The exhaustion of lymphocytes is the main factor that decreases the sensitivity of QFT-GIT detection in silicosis.

BACKGROUND: Tuberculosis infection is a major complication of silicosis, but there is no study on whether silicosis can affect the sensitivity of QuantiFERON-TB Gold In-Tube (QFT-GIT) assays. This study will analyze the relationship between silicosis and QFT-GIT, determine the main factor of the QFT-GIT sensitivity decrease in silicosis and explore the methods to increase the sensitivity. METHODS: Silicosis patients with positive tubercle bacillus cultures were collected. The QFT-GIT, flow cytometry and blocking antibodies were used. RESULTS: The sensitivity of QFT-GIT in silicosis patients (58.46%) was significantly decreased and the expression of PD-1 on T cells and CD56+NK cells in pulmonary tuberculosis combined with silicosis were higher than normal tuberculosis patients and silicosis only patients. Further analysis found that the ratio of PD-1+CD4+T and IFN-γwere negatively correlated and blockaded the PD-1 pathway with antibodies can restore the sensitivity of QFT-GIT in silicosis. CONCLUSIONS: This is the first study to analyze the relationship between immune exhaustion and QFT-GIT in silicosis and found that the sensitivity of QFT-GIT was decreased by the expression of PD-1 on lymphocytes. Antibody blocking experiments increased the expression of IFN-γ and provided a new method to improve the sensitivity of QFT in silicosis. The study also found that silicosis can increase PD-1 expression. As PD-1 functions in infectious diseases, it will promote immune exhaustion in silicosis and lead to tuberculosis from latent to active infection. The study provided theoretical evidence for the diagnosis and immunotherapy of silicosis complications, and it has great value in clinical diagnostics and treatment.

Upregulation of PD-1 expression on circulating CD8+ but not CD4+ T cells is associated with tuberculosis infection in health care workers.

BACKGROUND: Health care workers (HCWs) are at risk for occupationally acquired Mycobacterium tuberculosis infection and tuberculosis (TB) disease due to repeated exposure to workplace tubercle bacilli. To determine whether continual mycobacterial stimulation correlates with increased expression of inhibitory T cell receptors, here we compared PD-1 receptor expression on surfaces of circulating T cells between naïve (uninfected) HCWs and HCWs with latent TB infection (LTBI). RESULT: Data collected from 133 medical workers who met study selection criteria were included in the final analysis. QuantiFERON-TB Gold In-​Tube (QFT-GIT) testing yielded positive results for 32 HCWs, for an overall LTBI rate of 24.1%. Multivariate analysis identified HCW length of service > 15 years as an independent risk factor for a positive QFT-GIT result. In addition, comparisons of blood T cell subgroup profiles between QFT- and QFT+ groups indicated QFT+ subjects possessed greater proportions of mature (TM), transitional memory (TTM) and effector memory (TEM) CD4+ T cell subgroups and lower proportions of naïve T cells (TN). Moreover, the QFT+ group percentage of CD8+ T cells with detectable surface PD-1 was significantly higher than the corresponding percentage for the QFT- group. Meanwhile, no statistical intergroup difference was observed in percentages of CD4+ T cells with detectible surface PD-1. CONCLUSIONS: Our data demonstrated that upregulated PD-1 expression on circulating CD8+, but not CD4+ T cells, was associated with latent TB infection of HCWs. As compared to other hospitals, occupational TB infection risk in our hospital was substantially mitigated by implementation of multitiered infection control measures.

Clinical metagenomic sequencing for diagnosis of pulmonary tuberculosis.

OBJECTIVES: The aim of this study is to investigate the clinical usefulness of metagenomic Next-generation sequencing (mNGS) on bronchoalveolar lavage fluid (BALF) samples to discriminate pulmonary tuberculosis (PTB) from Non-TB community-acquired pneumonia (CAP) in PTB suspects. METHODS: We investigate the performance of mNGS on BALF samples from 110 PTB suspects, in comparison with conventional microbiological testing (solid media culture, acid-fast bacilli staining (AFS), Xpert) of BALF or sputum samples and final clinical diagnosis. RESULTS: We finally clinically diagnosed 48 cases of pulmonary tuberculosis patients and 62 cases of non-tuberculosis patients. Comparing to the final clinical diagnosis, mNGS produced a sensitivity of 47.92%, which was similar to that of Xpert (45.83%) and culture (46.81%), but much higher than that of AFS (29.17%) for TB diagnosis in BALF samples. Apart from detecting Mycobacterium tuberculosis, mNGS also identified mixed infections in PTB patients, including 3 fungal cases and 1 bacteria case. Meanwhile, mNGS efficiently identified 14 of 22 (63.63%) cases of non-tuberculous mycobacteria (NTM), 7 cases of fungi, 1 case of viral infection, and other common bacterial pathogens in Non-PTB group. Finally, mNGS identified 67.23% infection cases within 3 days, while the conventional methods identified 49.58% infection cases for over 90 days. CONCLUSION: Our data show that mNGS of BALF represents a potentially effective tool for the rapid diagnosis of PTB suspects.

