Rapid detection of pneumococcal antigen in serum samples for diagnosing pneumococcal pneumonia

doi:10.1016/j.jinf.2005.09.008

Journal of Infection

Volume 53, Issue 1, July 2006, Pages 21-24

https://doi.org/10.1016/j.jinf.2005.09.008 Get rights and content

Summary

Objectives

The aim of the study is to assess the usefulness of C polysaccharide and polysaccharide capsular antigen detection by immunochromatography (ICT) and enzyme immunoassay (EIA), respectively, in serum samples for diagnosing pneumococcal pneumonia.

Methods

Adult patients included in the study were classified in the following groups: In group 1 we studied 101 serum samples from patients with pneumonia due to Streptococcus pneumoniae. In 53 cases the pneumonia was bacteremic. The second group contained 113 serum samples from patients with no pneumococcal pneumonia. Group 3 was made up of 40 serum samples from healthy subjects with no clinical or radiological signs of pneumonia.

Results

Using ICT, antigen was detected in 50% of patients with pneumococcal pneumonia, in 64.3 and 40.9% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively. Using EIA, antigens were detected in 35.8% of patients with pneumococcal pneumonia, in 45 and 22.2% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively.

Conclusions

In conclusion, the sensitivity of the tests is low. However, in special situations, where obtaining large volume of urine is difficult, they could be a complementary method in the rapid diagnosis of pneumococcal pneumonia.

Introduction

A definitive diagnosis of pneumococcal pneumonia is difficult.¹ Immunological tests for detecting pneumococcal antigens provide a rapid diagnosis, and are also particularly useful for patients who have been treated with antibiotics. Several studies have shown the potential usefulness of detecting antigens by latex agglutination,² counterimmunoelectrophoresis (CIE)3, 4 and enzyme immunoassay (EIA).5, 6 An immunochromatographic test (ICT) (Binax Now Streptococcus pneumoniae Antigen Test, Portland, Maine, U.S.A.) has been developed to detect C polysaccharide (PnC) antigen in urine samples. The test has proven to be rapid, sensitive and specific in pneumococcal pneumonia in adults.⁷ There are several situations in which detecting urinary antigen is difficult. Obtaining large volumes of urine is not possible for some patients, especially for those who have oliguria secondary to sepsis and acute or chronic kidney failure, as well as, patients with altered mental status. Therefore, antigen detection in samples other than urine might be useful for obtaining a rapid and accurate diagnosis. The aim of the study is to assess the usefulness of PnC and PCA detection by ICT and EIA, respectively, in serum samples for diagnosing pneumococcal pneumonia.

Section snippets

Bacterial strains

In order to establish the reactivity of pneumococcal organisms and specificity of the assays, we used the following clinical isolates: S. pneumoniae serotypes 1 (2 strains), 3, 5, 6B, 7, 8, 9N, 9V, 10, 11, 12, 13, 14, 18C, 19, 20 and 23F, Streptococcus pyogenes Streptococcus constellatus, Streptococcus mitis, Streptococcus bovis II, Streptococcus salivarius, three strains of Streptococcus viridans group, Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus

Antigen detection in suspensions of pneumococcal and non-pneumococcal bacteria

All 18 pneumococcal strains tested in a dilution corresponding to 10⁶ cfu/ml were detected by EIA and ICT. Suspensions containing 10⁷ cfu/ml from 25 non-pneumococcal strains did not produce significant immune reactions, except for the two strains of H. influenzae biotype I, which showed cross-reacting antigens in the supernatants by the EIA test, and H. influenzae byotipe IV that showed cross-reacting antigens by the ICT test. No common antigens between H. influenzae and S. pneumoniae have been

Discussion

Different studies have demonstrated that ICT has high sensitivity and specificity in detecting pneumococcal urinary antigen and is useful for improving the number of diagnostics in the CAP for adults.7, 12 Furthermore, several studies have shown the potential usefulness of PCA detection by EIA.5, 6 In our experience, the sensitivity of both tests for detecting antigens in serum samples was not very high, especially when using the EIA test. Several factors are involved in the low sensitivity of

