The characteristics of patients with pulmonary Mycobacterium avium-intracellulare complex disease diagnosed by bronchial lavage culture compared to those diagnosed by sputum culture

Detection of Mycobacterium avium-intracellulare Complex (MAC) by Bronchial Lavage and the Relationship with Titers of Anti-Glycopeptidolipid-Core IgA Antibodies to MAC in Patients with Pulmonary MAC Disease

Background

Higher rates of diagnosis of pulmonary Mycobacterium avium-intracellulare complex (MAC) disease by bronchoscopy (BS) in patients who could not diagnose by sputum cultures have been suggested, but the detailed utility of BS, especially in combination with anti-glycopeptidolipid-core IgA antibodies (anti-MAC Ab), is still unclear.

Methods

A total of 111 patients at our hospital with suspected MAC who underwent BS because they were sputum-negative from April 2018 to March 2022 were analyzed prospectively. These patients were also divided into two groups, anti-MAC Ab-positive and anti-MAC Ab-negative, and compared.

Results

A total of 111 patients underwent BS, though 95 (38.0%) of 250 enrolled patients were sputum smear/culture-positive. The age of the 111 patients was 69.14 (31.0-89.0) years, and 90 (81.0%) were female; 69 (62.2%) of 111 patients were either smear-positive (n = 42, 37.8%) or culture-positive (n = 27, 24.3%) by BS. Of the total 111 patients, 69 (62.2%) were anti-MAC Ab-positive and 57 (82.6%) of 69 patients were also positive by BS. In contrast, only 12 (28.6%) of the 42 anti-MAC Ab-negative patients were positive by BS. The sensitivity and specificity of anti-MAC Ab for positive by BS were 82.6% and 71.4%, respectively, and the area under the curve (AUC) on receiver-operating characteristic (ROC) curve analysis was 0.807.

Conclusion

BS and anti-MAC Ab showed similar usefulness to confirm the diagnosis in patients who could not be diagnosed by sputum examination, but pulmonary MAC disease was strongly suspected based on chest radiography/CT findings. These two examinations were correlated, and their combination appeared to provide more accurate diagnosis and earlier therapy.

Efficacy of three sputum specimens for the diagnosis of Mycobacterium avium complex pulmonary disease

BACKGROUND

In Mycobacterium avium complex pulmonary disease (MAC-PD), diagnosis requires a positive culture from at least two separate expectorated sputum specimens. The optimal number of sputum examinations remains unclear.

OBJECTIVE

This study sought to elucidate the diagnostic yield of acid-fast bacilli in MAC-PD using 3 sputum specimens and to clarify the clinical characteristics of patients with MAC-PD diagnosed using 3 sputum specimens. Furthermore, we investigated the correlation between increased number of sputum specimens and diagnostic yield.

METHODS

We reviewed the medical records of 139 patients with MAC-PD diagnosed at Toho University Omori Medical Center for whom at least three sputum specimens were examined before treatment from November 2014 through June 2021. Patients were classified into the 3-sputum diagnosed and the non-3 sputum diagnosed groups based on diagnostic procedure; clinical and radiological characteristics were compared. We also assessed diagnostic yield with the increased number of sputum specimens.

RESULTS

Diagnostic yield with 3 sputum specimens was 16.5% (23/139). The 3-sputum diagnosed group had a lower body mass index [18.6(17-19.5) vs. 19.5(18-21.5); p = 0.014], and higher chest CT score [9(6.5-13) vs. 6(4-9); p = 0.011] including cavitary lesions (39.1% vs. 19%; p = 0.037) compared with the non-3 sputum diagnosed group. When the number of sputum specimens was increased to 6, the diagnostic yield increased to 23.7% (33/139).

CONCLUSION

Diagnostic yield with 3 sputum specimens was 16.5%. Patients diagnosed using 3 sputum specimens had more severe chest CT findings including cavitary lesions. Increasing the number of sputum specimens to 6 improved diagnostic yield by 7.2%.

Bronchial Brushing and Diagnosis of Pulmonary Nontuberculous Mycobacteria Infection

BACKGROUND

The optimal bronchoscopy procedure for diagnosis of pulmonary nontuberculous mycobacteria (NTM) infection is unclear.

