Comparison of two serological methods and a polymerase chain reaction-enzyme immunoassay for the diagnosis of acute respiratory infections with Chlamydia pneumoniae in adults

A relationship between respiratory Chlamydia pneumoniae infection (RCPI) and bronchial asthma is under discussion. Our objective was to study the frequency of RCPI and whether it is associated with markers of asthma in children with recurrent or chronic bronchitis as well as pneumonia. One-hundred and forty-eight children who underwent bronchoscopy were enrolled; 42 children with additional respiratory infections were excluded. Therefore, 106 children were examined, regarding a RCPI, by polymerase chain reaction (PCR) of tracheobronchial aspirate, eosinophilic inflammation of respiratory mucosa (cytology, eosinophilic cationic protein [ECP]), total serum immunoglobulin E (IgE) and specific IgE for six important allergens, as well as lung function tests if possible. There was a RCPI in 55 of 106 children (51.9%); 25.4% of PCR positives (14/55) were weakly positive (double cut-off), which was more prevalent in the 2-5-year age-group and teenagers. Children with RCPI, inclusive of weak positives, showed a milder eosinophilia of nasal mucosa than children without RCPI (5.58% vs. 9.35%, p=0.039). Eosinophilia of > or =13% in nasal- and/or bronchial swab, as a marker for respiratory allergy, was less frequent in patients with RCPI too (7.3% vs. 21.6%, p=0.035). There were no differences in ECP. Total IgE was lower in PCR-positive children (101 vs. 179 IU/ml, p=0.032). Specific IgE with a radioallergosorbent test (RAST) of at least class 3 (as a marker for a relevant allergy), as well as any RAST above zero (to characterize early forms of allergy), were both less frequent in the RCPI group. In contrast, weak positives showed the highest rates of sensitization, surpassing RCPI negatives. In lung-function tests, vital capacity was lower in RCPI patients (87.5% vs. 95.3%, p=0.045); all parameters characterizing obstructive disturbance tended to be higher. Weak positives had both the greatest reduction of vital capacity (75.3%) and the most impaired obstructive parameters. All differences were accentuated in children of 11-18 years of age. Hence, our results indicate that in the children selected, a RCPI is common and not associated with allergic respiratory inflammation. Weak positives, however, differ, having the highest rate of allergic sensitization, reduction of lung volume, and obstructive disturbance. This group might be important in clinically observed asthma after pneumonia caused by C. pneumoniae. In these children, early diagnosis and treatment of a RCPI is recommended.

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“…Petitjean et al. (26) tested 25 viral and bacterial species in this PCR assay and no hybridization was seen.…”

Section: Discussionmentioning

confidence: 99%

Bronchial Chlamydia pneumoniae infection, markers of allergic inflammation and lung function in children

Schmidt

Müller

Bruns

et al. 2001

Pediatric Allergy Immunology

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“…The inclusion of these cases as true C. pneumoniaerelated episodes would have increased the number of cases of chlamydia pneumonia from 11 to 56 and the percentage of cases of mixed pneumonia to 8%. Because the clinical signif- icance of a single high titer of IgG to C. pneumoniae is still unclear, we decided to consider this diagnosis only for cases in patients in whom seroconversion was evident [19,[22][23][24][25].…”

Section: Discussionmentioning

confidence: 99%

Etiology, Reasons for Hospitalization, Risk Classes, and Outcomes of Community‐Acquired Pneumonia in Patients Hospitalized on the Basis of Conventional Admission Criteria

et al. 2001

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We performed an observational analysis of prospectively collected data on 533 nonseverely immunosuppressed adult patients who were hospitalized for community-acquired pneumonia on the basis of conventional admission criteria. For this population, we correlated etiology, reasons for admission, and outcomes using the Pneumonia Severity Index (PSI), to identify major discrepancies between the PSI risk class and the conventional criteria for deciding the site of care. PSI classes and corresponding mortality rates were as follows: class I, 51 patients (0%); class II, 62 (2%); class III, 117 (3%); class IV, 198 (10%); and class V, 105 (29%). We identified significant discrepancies between both methods. Overall, 230 patients (40%) who were hospitalized according to conventional criteria were assigned to low-risk classes. Of these 230 patients, 137 (60%) needed supplementary oxygen or had pleural complications; for the remaining patients, there were no irrefutable reasons for admission. This latter group deserves prospective evaluation in randomized studies that compare ambulatory and in-hospital management.

