Polymerase chain reaction detection of Chlamydia pneumoniae in circulating white blood cells

Several recently published studies suggest that Chlamydia pneumoniae may represent a risk factor for atherosclerosis or its complications. In order to establish whether C. pneumoniae is causally linked to atherosclerotic diseases, clinical intervention trials may be needed. However, to identify eligible subjects with a persistent C. pneumoniae infection and to monitor the effect of antibiotic therapy, there is a need for a reliable diagnostic marker. Blood-based polymerase chain reaction assays may be of value for identifying patients persistently infected with C. pneumoniae and for assessing the microbiologic efficacy of antichlamydial therapy in clinical intervention trials.     

Persistent infection with Chlamydia pneumoniae following acute respiratory illness.

Chlamydia pneumoniae is emerging as a significant cause of respiratory disease, including pneumonia and bronchitis, in humans. In this recently completed study of infection due to C. pneumoniae in patients presenting with pneumonia to SUNY Health Science Center at Brooklyn, we identified two individuals for whom cultures were positive on multiple occasions over a 1-year period. To determine the frequency of persistent respiratory infection with C. pneumoniae, follow-up specimens were obtained from nine individuals with culture-documented C. pneumoniae infection. Five of these individuals had persistent infection: four had a flulike illness characterized by pharyngitis, and one had bronchitis with prominent bronchospasm. All five individuals appeared to have acute C. pneumoniae infection as determined by results of serologic tests (titers of IgM antibody for all individuals were greater than or equal to 1:16). For three patients, cultures remained positive for 11 months despite therapy with 10- to 21-day courses of tetracycline or doxycycline. These observations suggest that persistent infection with C. pneumoniae may follow acute infection and may persist for many months. Infection with C. pneumoniae may be very difficult to eradicate with use of currently available antibiotics even if there is a clinical response to therapy.     

Comparative study of community-acquired pneumonia caused by Streptococcus pneumoniae, Legionella pneumophila or Chlamydia pneumoniae

The objective of this study was to compare epidemiological data and clinical presentation of community-acquired pneumonia (CAP) caused by Streptococcus pneumoniae, Legionella pneumophila or Chlamydia pneumoniae. From May 1994 to February 1996, 157 patients with S. pneumoniae (n = 68), L. pneumophila (n = 48) and C. pneumoniae (n = 41) pneumonia with definitive diagnosis, were prospectively studied. The following comparisons showed differences at a level of at least p < 0.05. Patients with S. pneumoniae pneumonia had more frequently underlying diseases (HIV infection and neoplasm) and those with C. pneumoniae pneumonia were older and had a higher frequency of chronic obstructive pulmonary disease (COPD), while L. pneumophila pneumonia prevailed in patients without comorbidity, but with alcohol intake. Presentation with cough and expectoration were significantly more frequent in patients with S. pneumoniae or C. pneumoniae pneumonia, while headache, diarrhoea and no response to betalactam antibiotics prevailed in L. pneumophila pneumonia. However, duration of symptoms > or = 7 d was more frequent in C. pneumoniae pneumonia. Patients with CAP caused by L. pneumophila presented hyponatraemia and an increase in CK more frequently, while AST elevation prevailed in L. pneumophila and C. pneumoniae pneumonia. In conclusion, some risk factors and clinical characteristics of patients with CAP may help to broaden empirical therapy against atypical pathogens until rapid diagnostic tests are available.     

Treatment of Helicobacter pylori and Chlamydia pneumoniae infections decreases fibrinogen plasma level in patients with ischemic heart disease

BACKGROUND: Chronic Chlamydia pneumoniae and Helicobacter pylori infections could be a risk factor for ischemic heart disease (IHD), possibly by increasing fibrinogen levels. The aim of our study was to evaluate changes in fibrinogen level in patients with IHD and H pylori and/or C pneumoniae positivity randomly assigned to antibiotic treatment. METHODS AND RESULTS: Eighty-four patients with chronic IHD, H pylori and/or C pneumoniae antibodies, and normal acute-phase reactants were randomly assigned to treatment or no treatment. Treatment consisted of omeprazole, clarithromycin, and tinidazole in H pylori-positive patients and clarithromycin alone in C pneumoniae-positive patients. The effect of treatment and other baseline variables on fibrinogen levels, determined at 6 months, was evaluated by multivariate analysis. Treatment significantly reduced fibrinogen level at 6 months in the overall study population and in the groups of patients divided according to H pylori or C pneumoniae positivity. In the 43 treated patients, mean (+/-SD) basal fibrinogen was 3.65+/-0.58 g/L, and mean final fibrinogen was 3. 09+/-0.52 g/dL (P<0.001), whereas in the 41 untreated patients, mean basal and final fibrinogen levels were 3.45+/-0.70 and 3.61+/-0.71 g/L, respectively. The largest decrease was observed in patients with both infections. Fibrinogen changes were also significantly and negatively correlated with age. CONCLUSIONS: Our data suggest that a short, safe, and effective course of antibiotic therapy might be suggested as a means of interacting with an "emerging" risk factor.     

