How to diagnose and treat nontuberculous mycobacterial pulmonary infection?

*Only for medical professionals to read and refer to "The 3rd Pudong Forum on the Clinical Diagnosis and Treatment of Difficult and Rare Respiratory Diseases" to "solve" the difficulties and "see" the rare non-tuberculous mycobacterial (NTM) lung disease refers to the lung infection caused by NTM Lung tissue disease
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The clinical features of NTM pulmonary disease are very similar to those of tuberculosis, and clinicians can easily misdiagnose and mis-treat.
Because the treatment method is different from tuberculosis, once mistreated, it may cause serious consequences
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So, how should NTM pulmonary infection be treated, and what new developments and breakthroughs have been made in recent years? Don’t worry, at the 3rd "Pujiang Forum on Clinical Diagnosis and Treatment of Difficult and Rare Respiratory Diseases" held in Shanghai on October 29th, Professor Sha Wei from Shanghai Pulmonary Hospital affiliated to Tongji University gave everyone a "non-tuberculosis score".
Special lecture on new progress in the diagnosis and treatment of mycobacterial pulmonary infection
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What are you waiting for, let's take a look! Before introducing the new progress of related diagnosis and treatment, Professor Sha Wei first took everyone to review several common clinical manifestations of NTM lung disease: 1.
Most patients have underlying diseases in the lungs; 2.
The clinical symptoms and signs are very similar to those of tuberculosis; 3.
Symptoms of systemic poisoning are slightly milder than those of tuberculosis; 4.
Most people have slow onset, often manifested as the deterioration of chronic lung diseases; 5.
Acute onset may include cough, sputum, hemoptysis, chest pain, shortness of breath, night sweats, low fever, fatigue, weight loss And malaise and other symptoms
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At the meeting, Professor Sha Wei gave a detailed introduction to the common clinical manifestations of NTM, as well as a detailed interpretation of NTM's imaging manifestations, diagnostic criteria, treatment and other content.
Let us learn from Professor Sha Wei! Imaging features of NTM lung disease 1.
Multiple nodules, patches, and small patchy consolidation; 2.
Thin-walled cavities; 3.
Right lung and left lung lingual lobule central nodules (tree bud sign ) Combined with bronchiectasis; 4.
fiber stripe shadow; 5.
lesions may involve the lower lobes of both lungs; 6.
less pleural effusion
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At the same time, Professor Sha Wei also analyzed in detail the different types of imaging credits, let us take a look! 1.
Fibrous cavity type Figure 12.
Nodular bronchiectasis type Figure 23.
Mixed type (more common when the disease progresses to an advanced stage) Figure 3 There are also some rare imaging findings.
Friends who are interested can go to the medical doctor station APP to view related Play back the content
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In addition to the above, Professor Sha Wei also pointed out that clinical laboratories play a vital role in the diagnosis of NTM lung disease.
Everyone needs to pay attention to respiratory tract samples, sample processing and culture, bacterial identification, drug susceptibility testing (DST), etc.

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What should be paid attention to when obtaining respiratory samples: 1.
Multiple and long-interval specimens should be sent for examination; 2.
It is recommended to send more than two sputum examinations; 3.
Sputum specimens for hollow NTM lung disease can be sent; 4.
Bronchoalveolar lavage fluid (BALF) culture The positive rate is high; 5.
Contamination should be avoided during sampling and inspection
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How to distinguish between MTB (Mycobacterium tuberculosis) and NTM Professor Sha Wei pointed out that MTB and NTM must be distinguished before treatment is determined.
MPT64 antigen detection can be used to detect the specific antigen MPT64 of Mycobacterium tuberculosis complex (MTBc)
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This detection method can be used for solid or liquid positive cultures, and cannot be directly used for sputum.
The results can be obtained within 15 minutes.
Compared with standard biochemical tests, it has higher sensitivity and specificity
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Figure 4 Notes: 1.
When the gene encoding MPB64 antigen in MTB is mutated, false negative results will occur, and the probability of occurrence is mostly between 0%-3%; 2.
Detection sensitivity is related to the secretion of MPB64 antigen, some Under the circumstances, the specimens with negative results can obtain positive results after prolonging the culture time; 3.
Individual NTM strains, such as Mycobacterium marinum and Mycobacterium flavum, can produce a small amount of MPB64 antigen, so the test shows a weak positive result; 4.
When When MTBc-NTM grows together, the report result is positive, which cannot reflect the presence of NTM
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How to make a diagnosis, what are the diagnostic criteria for respiratory symptoms and/or systemic symptoms, chest imaging conforms to NTM manifestations, and other diseases have been excluded.
