duration of cough was 3 months (1-240). Nineteen patients (49%) and 19 controls had titres consistent with chronic infection, and the titre difference was not significant (P=0.592). Nine patients and two controls had titres consistent with acute infection (24.3% vs. 5.4%). Acute infection was significantly more prevalent in the patients with chronic cough (P=0.023). There was no difference in the C-reactive protein value (0.13 vs. 0.14, P=0.84). Three patients were positive for C. P. DNA.

CONCLUSION

Acute Chlamydia infection was more prevalent in patients with chronic cough, whereas chronic Chlamydia infection was not. There was no elevation of a systemic inflammatory marker in patients with chronic cough.

Evaluation of the diagnostic usefulness of real-time PCR for detection of Chlamydophila pneumoniae in acute respiratory infections

We investigated whether a real-time polymerase chain reaction (PCR) test is a useful diagnostic tool for identifying individuals with acute respiratory Chlamydophila pneumoniae infections. Nasopharyngeal swab specimens and peripheral blood mononuclear cells (PBMCs) from 100 patients with acute respiratory tract infections and 140 asymptomatic healthy subjects (controls) were analyzed using real-time PCR, culture, and serology for the detection of C. pneumoniae. Six patients had serological results indicating acute C. pneumoniae infections. C. pneumoniae DNA was detected in respiratory samples from eight patients (three of these cases were serologically confirmed as having C. pneumoniae infections) and four controls. The amount of C. pneumoniae DNA present in the real-time PCR for the samples was calculated, and no significant differences in the amount of DNA between symptomatic and asymptomatic subjects were found. On the other hand, traces of C. pneumoniae DNA were detected in PBMCs from eight patients, but this was confirmed in PBMCs from only seven of these patients. Only one patient had both respiratory and blood samples that were positive. C. pneumoniae DNA was also detected in samples from six controls, but no significant differences in the amount of C. pneumoniae DNA were observed between patients and controls. The present quantitative real-time PCR assay does not seem to be a useful method for differentiating between C. pneumoniae acute infections and persistent ones or nasopharyngeal carriage. In addition, the detection of C. pneumoniae DNA in PBMCs does not seem to be a suitable method for the diagnosis of acute respiratory C. pneumoniae infections.

Circulating Chlamydia pneumoniae DNA and advanced coronary artery disease

BACKGROUND

Chlamydia pneumoniae (C. pneumoniae) has been linked to atherosclerosis. Detection of this pathogen in peripheral blood cells may be valuable in the diagnosis of disease state. This study aimed to evaluate the prevalence of circulating C. pneumoniae DNA and its relationship with severity and extent of coronary artery disease (CAD).

METHODS

Blood samples from 269 patients undergoing coronary angiography were collected. The presence of circulating C. pneumoniae DNA was determined by real-time PCR assay. Data regarding coronary risk factors and severity and extent of CAD were collected. Severity and extent of CAD was defined by the number of major epicardial coronary arteries with >50% stenosis and by the Duke jeopardy score.

RESULTS

Sixteen of 269 specimens (5.9%) from the study cohort were positive for C. pneumoniae DNA. Thirteen specimens among 149 samples from patients with multi-vessel disease (8.7%) were positive for C. pneumoniae DNA compared with 3 of 120 (2.5%) among patients without multi-vessel CAD. The prevalence of circulating C. pneumoniae DNA was significantly associated with multi-vessel disease. The odds ratio was 5.1 (P=0.02) after adjustment for conventional risk factors.

CONCLUSIONS

Presence of circulating C. pneumoniae DNA is associated with advanced CAD, suggesting C. pneumoniae infection as a contributing factor to progression of coronary atherosclerosis.

Levels of antibodies to microorganisms implicated in atherosclerosis and of C-reactive protein among atomic bomb survivors

Although it has been suggested that cardiovascular disease incidence is increased among atomic bomb survivors, the existence of a causal relationship between radiation exposure and atherosclerosis is unclear. Microbial infections, including those caused by Chlamydia pneumoniae, Helicobacter pylori and cytomegalovirus, have recently been implicated in atherosclerosis. Since immune function is somewhat impaired among atomic bomb survivors, their immune defense against such infections might be diminished. To investigate this possibility, we measured antibody levels to the above microorganisms in the sera of survivors. We found that the levels of IgG and IgA antibodies to Chlamydia pneumoniae decreased significantly with radiation dose, whereas the levels of IgG antibodies to Helicobacter pylori or cytomegalovirus remained unchanged. The inflammation marker C-reactive protein was significantly and positively associated with level of antibodies to Chlamydia pneumoniae only in heavily exposed (>or=1000 mGy) survivors. These results may suggest that among atomic bomb survivors, immune response to Chlamydia pneumoniae is diminished and chronic inflammatory reactions related to Chlamydia pneumoniae infection are present.

