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Objective:To understand the diagnostic value of tuberculosis (TB) pathogenic detection methods (TPDM) in pathological tissue for TB.Methods:A retrospective study was conducted with 190 pathological specimens from different tissues suspected with TB from Third People′s Hospital of Shenzhen during May 2016 and May 2019. Specimens were divided into four groups according to histomorphology: group one, necrotizing granulomatous inflammation (109 cases); group two, non-necrotic granulomatous inflammation (20 cases); group three, non-granulomatous inflammation (45 cases); group four, non-tuberculous lesions (16 cases). The positive rates of each TPDM among specimens from four groups were compared. The positive rates of all TPDM for specimens from group one were compared. Meanwhile, the influence of antituberculosis treatment course on the TPDM was analyzed. Chi-square test or Fisher′s exact test was used for statistical analysis.Results:The positive rates of Ziehl-Neelsen acid-fast staining among the four groups were 17.4%(19/109), 5.0%(1/20), 4.4%(2/45) and 0(0/16), respectively. The positive rates of Mycobacterium tuberculosis (MTB) complex culture were 32.0%(32/100), 4/19, 4.8%(2/42) and 0(0/16), respectively. The positive rates of Mycobacterium tuberculosis/rifampin resistance real-time quantitative nucleic acid amplification detection system (Xpert MTB/RIF) were 74.3%(81/109), 15.0%(3/20), 13.3%(6/45) and 0(0/16), respectively. The positive rates of fluorescent quantitative polymerase chain reaction (FQ-PCR) were 63.0%(58/92), 0(0/15), 2.6%(1/38) and 0(0/10), respectively. The positive rates of simultaneous amplification and testing (SAT) were 32.4%(24/74), 0(0/10), 0(0/15) and 0(0/10), respectively. The differences of each TPDM among four groups were all statistically significant (all P<0.05). The positive rate of Xpert MTB/RIF in group one specimens was significantly higher than those of acid-fast staining, MTB culture and SAT ( χ2=71.016, 37.162 and 35.679, respectively, all P<0.01), while the difference was not statistically significant when compared with FQ-PCR ( χ2=2.517, P=0.112). The positive rate of combined TPDM (85.3%(93/109)) was significantly higher than Xpert MTB/RIF(74.3%(81/109)) ( χ2=4.100, P=0.043). The positive rates of acid-fast staining group 1A (anti-tuberculosis treatment course was less than one month) and group 1B (anti-tuberculosis treatment course was longer than one month) were 14.3%(7/49) and 20.0% (12/60), respectively ( χ2=0.612, P=0.434); those of MTB culture were 48.9% (22/45) and 18.2% (10/55), respectively ( χ2=10.721, P=0.001); those of Xpert MTB/RIF were 69.4%(34/49) and 78.3%(47/60), respectively ( χ2=1.131, P=0.287); those of FQ-PCR were 55.0%(22/40) and 69.2%(36/52), respectively ( χ2=1.965, P=0.161); those of SAT were 43.3%(13/30) and 25.0%(11/44), respectively ( χ2=2.736, P=0.098). Conclusions:The results of TPDM correlate closely with the typical histomorphological features of tuberculosis. Xpert MTB/RIF possesses significantly higher sensitivity than any other single TPDM, and is not attenuated by early anti-tuberculosis treatment. Combined TPDM could significantly improve the sensitivity of TB pathogenic detection, which is suggested to be applied when the tissue specimen is sufficient.