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“…Another study reported rather good agreement between different serological tests and detection of C. pneumoniae by PCR or culture (22). A poor correlation was found between rEIA and PCR in a third study, but only a few positive cases were detected (20).…”

Section: Discussionmentioning

confidence: 99%

Comparison of Five Serologic Tests for Diagnosis of Acute Infections by Chlamydia pneumoniae

Persson

Boman

2000

Clin Diagn Lab Immunol

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Serology is often used to diagnose acute infections by Chlamydia pneumoniae. In this study paired sera from patients with acute respiratory tract infection during an epidemic of C. pneumoniae infections were examined by five different antibody tests. These tests were the complement fixation (CF) test, the microimmunofluorescence (MIF) test, a recombinant enzyme immunoassay (rEIA) (Medac) based on a recombinant lipopolysaccharide of chlamydia and measuring antibodies to a common chlamydial antigen, and two tests that utilize preparations of C. pneumoniae organisms, the SeroCp-EIA (Savyon) (with preserved lipopolysaccharide) and the LOY-EIA (Labsystems) (without this antigen). Both of the last two tests should measure specific antibodies to C. pneumoniae, although cross-reacting antibodies may also be detected by the SeroCp-EIA. Acute infection of C. pneumoniae was serologically confirmed in 44% of the cases by at least two different tests. Using an expanded "gold standard," i.e., the presence of significant reactions in at least two tests, the sensitivity of the CF test was 69%, that of the MIF test was 88%, that of the rEIA was 89%, that of the LOY-EIA was 96%, and that of the SeroCp-EIA was 92%. Specificity was high for all methods, but adjustments of diagnostic criteria were made to several of the tests. The basis for these adjustments and supportive data are presented. Infections of C. pneumoniae were detected in patients from 8 to 83 years of age. Two peaks in the incidence of such infections were observed: one among young teenagers and a second in adults 30 to 45 years of age, corresponding to parents of young teen-agers. The tests were equally sensitive in different age groups. Reinfections seemed to be rare.Serological diagnosis has been important to unravel the clinical manifestations of acute infections by Chlamydia pneumoniae. Isolation of the organism or detection of its nucleic acid by PCR has extended the diagnostic arsenal. These methods can provide early diagnosis, which might be helpful for accurate treatment. Serology based on analysis of paired sera will detect acute infection even after antibiotic treatment has been started and might be useful to discriminate between infections by C. pneumoniae and Chlamydia psittaci.The complement fixation (CF) test based on the common lipopolysaccharide (LPS) antigen of chlamydia has been used for many years to detect acute infections by C. psittaci. After C. pneumoniae was recognized and infection by this new agent could be confidently diagnosed by the microimmunofluorescence (MIF) test, many cases previously detected by the CF test and thought to be cases of ornithosis were found to in fact be infections by C. pneumoniae (12,18). Although the CF test can detect acute infections by C. pneumoniae, its sensitivity has been considered low for such infections, especially in reinfection (13). The MIF test has been of paramount importance to detect acute infections by C. pneumoniae and to describe the prevalence of such infections. The performance of the test dep...

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Comparison of two serological methods and a polymerase chain reaction-enzyme immunoassay for the diagnosis of acute respiratory infections with Chlamydia pneumoniae in adults

Cited by 21 publications

References 29 publications

Bronchial Chlamydia pneumoniae infection, markers of allergic inflammation and lung function in children

Bronchial Chlamydia pneumoniae infection, markers of allergic inflammation and lung function in children

Etiology, Reasons for Hospitalization, Risk Classes, and Outcomes of Community‐Acquired Pneumonia in Patients Hospitalized on the Basis of Conventional Admission Criteria

Comparison of Five Serologic Tests for Diagnosis of Acute Infections by Chlamydia pneumoniae

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