Development of diabetes in non-obese diabetic mice promotes Chlamydia pneumoniae dissemination from lung to peripheral blood

We examined a possible association between development of diabetes in non-obese diabetic (NOD) mice and dissemination of Chlamydia (Chlamydophila) pneumoniae from lung to peripheral blood. By real-time reverse transcription-polymerase chain reaction (RT-PCR) with primers for C. pneumoniae 16S rRNA, following multiple intranasal inoculations, we detected bacteria in lung in NOD mice with diabetes (38.5%) as well as Institute of Cancer Research, USA (ICR) mice (40%), but prevalence of bacteria in NOD mice without diabetes (pre-diabetic NOD mice and non-diabetic retired NOD mice) was very low (4.8%). The bacteria were only detected in peripheral blood mononuclear cells (PBMCs) cultured with hydrocortisone of the NOD mice with diabetes (53.8%). Results of immunostaining with fluorescein isothiocyanate-conjugated antichlamydia monoclonal antibody also showed the presence of bacterial antigens in the lungs and the PBMCs judged as positive by the RT-PCR. However, C. pneumoniae from cultured PBMCs of all NOD mice was undetected by cultivation method with inclusion-forming units assay. In addition, no influence of C. pneumoniae intranasal inoculation on development of diabetes in NOD mice was confirmed. Thus, the development of diabetes in NOD mouse appears to be one of critical factors for promoting the dissemination of C. pneumoniae from lung to peripheral blood.

Diagnostic value of an ELISA using a recombinant 54-kDa species-specific protein from Chlamydia pneumoniae

The aim of this study was to evaluate a 54-kDa recombinant protein encoded by the CPn0980 gene for use in a Chlamydia pneumoniae-specific ELISA. The ability of this affinity-purified protein to detect C. pneumoniae-specific antibodies was evaluated with a panel of 105 serum samples from 62 patients with community-acquired pneumonia. The results of this assay were compared with those obtained with a direct PCR-based detection assay and an outer-membrane complex-based immunoassay. The 54-kDa protein induced specific antibodies following infection of humans, and the recombinant 54-kDa ELISA detected anti-C. pneumoniae IgG and/or IgM antibodies with a sensitivity of 66.7% and a specificity of 79.2% compared with the direct PCR-based detection assay.

Involvement of the antimicrobial peptide LL-37 in human atherosclerosis

OBJECTIVE

Antimicrobial peptides are effector molecules of the innate immune system. To understand the function of vascular innate immunity in atherosclerosis, we investigated the role of LL-37, a cathelicidin antimicrobial peptide, in the disease process.

METHODS AND RESULTS

Using real-time polymerase chain reaction, we found a 6-fold increase in human cationic antimicrobial protein 18/LL-37 transcript in human atherosclerotic lesions compared with normal arteries. Immunohistochemical analysis of atherosclerotic plaques showed that LL-37 was expressed mainly by macrophages and some endothelial cells. Western blot demonstrated existence of active LL-37 peptide and abundant proprotein in atheroma specimens. To understand the functional implication of LL-37 production in atherosclerosis, the transcription profile was assessed in endothelial cells treated with LL-37. Our data show that LL-37 induces expression of the adhesion molecule intercellular adhesion molecule-1 and the chemokine monocyte chemoattractant protein 1 in endothelial cells. Intriguingly, Chlamydia pneumoniae withstood the antimicrobial activity of LL-37 in vitro, although inflammatory response was induced on infection.

CONCLUSIONS

LL-37 is produced in atherosclerotic lesions, where it may function as an immune modulator by activating adhesion molecule and chemokine expression, thus enhancing innate immunity in atherosclerosis.

Chlamydia pneumoniae infections augment atherosclerotic lesion formation: a role for serum amyloid P

Multiple reports have demonstrated an association between Chlamydia pneumoniae (Cpn) and cardiovascular disease. In this study we evaluated the effect of Cpn infections on early lesion progression in C57BL/6J mice. Since plaque formation in these mice does not develop past the initial stage, we thought these mice might be a better model for unravelling the effect of Cpn infection on early lesion type progression. C57BL/6J mice were fed an atherogenic diet and injected 10 times with 5 x 10(7) IFU Cpn or mock. At sacrifice, lesion number, size and type were analysed. To study the role of Cpn in inflammation, serum amyloid P (SAP) in plasma was determined as well as T-cells, macrophages and SAP in the lesions. In the aortic sinus of both groups, type 2 lesions were found. Cpn infection resulted in a 2.2-fold increase in total lesion size (Cpn: 10821+/-2429 microm(2)vs mock: 5022+/-1348 microm(2); p=0.04). No difference in lesion number was observed. Also, Cpn infection increased SAP in the lesions from 1.10(-4)+/-0.1.10(-4) SAP-positive cells/lesion area to 10.10(-4)+/-1.10(-4) SAP-positive cells/lesion area (p=0.05). The influx of T-lymphocytes and macrophages in the lesions as well as SAP plasma levels were not different between groups. Multiple Cpn infections resulted in a significant increase in total lesion size of C57BL/6J mice. Increase in total SAP-positive area in infected mice suggests a role for this acute-phase protein in lesion enlargement.