Antibody levels against Chlamydia pneumoniae and outcome of roxithromycin therapy in patients with acute myocardial infarction. Results from a sub-study of the randomised Antibiotic Therapy in Acute Myocardial Infarction (ANTIBIO) trial

BACKGROUND: Results of studies concerning prevention of cardiovascular disease by treatment with macrolide antibiotics targeting C. pneumoniae infection are still controversial. This study describes the results of different tests for infection with C. pneumoniae as well as the effect of treatment with roxithromycin in patients with acute myocardial infarction (AMI) in relation to their serostatus against C. pneumoniae. METHODS: We analysed blood of 160 patients who came from the ANTIBIOtic therapy after an AMI ( ANTIBIO-) study, a prospective, randomised, placebo-controlled, double-blind study to investigate the effect of roxithromycin 300 mg/OD for 6 weeks in patients with an AMI. Anti- Chlamydia IgG-, IgA-, and IgM-antibodies of these patients were analysed by means of different test systems. RESULTS: There was a good correlation between the two IgG and IgA methods (r = 0.900, p < 0.001 and r = 0.878, p < 0.001, respectively), but marked differences in the prevalence of positive tests. This resulted in only moderate concordance values, as expressed by the Kappa coefficients, for IgG kappa = 0.611 (95% CI = 0.498-0.724, p < 0.001) and for IgA kappa = 0.431 (95% CI: 0.322-0.540, p < 0.001). No significant association between positive C. pneumonia titers and the combined clinical endpoint during the 12 month follow-up could be found. In all test systems used, patients with positive anti- C. pneumoniae titers did not benefit from roxithromycin therapy (p = ns). CONCLUSION: Depending on the test system used, there are large differences in the prevalence of anti- C. pneumoniae seropositive patients. Clinical events during the 12 month follow-up after AMI did not depend on serostatus against C. pneumoniae and treatment with roxithromycin did not influence these events, independently of the serostatus against C. pneumoniae. However, the power of this subgroup analysis was low to detect small but significant differences.     

Detection of Chlamydia pneumoniae in giant cell vasculitis and correlation with the topographic arrangement of tissue-infiltrating dendritic cells

OBJECTIVE: Recent studies suggest that giant cell arteritis (GCA) may be an antigen-driven disease. Since Chlamydia pneumoniae has been identified in arterial vessel walls, it was hypothesized that this organism might be associated with GCA. METHODS: Fourteen paraffin-embedded temporal artery biopsy specimens from 9 patients with GCA were examined by immunohistochemistry and by polymerase chain reaction (PCR) for the presence of C pneumoniae; for 5 patients, specimens were available from both the left and right arteries. Four temporal artery specimens from 3 patients with polymyalgia rheumatica (PMR) and 9 temporal artery specimens from 5 patients without GCA or PMR served as controls. RESULTS: C pneumoniae was detected by both immunohistochemistry and PCR in 6 GCA patient samples. One GCA patient sample was immunopositive only; another was PCR positive only. Thus, C pneumoniae was found in 8 of 9 GCA patients. One of 4 control samples from the PMR patients was immunopositive, but PCR negative, for C pneumoniae. The C pneumoniae-positive PMR patient also had respiratory symptoms. The remaining 9 control samples were negative for C pneumoniae by both immunohistochemistry and PCR. Immunohistochemistry showed that bacteria predominate in the adventitial layer of temporal arteries, in granulomatous infiltrates. Dendritic cells were examined by immunohistochemistry for their presence and localization in consecutive temporal artery specimens, and showed a strong topographic relationship with C pneumoniae. Like the bacterium, dendritic cells predominate in the adventitial layer of the arteries. CONCLUSION: C pneumoniae was found in temporal artery specimens from most GCA patients, in 1 specimen from a PMR patient, and in no other control specimens; thus, it may play a role in the pathogenesis of the disease. Dendritic cells may represent the antigen-presenting cells in this situation.     