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Understanding the mechanism that leads to immune dysfunction induced by SARS-CoV2 virus is crucial to develop treatment for severe COVID-19. Here, using single cell RNA-seq, we characterized the peripheral blood mononuclear cells (PBMC) from uninfected controls and COVID-19 patients, and cells in paired broncho-alveolar lavage fluid (BALF). We found a close association of decreased dendritic cells (DC) and increased monocytes resembling myeloid-derived suppressor cells (MDSC) which correlated with lymphopenia and inflammation in the blood of severe COVID-19 patients. Those MDSC-like monocytes were immune-paralyzed. In contrast, monocyte-macrophages in BALFs of COVID-19 patients produced massive amounts of cytokines and chemokines, but secreted little interferons. The frequencies of peripheral T cells and NK cells were significantly decreased in severe COVID-19 patients, especially for innate-like T and various CD8+ T cell subsets, compared to health controls. In contrast, the proportions of various activated CD4+ T cell subsets, including Th1, Th2 and Th17-like cells were increased and more clonally expanded in severe COVID-19 patients. Patients peripheral T cells showed no sign of exhaustion or augmented cell death, whereas T cells in BALFs produced higher levels of IFNG, TNF, CCL4 and CCL5 etc. Paired TCR tracking indicated abundant recruitment of peripheral T cells to the patients lung. Together, this study comprehensively depicts how the immune cell landscape is perturbed in severe COVID-19.
ABSTRACT
The ongoing SARS-CoV-2 outbreak has killed over twenty-one thousand and sickened over four hundred thousand people worldwide, posing a great challenge to global public health. A sensitive and accurate diagnosis method will substantially help to control disease expansion. Here, we developed a chemiluminescence-immunoassay method based on the recombinant nucleocapsid antigen and the magnetic beads for diagnosis of SARS-CoV-2 infections and surveillance of antibody changing pattern. Serums from 29 healthy individuals, 51 tuberculosis patients, and 79 SARS-CoV-2 confirmed patients were employed to evaluate the performance of this approach. Compared to the IgM testing, the IgG testing was more reliable in which it identified 65 SARS-CoV-2 infections from the 79 confirmed patients and only two false-positive cases from the 80 control group with a sensitivity and specificity reaching 82.28% and 97.5%, respectively. However, only a slight difference (not statistically significant) in the detected cases of SARS-CoV-2 infections was observed between the IgM and IgG testing manner in patients at a different time of onset of disease. A performance comparison between an ELISA kit using the same nucleocapsid antigen and our chemiluminescence method was undertaken. The same false-positive cases were seen in both methods from the paired control group, while ELISA kit can only detect half of the SARS-CoV-2 infections from paired SARS-CoV-2 confirmed patients group than that of the chemiluminescence method, indicating a higher performance for the chemiluminescence-immunoassay approach. Together, our studies provide a useful and valuable serological testing tool for the diagnosis of SARS-CoV-2 infections in the community.
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BackgroundThe outbreak of novel coronavirus pneumonia (NCP) caused by 2019-nCoV spread rapidly, and elucidating the diagnostic accuracy of different respiratory specimens is crucial for the control and treatment of this disease. MethodsRespiratory samples including nasal swabs, throat swabs, sputum and bronchoalveolar lavage fluid (BALF) were collected from Guangdong CDC confirmed NCP patients, and viral RNAs were detected using a CFDA approved detection kit. Results were analyzed in combination with sample collection date and clinical information. FindingsExcept for BALF, the sputum possessed the highest positive rate (74.4%[~]88.9%), followed by nasal swabs (53.6%[~]73.3%) for both severe and mild cases during the first 14 days after illness onset (d.a.o). For samples collected [≥] 15 d.a.o, sputum and nasal swabs still possessed a high positive rate ranging from 42.9%[~]61.1%. The positive rate of throat swabs collected [≥] 8 d.a.o was low, especially in samples from mild cases. Viral RNAs could be detected in all the lower respiratory tract of severe cases, but not the mild cases. CT scan of cases 02, 07 and 13 showed typical viral pneumonia with ground-glass opacity, while no viral RNAs were detected in first three or all the upper respiratory samples. InterpretationSputum is most accurate for laboratory diagnosis of NCP, followed by nasal swabs. Detection of viral RNAs in BLAF is necessary for diagnosis and monitoring of viruses in severe cases. CT scan could serve as an important make up for the diagnosis of NCP. FundingNational Science and Technology Major Project, Sanming Project of Medicine and China Postdoctoral Science Foundation.
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T-6 specific IFN-γ ELISPOT has higher specificity, sensitivity, the positive and negative predicative value. Therefore, the ELISPOT warrant for further improvement and clinical application.