Outbreak of Chlamydophila pneumoniae infection in long-term care facilities and an affiliated hospital

This paper reports an outbreak of Chlamydophila pneumoniae infection in long-term care facilities and an affiliated hospital. The outbreak involved rapid spread of infection, and was inconsistent with several outbreaks experienced among younger populations. In addition, there were differences in the incidences among facilities and the affiliated hospital in relation to mean age. Our findings indicate that it is possible that elderly residents may be more susceptible to acquiring this infection. Physicians and other health care providers in long-term care facilities should consider C. pneumoniae in the differential diagnosis of an outbreak of respiratory infection.

Seropositivity to Chlamydia pneumoniae is associated with risk of first ischemic stroke

BACKGROUND AND PURPOSE

Serologic evidence of infection with Chlamydia pneumoniae has been associated with cardiovascular disease, but its relationship with stroke risk remains uncertain. The objective of this study is to determine whether serological evidence of C pneumoniae infection is associated with risk of ischemic stroke.

METHODS

A population-based case-control study was performed in an urban, multiethnic population. Cases (n=246) had first ischemic stroke, and controls (n=474) matched for age, sex, and race-ethnicity were derived through random-digit dialing. Titers of C pneumoniae-specific IgG and IgA antibodies were measured using microimmunofluorescence, and positive titers were prospectively defined. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% CIs adjusting for medical, behavioral, and socioeconomic factors.

RESULTS

Mean age among cases was 72.3+/-9.7 years; 50.8% were women. Elevated C pneumoniae IgA titers were associated with increased risk of ischemic stroke after adjusting for hypertension, diabetes mellitus, current cigarette use, atrial fibrillation, and levels of high-density lipoprotein and low-density lipoprotein (adjusted OR, 1.5; 95% CI, 1.0 to 2.2). Elevated IgG titers were not associated with stroke risk (adjusted OR, 1.2; 95% CI, 0.8 to 1.8). There was a trend toward an association of elevated IgA titers with atherosclerotic and lacunar stroke but less so cardioembolic or cryptogenic subtypes.

CONCLUSIONS

Serologic evidence of C pneumoniae infection is associated with ischemic stroke risk. IgA titers may be a better marker of risk than IgG. This association is independent of other stroke risk factors and is present for atherosclerotic, lacunar, and cardioembolic subtypes. Further studies of the effect of C pneumoniae on stroke risk are warranted.

Inflammation and atrial fibrillation: Is Chlamydia pneumoniae a candidate pathogen of atrial fibrillation?

Atrial fibrillation is the most common arrhythmia, however, the mechanism of atrial fibrillation is not well explained. It has been considered that inflammation plays a role in atrial fibrillation, recently. Patients undergoing coronary artery bypass graft are at high risk for developing postoperative atrial fibrillation. The peak levels of C-reactive protein (CRP) were paralleled to the incidence of postoperative atrial fibrillation. In general population, CRP was also higher in patients with atrial fibrillation than in control people. Persistent atrial fibrillation patients had a higher CRP level than paroxysmal atrial fibrillation patients. CRP was not only associated with the presence of atrial fibrillation but may also predict patients at increased risk for future development of atrial fibrillation. Why inflammation markers in atrial fibrillation are high is a puzzling problem. We hypothesized that Chlamydia pneumoniae infection is a possible cause of atrial fibrillation by initiating inflammation response. It was demonstrated that infection of endothelial cells with C. pneumoniae elicited the production of Monocyte Chemoattractant Protein-1, interleukin-1, interleukin-8, interleukin-18, tumor necrosis factor, interferon and soluble intercellular adhesion molecule. Most of these cytokines play a crucial role in inflammation response that associate with the initiating and maintenance of atrial fibrillation. There are so many pathogens that can trigger inflammation. Some evidences showed that C. pneumoniae was the most likely pathogen of atrial fibrillation. In epidemic study, the incidence of atrial fibrillation increased from younger to elder and atrial fibrillation was more common in men than in women. C. pneumoniae has the same epidemic trend as the incidence of atrial fibrillation. Hypertension, myocardial infarction and reduced lung function are predictors of atrial fibrillation. C. pneumoniae infection is high in the patients with the above diseases. C. pneumoniae was found in endomyocardial biopsy samples, which supported C. pneumoniae was the candidate pathogen, too. Chlamydia infection can cause myocardial interstitial fibrosis and inflammation cells infiltration. The pathology characters of C. pneumoniae infection are similar to that found in atrial fibrillation. Seroepidemic study should be carried out to evaluate if there is relationship between C. pneumoniae and atrial fibrillation. If the hypothesis is confirmed, macrocyclic lactone antibiotics may be used to eliminate the pathogen. It will be a new target point to treat atrial fibrillation.