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Pneumococcal antigen detection in cerebrospinal fluid: a comparative study on counter immunoelectrophoresis, latex agglutination and coagglutination
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Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults
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Antigen detection for the diagnosis of pneumonia
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Comparison of immunological methods for diagnosis of pneumococcal pneumonia in biological fluids
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Detection of capsular polysaccharide in serum for the diagnosis of pneumococcal pneumonia: clinical and experimental evaluation
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Detection of Streptococcus pneumoniae antigen by a rapid immunochromatographic assay in urine samples
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Streptococcus

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Guidelines for the management of adult lower respiratory tract infections - Summary
2011, Clinical Microbiology and Infection
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L. pneumophila serogroup 1 antigen detection in urine is the most rapid method to diagnose or exclude the infection. A negative test makes legionella unlikely, but does not exclude legionella infection’ [A3] [209,214–242]. What can serological tests offer in the diagnosis of pneumonia?
This document is an update of Guidelines published in 2005 and now includes scientific publications through to May 2010. It provides evidence-based recommendations for the most common management questions occurring in routine clinical practice in the management of adult patients with LRTI. Topics include management outside hospital, management inside hospital (including community-acquired pneumonia (CAP), acute exacerbations of COPD (AECOPD), acute exacerbations of bronchiectasis) and prevention. The target audience for the Guideline is thus all those whose routine practice includes the management of adult LRTI.
Utility of pneumococcal urinary antigen detection in diagnosing exacerbations in COPD patients
2010, Respiratory Medicine
Citation Excerpt :
At the moment, a reliable method to distinguish between colonization and clinical infection in COPD patients does not exist. In the last years, a new immunochromatographic (ICT) test (Binax Now S. pneumoniae Antigen Test, Portland, Maine, USA) was developed for detecting polysaccharide C (PnC) in urine samples11–13 as well as serum14 and pleural fluid samples.15 The test has proven rapid, sensitive and specific in diagnosing pneumococcal pneumonia in adults.11,12,16
The aim of this study was to evaluate the utility of pneumococcal urinary antigen detection (Binax Now Streptococcus pneumoniae Antigen Test) in diagnosing pneumococcal exacerbation of chronic obstructive pulmonary disease (COPD). Forty-six patients with S. pneumoniae isolation in sputum culture were studied (29 collected in stable period and 17 collected during exacerbation). In the 29 patients with samples collected in a stable period the antigen was detected in 3 cases (10.3%) using nonconcentrated urine (NCU), and in 12 cases (41.4%) using concentrated urine (CU). Regarding patients recruited during an exacerbation period, the antigen was detected in 3 cases (17.6%) using NCU, and in 13 cases (76.5%) when CU was used. For the evaluation of the specificity of the ICT test we also tested 72 cases in which pneumococcus was not isolated in the sputum sample. ICT was positive in 1 NCU and 9 CU of these patients. To have had at least one previous exacerbation (P = 0.024), at least one exacerbation that required hospitalization (P = 0.027), and a pneumonia episode in the year before (P = 0.010) had statistically significant associated with the detection of specific antigen in CU. Using NCU, the only significant association was found when a previous pneumonia in the year before had occurred (P = 0.006). In summary, a positive result of pneumococcal urinary antigen from a COPD patient, in both bronchial exacerbation and pneumonia, should be evaluated with caution because the antigen detected could be related with previous infectious episode.
Contribution of a pleural antigen assay (Binax NOW) to the diagnosis of pneumococcal pneumonia
2007, Chest
Citation Excerpt :
Finally, the ICT assay was positive in 5 of 17 patients (29.4%) who had pneumonia with no identified pathogen The detection of pneumococcal antigen in the sputum,15 BAL fluid,16 cerebrospinal fluid,17 serum,18 and urine19 specimens as a method for the diagnosis of pneumococcal infection has been previously documented. However, it has seldom been performed in pleural fluid samples.11,1213
To determine whether the detection of pneumococcal antigen in pleural fluid augments conventional microbiological methods used for the etiologic diagnosis of pneumonia.
In this retrospective study, a rapid immunochromatographic test (ICT) [NOW Streptococcus pneumoniae assay; Binax; Scarborough, ME] was performed on pleural fluid samples from 34 patients with pneumonia due to S pneumoniae, 89 patients with effusions of nonpneumococcal origin, and 17 patients with pneumonia of unknown etiology. Data on blood cultures, pleural fluid cultures, and urinary antigen tests were recorded.
The ICT test result was positive in 24 of 34 patients (70.6%) with pneumococcal pneumonia and negative in 83 of 89 patients (93.3%) without pneumococcal pneumonia. The sensitivity of the pleural ICT test was higher than that obtained for blood (37.5%) and pleural fluid cultures (32.3%), but lower than the detection of pneumococcal antigen in urine samples (82.1%). However, three patients with pneumococcal pneumonia and a negative ICT urine test result had a positive pleural fluid antigen detection result test. Previous antibiotic exposure did not influence pneumococcal antigen detection in either pleural fluid or urine specimens. Six additional patients with empyema due to anaerobes (three patients), Streptococcus viridans (two patients), and Enterococcus faecalis (one patient) had false-positive pleural ICT test results. Finally, the ICT assay finding was also positive in 5 of 17 patients (29.4%) with pneumonia without a definite microbiological cause.
The ICT test performed on pleural fluid samples augments the standard diagnostic methods of blood and pleural fluid cultures, even in the case of prior antibiotic therapy, and enhances the ICT urinary antigen assay.
Microbiology of bacterial CAP using traditional and molecular techniques
2014, European Respiratory Monograph
Point-of-care testing for community-acquired pneumonia: Do we have all the answers?
2007, Medical Journal of Australia
Pneumonia severity related to detection of pneumococcal polysaccharides in urine and serum [1]
2007, Scandinavian Journal of Infectious Diseases