More significance of TB-IGRA except for the diagnose of tuberculosis.

OBJECTIVE: Tuberculosis (TB)-interferon gamma release assay (IGRA) test has the characteristics of short time, high specificity, and high sensitivity, but it lacks the correlation research between TB-IGRA test results and body's immune cells, disease progression and prognosis, which is explored in this study. DESIGN: A retrospective study was carried out on positive TB-IGRA patients who were infected with TB and diagnosed at our hospital from January 2014 to June 2015. The TB-IGRA, routine blood test, T-cell subgroup data were collected for statistical analysis. RESULTS: TB-IGRA results were in positive proportion to the lymphocytes, CD4+ T cells and CD4+ CD28+ T cells, whereas negative to the Treg cells. Patient with unilateral pulmonary lesion had higher TB-IGRA than those with bilateral pulmonary lesions. After the stimulation of TB-specific antigen, the proportion of CD4+ IFN-γ+ and CD8+ IFN-γ+ T Tcells were both increased and the CD4+ IFN-γ+ T had positive correlation with the value of TB-IGRA. CONCLUSIONS: IFN-γ was tested with TB-IGRA in patients with TB by the specific TB T cells and correlated with the lymphocytes, while the lymphocytes also closely related to the host's anti-TB immunity and disease outcome. Hence the result of TB-IGRA could reflect the specific anti-TB immunity ability of the host, disease progression and prognosis. This study further expands the application scope of TB-IGRA technology in the diagnosis of TB and lays a foundation for clinical practice to understand the immunity state of the patients with TB and the application of auxiliary clinical immunity regulators.

Risk factors of latent tuberculosis infection and immune function in health care workers in Suzhou, China.

BACKGROUND: The Chinese government has pay attention about tuberculosis infection among medical staff in infectious disease hospitals, but the effects have not yet been reported. This study will explore latent infection and immune function in the medical staff and systematically analyze the associated influencing factors. METHODS: Ninety-four medical staffs were enrolled and 20 medical staffs were defined as low risk group and others were high risk group. We used IFN-γ release assay and flow cytometry to analyze the latent TB infection status and immune function. Logistic regression analyses were performed to identify the independent risk factors of latent TB infection. RESULTS: This study explored and compared the infection status of medical workers and found that the rate of positive TB-IGRA results was higher among high risk group than in low risk group. Working environment, occupational history and work type were risk factors for TB infection in hospital. This study also found that high risk group had higher IFN-γ expression and a lower ratio of CD4+ to CD8+ T cells and further analysis found that this immune disorder is associated with wards and occupations. CONCLUSIONS: This study through rigorous sample collection and analysis found the risk factors of latent tuberculosis infection in health care workers. This finding may provide a theoretical basis to be used by the countries with a high TB burden to further improve their strategies for the prevention of TB infections in hospitals and may give an indication for improving the personal health of medical staff in infectious disease hospitals.

The Expression of B7-H3 in Circulating CD4+CD25high T Cells, Circulating CD14+ Monocytes and Plasma during Hepatitis B Virus Infection Progression.

BACKGROUND: B7-H3 is frequently upregulated in response to autoantigens and pathogens during host T cell immune responses. However, the role of B7-H3 which express in CD14+ monocytes and CD4+CD25high T cells had not been investigated. METHODS: Cytometry and ELISA were used in this study. RESULTS: The study showed that B7-H3 expression in CD14+ monocytes, CD4+CD25high T cells, and plasma was significantly increased in AHB, CHB, HBV-LC, and HBV-HCC group. In CHB group, the expression of B7-H3 was positively correlated with the ALT and AST levels. CONCLUSIONS: B7-H3 expression in peripheral CD14+ monocytes, CD4+CD25high T cells, and plasma changed with HBV infection progression and had a significant correlation with liver function in CHB. B7-H3 expression could be utilized as a potential clinical indicator to determine the extent of liver injury.

New attempt in tuberculosis treatment: autologous cytokine-induced killer after chemotherapy treatment failure in a case of multi-drug resistant tuberculosis (MTB).

A 32-year-old woman was diagnosed as pulmonary tuberculosis 15 years ago and recurred several times due to long-term nonstandard treatment. Drug sensitivity test indicated that multidrug-resistant tuberculosis had emerged and we determined relevant therapeutic schedule according to this result. However, it didn't show any amelioration of the disease after 3-month chemotherapy. We formulated 3-course CIK immunotherapy based on patient's condition. After 3 courses of immunotherapy, we found obvious amelioration of the patient's condition. And there was no recurrence during the follow-up in the past 3 years. Therefore, we considered that the CIK immunotherapy is an effective method for tuberculosis treatment and recurrence prevention. (Sarcoidosis Vasc Diffuse Lung Dis 2017; 34: 97-99).