OBJECTIVE

This study investigated the usefulness of bronchial brushing in bronchoscopy for diagnosis of pulmonary NTM infection in patients with suspected NTM lung disease and nodular bronchiectasis on chest computed tomography (CT) images.

METHODS

Bronchoscopy was prospectively performed for 69 patients with clinically suspected pulmonary NTM infection on chest CT from December 2017 through December 2019. Before and after bronchial brushing, bronchial washing was performed with 20 or 40 mL of normal sterile saline at the same segmental or subsegmental bronchi. Before and after bronchial brushing, samples of the washing fluid (pre- and postbrushing samples) and brush deposits (brush samples) were obtained and cultured separately.

RESULTS

NTM was detected in 37 of the 69 (53.6%) patients (Mycobacterium avium in 27, Mycobacterium intracellulare in 7, M. abscessus in 2, and M. kansasii in 2). NTM was detected in 34 (49.3%) prebrushing samples, in 27 (39.1%) postbrushing samples, and in 20 (29.0%) brush samples from the 69 patients. In 2 (2.9%) patients, NTM was detected only in postbrushing samples; in 1 (1.4%) patient, NTM was detected only in a brush sample. As compared with bronchial washing only, additional bronchial brushing increased the NTM culture-positive rate by 4.3% (3/69). Bronchial brushing caused bleeding, requiring hemostasis in 5 (7.2%) patients.

CONCLUSION

Additional bronchial brushing increased the NTM culture-positive rate by only 4.3% (3/69), as compared with bronchial washing alone. Thus, the usefulness of brushing appears to be limited.

Bronchial lavage under fiberoptic bronchoscopy in the treatment of severe pulmonary infection

Objective:

To investigate the clinical efficacy of bronchial lavage under fiberoptic bronchoscopy in the treatment of severe pulmonary infection.

Methods:

One hundred forty eight patients with severe pulmonary infection who were admitted to our hospital from October 2016 to December 2017 were included in this study. According to the random number table method, they were divided into a control group and an observation group with 79 patients each. The control group was given conventional treatment, while the observation group was given bronchoalveolar lavage with fiberoptic bronchoscopy on the basis of the treatment in the control group. The clinical efficacy of the two groups was compared, the duration of mechanical ventilation, antibiotic use and symptoms improvement of the two groups were recorded, and the respiratory mechanics parameters, serum procalcitonin (PCT) and transforming growth factor β (TGF-β) level were measured before and after treatment.

Results:

The duration of mechanical ventilation, antibiotic use, respiratory failure correction, body temperature decline and white blood cell recovery in the observation group were significantly shorter than those in the control group (P<0.05). The total efficacy of the observation group was significantly higher than that of the control group (92.4% vs. 74.7%). The respiratory mechanics parameters of the two groups after treatment were higher than those before treatment (P<0.05) and the increase of the observation group was more obvious than that of the control group (P<0.05). The serum PCT and TGF-β levels of the two groups after treatment were lower than those before treatment (P<0.05), and the decrease level in the observation group was more obvious (P<0.05).

Conclusion:

Bronchial lavage under fiberoptic bronchoscopy can improve the clinical efficacy, accelerate the improvement of clinical symptoms and respiratory mechanics parameters, significantly reduce the PCT and TGF-β levels, and promote the rapid recovery of patients in the treatment of severe pulmonary infection.

Prevalence of non-tuberculous mycobacteria in HIV-infected patients admitted to hospital with pneumonia

