No evidence of Chlamydia pneumoniae in the synovia of patients with osteoarthritis.

OBJECTIVE: Osteoarthritis (OA) is a common cause of disability affecting millions of people of all ages worldwide. The pathogenesis involves an inflammatory component, but the cause of the inflammation remains incompletely understood. The intracellular bacteria Chlamydia trachomatis and C. pneumoniae have been demonstrated in patients with reactive arthritis. Both of these microorganisms can cause chronic and persistent infections, with C. trachomatis being the most common cause of reactive arthritis. This study was performed to investigate the presence of C. pneumoniae in a large number of patients with primary OA. METHODS: The study included 75 patients who underwent total knee arthroplasty. During surgery, a synovial biopsy was performed and synovial fluid drawn. Real-time polymerase chain reaction (PCR) of C. pneumoniae was run on all patients, and real-time PCR of bacterial 16S rDNA was conducted on 30 of the 75 patients to screen for the presence of other bacteria. RESULTS: Real-time PCR showed no evidence of the presence of C. pneumoniae in the patients' specimens, nor were other bacteria detected. CONCLUSIONS: Although an inflammatory component is part of the pathogenesis of OA, we found no evidence indicating that C. pneumoniae is a stimulator of that inflammation.

Iron Homeostasis in Tissues Is Affected during Persistent Chlamydia pneumoniae Infection in Mice.

Chlamydia pneumoniae (C. pneumoniae) may be a mediator in the pathogenesis of atherosclerosis. For its growth C. pneumoniae depends on iron (Fe), but how Fe changes in tissues during persistent infection or affects bacterial replication in tissues is unknown. C. pneumoniae-infected C57BL/6J mice were sacrificed on days 4, 8, 20, and 40. Mice had bacteria in the lungs and liver on all days. Inflammatory markers, chemokine Cxcl2 and interferon-gamma, were not affected in the liver on day 40. The copper (Cu)/zinc (Zn) ratio in serum, another marker of infection/inflammation, increased on day 4 and tended to increase again on day 40. The Fe markers, transferrin receptor (TfR), Hepcidin (Hamp1), and ferroportin 1 (Fpn1), increased in the liver on day 4 and then normalized except for TfR that tended to decrease. TfR responses were similar to Fe in serum that increased on day 4 but tended to decrease thereafter. In the liver, Fe was increased on day 4 and also on day 40. The reappearing increases in Cu/Zn on day 40 concomitant with the increase in liver Fe on day 40, even though TfR tended to decrease, and the fact that viable C. pneumoniae was present in the lungs and liver may indicate the early phase of activation of recurrent infection.

Cholesterol uptake in the mouse aorta increases during Chlamydia pneumoniae infection.

Chlamydia pneumoniae has been suggested as a stimulator of the atherosclerotic process. Mice fed a normal diet were infected intranasally with C. pneumoniae and given one intraperitoneal injection of 14C-cholesterol tracer per day for 12 days. Bacteria were demonstrated in the aorta in the early phase of infection and in lungs and liver throughout the study period of 20 days. 14C-cholesterol was not affected in the heart but increased in the blood, liver and aorta on day 4 when the infection was clinically most severe. Furthermore, on day 20 14C-cholesterol tended to be increased in the aorta. Accordingly, copper- and zinc levels and expressions of the infection biomarkers Cxcl2 and Ifng increased in the liver on day 4 with a tendency of increased of copper, zinc and Ifng on day 20. In mice where bacteria could be cultivated from the lungs, expressions of cholesterol transporters Abca1 and Idol were both increased in the liver on day 4. The increased levels of 14C-cholesterol in blood and aorta together with increased Abca1 and Idol in the liver during C. pneumoniae infection in mice fed a normal diet suggest that this pathogen may have a role in the initiation of the atherosclerotic process.

Trace Element Changes in Thoracic Aortic Dissection.