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Journal of Infection

Summary

Objectives

Methods

Results

Conclusions

Introduction

Section snippets

Bacterial strains

Antigen detection in suspensions of pneumococcal and non-pneumococcal bacteria

Discussion

References (16)

Pneumococcal antigen detection in cerebrospinal fluid: a comparative study on counter immunoelectrophoresis, latex agglutination and coagglutination

Comp Immunol Microbiol Infect Dis

Update of practice guidelines for the management of community-acquired pneumonia in immunocompetent adults

Clin Infect Dis

Antigen detection for the diagnosis of pneumonia

Pediatr Pulmonol

Detection of type-specific pneumococcal antigens by counterimmunoelectrophoresis. I. Methodology and immunologic properties of pneumococcal antigens

J Lab Clin Med

Comparison of immunological methods for diagnosis of pneumococcal pneumonia in biological fluids

Eur J Clin Microbiol

Detection of capsular polysaccharide in serum for the diagnosis of pneumococcal pneumonia: clinical and experimental evaluation

J Infect Dis

Detection of Streptococcus pneumoniae antigen by a rapid immunochromatographic assay in urine samples

Chest

Streptococcus

Cited by (7)

Guidelines for the management of adult lower respiratory tract infections - Summary

Utility of pneumococcal urinary antigen detection in diagnosing exacerbations in COPD patients

Contribution of a pleural antigen assay (Binax NOW) to the diagnosis of pneumococcal pneumonia

Microbiology of bacterial CAP using traditional and molecular techniques

Point-of-care testing for community-acquired pneumonia: Do we have all the answers?

Pneumonia severity related to detection of pneumococcal polysaccharides in urine and serum [1]