Toshinori Kawanami

Significance of Anaerobes and Oral Bacteria in Community-Acquired Pneumonia

Background Molecular biological modalities with better detection rates have been applied to identify the bacteria causing infectious diseases. Approximately 10–48% of bacterial pathogens causing community-acquired pneumonia are not identified using conventional cultivation methods. This study evaluated the bacteriological causes of community-acquired pneumonia using a cultivation-independent clone library analysis of the 16S ribosomal RNA gene of bronchoalveolar lavage specimens, and compared the results with those of conventional cultivation methods. Methods Patients with community-acquired pneumonia were enrolled based on their clinical and radiological findings. Bronchoalveolar lavage specimens were collected from pulmonary pathological lesions using bronchoscopy and evaluated by both a culture-independent molecular method and conventional cultivation methods. For the culture-independent molecular method, approximately 600 base pairs of 16S ribosomal RNA genes were amplified using polymerase chain reaction with universal primers, followed by the construction of clone libraries. The nucleotide sequences of 96 clones randomly chosen for each specimen were determined, and bacterial homology was searched. Conventional cultivation methods, including anaerobic cultures, were also performed using the same specimens. Results In addition to known common pathogens of community-acquired pneumonia [Streptococcus pneumoniae (18.8%), Haemophilus influenzae (18.8%), Mycoplasma pneumoniae (17.2%)], molecular analysis of specimens from 64 patients with community-acquired pneumonia showed relatively higher rates of anaerobes (15.6%) and oral bacteria (15.6%) than previous reports. Conclusion Our findings suggest that anaerobes and oral bacteria are more frequently detected in patients with community-acquired pneumonia than previously believed. It is possible that these bacteria may play more important roles in community-acquired pneumonia.

A Higher Significance of Anaerobes: The Clone Library Analysis of Bacterial Pleurisy

BACKGROUND The frequencies of etiologic bacterial agents of intrapleural infections reported until now have been widely varied, largely depending on the implemented detective methods. The aims of this study were to evaluate bacterial etiologies of bacterial pleurisy using a cultivation-independent method. METHODS Pleural fluids were collected from 42 febrile patients with hemipleural effusion. The bacterial flora was analyzed by a clone library method using amplified fragments of the 16S ribosomal RNA gene (rDNA) with universal primers in addition to conventional cultivation methods. RESULTS Forty-two specimens were obtained from 26 patients with bacterial pleurisy, seven with mycobacterial pleurisy, and nine with other pleural effusions. In the 26 bacterial cases, 16 (61.5%) showed positive results for 16S rDNA sequencing analysis, of which 11 (42.3%) were also positive for cultivation method. In seven (43.8%) of the 16 polymerase chain reaction-positive cases, anaerobic phylotypes were predominantly detected. Anaerobic phylotypes (six of these seven cases) were not detected by cultivation method. In nine (34.6%) of the 26 bacterial pleural cases, the results from the clone library methods were not accordant with those of the cultivation method. In seven of these nine cases, the discrepancies between the two detection methods were due to the existence of anaerobes. CONCLUSION The clone library analysis using the 16S rDNA of pleural fluid showed a higher incidence of anaerobic bacteria in infectious pleurisy than that previously expected and provided additional bacterial information for cultivation methods.

High-resolution CT scoring system-based grading scale predicts the clinical outcomes in patients with idiopathic pulmonary fibrosis.

