-
Categories
-
Pharmaceutical Intermediates
-
Active Pharmaceutical Ingredients
-
Food Additives
- Industrial Coatings
- Agrochemicals
- Dyes and Pigments
- Surfactant
- Flavors and Fragrances
- Chemical Reagents
- Catalyst and Auxiliary
- Natural Products
- Inorganic Chemistry
-
Organic Chemistry
-
Biochemical Engineering
- Analytical Chemistry
- Cosmetic Ingredient
-
Pharmaceutical Intermediates
Promotion
ECHEMI Mall
Wholesale
Weekly Price
Exhibition
News
-
Trade Service
This article uses a case to introduce you to the imaging manifestations, laboratory screening and treatment of non-tuberculous mycobacteria.
The patient was 74 years old.
Chronic dry cough lasts for several months.
The chest CT is shown in the following figure: Figure 1 CT CT of the patient's chest found consolidation around the bronchus, with tree bud sign, varicose-like and cystic bronchiectasis, the right lower lobe and upper right middle lobe are the most obvious.
Based on the above CT findings, what is the most likely diagnosis? A.
Non-tuberculous mycobacteria infection B.
Fungal infection C.
Viral pneumonia D.
Chronic bronchitis/bronchiolitis E.
Bacterial pneumonia F.
Pneumoconiosis Correct answer: A Non-tuberculous mycobacteria (NTM) was also called Atypical Mycobacterium (MOTT) refers to mycobacteria other than Mycobacterium tuberculosis complex bacteria and Mycobacterium leprosy.
The diseases caused include chronic lung disease, lymphadenitis, skin and soft tissue infections, and systemic disseminated NTM disease.
Compared with Mycobacterium tuberculosis, NTM has lower virulence and pathogenicity, and is usually an opportunistic pathogen.
Mycobacterium tuberculosis is mostly secondary to chronic lung diseases such as bronchiectasis, silicosis (silicosis) and tuberculosis.
It is a common complication of human immunodeficiency virus (AIDS) and can also be a nosocomial infection caused by inadequate disinfection.
The imaging findings of NTM, like tuberculosis bacilli, can invade many organs and tissues throughout the body, and the lungs are the most common.
Pulmonary lesions caused by NTM are very similar to tuberculosis.
Most of the symptoms are mild and lack characteristic.
Generally, there are cough, sputum, low fever and fatigue, or only hemoptysis.
98.
9%~100.
0% of NTM cases have imaging changes, of which consolidation, voids, and fibrous cord shadows are the most common. The imaging findings can be divided into the following categories: 1.
Typical infections (extremely similar to those of tuberculosis) are the most common, mostly males, especially in the elderly between 50 and 70 years old.
Many patients have chronic obstructive pulmonary disease (COPD).
), pulmonary fibrosis, tuberculosis, lung cancer and other basic lung diseases.
Clinical symptoms such as weight loss, fever, fatigue, cough and hemoptysis may appear, of which cough is the most common (60% to 100%).
Imaging findings and secondary tuberculosis are often difficult to distinguish, but NTM lung disease progresses more slowly than active tuberculosis.
The most common manifestations are linear shadows and nodules with or without calcification in the apical and posterior segments of the upper lobe.
Lesions of the lower lobe are rare.
The range of lesions can range from small abnormalities involving only one segment to multi-segmental lesions in both lungs.
About 80%-95% of patients have holes in the image, mostly in the upper lobe.
2.
Atypical infections (imaging is very different from traditional tuberculosis) Among NTM patients without immunosuppression, 20% to 30% may have atypical infections.
Most of the patients had no lung disease before, mainly middle-aged and elderly women, with chronic cough, and some patients had hemoptysis or fever.
Chest radiographs often show multiple, patchy, unclear-edged alveoli or dense interstitial shadows.
In many cases, there are tubular and ring-like shadows that resemble bronchiectasis.
On CT, there are scattered mild to moderate columnar expansions and multiple occurrences.
The central nodules of the lobules are of different sizes, but are mostly less than 1cm in diameter.
The nodules tend to involve the airway and may show a "tree bud sign.
"
3.
Asymptomatic nodules.