Thoracic aortic dissection is a life-threatening condition with an incompletely understood pathogenesis. Trace elements are essential for the functioning of different processes in the body, including the immune system and associated responses to infection/inflammation. Because inflammation may be part of the pathogenesis of thoracic aortic dissection, we investigated whether trace element changes associated with inflammation occur in serum and tissue samples during the disease. The study included 21 patients undergoing surgery for thoracic aortic dissection, 10 forensic autopsy specimens for tissue controls and 23 healthy blood donors for serum controls. Levels of magnesium (Mg), calcium (Ca), vanadium (V), manganese (Mn), iron (Fe), cobalt (Co), copper (Cu), zinc (Zn), arsenic (As), selenium (Se), cadmium (Cd) and mercury (Hg) were measured in the aortic tissue and serum by inductively coupled plasma-mass spectrometry (ICP-MS). In the serum, Ca, V, Cu and Zn decreased, whereas Fe increased. In the tissue, Cu and Zn decreased and Fe tended to increase. The Cu/Zn ratio in the serum, a marker of infection/inflammation, did not change in the patients. Concerning trace element changes in the serum and tissue, our data do not support the hypothesis that inflammation is involved in the pathogenesis of thoracic aortic dissection.

Persistent Chlamydophila pneumoniae infection in thoracic aortic aneurysm and aortic dissection?

OBJECTIVES: Chlamydophila pneumoniae (C. pneumoniae) has been associated with atherosclerosis and abdominal aortic aneurysm and is probably disseminated by peripheral blood mononuclear cells (PBMC). Viable and metabolically active bacteria can be demonstrated by the presence of bacterial mRNA and on-going dissemination by the presence of bacteria in PBMC. The aim of this study was to determine the prevalence of C. pneumoniae DNA and mRNA in aortic biopsies and C. pneumoniae DNA in PBMC in thoracic aortic aneurysm and aortic dissection patients. DESIGN: Real-time PCR was used to detect C. pneumoniae DNA and mRNA in biopsies and C. pneumoniae DNA in PBMC. RESULTS: C. pneumoniae DNA was found in biopsies in 26% (6/23) of aneurysm patients and 11% (2/18) of dissection patients but in none of the forensic autopsy controls. C. pneumoniae mRNA was not found in any biopsy, and all PBMC were C. pneumoniae-negative. CONCLUSIONS: Presence of C. pneumoniae DNA but not mRNA in aortic biopsies and no evidence of C. pneumoniae in PBMC suggest that the infection in the aorta has passed into a state of persistence.

Presence of Chlamydophila pneumoniae DNA but not mRNA in stenotic aortic heart valves.

BACKGROUND: The pathogenesis of aortic valve stenosis may involve inflammation and we have previously demonstrated Chlamydophila pneumoniae (C. pneumoniae) DNA in stenotic aortic heart valves. Dissemination of these bacteria is probably mediated by alveolar macrophages. Bacterial DNA alone does not indicate whether the bacteria are viable and replicating. This study aimed to investigate the presence of C. pneumoniae mRNA, a marker of replicating bacteria, and C. pneumoniae DNA in stenotic aortic valves and the prevalence of C. pneumoniae in peripheral blood mononuclear cells (PBMC). METHODS: DNA was extracted from heart valves and PBMC and mRNA from heart valves from 76 patients undergoing aortic valve replacement surgery. C. pneumoniae DNA and mRNA were measured by real-time PCR targeting the ompA gene. RESULTS: C. pneumoniae DNA was demonstrated in 22% of heart valves and in 5% of PBMC. C. pneumoniae mRNA was not detected in any valve. Patients positive for C. pneumoniae in the valve underwent coronary artery by-pass grafting more often (p=0.01) and suffered from angina pectoris (p=0.02) and arterial hypertension (p=0.03) more often than patients negative for C. pneumoniae in the valve. CONCLUSIONS: These findings support a role for C. pneumoniae in the pathogenesis of aortic valve stenosis and indicate that the bacteria disseminate from the respiratory tract long before the patients were in need of surgery and that the valve infection thereafter entered into a persistent and non-replicative state. Moreover, patients positive for C. pneumoniae in the valve more often needed by-pass grafting because of more advanced coronary disease.

Thoracic aortic aneurysm patients with Chlamydophila pneumoniae infection showed a shift in trace element levels in serum and diseased aortic tissue.