Chlamydia pneumoniae immunoreactivity in coronary artery plaques of patients with acute coronary syndromes and its relation with serology

BACKGROUND

An association between Chlamydia pneumoniae (Cpn) infection and coronary artery disease has been reported and examined by different techniques. However, its immunoreactivity in coronary artery plaques of patients with acute coronary syndrome (ACS) and its relation with serology are less well defined.

METHODS

We divided 40 coronary plaque specimens from 40 patients who underwent thrombectomy or directional coronary atherectomy into an ACS group (n = 22) and a non-ACS group (n = 18). Cpn in specimens was detected immunohistochemically and compared quantitatively. Serum immunoglobulin (Ig)A and IgG antibodies to Cpn and high-sensitivity C-reactive protein (hs-CRP) were measured. The relation between serology and immunohistochemical analysis was also investigated.

RESULTS

Cpn immunopositive cells per square millimeter (Cpn+ cells/mm2) in the ACS group were significantly more numerous than in the non-ACS group (median 7.44 vs 1.50, P = .0018). Cpn IgA seropositivity rates and titers in the ACS group were significantly higher than those in the non-ACS group (86.3% vs 22.2%, P = .0002; median titer 1.403 vs 0.545, P = .003). There were no differences in IgG antibodies between the 2 groups. The hs-CRP values (in milligrams per liter) in ACS group were significantly higher than in non-ACS group (median 2.8 vs 1.2, P = .0019). Serum IgA titers in patients with at least 5 Cpn+ cells/mm2 in the specimens were significantly higher than in patients with fewer Cpn+ cells (median 1.52 vs 0.86, P = .026). There was no difference in serum hs-CRP values in patients with more Cpn+ cells but a trend to an increase.

CONCLUSION

Immunohistology frequently detected Cpn in coronary plaques; Cpn+ cells were more prevalent in plaques associated with ACS, and Cpn IgA but not IgG titers were increased with ACS and with high densities of Cpn+ cells within plaque.

Chlamydia pneumoniae and lung cancer: epidemiologic evidence

Chlamydia pneumoniae is a common cause of acute respiratory infection and has been hypothesized to cause several chronic diseases, including lung cancer. The purpose of this article is to identify, describe, and critically examine the published studies on the association between C. pneumoniae infection and risk of lung cancer. In the six studies identified, previous C. pneumoniae infection was defined on the basis of serologic criteria, which varied between studies. All studies reported elevated relative risk estimates for the association of serologic evidence of infection and risk of lung cancer. The three studies in which past infection was defined based on testing of prediagnostic blood specimens tended to have weaker results (odds ratio range, 1.2-2.1) than those based on postdiagnostic blood specimens (odds ratio range, 1.4-9.9). Selection bias, measurement error, and inadequate control for confounding are concerns in some of these studies. Nevertheless, results were relatively consistent, supporting a causal association. Inflammation caused by chronic infection with C. pneumoniae may be involved in the carcinogenic process but this relationship will be difficult to further define through serologic data. To better understand the nature of this association, both experimental study designs, such as those based on animal models or randomized controlled antibiotic treatment trials in humans, and observational study designs (e.g., studies that involve detection of C. pneumoniae in pulmonary specimens obtained before cancer onset) could be explored and may shed additional light on this important association.

Overexpression of MMP9 and Tissue Factor in Unstable Carotid Plaques Associated with Chlamydia pneumoniae, Inflammation, and Apoptosis

Tissue remodeling by matrix metalloproteinases (MMPs) and plasminogen activators such as tissue factor (TF) is postulated to be involved in the pathogenesis of atherosclerosis. The in situ expression of MMP9 and TF in unstable atherosclerotic plaques has not been examined in detail. Moreover, interference of tissue remodeling by vascular inflammation, apoptosis, and Chlamydia pneumoniae inside plaque subregions is unclear. A total of 40 autopsy carotid arteries (controls) and 20 atherosclerotic carotid endarterectomy specimens (with type VI lesions, according to the American Heart Association classification) from stroke patients were analyzed for expression of MMP9 and TF using in situ techniques. The data on tissue remodeling were correlated with the presence of inflammatory cells (T cells, B-cells, macrophages), apoptosis, and the presence of C. pneumoniae using immunohistochemistry and Western blot analyses. We found a significant overexpression of MMP9 and TF in progressive atherosclerotic carotid arteries, especially in the shoulder and cap subregions (both p < 0.05). Expression of MMP9 and TF correlated significantly with T-cell and macrophage infiltrates as well as with apoptosis (p < 0.05). C. pneumoniae infection was significantly associated with elevated TF expression (p < 0.01) but not with MMP9. MMP9 and TF are thus significantly overexpressed in progressive atherosclerotic plaques, and their relevant subregions (shoulder and cap) are involved in plaque instability. This process is associated with local inflammatory cell infiltrates and apoptosis, which might be influenced by infectious agents such as C. pneumoniae.