<sec id="st1"> <title>BACKGROUND</title> People living with the human immunodeficiency virus (PLWH) may be particularly vulnerable to the consequences of non-tuberculous mycobacteria (NTM) given their defective T cell-mediated immunity and high rates of structural lung disease. </sec> <sec id="st2"> <title>OBJECTIVE</title> To determine the prevalence of NTM in PLWH hospitalized with pneumonia and to assess the potential predictors of NTM isolation. </sec> <sec id="st3"> <title>METHODS</title> Secondary data analysis of a prospective cohort study (2007-2011) of early bronchoscopy in PLWH presenting with suspected pneumonia was undertaken. Subjects with any species of NTM, henceforth described as 'NTM of undetermined significance' (NTM-US), isolated from sputum or bronchoalveolar lavage fluid (BALF), were included in the analysis. Potential predictors were chosen a priori. </sec> <sec id="st4"> <title>RESULTS</title> Among 196 HIV-infected subjects hospitalized with pneumonia, 96 had respiratory samples positive for NTM-US, with 91% of all NTM-US isolated from sputum compared with BALF. The overall prevalence of NTM-US was 49% (96/196). More NTM subjects were smokers (P = 0.08), with a history of chronic obstructive pulmonary disease (P = 0.08). Among those with pathogenic NTM, 39% (34/88) would have met American Thoracic Society microbiologic criteria for NTM pulmonary disease (17% of total cohort). </sec> <sec id="st5"> <title>CONCLUSIONS</title> Respiratory cultures, predominantly sputum samples, were positive for NTM-US in 45% of HIV-infected subjects admitted to hospital for pneumonia. Further research is needed to characterize the prevalence of NTM in PLWH and help establish specific diagnostic criteria in this population. </sec>.

Incidental diagnosis of pulmonary mycobacteriosis among patients scheduled for lung cancer surgery: results from a series of 3224 consecutive operations

Background

The relation between pulmonary mycobacteriosis and lung cancer has been scrutinized for many years but the current evidence is inconsistent as some studies found an association between the two, whereas others have reported an insignificant relation.

Materials and methods

3224 consecutive patients undergoing elective thoracic surgery at the Department of Thoracic Surgery of a comprehensive cancer center over a four-year period were considered. Patients diagnosed with pulmonary mycobacteriosis with microbiological confirmation on their surgical specimen were further analyzed.

Results

30 patients were diagnosed with pulmonary mycobacteriosis: six of them had a history of cancer. 18 patients received wedge resection, four patients received anatomic segmentectomy, two were submitted to lobectomy, one underwent pneumonectomy and five patients received other types of lesser procedures. Pulmonary mycobacteriosis and synchronous lung cancer were observed in four patients.

Conclusions

Although rare, the incidental diagnoses of pulmonary mycobacteriosis among patients scheduled for lung cancer resection is not negligible. Pulmonologists, anesthesiologists and thoracic surgeons should be aware of this possibility before planning pulmonary resections of histologically undiagnosed lung nodules.

Characteristics of patients with bronchoscopy-diagnosed pulmonary Mycobacterium avium complex infection

BACKGROUND

We occasionally treat patients with clinically suspected pulmonary Mycobacterium avium complex (MAC) infection and negative MAC culture on bronchoscopy.

OBJECTIVE

This study aimed to investigate the usefulness of bronchoscopy in patients with suspected MAC lung disease with nodular bronchiectasis on chest computed tomography (CT) and to clarify the clinical characteristics of these patients.

METHODS

We reviewed the records of 71 patients with clinically suspected pulmonary MAC infection on chest CT who underwent bronchoscopy. The patients were classified on the basis of MAC culture result, and their clinical characteristics were compared.

RESULTS

MAC was detected in 33 of the 71 (46.5%) patients (positive group), and 35 (49.3%) were culture-negative for nontuberculous mycobacteria (NTM) (negative group). NTM other than MAC were detected in 3 of 71 (4.2%) patients. MAC was not detected in 14 of 38 (36.8%) patients positive for GPL core IgA antibody. Patients in the positive group had a higher body mass index (20.1 ± 3.4 vs 18.5 ± 2.9 kg/m²; p = 0.047) and positive rate for GPL core IgA antibody (72.7% vs 40%; p = 0.006) and a lower chronic obstructive pulmonary disease assessment test score (6.6 ± 6.6 vs 11.7 ± 8.5; p = 0.016) and rate of positive culture for Pseudomonas aeruginosa or Haemophilus influenzae (12.1% vs 45.7%; p = 0.003), as compared with the negative group.

CONCLUSION

Bronchoscopy is useful for diagnosis of MAC in patients who cannot be diagnosed by sputum examination. In addition, patients with pulmonary MAC disease had less severe subjective symptoms and weight loss than did those with a negative MAC culture on bronchoscopy.