BackgroundThe 2011 idiopathic pulmonary fibrosis (IPF) guidelines are based on the diagnosis of IPF using only high-resolution computed tomography (HRCT). However, few studies have thus far reviewed the usefulness of the HRCT scoring system based on the grading scale provided in the guidelines. We retrospectively studied 98 patients with respect to assess the prognostic value of changes in HRCT findings using a new HRCT scoring system based on the grading scale published in the guidelines.MethodsConsecutive patients with IPF who were diagnosed using HRCT alone between January 2008 and January 2012 were evaluated. HRCT examinations and pulmonary function tests were performed at six-month intervals for the first year after diagnosis. The HRCT findings were evaluated using the new HRCT scoring system (HRCT fibrosis score) over time. The findings and survival rates were analyzed using a Kaplan-Meier analysis.ResultsThe HRCT fibrosis scores at six and 12 months after diagnosis were significantly increased compared to those observed at the initial diagnosis (p < 0.001). The patients with an elevated HRCT fibrosis score at six months based on a receiver operating characteristic (ROC) curves analysis had a poor prognosis (log-rank, hazard ratio [HR] 2.435, 95% CI 1.196-4.962; p = 0.0142). Furthermore, among the patients without marked changes in %FVC, those with an elevated score above the cut-off value had a poor prognosis (HR 2.192, 95% CI 1.003-4.791; p = 0.0491).ConclusionsOur data demonstrate that the HRCT scoring system based on the grading scale is useful for predicting the clinical outcomes of IPF and identifying patients with an adverse prognosis when used in combination with spirometry.

Original ResearchDisorders of the PleuraA Higher Significance of Anaerobes: The Clone Library Analysis of Bacterial Pleurisy

BACKGROUND The frequencies of etiologic bacterial agents of intrapleural infections reported until now have been widely varied, largely depending on the implemented detective methods. The aims of this study were to evaluate bacterial etiologies of bacterial pleurisy using a cultivation-independent method. METHODS Pleural fluids were collected from 42 febrile patients with hemipleural effusion. The bacterial flora was analyzed by a clone library method using amplified fragments of the 16S ribosomal RNA gene (rDNA) with universal primers in addition to conventional cultivation methods. RESULTS Forty-two specimens were obtained from 26 patients with bacterial pleurisy, seven with mycobacterial pleurisy, and nine with other pleural effusions. In the 26 bacterial cases, 16 (61.5%) showed positive results for 16S rDNA sequencing analysis, of which 11 (42.3%) were also positive for cultivation method. In seven (43.8%) of the 16 polymerase chain reaction-positive cases, anaerobic phylotypes were predominantly detected. Anaerobic phylotypes (six of these seven cases) were not detected by cultivation method. In nine (34.6%) of the 26 bacterial pleural cases, the results from the clone library methods were not accordant with those of the cultivation method. In seven of these nine cases, the discrepancies between the two detection methods were due to the existence of anaerobes. CONCLUSION The clone library analysis using the 16S rDNA of pleural fluid showed a higher incidence of anaerobic bacteria in infectious pleurisy than that previously expected and provided additional bacterial information for cultivation methods.

Severe Pneumonia with Leptotrichia sp. Detected Predominantly in Bronchoalveolar Lavage Fluid by Use of 16S rRNA Gene Sequencing Analysis

ABSTRACT We present the first case of severe pneumonia possibly caused by Leptotrichia species with oral bacteria. This was found in a healthy but elderly subject whose bronchoalveolar lavage fluid was analyzed by 16S rRNA gene sequencing analysis. The combination of this method and microscopic observation provided useful information for diagnosis and treatment.

Detection of MALT1 Gene Rearrangements in BAL Fluid Cells for the Diagnosis of Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma

