Wei Sha

Evaluation of Cerebrospinal Fluid Adenosine Deaminase Activity for the Differential Diagnosis of Tuberculous and Nontuberculous Meningitis

Introduction: The diagnosis value of adenosine deaminase (ADA) activity in cerebrospinal fluid (CSF) of tuberculous meningitis (TBM) has been well documented. However, the cutoff point of CSF ADA has not been fully assessed. In the current study, the authors set to calculate the cutoff points of ADA and monitor the changes of CSF ADA activities in patients with TBM after antitubercular therapy. Methods: CSF ADA activity in patients with different types of meningitis was measured by Trinder enzyme-coupled assay. Results: The mean CSF ADA values in the patients with TBM, bacterial meningitis, viral meningitis, cryptococcal meningitis and noninfectious neurologic disorders were 14.1 ± 5.4, 9.6 ± 5.5, 4.3 ± 2.5, 7.8 ± 3.4 and 2.6 ± 1.3 U/L, respectively. CSF ADA activity was significantly higher in TBM compared with patients with non-TBM (P < 0.05). Moreover, the best cutoff point for differentiating between TBM and non-TBM was 9.5 U/L. In addition, CSF ADA activity was decreased in patients with TBM after antitubercular therapy in a time-dependent manner. Conclusions: The determination of ADA with a cutoff value of 9.5 U/L in CSF is a useful aid for the differential diagnosis of TBM and non-TBM. Moreover, dynamic monitoring of CSF ADA activity may be an indicator for evaluating antitubercular therapy in TBM.

Prevalence, risk factors, management, and treatment outcomes of first-line antituberculous drug-induced liver injury: a prospective cohort study

Antituberculosis drug‐induced liver injury (ATDILI) is one of the most deleterious side effects associated with chemotherapy against tuberculosis (TB). In this study, our objective was to determine the incidence, risk factors, and management of ATDILI and analyze its impact on the treatment outcome in patients receiving standard anti‐TB chemotherapy.

Lysine acetylation of DosR regulates the hypoxia response of Mycobacterium tuberculosis

Tuberculosis caused by Mycobacterium tuberculosis (Mtb) infection remains a large global public health problem. One striking characteristic of Mtb is its ability to adapt to hypoxia and trigger the ensuing transition to a dormant state for persistent infection, but how the hypoxia response of Mtb is regulated remains largely unknown. Here we performed a quantitative acetylome analysis to compare the acetylation profile of Mtb under aeration and hypoxia, and showed that 377 acetylation sites in 269 Mtb proteins were significantly changed under hypoxia. In particular, deacetylation of dormancy survival regulator (DosR) at K182 promoted the hypoxia response in Mtb and enhanced the transcription of DosR-targeted genes. Mechanistically, recombinant DosRK182R protein demonstrated enhanced DNA-binding activity in comparison with DosRK182Q protein. Moreover, Rv0998 was identified as an acetyltransferase that mediates the acetylation of DosR at K182. Deletion of Rv0998 also promoted the adaptation of Mtb to hypoxia and the transcription of DosR-targeted genes. Mice infected with an Mtb strain containing acetylation-defective DosRK182R had much lower bacterial counts and less severe histopathological impairments compared with those infected with the wild-type strain. Our findings suggest that hypoxia induces the deacetylation of DosR, which in turn increases its DNA-binding ability to promote the transcription of target genes, allowing Mtb to shift to dormancy under hypoxia.

Adenylate kinase: a novel antigen for immunodiagnosis and subunit vaccine against tuberculosis

Mycobacterium tuberculosis (M.tb)-derived antigens capable of inducing strong cellular and/or humoral responses are potential targets for both immunodiagnosis and vaccine development against tuberculosis (TB). In the present study, we identified adenylate kinase (ADK, Rv0733) as an antigen that induces high cellular and antibody responses in active TB patients. We consequently tested the use of ADK-specific T cells and antibodies as biomarkers for TB diagnosis. The ADK-specific IFN-γ-producing cells detected by ELISPOT assay showed a sensitivity of 85.0xa0% and specificity of 94.15xa0% for TB diagnosis while ADK-specific IgG antibody showed a sensitivity of 40.35xa0% and specificity of 96.43xa0%. Combining ADK-specific cellular and antibody responses increased the sensitivity to 91.59xa0% and the specificity to 96.15xa0%. Immunogenicity and protection against M.tb infection were further tested in a murine model. Immunization with ADK protein elicited strong specific T- and B-cell responses, and provided protection against the virulent H37Rv stain of M.tb resulting in lower bacilli load in the spleens and lungs. More ADK-specific polyfunctional Th1 cells were observed in the lungs when compared to adjuvant-immunized mice. ADK thus may serve as a novel M.tb antigen for TB immunodiagnosis and development of subunit vaccines.Key messagesADK induces strong immune responses both in humans and mice.ADK-specific IFN-γ production and B-cell responses have high potential for TB diagnosis.ADK immunization provides protection against M.tb infection.