Progression of peripheral arterial occlusive disease is associated with Chlamydia pneumoniae seropositivity and can be inhibited by antibiotic treatment

A possible influence of Chlamydia pneumoniae seropositivity on the clinical course of peripheral arterial occlusive disease (PAOD) has not been investigated previously. Though roxithromycin therapy was found to inhibit progression of PAOD, the nature of this effect (antibiotic or anti-inflammatory) has remained elusive. The course of PAOD was prospectively assessed in elderly men during 4 years, comparing 51 C. pneumoniae seropositive (IgG>/=1:128) with 46 seronegative patients (IgG<1:64 and IgA<1:32). Twenty of the seropositive patients were treated with roxithromycin (400 mg daily) for 4 weeks. Limitation of the walking distance to 200 m or less was observed in 55% of the seropositive untreated patients as compared to 30% of both, seronegative and macrolide-treated patients. The number of invasive revascularizations per patient was 1.7 in the seropositive untreated group as compared to 0.5 in the seronegative and the macrolide-treated group. Considering possible confounding variables, such as classical vascular risk factors, ordinal regression analyses showed a significant association of C. pneumoniae seropositivity with limitation of the walking distance (p=0.027) and need for invasive revascularization (p=0.037). The effect of macrolide treatment on these outcome measures was marked (p<0.001 and p=0.040, respectively) during 2.7 years but decreased in the second part of the observation period. This study provides good evidence that C. pneumoniae are involved in the progression of PAOD and that antibiotic treatment directed against C. pneumoniae is effective in inhibiting this process.     

Chlamydia pneumoniae not detected in temporal artery biopsies from patients with temporal arteritis

In a recent report Chlamydia pneumoniae (C. pneumoniae), examined with both immunohistochemistry and polymerase chain reaction (PCR), was detected in positive temporal artery biopsies from patients with temporal arteritis (TA). Our aim was to examine whether C. pneumoniae could be detected in patients with TA recruited from a high endemic area of TA in southern Norway. Twenty paraffin-embedded temporal artery biopsies showing convincing inflammation in the vessel wall with lymphocytic infiltration (giant cells in 12 biopsies) from 20 patients with TA were examined for the presence of C. pneumoniae using an established PCR technique. All examined TA patients (mean age 74.4 (SD 7.5) years, 75% females) fulfilled the ACR-1990 criteria. C. pneumoniae was not detected in any of the biopsies. In conclusion, our results indicate that C. pneumoniae, at least in the population of southern Norway, does not have any pathogenetic role in TA.     

Evidence that Chlamydia pneumoniae affects platelet activity in patients with acute myocardial infarction and ST-segment elevations.

This study concerns platelet activity at myocardial infarctions and possible relationships with Chlamydia pneumoniae seroreactivity. Fourteen patients with acute myocardial infarction and ST-segment elevations were enrolled. They all received thrombolytic therapy. The subjects were examined within 24 h after hospital admission (Day 1) and after 6 months of recovery. On Day 1, C. pneumoniae IgM antibody titres were analysed and on Day 1 and during recovery C. pneumoniae IgG and soluble P-selectin were determined. P-selectin was used to estimate platelet activation. C. pneumoniae IgM titres at the infarction were closely related to both Day 1 IgG titres (r = 0.6; p < 0.05) and to IgG levels after 6 months (r = 0.8; p < 0.01). These results indicate a possible reactivation of a chronic infection. C. pneumoniae IgM was related to platelet activation. The correlation coefficient was r = 0.7 (p < 0.01) when comparing IgM titres with Day 1 plasma P-selectin. A similar relationship was found when comparing IgM and recovery P-selectin (r = 0.8; p < 0.01). The pathogen appears to contribute to platelet responses occurring during myocardial infarctions with ST-segment elevations. It is concluded that an ongoing reactivation of a chronic infection is related to increased platelet activity.     

Acute exacerbation of idiopathic pulmonary fibrosis: role of Chlamydophila pneumoniae infection