On the premise of ensuring that the specimens are free of exogenous contamination, those who meet one of the following conditions can do Diagnosis of NTM lung disease: ① NTM culture of sputum was the same pathogenic bacteria twice; ② NTM culture was positive in BALF once; ③ Lung biopsy by bronchoscopy or other ways found the histopathological characteristics of mycobacterial disease Changes (granulomatous inflammation or positive acid-fast staining), and positive NTM culture; ④The histopathological characteristic changes of mycobacterial disease (granulomatous inflammation or positive acid-fast staining) found on lung biopsy, and sputum specimens And (or) NTM culture positive in BALF ≥ 1 time
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At the same time, Professor Sha Wei also pointed out that the following points should be paid attention to in the diagnosis: the lesions complying with the characteristics of NTM is the first condition for the diagnosis of lung disease; the upper respiratory tract contamination must be excluded when the sputum is cultured to the same NTM repeatedly; BALF culture should be performed as much as possible, and the sputum is pure One culture cannot confirm the diagnosis; molecular biological identification cannot replace sputum culture as a diagnostic basis, and tuberculosis and NTM may exist at the same time
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How to treat (1) Interpretation of the latest US guidelines 1.
Recommendations: For patients who meet the diagnostic criteria of NTM lung disease, it is recommended to start treatment immediately instead of waiting, especially in the case of acid-fast bacilli sputum smear positive and/or cavity lung disease 2.
Evidence summary: There is no randomized controlled trial to test the effect of treatment on survival rate or quality of life.
Limited retrospective observation data fails to prove that treatment of NTM lung disease can prolong survival more than watchful waiting; 3.
Reasons and implementation Note: The decision for antibacterial treatment of NTM lung disease should be individualized based on clinical factors, infection types, and individual patient priorities
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(2) Principles of NTM lung disease treatment A.
Combination of 5-6 drugs; B.
New macrolides as the core drug; C.
Different pathogens and different protocols; D.
No diagnostic treatment for suspected cases; E.
Intensive phase : 6-12 months, total treatment course: 12 months after sputum negative conversion
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(3) MAC (Mycobacterium avium) treatment plan 1.
Patients with MAC lung disease with non-cavitary nodules or bronchiectasis in the lung: 3 times a week treatment plan: clarithromycin 1000mg (or azithromycin 500mg), Rifampicin 600mg and ethambutol 25mg/kg; 2.
For patients with MAC lung disease with cavitation or severe/progressive bronchiectasis: the daily treatment plan is: clarithromycin 1000mg (or azithromycin 250mg), rifle Ping 450-600mg and ethambutol 15mg/kg; 3.
Patients with MAC lung disease with cavitation or progression/severe bronchiectasis or resistance to macrolides, it is recommended to give intestines including amikacin or streptomycin The initial treatment plan including external administration
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At the same time, please note: For patients with macrolide-sensitive Mycobacterium avium complex lung disease, azithromycin-based treatment is recommended instead of clarithromycin-based treatment; in the initial treatment plan, azithromycin is better than clarithromycin Vegetarian
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(Azithromycin is better tolerated, and the drug-drug interaction mediated by the cytochrome P450 system is less than that of clarithromycin) (4) Kansas mycobacterial disease treatment plan 1.
Daily treatment plan: rifampicin 10mg /kg (the maximum amount is 600mg), ethambutol 15mg/kg, isoniazid 5mg/kg (the maximum amount is 300mg) or clarithromycin 1000mg or azithromycin 250mg; 2.
For those who are resistant to rifampicin, it is recommended to take Based on the in vitro susceptibility test, the treatment plan consists of 3-4 drugs, including clarithromycin or azithromycin, moxifloxacin, ethambutol, sulfamethoxazole or streptomycin
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(5) M.
abscessus treatment plan 1.
Intensive period (2-4 months): 1-2 kinds of intravenous drugs + oral macrolides (including 3 active drugs), intravenous drugs can be selected Cefoxitin (200mg/kg single dose, maximum dose 12g/day), amikacin (10-15mg/kg, for renal insufficiency, every other day), imipenem (500-1000mg/day, divided into 2- 4 times), tigecycline (50mg twice a day); 2.
Consolidation period: oral 3 kinds of anti-NTM drugs and macrolides, oral drugs include fluoroquinolone, linezolid, clofazimine or fog 3.
The course of treatment: 12 months after the negative conversion; 4.
The focus of the lesion: anti-NTM for more than two months can be treated surgically
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For patients with M.
abscessus lung disease caused by inducible or macrolide resistant mutant strains, although macrolides are not used as active drugs in a multi-drug regimen, if the use of such drugs has immunomodulatory properties, a treatment plan is recommended Contains macrolide drugs
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Professor Sha Wei also summarized the need to pay close attention to follow-up observation during treatment, refer to the results of drug susceptibility, internal medicine combined with surgery, and adjust or stop the drug in time according to the patient's condition
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At the end of the surgical treatment, Professor Sha Wei also introduced the related content of the surgical treatment
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Professor Sha Wei pointed out that surgical treatment should be considered at the time of diagnosis, and surgical treatment should be considered when recurrence.
Severe diseases with limited focus are indicated for surgery, and surgery should be performed in a treatment center with rich experience in NTM disease diagnosis and treatment.
At the same time, medical treatment should be carried out before treatment.
The postoperative course of treatment is 12 months after sputum negative conversion.
Single NTM nodules can not be treated after surgery
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