Lack of association between Chlamydia Pneumoniae serology and endothelial dysfunction of coronary arteries

BACKGROUND

Recent publications brought up the hypothesis that an infection with Chlamydia Pneumoniae (CP) might be a major cause of coronary artery disease (CAD). Therefore, we investigated whether endothelial dysfunction (ED) as a precursor of atherosclerosis might be detectable in patients with previous infection with CP but without angiographic evidence of CAD.

METHODS

We included 16 patients (6 male / 10 female) of 52 consecutive patients with normal coronary angiography who had typical angina pectoris and pathologic findings in the stress test. Exclusion criteria were: active smoker, elevated cholesterol, hypertension, age > 65 years, diabetes mellitus, treatment with ACE-inhibitors, or known CAD. Blood sample analysis for serum titer against CP (aCP-IgG) was performed after coronary angiography. We looked for endothelial dysfunction analyzing the diameter of the left anterior descending coronary artery (LAD) before and after acetylcholine (ACh) i. c. Quantitative analysis of luminal diameter (LD) was performed in at least two planes during baseline conditions and after ACh for 2 minutes in dosages of 7.2 microg/min and 36 microg/min with an infusion speed of 2 ml/min. Using Doppler guide wire, the coronary flow velocity was measured continuously in the LAD. The coronary flow velocity reserve (CFVR) was measured after 20 microg adenosine i. c.

RESULTS

10 patients had an elevated aCP-IgG (> 1:8). 6 patients with negative titers (aCP-IgG <or= 1:8) served as control (CTRL). Both groups were comparable in age, gender, angina class, results of non-invasive stress-test and the baseline values of LD and flow. In the CP positive group 3 patients (30%) did not show an increase of LD after ACh as evidence of ED. In the CTRL group 4 patients (67 %) had ED. There was no association between aCP-IgG and changes of coronary blood flow after ACh. All patients showed normal CFVR (3.0 +/- 0.27) irrespective of their aCP-IgG values.

CONCLUSION

In patients with typical symptoms of coronary ischemia but without angiographically visible CAD and absence of other factors affecting the endothelial function, a previous infection with CP is not associated with endothelial dysfunction.

Serum Lipid Profiles Poorly Correlate With Chlamydia pneumoniae , Helicobacter pylori , and Cytomegalovirus Seropositivity in Prospectively Followed-Up Healthy Children

Objective— Chronic Chlamydia pneumoniae ( Cpn ), Helicobacter pylori ( Hp ), and herpes virus infections have been associated with atherogenic serum lipid profile and an excess of cardiovascular events in adults. Because mechanisms leading to atherosclerosis are active since early childhood, we examined whether Cpn, Hp , or cytomegalovirus (CMV) seropositivity relates to serum lipid, lipoprotein, or apolipoprotein concentrations in children. We also looked for factors increasing probability of Cpn seropositivity in children.

Methods and Results— Cpn- specific IgG and IgA, as well as Hp- specific and CMV-specific IgG antibodies were assessed by enzyme immunoassay in 199 apparently healthy children, followed-up from 7 to 11 years of age. Serum lipid profiles were studied at the ages of 7, 9, and 11 years using standard methods. Neither seroconversion to Cpn IgG or IgA antibody positivity nor persistent seropositivity for Cpn, Hp , or CMV was associated with proatherogenic serum lipid values. Children with siblings were more likely to possess Cpn antibodies than children without siblings (IgG: OR, 5.24; 95% CI, 1.63 to 16.82; IgA: OR, 3.32; 95% CI, 1.15 to 9.57).

Conclusions— These data suggest that contrary to the observations in adults, Cpn, Hp , and CMV seropositivity in otherwise healthy children is not associated with disturbances in serum lipid profile.

Chlamydia pneumoniae IgG serological status and venous thromboembolism: a cross-sectional hospital based study

OBJECTIVE

To search for a link between Chlamydia pneumoniae serological status and venous thromboembolic disease.