BACKGROUND AND OBJECTIVES: Patients with idiopathic pulmonary fibrosis (IPF) may experience acute exacerbations of their illness. The actual trigger(s) of such exacerbations is unknown. Chlamydophila pneumoniae infection can cause exacerbation of asthma and COPD. A prospective study was conducted to investigate the possible role of C. pneumoniae infection in triggering acute exacerbations of IPF. METHODS: A prospective observational study over 5 years of consecutive IPF patients who fulfilled the criteria for acute exacerbation. Sputum, blood cultures and acute and convalescent serology for C. pneumoniae IgG and IgA (ELISA) were performed. RESULTS: Previous infection with C. pneumoniae is common. Of the 27 study patients, 15 had a C. pneumoniae IgG index of 1.10-2.99 (positive) and 3 had a C. pneumoniae IgG index of >2.99 (strongly positive) at the time of presentation with an acute exacerbation. In addition, 15 subjects had a C. pneumoniae IgA index of 1.10-2.99 (positive) and 6 subjects had a C. pneumoniae IgA index of >2.99 (strongly positive). However, only two of the 15 subjects (13%) for whom paired sera were tested exhibited a significant rise in antibody response (change in index of 1.90 for C. pneumoniae IgG and 1.54 for IgA, respectively) indicating either acute or reactivated infection with C. pneumoniae. There were 15 deaths (56%) despite supportive care that included high-dose corticosteroid therapy and oxygen supplementation. CONCLUSIONS: Mortality is high with acute exacerbation of IPF. Acute infection with C. pneumoniae is uncommon at the time of presentation with acute exacerbation of IPF.     

Importance of acute Mycoplasma pneumoniae and Chlamydia pneumoniae infections in children with wheezing.

In order to evaluate the role of Mycoplasma pneumoniae and Chlamydia pneumoniae in reactive airway disease, 71 children aged 2-14 yrs with an acute episode of wheezing and 80 age-matched healthy children were studied. Sera for the determination of specific antibody levels and nasopharyngeal aspirates for the detection of M. pneumoniae and C. pneumoniae deoxyribonucleic acid were obtained on admission and after 4-6 weeks. All children with wheezing received a standard therapy with inhaled corticosteroids and bronchodilators for 5-7 days; when antibiotic was added on the basis of the judgement of the paediatrician in charge, clarithromycin 15 mg.kg body weight(-1).day(-1) for 10 days was used. Acute M. pneumoniae and C. pneumoniae infections were detected significantly more often in children with wheezing than in controls. In patients infected with one of the two pathogens, a history of recurrent wheezing was significantly more frequent than in those without either infection. During a 3-month follow-up period, among nonantibiotic-treated children, those with acute M. pneumoniae and/or C. pneumoniae infection showed a significantly higher recurrence of wheezing than those without acute M. pneumoniae and/or C. pneumoniae infection (p=0.03). These results highlight the apparently significant relationship of Mycoplasma pneumoniae and Chlamydia pneumoniae with wheezing in children, particularly in subjects with a history of recurrent episodes, and the possible improvement in the course of reactive airway disease within paediatric patients with acute Mycoplasma pneumoniae and/or Chlamydia pneumoniae infection.     

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.     

Association of Chlamydia pneumoniae antibody with the cholesterol-lowering effect of statins

To investigate the association between Chlamydia pneumoniae (C. pneumoniae) infection and atherosclerosis, we compared the effect of lipid-lowering drugs on carotid intima-media thickness (IMT) between patients who were positive and negative for C. pneumoniae antibodies. A total of 165 asymptomatic hypercholesterolemic patients were randomized to probucol (500 mg per day, n = 82) or pravastatin (10 mg per day, n = 83) and followed for 2 years. The 2-year change of IMT in the common carotid artery was the primary endpoint, while mean IMT change and major cardiovascular events were secondary endpoints. C. pneumoniae antibodies (IgA and IgG) were measured by enzyme-linked immunosorbent assay. The 50 patients without C. pneumoniae antibodies showed significant reduction of IMT progression (-19%), while no significant change of IMT was noted in the 115 antibody-positive patients (-6%). Significant inverse associations were found between the reduction of IMT progression and the C. pneumoniae IgA- and IgG-antibody index (P < 0.01 and 0.01, respectively). No significant differences in the reduction of serum total-cholesterol and LDL-cholesterol were found between antibody-positive and -negative patients. There was no significant difference of efficacy between probucol and pravastatin. These observations suggest that C. pneumoniae infection reduces the effect of lipid-lowering therapy on carotid atherosclerosis and that this organism may play a role in the progression of atherosclerosis.     

