A Case of Tuberculosis Misdiagnosed as Sarcoidosis and then Confirmed by NGS Testing.

BACKGROUND: Pulmonary tuberculosis (PTB) is an important infectious disease that threatens the health and life of human beings. In the diagnosis of PTB, imaging plays a dominant role, but due to the increasing drug resistance of Mycobacterium tuberculosis, atypical clinical manifestations, "different images with the same disease" or "different diseases with the same image" in chest imaging, and the low positivity rate of routine sputum bacteriology, which leads to a high rate of misdiagnosis of PTB. We report a case of pulmonary tuberculosis that was misdiagnosed on imaging. We report a case of pulmonary tuberculosis that resembled sarcoidosis on imaging and was negative for antacid staining on sputum smear and alveolar lavage fluid, and was later diagnosed by microbial next-generation sequencing (NGS). The case was initially misdiagnosed as sarcoidosis. METHODS: Alveolar lavage fluid NGS, chest CT, bronchoscopy. RESULTS: Chest CT showed multiple inflammatory lesions in both lungs, multiple nodular foci in both lungs, and multiple enlarged lymph nodes in the mediastinum and hilar region on both sides. Fiberoptic bronchoscopy was performed in the basal segment of the left lower lobe of the lungs to carry out bronchoalveolar lavage, and the lavage fluid was sent to the NGS test and returned the following results: Mycobacterium tuberculosis complex group detected in the number of sequences of 293. Based on the results of the NGS test, the diagnosis of pulmonary tuberculosis could be confirmed. CONCLUSIONS: The diagnosis of pulmonary tuberculosis cannot be easily excluded in patients with "different images with the same disease" or "different diseases with the same image" on chest imaging without the support of sputum positivity. The goal was to improve the alertness of medical personnel to the misdiagnosis of tuberculosis and the application of NGS technology.

CEA Negative Initial Diagnosis of HP Infection Finally Confirmed by Bronchoscopic Biopsy as Lung Adenocarcinoma.

BACKGROUND: Carcinoembryonic antigen (CEA) is a polysaccharide complex that is found in the human respiratory system. It is of significant use in disease surveillance of lung cancer; however, serum CEA can occasionally only offer little assistance. We present a case of recurring infection initially diagnosed as carcinoembryonic antigen-negative in a patient with a history of hypersensitivity pneumonitis infection, which finally led to the diagnosis of lung adenocarcinoma following percutaneous lung puncture. METHODS: Appropriate laboratory tests, chest CT, bronchoscopy, percutaneous lung puncture, and pathologic examination were performed to explore the cause of the disease. RESULTS: Because CEA was negative and a chest CT showed interstitial changes in both lungs with numerous hyperdense shadows, coupled with the patient's history of hypersensitivity pneumonitis, we initially believed that the infection was relapsing. However, a percutaneous lung puncture eventually revealed that the patient had lung adenocarcinoma. CONCLUSIONS: Vigilance needs to be increased in clinical work for patients with interstitial lung disease, low tumor markers such as CEA, and imaging suggestive of inflammatory progression, which in fact turns into lung cancer. When the treatment is ineffective after standardized application of hormone and anti-infection, lung tissue should be obtained for pathological examination in time to obtain pathological evidence.

Accidental Detection of Tuberculous Empyema at Health Check-Up.

BACKGROUND: Patients with tuberculous empyema (TE) can have a serious impact on lung function as their disease progresses, and, if left untreated, can cause damage to other parts of the body such as the thorax and spine, causing pain and inconvenience to the patient. Early diagnosis and the search for appropriate treatment are key to improving the survival rate of the disease. METHODS: We report a case of a young patient with an unexpected finding of right pleural effusion on physical examination, who was eventually diagnosed with TE using next-generation sequencing of pleural tissue. We analyzed the literature to improve clinicians' understanding of TE and how to properly diagnose and treat the disease. RESULTS: Laboratory results of the pleural effusion suggested a possible Mycobacterium tuberculosis infection, but pathogen-related tests were negative, and the diagnosis was eventually successfully confirmed by thoracoscopic pleural biopsy. CONCLUSIONS: The diagnosis of TE should be considered in young patients with pleural thickening of the empyema. Adenosine deaminase may provide diagnostic direction in patients with unexplained thorax abscess. Pleural biopsy, although an invasive procedure, is an essential diagnostic tool in some cases.

Acute Eosinophilic Pneumonia Masquerading as a Lung Abscess.

BACKGROUND: Acute Eosinophilic Pneumonia (AEP) is a rare form of non-infectious pneumonia that is easily missed and misdiagnosed because of its atypical clinical symptoms and misleading laboratory and imaging studies. METHODS: By reporting a case of an initial diagnosis of lung abscess, which was treated with antibiotics and then CT suggesting that the lesion continued to worsen, it was eventually confirmed to be AEP by lung biopsy, A joint literature analysis was conducted to improve clinicians' understanding of the diagnosis and treatment of AEP. RESULTS: Initially, because of the atypical ancillary findings, we thought the disease was a lung abscess, which was eventually confirmed by pathology as AEP. CONCLUSIONS: The presence of AEP needs to be considered when various laboratory findings point to infectious dis-ease, but anti-infection is not effective. Diagnosis can be confirmed by bronchoalveolar lavage and lung tissue biopsy. Prompt treatment can provide rapid relief and reduce the risk of patient death.

Molecular dynamics study of DNA binding by INT-DBD under a polarized force field.

The DNA binding domain of transposon Tn916 integrase (INT-DBD) binds to DNA target site by positioning the face of a three-stranded antiparallel ß-sheet within the major groove. As the negatively charged DNA directly interacts with the positively charged residues (such as Arg and Lys) of INT-DBD, the electrostatic interaction is expected to play an important role in the dynamical stability of the protein-DNA binding complex. In the current work, the combined use of quantum-based polarized protein-specific charge (PPC) for protein and polarized nucleic acid-specific charge (PNC) for DNA were employed in molecular dynamics simulation to study the interaction dynamics between INT-DBD and DNA. Our study shows that the protein-DNA structure is stabilized by polarization and the calculated protein-DNA binding free energy is in good agreement with the experimental data. Furthermore, our study revealed a positive correlation between the measured binding energy difference in alanine mutation and the occupancy of the corresponding residue's hydrogen bond. This correlation relation directly relates the contribution of a specific residue to protein-DNA binding energy to the strength of the hydrogen bond formed between the specific residue and DNA.