METHODS

From March 1992 to October 1999, we conducted a cross-sectional hospital-based study of consecutive unselected outpatients referred to us for clinical suspicion of venous thromboembolism. We compared the Chlamydia pneumoniae serological status with respectively, the venous thromboembolism, the deep vein thrombosis and the proximal deep vein thrombosis status.

RESULTS

Among 1193 patients registered for suspected venous thromboembolism, 1010 samples were available (499 negative and 511 positive patients for venous thromboembolism). Seventy-nine patients were Chlamydia pneumoniae positive. Our work failed to demonstrate any clear association between Chlamydia pneumoniae and venous thromboembolism status. Nevertheless, we identified a statistical difference regarding Chlamydia pneumoniae seropositivity and proximal vein thrombosis status (adjusted odds ratio of 1.70, CI95%: 1.05 to 2.77).

CONCLUSION

The presence of Chlamydia pneumoniae antibodies might be a minor risk factor for venous thrombosis.

Interlaboratory reliability of microimmunofluorescence test for measurement of Chlamydia pneumoniae-specific immunoglobulin A and G antibody titers

To evaluate the reliability of Chlamydia pneumoniae-specific immunoglobulin G (IgG) and IgA antibody titers as measured by the microimmunofluorescence (MIF) test, we compared results from 392 individuals using a standard MIF protocol at two academic laboratories. The kappas for dichotomous titers (>/=16 versus <16) were 0.39 for IgA and 0.53 for IgG. Measurement error likely attenuates C. pneumoniae-disease associations; the magnitude of attenuation can be estimated from results of studies such as this one.

Seroepidemiological studies of Chlamydia pneumoniae infections in 1-36 months old children with respiratory tract infections and other diseases in Poland

Presence of specific IgM, IgG and IgA antibodies against Chlamydia pneumoniae was evaluated in children aged 1 week to 36 months to investigate the role of C. pneumoniae in respiratory infections and other diseases. Serum samples were obtained from 150 hospitalized children, including 123 children presenting the clinical symptoms of various respiratory tract infections, two children with acute diarrhoea, two children with meningitis, 14 children with urinary tract infection, and 9 children with non-infectious diseases. Levels of specific C. pneumoniae IgM, IgG and IgA serum antibodies were measured by enzyme-linked immunoassay (ELISA). C. pneumoniae IgM antibodies were detected in 16 (13.0 %) of 123 children with respiratory tract infections. Specific IgG antibodies were found in sera of 11 children under 12 months old. Among 27 children without symptoms of a respiratory tract disease, specific C. pneumoniae IgM were found in two (7.4%) children, including one child with meningitis and another child with urinary tract infection. Specific IgA antibodies were not found in any tested child. All cases of C. pneumoniae infections were identified within two calendar years out of eight that were analyzed, i.e. in 1997 and 2000. The incidence of C. pneumoniae infections varied seasonally, with most children infected in autumn. C. pneumoniae IgM antibodies were detected more often in girls (17.9%) then in boys (7.2%). C. pneumoniae infections occur among small children in central Poland. The results of this study indicate that C. pneumoniae may play a role in the etiology of respiratory tract infections in infants and young children.

Ectasia and severe atherosclerosis: relationships with chlamydia pneumoniae, helicobacterpylori, and inflammatory markers

To date, there has been no convincing evidence for an association between Chlamydia pneumoniae or Helicobacter pylori and ectasia. In this case-control study, we have investigated the association of H. pylori and C. pneumoniae seropositivity with ectasia, severe coronary atherosclerosis, and normal vessels, which were so classified by coronary angiography. We have also evaluated the influence of these infections on inflammatory markers such as high-sensitive C-reactive protein (hsCRP) and interleukin 6 (IL-6). Of the 796 patients undergoing coronary angiography for suspected ischemic heart disease, 244 patients were recruited. Of these, 91 had normal vessels, 88 had 3 or more obstructed vessels, and 65 had ectatic vessels without atherosclerosis. Eighty-seven atherosclerotic patients (98.9%) were positive for C. pneumoniae IgG, as were 64 ectatic patients (98.5%) and 76 controls (83.5%) (P < 0.001). Forty-two atherosclerotic patients (47.7%) were positive for C. pneumoniae IgM, as were 43 ectatic patients (66.2%) and 43 controls (47.3%) (P = 0.036). Seventy-two atherosclerotic patients (81.8%) were positive for H. pylori IgA, as were 26 ectatic patients (40.0%) and 44 controls (48.4%) (P < 0.001). High-sensitive CRP levels were significantly higher in ectatic patients (5.639 mg/L) than in controls (4.390 mg/L) (P = 0.032), and IL-6 levels were significantly higher in atherosclerotic patients (33.92 U/L) than in controls (14.01 U/L) (P < 0.001). Interleukin-6 levels were higher in H. pylori seropositive patients, and hsCRP levels were higher in C. pneumoniae seropositive patients, when compared with seronegatives. We suggest that, as in atherosclerosis, C. pneumoniae infection is related to ectasia, with raised CRP levels.

