Slide repository module 5 Diagnosis of NTM-LD Slide repository module 5 NP-EU6-00041

Eradication or disease management3 Potential misdiagnosis phase The patient journey is typically long and difficult before diagnosis Only a few are diagnosed correctly from the outset1 Pulmonary symptoms worsen over time Eradication or disease management3 Primary care doctor Seek out physician Potential misdiagnosis phase Treatment initiation Misdiagnosis Bronchitis2 COPD2 Treatment initiation Diagnosis correction Symptom persistence Asthma2 Referral to expert centre3 Prolonged misdiagnosis phase due to non-specific symptoms similar to underlying disease may lead to late diagnosis and delayed treatment. Tuberculosis2 COPD, chronic obstructive pulmonary disease. 1. Mirsaeidi M, et al. Int J Infect Dis 2013; 17:e1000-4; 2. Infectious disease advisor - Rapidly Growing Nontuberculous Mycobacteria. 2018. Accessed March, 2018; available at https://www.infectiousdiseaseadvisor.com/infectious-diseases/rapidly-growing-nontuberculous-mycobacteria-ntm/article/608933/; 3. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Diagnosis

Symptoms of NTM-LD are frequently non-specific Weight loss General malaise Haemoptysis Chronic, recurrent cough Fatigue Chest pain Fever Dyspnoea Sputum production = All patients = variable symptoms Physical symptoms are more common in advanced disease. Assessment is often difficult, as the symptoms overlap with those of the underlying lung diseases (e.g. COPD, bronchiectasis) COPD, chronic obstructive pulmonary disease; NTM-LD, non-tuberculous mycobacterial lung disease. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Sputum, bronchial wash or lung biopsy* Exclusion of other diagnoses Diagnostic criteria: Clinical, radiographic, and microbiologic criteria must be met to make a diagnosis of NTM-LD Pulmonary symptoms Sputum, bronchial wash or lung biopsy* Exclusion of other diagnoses Clinical criteria ? Microbiological criteria Positive culture required Radiographic criteria Chest radiograph: HRCT: multifocal bronchiectasis, multiple nodules Nodular and cavitary opacities *Bronchial wash only used when sputum samples are unavailable. HRCT, high resolution computed tomography; NTM-LD, non-tuberculous mycobacterial lung disease. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Diagnosis of NTM-LD ATS diagnostic criteria Symptoms correlate with NTM-LD Radiological findings compatible with NTM-LD (nodular/bronchiectatic or fibrocavitary) At least two of three positive early-morning sputum samples over the course of a week The NTM species should be identified by molecular methods ATS, American Thoracic Society; NTM, non-tuberculous mycobacteria; NTM-LD, non-tuberculous mycobacterial lung disease. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Diagnostic criteria for NTM-LD1,2 Radiological criteria1 Nodular or cavitary structures on chest radiograph or Multifocal bronchiectasis with multiple small nodules on the HRCT scan and Exclusion of other causes Microbiological criteria1,2 Three positive sputum cultures1,2 or Positive culture from bronchoalveolar lavage1,2 Transbronchial/other lung biopsy with mycobacterial histopathological features and positive culture or biopsy with mycobacterial, histopathological features and ≥ 1 positive culture from sputum/ bronchoalveolar lavage1,2 Clinical criteria1 Bronchopulmonary symptoms and Exclusion of other lung diseases Bronchoalveolar lavage is only appropriate when patients cannot produce sputum samples, or their specimens do not grow mycobacteria2 HRCT, high resolution computed tomography; NTM-LD, non-tuberculous mycobacterial lung disease. 1. Griffith DE, et al. Am J Crit Care Med 2007; 175:367-416; 2. van Ingen J. Clin Chest Med 2015; 36:43-54.

Radiographic criteria Nodular or cavitary opacities on chest radiograph Or multifocal bronchiectasis with multiple small nodules on HRCT scan Fibrocavitary disease1 Chest HRCT indicated for evaluation Nodular/bronchiectatic disease1 Chest HRCT indicated for evaluation HRCT should also be used during treatment follow-up2 HRCT, high resolution computed tomography. 1. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416; 2. personal communication by scientific committee.