BACKGROUND Mucosa-associated lymphoid tissue (MALT) lymphoma constitutes approximately 90% of primary pulmonary lymphoma, and the diagnosis of pulmonary MALT lymphoma often requires invasive methods such as surgical lung biopsy. Chromosomal rearrangements involving MALT lymphoma translocation gene 1 (MALT1) have been reported to be specific for MALT lymphoma. The combination of BAL and cytologic approaches with molecular methods is useful for the diagnosis of lymphoproliferative disorders. Therefore, we examined the detection of MALT1 gene rearrangements in BAL fluid (BALF) cells for the diagnosis of MALT lymphoma. METHODS We determined the percentage of BALF cells with MALT1 gene rearrangements by using the fluorescence in situ hybridization (FISH) method in 10 patients suspected to have pulmonary MALT lymphoma. RESULTS MALT1 gene rearrangements in BALF cells were found in four of five cases with pulmonary MALT lymphoma (percentage of BALF cells with MALT1 gene rearrangements: 21.8% ± 6.8%). On the other hand, MALT1 gene rearrangements in BALF cells were negative in the five cases without pulmonary MALT lymphoma and one case with pulmonary MALT lymphoma. CONCLUSION These results suggest that the detection of MALT1 gene rearrangements in BALF cells is useful for the diagnosis of pulmonary MALT lymphoma, as it is a specific method that is less invasive than surgical biopsy. Because of the small number of patients in this study, further investigations are necessary to evaluate the detection rate of MALT1 gene rearrangements in BALF cells from patients with pulmonary MALT lymphoma.

Assessment of Pathologically Diagnosed Patients with Castleman’s Disease associated with Diffuse Parenchymal Lung Involvement Using the Diagnostic Criteria for IgG4-Related Disease

BackgroundIgG4-related disease (IgG4RD) is a recently recognized disease entity. Differentiating IgG4RD from plasma cell type Castleman’s disease (PCD) is important but also difficult using only pathological findings. In addition, little is known about the association between these two diseases with diffuse parenchymal lung involvement.MethodsWe analyzed the serum IgG4 levels and the ratio of IgG4/IgG-positive plasmacytes in the lung and lymph node specimens of eight patients previously pathologically diagnosed of PCD with diffuse parenchymal lung involvement (DL-PCD). We also compared the clinical and laboratory findings observed in these patients.ResultsSix of the eight patients exhibited abundant IgG4-positive plasmacytes in the lung and lymph node tissues and elevated serum IgG4 levels, thereby fulfilling the diagnostic criteria of IgG4RD with DL (DL-IgG4RD) in addition to having obstructive phlebitis and massive lymphoplasmacytic infiltration with fibrosis. However, three of these six patients exhibited higher levels of serum interleukin-6 and were still diagnosed with DL-PCD. Accordingly, three of these eight patients were considered as IgG4RD with DL (DL-IgG4RD), and the other five patients were ultimately given a diagnosis of DL-PCD. These two diseases have different characteristics in terms of age, symptoms, serum levels of C-reactive protein, and IgA, complicating allergic disorders, response to corticosteroids, and prognosis.ConclusionsThis is the first report to show a high prevalence of DL-IgG4RD in DL-PCD patients, although additional large investigations are necessary. Clinical and laboratory findings are important for distinguishing between these two diseases in other organs, as previously described.

Bacteriological Assessment of Healthcare-Associated Pneumonia Using a Clone Library Analysis

Background The causative pathogens of healthcare-associated pneumonia (HCAP) remain controversial, and the use of conventional cultivation of sputum samples is occasionally inappropriate due to the potential for oral bacterial contamination. It is also sometimes difficult to determine whether methicillin-resistant Staphylococcus aureus (MRSA) is a true causative pathogen of HCAP. Methods We evaluated the bacterial diversity in bronchoalveolar lavage fluid (BALF) using molecular and cultivation methods in 82 HCAP patients. BALF specimens were obtained from the lesions of pneumonia using bronchoscopy. The bacterial flora was analyzed according to the clone library method using amplified fragments of the 16S ribosomal RNA gene with universal primers. In addition, sputum cultures and the above specimens were assessed. Results Eighty (97.6%) of the 82 BALF samples obtained from the patients with HCAP showed positive polymerase chain reaction results. The predominant phylotypes detected in the BALF in this study included bacteria common in cases of community- and hospital-acquired pneumonia. In addition, the phylotypes of streptococci and anaerobes were detected in 19 (23.2%) and 8 (9.8%) cases, respectively. In particular, phylotypes of streptococci were highly detected among the patients 75 of age or older. Staphylococcus aureus was cultured in 23 (28.0%) cases using conventional cultivation methods and detected in only 6 (7.3%) cases as predominant phylotypes according to the clone library method. Conclusions The clone library analysis of BALF in the HCAP patients detected heterogeneous bacteria and a high incidence of streptococci compared with that observed using cultivation methods. In addition, the results of our study may indicate a lower incidence of MRSA than previously expected in HCAP patients.