Asymptomatic carotid atherosclerosis is associated with circulating chlamydia pneumoniae DNA in younger normotensive subjects in a general population survey

OBJECTIVE

Chlamydia pneumoniae infection has been associated with atherosclerosis, but serodiagnosis is unreliable in predicting vascular infection. Direct detection of circulating chlamydial DNA in peripheral blood mononuclear cells (PBMCs) was thus evaluated as a marker for cardiovascular risk in a general population survey using the common carotid intima-media thickness (IMT) as surrogate marker of asymptomatic atherosclerosis.

METHODS AND RESULTS

C pneumoniae DNA in PBMCs was determined by nested polymerase chain reaction and associated with IMT for 1032 healthy participants of a general population survey who were within the highest or lowest IMT distribution quartile. C pneumoniae DNA was more prevalent in those with increased IMT (13.4% versus 10.7%), but this was not significant in univariate and of borderline significance in multivariate analysis. Testing for potential effect modifications by known strong determinants of an increased IMT in group interaction analysis revealed an independent association between C pneumoniae DNA and IMT in normotensive subjects (odds ratio [OR], 2.06; 95% CI, 1.05 to 4.03; P=0.04) and in those <70 years old (OR, 1.84; 95% CI, 1.06 to 3.19; P=0.03).

CONCLUSIONS

Asymptomatic atherosclerosis is associated with circulating C pneumoniae DNA independently of classical cardiovascular risk factors in normotensive subjects and those <70 years old. C pneumoniae has been implicated in atherogenesis. We determined the association of chlamydial DNA in peripheral blood mononuclear cells with the carotid intima-media thickness from 1032 healthy subjects from a general population survey. A stratified group interaction analysis revealed an independent association in normotensive subjects and those <70 years old.

Repetitive measurements of Chlamydia pneumoniae DNA in peripheral blood mononuclear cells in healthy control subjects and dialysis patients: a prospective study

Infection with Chlamydia pneumoniae has been suggested to play a role in the development and maintenance of atherosclerosis. However, the course of C. pneumoniae infection is not clarified. Thus, both the persistence of C. pneumoniae DNA in blood and the tendency to recurrence have not been studied. We determined the prevalence of C. pneumoniae DNA in the white cells of the peripheral blood in 98 dialysis patients and in 52 healthy subjects. Blood samples were collected approximately 6 times from each subject during a period of 1 y with an interval of approximately 2 months and analysed with a polymerase chain reaction. C. pneumoniae DNA was detectable in 47 out of 150 subjects at least once during a y. Reinfection was a rare phenomenon and the presence of C. pneumoniae DNA in blood was of less than 2 months' duration in almost all patients. There was a significant association between the presence of C. pneumoniae DNA during 1 y and the presence of atherosclerosis in the legs of dialysis patients (OR=3.50, p=0.03). Additionally, a significant association was found between the presence of C. pneumoniae DNA and an abnormal electrocardiogram (ECG) (OR=3.16, p=0.01). These findings may support the hypothesis of an association between infection with C. pneumoniae and the presence or development of atherosclerosis.

High prevalence of Chlamydia pneumoniae seropositivity in Mexican patients with ischemic heart disease

BACKGROUND

Risk factors for development of atherosclerosis, such as hyperlipidemia, high blood pressure, smoking habit, and diabetes mellitus, have been identified. The possibility that infectious agents may unchain biological and biochemical reactions related to inflammation, atherogenesis, and vascular thromboses events have recently been described. Chlamydia pneumoniae has been associated with coronary artery disease in some seroepidemiology studies. Reports of this association are limited in the Latin American population; therefore, we conducted a case-control study to explore this issue in the Mexican population.

METHODS

Eighty nine patients with scintigraphic evidence of coronary artery disease compared with a control group of 105 individuals were analyzed. Serum levels of IgA, IgM, and IgG against Chlamydia pneumoniae were determined using enzyme immunoassay method in all subjects. Conventional risk factors were also analyzed.

RESULTS

High seroprevalence of IgA and IgG with no significant difference between the two groups was found. Prevalence of antibodies was as follows: IgA 56.2% (50/89 patients); IgG 66.3% (59/ 89 patients) in coronary artery disease group; IgA 56.2% (59/105 patients), and IgG 70.5% (74/105 patients) in control group. Among common risk factors for coronary artery disease, significant differences were found in males, in patients with diabetes, and in habitual smokers.

CONCLUSIONS

These results suggest a high prevalence of C. pneumoniae infection in the studied population. However, in this series seroprevalence was not evidently associated with coronary artery disease (CAD). To clarify the possible relation between C. pneumoniae and coronary atherosclerosis, additional studies must be performed.