Radiographic criteria: Nodular/bronchiectatic form Characteristic pulmonary infiltrates in “tree-in-bud” pattern1,2 Bilateral small nodules in the lungs1,2 Cylindrical bronchiectasis often affects the right middle lobe and the lingual middle and lower lung fields2 In later stages cavities may also develop1 HRCT image courtesy of W. Hoefsloot. HRCT, high resolution computed tomography. 1. Weiss CH, Glassroth J. Expert Rev Respir Med 2012; 6:597-612; quiz 3; 2. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Radiographic criteria: Fibrocavitary form Radiological features are similar to tuberculosis1 Areas of increasing opacity and cavitation2 Usually the upper lobes of the lung are affected2 Frequent apical pleural thickening and fibrosis with volume loss and bronchiectasis visible2 Differences to tuberculosis:1 Thin-walled cavities with less surrounding parenchymal opacity Less bronchogenic, but more related spread of the disease Increased involvement of the pleura in the affected areas of the lungs HRCT image courtesy of W. Hoefsloot. HRCT, high resolution computed tomography. 1. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416; 2. Bonaiti G, et al. Biomed Res Int 2015; 2015:197950.

Radiographic criteria: Hypersensitivity-like pneumonitis X-rays or chest CT scans are always abnormal Most of them show diffuse nodular infiltration Ground-glass opacities and mosaic patterns are commonly seen on HRCT scans HRCT image courtesy of W. Hoefsloot. CT, computed tomography; HRCT, high resolution computed tomography. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Microbiologic criteria: Culture of NTM essential for diagnosis DIAGNOSIS REQUIRES: Sputum: Positive NTM culture at least 2 of 3 early morning samples collected on different days Lung biopsy: Mycobacterial histopathologic features and positive NTM culture Bronchial wash/lavage: Positive NTM culture from  1 sample* OR OR OR Combination of samples Mycobacterial histopathologic features on lung biopsy and  1 NTM culture-positive sputum or bronchial wash sample *Only applicable if sputum samples cannot be obtained. NTM, non-tuberculous mycobacteria. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Potential for contamination of samples Environmental contamination must be avoided during sample collection Bronchial washes are less likely to be contaminated than expectorated sputum samples If culture reveals NTM that are environmental contaminants or infrequently encountered, expert guidance regarding clinical significance is necessary ! NTM, non-tuberculous mycobacteria. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Drug susceptibility testing in NTM Grouping/species First choice Alternatives MAC Broth macrodilution in 12B medium Broth microdilution in CAMH M. kansasii Macrodilution, agar proportion Other SGM Broth microdilution in CAMH* No recommendation Fastidious species M. marinum Macrodilution, agar dilution Rapid growers Not established Macrolide susceptibility in MAC and rapid-growing species can be tested by analysing mutations in the 23S rRNA and erm genes Aminoglycoside resistance can be tested by analysing the 16S rRNA gene in MAC and M. abscessus *M. xenopi grows poorly in this medium. CAMH, cation-adjusted Mueller-Hinton broth; MAC, Mycobacterium avium complex; rRNA, ribosomal ribonucleic acid; SGM, slow-growing mycobacteria. van Ingen J, et al. Drug Resist Update 2012; 15:149-61.

Species-level identification of NTM is clinically important Genotypic testing Commercially available nucleic acid hybridization probes1 PRA1 DNA sequence analysis1 Rapid, high sensitivity and specificity; not available for all NTM species1 Rapid and accurate2 Based on analysis of hsp65, rpoB, and 16S-23S rRNA sequences3 Species identification is vital to determining the course of treatment and, in the case of recurrent infection, whether it is new or due to a relapse1 It is important to identify NTM-LD caused by M. abscessus1 Presently no reliable or dependable antibiotic regimen to produce a cure for M. abscessus lung disease1 Sudden onset, rapidly progressive disease can occur in association with gastroesophageal diseases and CF1 CF, cystic fibrosis; MAC, Mycobacterium avium complex; NTM, non-tuberculous mycobacteria; NTM-LD, non-tuberculous mycobacterial lung disease; PRA, polymerase chain reaction restriction endonuclease assay; rRNA, ribosomal ribonucleic acid. 1. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416; 2. Verma AK, et al. Can J Microbiol. 2015; 61: 293-6; 3. Jang M-A, et al. J Clin Microbiol. 2014; 52: 1207–1212; 4.