Few studies have been performed on trace elements in tissues and serum in cardiovascular disease and none in aortic aneurysm. In this study the concentrations of 10 trace elements were determined in serum and aneurysmatic aortic tissue from 23 patients undergoing thoracic surgery. Macroscopically, normal thoracic aortic tissue specimens from 10 forensic autopsies and serum from 23 healthy blood donors served as controls. DNA from the intracellular respiratory pathogen Chlamydophila pneumoniae (C. pneumoniae), which may be involved in the pathogenesis of atherosclerosis, was found in 26% (6/23) of the patients but in none of the controls. The serum copper/zinc ratio, a well-known marker of ongoing infection and/or inflammation, was higher (26%, p<0.001) in aneurysm patients. C. pneumoniae requires iron for its growth. In our aneurysm patients iron was higher in serum (by 54%, p<0.001) and aneurysmal tissue (by 60%, p<0.001). Although calcium was lower in patient sera (by 8%, p<0.001), it tended to be higher (by 20%, ns) in aneurysmatic tissue. In addition, mercury concentrations in serum and aneurysmatic tissue were positively correlated (r=0.51, p<0.05). Moreover, C. pneumoniae-positive aneurysmatic tissues had lower concentrations of manganese (46%, p<0.05) and zinc (26%, ns) but a higher concentration of mercury (50%, p<0.05) than C. pneumoniae-negative aneurysmatic tissues. In conclusion, aneurysm patients showed a shift in trace element levels in serum and in the diseased part of the aorta, the pattern being partly different in C. pneumoniae-positive compared with C. pneumoniae-negative patients. The results are compatible with active infection and/or inflammation, possibly initiated by C. pneumoniae.

Chlamydophila pneumonia: Specific mRNA in aorta ascendens in patients undergoing coronary artery by-pass grafting.

The objective of this prospective study was to investigate if Chlamydophila pneumoniae (Cp)-specific DNA and mRNA are present in tissue samples from the wall of aorta ascendens in patients undergoing by-pass surgery for coronary artery disease (CAD) that includes stable angina pectoris (SAP, 25 patients) and acute coronary syndrome (ACS, 19 patients). Viable Cp was detected in 8/44 (18%) patients using reversed transcriptase PCR (RT-PCR) against bacterial mRNA with detection of cDNA using real-time PCR against the MOMP gene. Cp DNA was detected by nested PCR in 22/44 (50%) patients and by real-time PCR in 13/44 (30%) patients. In total, 24/44 (55%) patients were positive for Cp nucleic acid in any PCR. Antibodies to Cp were detected in 13/24 (54%) Cp PCR-positive and in 15/20 (75%) Cp PCR-negative patients. Nested PCR was run on throat swabs from all patients. No significant differences were noted between SAP and ACS patients regarding PCR results or serology. It has been suggested that Cp may be a 'silent passenger' picked up by the atherosclerotic plaque. Our findings of viable and metabolically active bacteria in aortic tissue add further support to the hypothesis that Cp may have an active role in the pathogenesis of atherosclerosis.

Trace element changes in sclerotic heart valves from patients are expressed in their blood.

The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. However, whether blood trace element changes exist that are related to changes in the cardiovascular system are, in most cases, unknown. In this study, blood trace element levels were analysed in 46 patients with non-rheumatic aortic valve sclerosis that were previously shown to have a disturbed trace element balance in their valve tissue, including 11/15 elements. Results showed significant changes of blood levels of 8/15 trace elements in these patients when compared with blood levels in 46 healthy controls. Of these elements, Cd and Mg were the only elements that increased in both blood and valves. Cu and Se were increased in blood but decreased in valves, whereas Co and Zn were decreased in blood but increased in valves. Several elements (As, Ca, Fe, Pb, and V) were unchanged in blood although changed in valves. Although Mn and Hg showed changes in blood, this was not evident in the valves. Al and Ag were the only elements that did not change in both blood and valves. Significant covariation in blood and valve levels was only observed for Al and Pb. The recorded pattern of trace element changes indicates a complex competition/exchange between body compartments in this disease, where the increased blood Cu/Zn ratio suggests an ongoing infectious/inflammatory process.

Interactions between Chlamydia pneumoniae and trace elements: a possible link to aortic valve sclerosis.

