echemi logo
Product
  • Product
  • Supplier
  • Inquiry
    Home > Active Ingredient News > Infection > For non-tuberculous mycobacteria infection, these contents must be clear!

    For non-tuberculous mycobacteria infection, these contents must be clear!

    • Last Update: 2021-04-18
    • Source: Internet
    • Author: User
    Search more information of high quality chemicals, good prices and reliable suppliers, visit www.echemi.com
    An introduction to nontuberculous mycobacteria (NTM), also known as atypical mycobacteria, with the improvement of diagnosis level, doctors' ability, and the increase of immunosuppressed population, the diagnosis rate of NTM is also gradually increasing.

    This article summarizes the latest literature and guidelines, and outlines the current manifestations, diagnosis, and pre-treatment management of lung disease in NTM disease.

    There are more than 190 species of non-tuberculous/atypical mycobacteria, which are widespread in the environment, especially in water and soil.
    Among the more than 190 species, only a few can infect humans and cause disease.

    The most common clinical manifestations after illness include lung disease, lymphatic disease (usually seen in young children and HIV carriers), skin and soft tissue infections (such as trauma, fish contact, or surgery), and disseminated diseases.

    ➤Any inherited or acquired lung diseases: such as cystic fibrosis (CF), ciliary dyskinesia syndrome, non-cystic fibrosis bronchiectasis, α-1 antitrypsin deficiency, chronic obstructive pulmonary disease ( COPD), lung cancer and tuberculosis, etc.
    , all increase the risk of NTM infection.

    ➤Patients with primary immunodeficiency syndromes (PIDs): If genetic mutations in IL-12 and IFN-γ related immune pathways cause genetic defects, the risk of NTM disease is higher.

    ➤Acquired immunodeficiency: such as AIDS, hematological malignancies or other acquired immunodeficiency states (such as hematopoietic stem cell/organ transplantation, the use of immunosuppressive drugs) can also easily lead to NTM infection, and more likely to appear in the lungs, extrapulmonary or disseminated NTM disease.

    At present, the diagnosis rate of NTM disease is gradually increasing due to the improvement of the diagnosis level, the ability of doctors, and the increase of immunosuppressed population.

    International guidelines divide NTM lung diseases into two types: nodular/bronchiectasis (mainly seen in tall, thin, and menopausal women) and fibrous hollow type (mainly seen in middle-aged men with COPD); Chinese guidelines divide them into Four types: fibrous cavity or tuberculosis-like type, bronchiectasis type, nodular type and other types (including pulmonary fibrosis, emphysema, atelectasis, etc.
    ).

    NTM lung disease can be caused by a variety of pathogens, including slow-growing Mycobacterium avium, Mycobacterium kansas, Mycobacterium geneva, Mycobacterium malmo, Mycobacterium, and Mycobacterium fast-growing.
    Mycobacterium abscesses is more likely to cause disease.

    Clinical manifestations of NTM lung disease can occur at any age, and it is more common in women and the elderly, especially in menopausal women.

     Its clinical manifestations are similar to those of tuberculosis, but the symptoms of systemic poisoning are milder than those of tuberculosis.

    Even if infected with NTM, some patients may have no obvious symptoms for a long time, and some patients only have cough and sputum; some patients have rapid disease progression and may also experience symptoms such as hemoptysis, chest pain, chest tightness, and asthma.

    If spread to the whole body, symptoms such as fever, weight loss, abdominal pain, and diarrhea may occur.

     Diagnosis of NTM disease is usually based on the comprehensive judgment of clinical manifestations, imaging manifestations, etiology and pathological examination results.

    The diagnostic criteria of the international guidelines (see the table below): China's guidelines are: with respiratory symptoms and/or systemic symptoms, cavitation shadows, multifocal bronchiectasis, and multiple small nodules are found by chest imaging examination Etc.
    , other lung diseases have been ruled out.
    On the premise of ensuring that the specimens are free of exogenous contamination, a person who meets one of the following conditions can be diagnosed as NTM lung disease: ✔ 2 separate sputum specimens are positive for NTM culture and identified as the same cause Bacteria, and/or NTM molecular biology test are the same pathogen; ✔Bronchoalveolar lavage fluid or bronchoalveolar lavage fluid NTM culture and/or molecular biology test is positive for 1 time; ✔Lung live by bronchoscopy or other means Tissue examination found characteristic changes in the histopathology of mycobacterial disease (granulomatous inflammation or positive acid-fast staining), and positive NTM culture and/or molecular biology test; ✔Bronchoscopic or other lung biopsy found Histopathological characteristics of mycobacterial disease (granulomatous inflammation or positive acid-fast staining), and 1 or more sputum specimens, bronchial lavage fluid or bronchoalveolar lavage fluid in NTM culture and/or molecular biology Test positive.

     Drug susceptibility test Before treatment, a baseline drug susceptibility test should be performed on specific drugs to test the sensitivity of Mycobacterium avium complex and Mycobacterium abscesses to macrolides and amikacin; test the Kansas points The sensitivity of mycobacteria to rifampicin.

     Is treatment immediately after diagnosis? Even if the above criteria are met, it does not mean the use of antibiotics.
    The 2020 ATS guidelines recommend that the clinical condition, imaging findings, pathogenicity, treatment risks and benefits, and treatment goals should be discussed with the patient before starting treatment.

    Patients undergoing "long-term observation" (regular clinical examination, sputum culture/bronchoscopy and imaging observation of disease progression) may be better than antibiotic therapy, and a multidisciplinary team needs to make such a decision and follow up for a long time.

    However, for patients with positive sputum smears of acid-fast bacilli (with a large pathogen load), Mycobacterium toad or Mycobacterium Kansas, cavitary lung disease and diseases that seriously affect the quality of life, antibiotic treatment is recommended immediately.

    References: 1.
    Haworth CS, Banks J, Capstick T, et al.
    British Thoracic Society guidelines for the management of nontuberculous mycobacterial pulmonary disease (NTM-PD).
    Thorax 2017; 72:ii1–ii64.
    2.
    Daley CL, Iaccarino JM , Lange C, et al.
    Treatment of nontuberculous mycobacterial pulmonary disease: an official ATS/ERS/ESCMID/IDSA clinical practice guideline.
    Eur Respir J 2020; 56:2000535.
    3.
    Gill LI, Dominic C, Tiberi S.
    Atypical mycobacterial infections-management and when to treat.
    Curr Opin Pulm Med.
    2021 May 1;27(3):216-223.
    4.
    Chinese Medical Association Tuberculosis Branch.
    Guidelines for the diagnosis and treatment of non-tuberculous mycobacterial diseases (2020 edition)[J].
    Chinese Journal of Tuberculosis and Respiratory Medicine, 2020, 43(11):918-946.
    This article is an English version of an article which is originally in the Chinese language on echemi.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to service@echemi.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

    Contact Us

    The source of this page with content of products and services is from Internet, which doesn't represent ECHEMI's opinion. If you have any queries, please write to service@echemi.com. It will be replied within 5 days.

    Moreover, if you find any instances of plagiarism from the page, please send email to service@echemi.com with relevant evidence.