NTM-LD and TB must be differentiated It is important to differentiate between pulmonary TB and NTM-LD1 Treatment is different for the two diseases1* Cystic fibrosis Symptoms, radiography or smear microscopy are not sufficient to differentiate between TB & NTM-LD1 Molecular methods are the methods of choice for identifying NTM1 *Approved first line TB drugs: Isoniazid, Rifampicin, Pyrazinamide, Ethambutol, Streptomycin2. NTM, non-tuberculous mycobacteria; NTM-LD, non-tuberculous mycobacterial lung disease; TB, tuberculosis. 1. Kwon YS, Koh W-J. Tuberc Respir Dis 2014; 77: 1-5; 2. WHO, Treatment of Tuberculosis: Guidelines, 4th edition, Geneva; 2010.

Pulmonary TB and NTM-LD: Comparison of radiographic findings Plain chest radiography HRCT TB Poorly defined nodules, linear opacities and cavities1 Focal or patchy heterogeneous consolidation1 Centrilobular nodules1 Tree-in-bud lesions1 Patchy or lobular consolidations1 Cavities1 NTM-LD Fibrocavitary NTM-LD Thin-walled cavities with less surrounding parenchymal opacity than TB2 Less bronchogenic but more contiguous spread of disease than TB2 More marked involvement of pleura over involved areas of lungs than TB2 Nodular/bronchiectatic NTM-LD Bilateral multifocal bronchiectasis and bronchiolitis1,2 Clusters of small (< 5 mm) nodules2 Considerable overlap with appearance of TB1 There is considerable overlap in the radiographic manifestations of pulmonary TB and NTM-LD, and radiographic find­ings alone cannot be used to differentiate the two diseases1 HRCT, high resolution computed tomography; NTM-LD, non-tuberculous mycobacterial lung disease; TB, tuberculosis. 1. Kwon YS, Koh W-J. Tuberc Respir Dis 2014; 77: 1-5; 2. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Adequate numbers of respiratory specimens should be collected Colonisation Colonisation without infection has not been proven, and suspected cases may represent indolent or slowly progressive infection Guideline-based criteria should be used to determine the clinical significance of any NTM identified Adequate numbers of respiratory specimens should be collected Individuals with NTM-positive sputum but no disease symptoms should be monitored closely and expert opinion sought NTM, non-tuberculous mycobacteria. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-416.

Summary Relatively few patients with NTM are diagnosed correctly at the outset1 Diagnostic symptoms are non specific and can be mistaken for other conditions2 Several diagnostic criteria have to be met in order to diagnose a case of NTM-LD2,3 Nodular or cavitary structures on chest radiograph, or multifocal bronchiectasis with multiple small nodules by HRCT scan2 Three positive sputum cultures, or positive cultures from biopsy or bronchoalveolar lavage; 2,3 care must be taken that these are not contaminated2 Bronchopulmonary symptoms2 Other causes of disease should be excluded2 It is important to differentiate between NTM species and to rule out TB as a possible cause,2,4 and this can be achieved using molecular techniques and identification of key radiographic findings2,5 Colonisation without infection is unproven and is likely to represent indolent or slowly progressing infection2 HRCT, high resolution computed tomography; NTM, non-tuberculous mycobacteria; NTM-LD, non-tuberculous mycobacterial lung disease; TB, tuberculosis. 1. Mirsaeidi M, et al. Int J Infect Dis 2013; 17:e1000-4; 2. Griffith DE, et al. Am J Respir Crit Care Med 2007; 175:367-41; 3. van Ingen J. Clin Chest Med 2015; 36:43-54; 4. Kwon YS, Koh W-J. Tuberc Respir Dis 2014; 77: 1-5; 5. Jang M-A, et al. J Clin Microbiol. 2014; 52: 1207–1212.

Glossary Agar proportion Involves testing bacterial susceptibility to antibiotics by growing colonies on agar plates with different concentrations of antibiotic Bronchoalveolar lavage a medical procedure in which a bronchoscope is passed through the mouth or nose into the lungs and fluid is squirted into a small part of the lung and then collected for examination, typically performed to diagnose lung disease Broth macrodilution Involves testing bacterial susceptibility to antibiotics by bacterial cells in suspension in volumes of 1 ml or greater Broth microdilution Involves testing bacterial susceptibility to antibiotics by bacterial cells in suspension in a microtiter plate format Fastidious NTM Species with very specific growth requirements NTM, non-tuberculous mycobacteria.