Like other pulmonary granulomatous diseases, NTM lung disease can occasionally manifest as isolated or multiple nodules.
It is often found accidentally in asymptomatic patients, and the true cause of the disease is unclear.
4.
Infections in patients with achalasia.
Patients with a history of repeated inhalation, such as achalasia or obstruction of the gastric outlet, are susceptible to NTM pulmonary disease, which is often caused by mycobacterium fortuitum infection in fast-growing bacteria.
The image resembles aspiration pneumonia, and is typically manifested as non-specific, patchy air cavity consolidation on both sides.
5.
Infection in immunosuppressed patients In patients with significant immunosuppression, the risk of NTM blood spread is increased.
(1) AIDS patients: The patient's lung symptoms are not many, and the chest radiograph is usually normal.
Mediastinal hilar lymph node enlargement is the most common manifestation.
Lymph nodes swollen on CT can be solid or have central necrosis.
(2) Other immunosuppressed patients: The imaging findings vary, including extensive mediastinal or hilar lymphadenopathy, focal lung infiltration, nodules, and cavities , Miliary nodules and diffuse interstitial infiltration.
Laboratory screening Because most NTMs have similar clinical symptoms and imaging findings to tuberculosis, a clear diagnosis generally requires culture screening and identification.
NTM screening is not only helpful in the diagnosis of NTM disease, but also has important significance in avoiding the interference of NTM in the diagnosis of tuberculosis.
The NTM laboratory screening process can be seen in Figure 2.
Figure 2 Recommended procedures for laboratory screening of non-tuberculous mycobacteria (NTM) Note: AFB, acid-fast bacilli; MTC, Mycobacterium tuberculosis complexes treat most NTMs resistant to anti-tuberculosis drugs, and anti-tuberculosis drugs are not effective in treatment .
The high hydrophobicity on the surface of NTM cells and the cell wall permeability barrier are the physiological basis for their broad-spectrum drug resistance and are an obstacle to effective chemotherapy.
In order to overcome the barrier of drug entry into cells, it is advisable to use drugs that destroy cell walls, such as ethambutol, in combination with other drugs with different mechanisms of action, such as streptomycin and rifampin.
Some new antibiotics are effective against NTM.
Such as rifabutin, rifapentin, benzoxazine and rifamycin 1648 of rifamycins, ciprofloxacin, ofloxacin, levofloxacin, levofloxacin, sparfloxacin, moxifloxacin of fluoroquinolones, New macrolides such as clarithromycin, roxithromycin, azithromycin, cephalosporins, cefoxitin, cefmetazole, carbapenems, imipenem/cilastatin, etc.
Recently, it has been discovered that older generation antibiotics such as sulfamethoxazole, doxycycline, minocycline, tobramycin and amikacin also have antibacterial activity against NTM.
Since NTM resistance varies with different subgroups, it is still very important to conduct drug sensitivity tests before treatment.
At present, there is no unified standard for NTM rationalization treatment plan and treatment course.
It is advocated that 4~5 kinds of drugs are combined for treatment.
After the acid-fast bacilli become negative, continue the treatment for 18~24 months, at least 12 months.
Avoid single medication during treatment and pay attention to adverse drug reactions.
References[1] He Wei, Pan Jishu, Zhou Xinhua, etc.
Imaging manifestations of nontuberculous mycobacterial lung disease[J].
Chinese Journal of Tuberculosis and Respiratory,2004,27(8):553-556.
DOI:10.
3760 /j:issn:1001-0939.
2004.
08.
024.
[2] Chinese Medical Association Tuberculosis Branch, Non-tuberculous Mycobacterial Disease Laboratory Diagnosis Expert Consensus Writing Group.
Non-tuberculous Mycobacterial Disease Laboratory Diagnosis Expert Consensus[J].
Chinese Journal of Tuberculosis and Respiratory Medicine, 2016,39(6):438-443.
DOI:10.
3760/cma.
j.
issn.
1001-0939.
2016.
06.
007.
[3] Luo Daobao, Liu Yan, Yang Fangling, etc.
Nontuberculous Mycobacteria Analysis of 4 cases of lung disease[J].