Chlamydia pneumoniae infection in HIV-positive patients: prevalence and relationship with lipid profile

OBJECTIVES: The aims of this study were to evaluate the prevalence and impact of Chlamydia pneumoniae infection in HIV-positive patients and to establish the relationship between C. pneumoniae infection and lipid profile. METHODS: Detection of C. pneumoniae was by polymerase chain reaction (PCR) on Peripheral Blood Mononuclear Cells (PBMCs) collected from 97 HIV-positive patients. Samples were collected after overnight fast in EDTA-treated tubes. On the same day, patients were also tested for routine chemistry, HIV viral load, CD3, CD8 and CD4 cell counts and lipid profile [cholesterol, high-density lipoproteins (HDLs), low-density lipoproteins (LDLs) and triglycerides]. RESULTS: The overall prevalence of C. pneumoniae was 39%. The prevalence of C. pneumoniae was inversely related to the CD4 lymphocyte count (P=0.03). In the naive group, C. pneumoniae-positive patients had both significantly higher HIV load (71 021+/-15 327 vs. 14 753+/-14 924 HIV-1 RNA copies/mL; P=0.03) and lower CD4 cell count (348.0+/-165.4 vs. 541.7+/-294.8; P=0.04) than C. pneumoniae-negative patients. Moreover, treatment-naive patients with C. pneumoniae infection had significantly higher mean levels of cholesterol (185.3+/-56.2 vs. 124.8+/-45.9 mg/dL; P=0.01), triglycerides (117.2+/-74.7 vs. 68+/-27.6 mg/dL; P=0.04) and LDL (122.4+/-60.1 vs. 55.6+/-58 mg/dL; P=0.05) than C. pneumoniae-negative patients. CONCLUSIONS: These data indicate that, in HIV-positive subjects, C. pneumoniae infection is relatively frequent and is associated with both low CD4 cell count and high HIV load. Furthermore, C. pneumoniae appears to be associated with hyperlipidaemia and might therefore represent a further risk factor for cardiovascolar disease in HIV-positive patients.     

Chlamydia pneumoniae infection and Mycoplasma pneumoniae infection in pediatric patients

We evaluated a total of 1104 pediatric patients with acute lower respiratory tract infection for C. pneumoniae infection and M. pneumoniae infection by serology during July 1995 to December 1998. A microimmunofluorescence test was used for diagnosis of C. pneumoniae infection and a high density particle agglutination test for that of M. pneumoniae infection. Acute C. pneumoniae infection was found in 149 patients (13.5%), acute M. pneumoniae infection in 118 patients (10.7%), and dual infection in 27 patients (2.4%). Among 305 patients with pneumonia, M. pneumoniae infection (83 patients, 27.2%) was more common than C. pneumoniae infection (47 patients, 15.4%). However among 799 patients with bronchitis. C. pneumoniae infection (102 patients, 12.8%) was more common than M. pneumoniae infection (35 patients, 4.4%). Patients with C. pneumoniae infection were more younger and more frequently wheezing than patients with M. pneumoniae infection. These findings demonstrate that C. pneumoniae infection in very common pathogen of pediatric lower respiratory tract infection as M. pneumoniae infection in Japan.     

Chlamydia pneumoniae infections in asthma: clinical implications

Chlamydia pneumoniae is an intracellular pathogen that has been suggested to play a role in the pathology of asthma. However, so far none of the studies have provided clear evidence for a causative role of C. pneumoniae infections in asthma, although there is little doubt that chronic C. pneumoniae infection does aggravate asthma and should be treated. The diagnosis of C. pneumoniae infection is still a matter of concern for it is dependent on trained skilled personnel and can vary significantly between different diagnostic laboratories. This fact is also one of the major problems encountered when comparing epidemiological studies investigating the possible role of C. pneumoniae infections and their impact on the pathogenesis of other diseases. With regard to therapy, long-term treatment with macrolides is the best available method to eradicate C. pneumoniae. Successful therapy for C. pneumoniae, however, can also be complicated by the high possibility of de novo infection as epidemiological studies have shown that the prevalence of antibodies to C. pneumoniae increases with age in all populations studied. In the northern hemisphere the prevalence of C. pneumoniae is also affected by seasonal conditions. It is too early to draw any conclusions from the equatorial belt countries. The available data on C. pneumoniae in tropical countries indicate a much faster infection rate during early adulthood with 100% serological prevalence at an age greater than 25 years. This data, if confirmed, would argue against C. pneumoniae causing asthma since the asthma prevalence in those countries does not increase in a parallel pattern. An alternative interpretation of most studies could be that the increased rate of C. pneumoniae infections in patients with asthma results from a modified susceptibility towards the microorganism, due to yet unknown changes of the host cell's physiology. It should be kept in mind that increased prevalence of C. pneumoniae infection is not restricted to asthma. Further studies are needed to understand the role of C. pneumoniae, especially of chronic infection, in the pathogenesis of inflammatory diseases with a specific focus on the effect that the microorganism triggers in the infected host cell. Only when we understand what C. pneumoniae does to its host cell will we be able to judge its impact on the overall status of an affected patient, and this knowledge will help us to develop a successful therapy.     

Clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults

STUDY OBJECTIVE: To investigate the clinical presentation of community-acquired Chlamydia pneumoniae pneumonia in adults. DESIGN: Prospective study. SETTING: Kawasaki Medical School Hospital, Kawasaki Medical School Kawasaki Hospital, and Kurashiki Daiichi Hospital in Japan. PARTICIPANTS: Forty patients with community-acquired pneumonia with C pneumoniae as the only pathogen identified admitted to three hospitals between April 1996 and March 2001 and their clinical presentations were compared to patients with Streptococcus pneumoniae and Mycoplasma pneumoniae pneumonia. MEASUREMENTS: The diagnosis of C pneumoniae infection was based on isolation and serologic testing of antibodies by the microimmunofluorescence test. RESULTS: The clinical presentations, except for shortness of breath, were similar for the three major etiologic agents. The mean temperature of C pneumoniae patients on hospital admission was 37.9 degrees C, which was lower than that of patients with S pneumoniae and M pneumoniae. The mean WBC count on hospital admission was lower in the patients with C pneumoniae (mean, 9,100/microL) than in those with S pneumoniae pneumonia but higher than in those with M pneumoniae pneumonia. No patients required respiratory support or admission to an ICU, and no deaths occurred among the C pneumoniae pneumonia patients. CONCLUSIONS: Our results indicate that C pneumoniae pneumonia as a single etiologic agent is mild and that the underlying conditions and clinical symptoms closely resemble those of S pneumoniae pneumonia. However, the physical examinations, laboratory findings, and prognostic factors of the C pneumoniae patients resembled those of patients with M pneumoniae pneumonia.     

Detection of Chlamydia pneumoniae by polymerase chain reaction-enzyme immunoassay in intestinal mucosal biopsies from patients with inflammatory bowel disease and controls

BACKGROUND AND AIM: It has been suggested that Chlamydia is an organism that may have the potential to cause inflammatory bowel disease (IBD) in susceptible individuals. Chlamydia pneumoniae has emerged as an important human pathogen in the last decade. The objective of the present study was to investigate the frequency of the presence of C. pneumoniae DNA in intestinal biopsies from patients with IBD and from non-IBD controls. METHODS: The DNA was extracted from 222 colonoscopic biopsies, which were obtained from 11 patients with Crohn's disease (CD), 18 patients with ulcerative colitis (UC) and from 37 non-IBD control patients. The presence of the C. pneumoniae omp1 gene and C. trachomatis 16S rRNA gene was determined using a rapid and sensitive polymerase chain reaction-enzyme immunoassay (PCR-EIA). RESULTS: The C. pneumoniae-specific DNA was detected in 32 (14.4%) of 222 endoscopic biopsies. Among them, C. pneumoniae DNA were found in nine of 42 (21.4%) biopsies from patients with CD, nine of 59 (15.3%) biopsies from patients with UC, and 14 out of 122 (11.4%) biopsies from non-IBD control patients, respectively. Moreover, the percentage of patients with at least one biopsy positive for C. pneumoniae was higher, although not statistically significant, in CD (36.4%) and UC patients (38.9%) compared to non-IBD controls (16.2%). In contrast, C. trachomatis DNA was detected in only two of 222 (0.9%) biopsy samples. CONCLUSION: The C. pneumoniae DNA was detected in the intestine of both patients with IBD and in non-IBD control patients, probably reflecting the high prevalence of this organism in the environment. The moderate yield of positive biopsies in our IBD patients and the fact that the detection rate of C. pneumoniae DNA was similar in endoscopic biopsies from IBD patients and non-IBD controls does not support a direct role for this organism in the pathogenesis of IBD.     

Role of Chlamydia pneumoniae infection in asthma in Northeast of Iran

The role of Chlamydia pneumoniae in asthma has drawn much attention in recent years. In this study we assessed the prevalence of C. pneumoniae infections in patients with chronic stable and acute exacerbation of asthma and compared it with normal population. Twenty adult patients with chronic stable asthma and 21 patients with acute exacerbations of asthma and 41 matched control subjects were studied for presence of C. pneumoniae using cell culture. This study suggests that positive results of C. pneumoniae culture are associated with both chronic stable and acute exacerbation of asthma. It could be concluded that C. pneumoniae is a risk factor for either development or exacerbation of asthma.