Relationship between the ratios of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid and lymph nodes in patients with sarcoidosis

BACKGROUND Evaluating the ratio of CD4/CD8 T-lymphocytes in the bronchoalveolar lavage fluid (BALF) is important for understanding the clinical and pathological conditions of patients with sarcoidosis. However, few studies have thus far demonstrated the usefulness of evaluating the relationship between the ratios of CD4/CD8 T-lymphocytes in the mediastinal lymph nodes and BALF. This study aimed to investigate and identify the relationships between CD4/CD8 T-lymphocyte ratio in the mediastinal lymph nodes and BALF in patients with sarcoidosis. METHODS Thirty-three consecutive patients with sarcoidosis with enlarged mediastinal and/or hilar lymphadenopathy were enrolled in the study, and endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and bronchoalveolar lavage (BAL) were simultaneously performed. The CD4/CD8 T-lymphocyte ratios in the mediastinal lymph nodes and BALF were evaluated using immunohistochemistry and flow cytometry, respectively. RESULTS The interobserver variability in the CD4/CD8 ratio in the mediastinal lymph nodes as determined by immunostaining was low, and the pathological and cytological profiles of T-lymphocytes in the mediastinal and/or hilar lymph nodes and BALF were correlated in patients with sarcoidosis. Additionally, the CD4/CD8 T-lymphocyte ratios in BALF were significantly higher than those in the mediastinal lymph nodes. Importantly, non-caseating granulomas were detected at a high rate by using EBUS-TBNA. CONCLUSIONS Performing EBUS-TBNA in patients with sarcoidosis allows correct diagnosis as well as the estimation of the ratio of CD4/CD8 T-lymphocytes in BALF.

Evaluation of a rapid immunochromatographic ODK0501 assay for detecting Streptococcus pneumoniae antigens in the sputum of pneumonia patients with positive S. pneumoniae urinary antigens.

BACKGROUND A novel, rapid and noninvasive test (ODK0501, RAPIRUN(®)Streptococcus pneumoniae) uses polyclonal antibodies to detect C polysaccharide of S. pneumoniae derived from sputum samples using an immunochromatographic assay. We evaluated its usefulness in Japanese patients with pneumonia who exhibited positive urinary antigen tests for S. pneumoniae (BinaxNOW(®)S. pneumoniae). PATIENTS AND METHODS Forty adult patients with pneumonia treated between May 2011 and August 2013 were enrolled. Bacterial cultures, Gram staining and ODK0501 assays of sputum as well as urinary antigen tests for S. pneumoniae using urine samples obtained from the same patients were performed upon admission, the fourth day after starting antimicrobial treatment and at the end of the antimicrobial treatment. RESULTS Twenty-seven of the 40 patients were positive for ODK0501, while a negative result for ODK0501 was associated with low-quality sputum samples according to the Geckler classification of sputum. The sensitivity and specificity of the ODK0501 assay in the 40 patients were 90.9% and 61.1%, respectively, based on the culture results. The results obtained with this kit were more favorable than those observed on Gram staining. The ODK0501 assay also showed a rapid reaction to the disappearance of S. pneumoniae in the sputum samples, while approximately 80% of the patients exhibited persistent positive results on the urinary antigen detection tests at the end of treatment. CONCLUSIONS The ODK0501 test is a noninvasive, rapid and accurate tool for diagnosing respiratory infections caused by S. pneumoniae, although good quality sputum must be obtained prior to adequate treatment with antibiotics.