An association between Chlamydia pneumoniae and atherosclerotic cardiovascular diseases has been suggested. However, other factors may interact in the pathogenesis of valve sclerosis. Therefore, trace elements important for C. pneumoniae growth and host defense and markers of C. pneumoniae infection were studied in sclerotic valves and serum. Forty-six patients undergoing surgical valve replacement due to advanced aortic sclerosis were prospectively studied. Valves from 15 forensic cases with no heart valve disease and plasma from 46 healthy volunteers served as controls. C. pneumoniae was detected in 16/46 (34.8 %) sclerotic valves and in 0/15 forensic controls. IgG and IgA antibodies to C. pneumoniae were present in 54.3% and 26.1 % patients, respectively. In the patients' valves, iron, magnesium, and zinc each correlated to calcium, a marker of the histopathological severity of disease. Patients showed 10- to 70-fold increases of these trace elements in valves and an increased copper/zinc ratio in serum. In a majority of aortic sclerosis patients, one of several markers of C. pneumoniae infection were detected and all patients had a disturbed trace element balance in valves and serum suggestive of active immune process and infection. The pattern of trace element changes was essentially similar regardless of positive makers of C. pneumoniae, suggesting a similar etiopathogenesis in both subgroups. The 20-fold increase in iron, essential for C. pneumoniae growth, in sclerotic valves suggests a new possible link to this infection in aortic sclerosis.

Trace element changes in sclerotic heart valves from patients undergoing aortic valve surgery.

Several trace elements are essential nutrients for an optimal functioning of organs and tissues, including the immune system and the heart. The pathogenesis of some heart diseases has been associated with changes in the balance of certain trace elements. The etiology of nonrheumatic aortic valve sclerosis is unknown, however. A prospective study was performed on trace element changes in the sclerotic valves of 46 patients undergoing surgical aortic valve replacement because of aortic stenosis. Valves from 15 individual forensic cases without known cardiac disease served as controls. The contents of 15 trace elements (Al, As, Cd, Ca, Co, Cu, Fe, Pb, Mg, Mn, Hg, Se, Ag, V, and Zn) were measured by inductively coupled plasma - mass spectrometry (ICP-MS) of aortic valve tissue from both patients and forensic autopsy controls. Some trace elements showed similar concentrations in sclerotic and control valves (Al, Ag, Hg, Mn), whereas a few were moderately changed in the sclerotic as compared with the control valves, including an increase in Cd by 52% (p < 0.05) and decreases in Se by 14% (p < 0.05), in V by 42% (p < 0,001), and in Cu by 45% (p < 0.001). However, there were pronounced increases (p < 0.001) in the concentrations of As (5-fold), Ca (70-fold), Co(10-fold), Fe (20-fold), Pb (8-fold), Mg (20-fold), and Zn (10-fold) in the sclerotic valves. Thus, sclerotic aortic valve disease is associated with a pronounced imbalance in several trace elements of well-known importance for cardiovascular and immune function as well as in trace elements with hitherto unknown significance.

Chlamydia pneumoniae in patients undergoing surgery for thoracic aortic disease.

OBJECTIVE: To investigate if Chlamydia pneumoniae is present in the wall of the thoracic aorta in patients operated on for aneurysm or aortic dissection. DESIGN: Consecutive patients undergoing surgery for thoracic aortic aneurysm (TAA, 32 patients) and for aortic dissection (6 patients) were included in this prospective study. Tissue samples from the aorta were analysed for the presence of C. pneumoniae by polymerase chain reaction (PCR), histopathology, immunohistochemistry and in one aortic tissue sample C. pneumoniae was verified by electron microscopy and immunogold labelling technique. Cultured Hep 2 cells infected with C. pneumoniae were used as a positive control for electron microscopy. Sera for microimmunofluorescence were obtained in 36/38 and throat swabs for C. pneumoniae PCR in 17/38 patients. RESULTS: Chlamydia pneumoniae was detected by PCR in 4 of 32 TAA tissue samples (12%) and in 0 of 6 patients operated on for aortic dissection. Chlamydia pneumoniae inclusion bodies in one of the PCR positive tissue samples were verified by electron microscopy. IgG antibodies to C. pneumoniae were present in 17/31 (55%) and IgA in 15/31 (48%) of the TAA patients and in none of five tested patients with dissection. None of the tested throat swabs was positive. CONCLUSION: In this study we report the presence of C. pneumoniae by PCR and electron microscopy in the wall of TAA. A high prevalence of serum IgA antibodies to C. pneumoniae was found in TAA patients. In contrast no signs of C. pneumoniae were detected in patients with thoracic aortic dissection.