[Etiology of the epidemic outbreak of community-acquired pneumonia in children in St. Petersburg]

In September-December 1998 the epidemic rise of outhospital pneumonia (EP) among children was observed in St. Petersburg, which led to a twofold increase in morbidity rate this year. The study of the etiology of EP during the period of 1998-2001 confirmed the prime role of Streptococcus pneumoniae (74.5%) and, for the first time in Russia, revealed the epidemic outbreak of acute chlamydiosis (Chlamydia pneumoniae), diagnosed in 67.3% of children, the maximum occurrence (87.5%) in 1998 with only 19% of the patients having the disease in the form of monoinfection. The prevalence of S. pneumoniae and C. pneumoniae in the etiology of EP and more severe course of mixed infection suggested that these infective agents played a leading role in the epidemic outbreak of acute respiratory infections in St. Petersburg.

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.

An MRI study of Chlamydia pneumoniae infection in Italian multiple sclerosis patients

We amplified sequences of the Chlamydia pneumoniae (CP) major-outer membrane protein in the cerebrospinal fluid (CSF) from 23 of 107 (21.5%) relapsing-remitting or secondary progressive multiple sclerosis (MS) patients and two of 77 (2.6%) patients with other neurological diseases (OND) (P = 0.00022). CP+ patients showed magnetic resonance imaging (MRI) evidence of more active disease (P = 0.02) compared to CP- MS patients and tended to have an anticipation of age at disease onset (32.3 +/- 12 versus 28.5 +/- 10 years; P = ns) causing a longer disease duration (7.5 +/- 5 versus 4.4 +/- 4 years; P = 0.016) at the time of clinical evaluation. These findings, although indirectly, suggest that CP infection of the central nervous system (CNS) might affect disease course in a subgroup of MS patients.

[Lack of association between Chlamydia pneumoniae seropositivity and common carotid intima-media thickness in type 2 diabetic patients]

BACKGROUND

The current body of evidence suggests that Chlamydia Pneumoniae (CP) infections may play a role in the development and maintenance of atherosclerosis process and related clinical complications.

METHODS

In our study we assess the association between seropositivity of CP antibody IgG to common carotid intima-media thickness (IMT) in patients with type 2 diabetes mellitus (DM). One hundred thirty DM patients (mean age 53 +/- 10 years, 70 female) were enrolled for study. Serum CP IgG antibody were detected by microimmunofluorescent technique; IMT and plaques or stenosis in the common carotid were assessed by ultrasonography.

RESULTS

In univariate analysis common carotid IMT was significantly associated with age (P>0.00001), body mass index [(BMI) P>0.0003], acid uric (P>0.004), systolic blood pressure (P>0.03), glycemia (P>0.03) and total cholesterol (P>0.04). No significant correlation was found between CP antibody IgG titer and IMT. In multiple regression analysis only age (P>0.0001), uric acid (P>0.03), glycemia and BMI (P>0.05) were independently associated with IMT.

CONCLUSION

Lack of association was found between CP seropositivity and common carotid IMT in patients with DM.

Prospective study of Chlamydia pneumoniae IgG and IgA seropositivity and risk of incident ischemic stroke

BACKGROUND AND PURPOSE

Chlamydia pneumoniae infection or exposure to C. pneumoniae was implicated as a risk factor for ischemic stroke. Our aim was to evaluate prospectively the association between the presence of antibodies to C. pneumoniae (IgG and IgA) and the risk of incident ischemic stroke among patients with pre-existing vascular disease.

METHODS

Sera were collected from 3,090 coronary heart disease patients enrolled in a secondary prevention trial. We measured baseline antibodies (IgG and IgA) in the sera of patients who developed subsequent ischemic strokes (cases, n = 134) during follow-up (mean 8.2 years), and in 134 age- and gender-matched pairs without subsequent stroke or myocardial infarction.

RESULTS

The crude relative odds (95%CI) of incident ischemic strokes in seropositive patients at baseline (>1.1 relative value units) were 1.29 (95%CI, 0.69-2.47) for IgG and 1.31 (95% CI, 0.69-2.55) for IgA by matched-pair analyses, and 1.42 (95%CI, 0.69-2.98) for IgG and 1.57 (95%CI, 0.76-3.35) for IgA after adjustments for conventional risk factors and the inflammatory marker, soluble intercellular adhesion molecule-1. We explored the possibility that the risk of ischemic stroke may increase in parallel to increasing antibody titers, but did not demonstrate any significant association.

CONCLUSIONS

Serological evidence for prior infection with C. pneumoniae did not emerge as an independent risk factor for incident ischemic stroke among patients at high risk due to pre-existing vascular disease.