Chinese Journal of Misdiagnosis,2007,7(23):5690-5690.
DOI:10.
3969/j.
issn.
1009-6647.
2007.
23.
226.
[4] 74-year-old woman with chronic cough -auntminnie-May 18, 2020.
[5] Cai Baiqiang, Li Longyun.
Concord Respiratory Medicine (Second Edition)[M].
China Peking Union Medical College Press, 2016.
The patient was 74 years old.
Chronic dry cough lasts for several months.
The chest CT is shown in the following figure: Figure 1 CT CT of the patient's chest found consolidation around the bronchus, with tree bud sign, varicose-like and cystic bronchiectasis, the right lower lobe and upper right middle lobe are the most obvious.
Based on the above CT findings, what is the most likely diagnosis? A.
Non-tuberculous mycobacteria infection B.
Fungal infection C.
Viral pneumonia D.
Chronic bronchitis/bronchiolitis E.
Bacterial pneumonia F.
Pneumoconiosis Correct answer: A Non-tuberculous mycobacteria (NTM) was also called Atypical Mycobacterium (MOTT) refers to mycobacteria other than Mycobacterium tuberculosis complex bacteria and Mycobacterium leprosy.
The diseases caused include chronic lung disease, lymphadenitis, skin and soft tissue infections, and systemic disseminated NTM disease.
Compared with Mycobacterium tuberculosis, NTM has lower virulence and pathogenicity, and is usually an opportunistic pathogen.
Mycobacterium tuberculosis is mostly secondary to chronic lung diseases such as bronchiectasis, silicosis (silicosis) and tuberculosis.
It is a common complication of human immunodeficiency virus (AIDS) and can also be a nosocomial infection caused by inadequate disinfection.
The imaging findings of NTM, like tuberculosis bacilli, can invade many organs and tissues throughout the body, and the lungs are the most common.
Pulmonary lesions caused by NTM are very similar to tuberculosis.
Most of the symptoms are mild and lack characteristic.
Generally, there are cough, sputum, low fever and fatigue, or only hemoptysis.
98.
9%~100.
0% of NTM cases have imaging changes, of which consolidation, voids, and fibrous cord shadows are the most common. The imaging findings can be divided into the following categories: 1.
Typical infections (extremely similar to those of tuberculosis) are the most common, mostly males, especially in the elderly between 50 and 70 years old.
Many patients have chronic obstructive pulmonary disease (COPD).
), pulmonary fibrosis, tuberculosis, lung cancer and other basic lung diseases.
Clinical symptoms such as weight loss, fever, fatigue, cough and hemoptysis may appear, of which cough is the most common (60% to 100%).
Imaging findings and secondary tuberculosis are often difficult to distinguish, but NTM lung disease progresses more slowly than active tuberculosis.
The most common manifestations are linear shadows and nodules with or without calcification in the apical and posterior segments of the upper lobe.
Lesions of the lower lobe are rare.
The range of lesions can range from small abnormalities involving only one segment to multi-segmental lesions in both lungs.
About 80%-95% of patients have holes in the image, mostly in the upper lobe.
2.
Atypical infections (imaging is very different from traditional tuberculosis) Among NTM patients without immunosuppression, 20% to 30% may have atypical infections.
Most of the patients had no lung disease before, mainly middle-aged and elderly women, with chronic cough, and some patients had hemoptysis or fever.
Chest radiographs often show multiple, patchy, unclear-edged alveoli or dense interstitial shadows.
In many cases, there are tubular and ring-like shadows that resemble bronchiectasis.
On CT, there are scattered mild to moderate columnar expansions and multiple occurrences.
The central nodules of the lobules are of different sizes, but are mostly less than 1cm in diameter.
The nodules tend to involve the airway and may show a "tree bud sign.
"
3.
Asymptomatic nodules.
Like other pulmonary granulomatous diseases, NTM lung disease can occasionally manifest as isolated or multiple nodules.
It is often found accidentally in asymptomatic patients, and the true cause of the disease is unclear.
4.
Infections in patients with achalasia.
Patients with a history of repeated inhalation, such as achalasia or obstruction of the gastric outlet, are susceptible to NTM pulmonary disease, which is often caused by mycobacterium fortuitum infection in fast-growing bacteria.
The image resembles aspiration pneumonia, and is typically manifested as non-specific, patchy air cavity consolidation on both sides.
5.
Infection in immunosuppressed patients In patients with significant immunosuppression, the risk of NTM blood spread is increased.
(1) AIDS patients: The patient's lung symptoms are not many, and the chest radiograph is usually normal.
Mediastinal hilar lymph node enlargement is the most common manifestation.
Lymph nodes swollen on CT can be solid or have central necrosis.
(2) Other immunosuppressed patients: The imaging findings vary, including extensive mediastinal or hilar lymphadenopathy, focal lung infiltration, nodules, and cavities , Miliary nodules and diffuse interstitial infiltration.
Laboratory screening Because most NTMs have similar clinical symptoms and imaging findings to tuberculosis, a clear diagnosis generally requires culture screening and identification.
NTM screening is not only helpful in the diagnosis of NTM disease, but also has important significance in avoiding the interference of NTM in the diagnosis of tuberculosis.
The NTM laboratory screening process can be seen in Figure 2.
Figure 2 Recommended procedures for laboratory screening of non-tuberculous mycobacteria (NTM) Note: AFB, acid-fast bacilli; MTC, Mycobacterium tuberculosis complexes treat most NTMs resistant to anti-tuberculosis drugs, and anti-tuberculosis drugs are not effective in treatment .
The high hydrophobicity on the surface of NTM cells and the cell wall permeability barrier are the physiological basis for their broad-spectrum drug resistance and are an obstacle to effective chemotherapy.
In order to overcome the barrier of drug entry into cells, it is advisable to use drugs that destroy cell walls, such as ethambutol, in combination with other drugs with different mechanisms of action, such as streptomycin and rifampin.
Some new antibiotics are effective against NTM.
Such as rifabutin, rifapentin, benzoxazine and rifamycin 1648 of rifamycins, ciprofloxacin, ofloxacin, levofloxacin, levofloxacin, sparfloxacin, moxifloxacin of fluoroquinolones, New macrolides such as clarithromycin, roxithromycin, azithromycin, cephalosporins, cefoxitin, cefmetazole, carbapenems, imipenem/cilastatin, etc.
Recently, it has been discovered that older generation antibiotics such as sulfamethoxazole, doxycycline, minocycline, tobramycin and amikacin also have antibacterial activity against NTM.
Since NTM resistance varies with different subgroups, it is still very important to conduct drug sensitivity tests before treatment.
At present, there is no unified standard for NTM rationalization treatment plan and treatment course.
It is advocated that 4~5 kinds of drugs are combined for treatment.
After the acid-fast bacilli become negative, continue the treatment for 18~24 months, at least 12 months.
Avoid single medication during treatment and pay attention to adverse drug reactions.
References[1] He Wei, Pan Jishu, Zhou Xinhua, etc.
Imaging manifestations of nontuberculous mycobacterial lung disease[J].
Chinese Journal of Tuberculosis and Respiratory,2004,27(8):553-556.
DOI:10.
3760 /j:issn:1001-0939.
2004.
08.
024.
[2] Chinese Medical Association Tuberculosis Branch, Non-tuberculous Mycobacterial Disease Laboratory Diagnosis Expert Consensus Writing Group.
Non-tuberculous Mycobacterial Disease Laboratory Diagnosis Expert Consensus[J].
Chinese Journal of Tuberculosis and Respiratory Medicine, 2016,39(6):438-443.
DOI:10.
3760/cma.
j.
issn.
1001-0939.
2016.
06.
007.
[3] Luo Daobao, Liu Yan, Yang Fangling, etc.
Nontuberculous Mycobacteria Analysis of 4 cases of lung disease[J].
Chinese Journal of Misdiagnosis,2007,7(23):5690-5690.
DOI:10.
3969/j.
issn.
1009-6647.
2007.
23.
226.
[4] 74-year-old woman with chronic cough -auntminnie-May 18, 2020.
[5] Cai Baiqiang, Li Longyun.
Concord Respiratory Medicine (Second Edition)[M].
China Peking Union Medical College Press, 2016.