Drug-induced lymphocyte stimulation test in the prediction of drug-induced hypersensitivity to antituberculosis drugs

Antituberculosis (TB) chemotherapeutic drugs may cause a variety of adverse drug reactions (ADRs). To assess the potential of drug-induced lymphocyte stimulation test (DLST) in screening ADRs in patients treated with anti-TB drugs, we performed DLST in 272 TB patients (176 cases with ADRs and 96 controls without ADRs) treated with anti-TB drugs isoniazid (INH), rifampicin (RFP), ethambutol (EMB), and pyrazinamide (PZA). The ADRs were diagnosed by drug provocation test based on clinical and laboratory examinations. The sensitivities of DLST in the diagnosis of INH-, RFP-, EMB-, or PZA-induced ADRs were 57.8%, 37.1%, 42.4%, and 23.1%, respectively, with the corresponding specificities being 93.4%, 94.0%, 97.5%, and 98.8%. DLST has high specificity and limited sensitivity in the diagnosis of anti-TB drug-induced ADRs. In combination with clinical observation and drug use history, DLST could have a predictive validity of ADRs, especially when a positive result is obtained.

Bronchoscopic balloon dilatation for tuberculosis-associated tracheal stenosis: a two case report and a literature review.

BackgroundBronchoscopic balloon dilatation (BBD) is a common strategy in the treatment of bronchostenosis. However, the longer dilating time in each inflation cycle (approximately 3–5xa0min) without mechanical ventilation is not possible for the treatment of tracheal stenosis.Case presentationIn this study, we reported our experience of BBD with shorter dilating time (10xa0s or 1xa0min) and intermittent ventilation for the repair of tuberculous-associated tracheal stenosis in two cases of our hospital. After the surgeries, the physical examinations and pulmonary function were tested. In case 1, the cough and dyspnea syndromes subsided, wheeze and strid or in lungs were remarkably reduced, tracheal lumen was considerably expanded and pulmonary function was improved following the treatment. For the case 2, her chest tightness, shortness of breath symptoms were alleviated after the treatment. The middle and lower trachea stenosis was dilated and patent, but the right main bronchus stenosis was slightly improved. No restenosis occurred in the two patients in 1xa0year outpatient follow-up.ConclusionsThese findings suggest that our modification in BBD is safe and effective for treating this patient with tracheal stenosis caused by tuberculosis, but the longer-term effect of the surgery in a large number of patients with longer follow-up remains to be seen.

Clinical features and treatment of drug fever caused by anti-tuberculosis drugs

Tuberculosis is a major global health problem. However, anti‐tuberculosis drug treatment has many adverse effects, such as drug‐caused fever. The aim of this study was to investigate the clinical features and treatments of anti‐tuberculosis drugs‐induced fever.

Genetic Polymorphisms of SLCO1B1, CYP2E1 and UGT1A1 and Susceptibility to Anti-Tuberculosis Drug-Induced Hepatotoxicity: A Chinese Population-Based Prospective Case–Control Study

BackgroundDrug transporters and drug-metabolizing enzymes have been linked to drug-induced hepatotoxicity. Solute carrier organic anion transporter family member 1B1 (SLCO1B1), cytochrome P450 2E1 (CYP2E1), and UDP glucuronosyltransferase 1A1 (UGT1A1) were selected as candidate genes to explore their association with susceptibility to anti-tuberculosis drug-induced hepatotoxicity (ATDH).MethodsThirty-four tag single nucleotide polymorphisms (tagSNPs) in SLCO1B1, CYP2E1, and UGT1A1 with 10-kb expansion up- and down-stream were genotyped in 461 patients with ATDH and 466 patients without ATDH in a prospective 1:1 matched case–control study. The frequencies and distributions of genotypes and haplotypes were compared between the groups using three genetic models (dominant, recessive, and additive) to identify associations with susceptibility to ATDH.ResultsPatients with the rs4149034 G/A, rs1564370 G/C, and rs2900478 T/A genotypes of SLCO1B1 had a significantly lower risk of ATDH, while those carrying the rs2417957 T/T and rs4149063 T/T genotypes had an increased risk. The rs4148323 A/A genotype of UGT1A1 was found to significantly reduce the risk of ATDH. Haplotype analysis showed the TGTG, TTTC, and GTTC haplotypes of SLCO1B1 were associated with an increased ATDH risk, whereas the GACC haplotype was related to a reduced risk. The ATG haplotype of UGT1A1 reduced the risk of ATDH. Moreover, treatment outcomes in tuberculosis patients were further affected by genetic variants of SLCO1B1.ConclusionsGenetic polymorphisms of SLCO1B1 and UGT1A1 were found to be associated with susceptibility to ATDH. Molecular identification of susceptibility genes provides a theoretical foundation for predicting the likelihood of ATDH and predicting treatment outcomes in tuberculosis patients.

Genome-wide association study identifies two risk loci for tuberculosis in Han Chinese

Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (Mtb), and remains a leading public health problem. Previous studies have identified host genetic factors that contribute to Mtb infection outcomes. However, much of the heritability in TB remains unaccounted for and additional susceptibility loci most likely exist. We perform a multistage genome-wide association study on 2949 pulmonary TB patients and 5090 healthy controls (833 cases and 1220 controls were genome-wide genotyped) from Han Chinese population. We discover two risk loci: 14q24.3 (rs12437118, Pcombinedu2009=u20091.72u2009×u200910−11, ORu2009=u20091.277, ESRRB) and 20p13 (rs6114027, Pcombinedu2009=u20092.37u2009×u200910−11, ORu2009=u20091.339, TGM6). Moreover, we determine that the rs6114027 risk allele is related to decreased TGM6 transcripts in PBMCs from pulmonary TB patients and severer pulmonary TB disease. Furthermore, we find that tgm6-deficient mice are more susceptible to Mtb infection. Our results provide new insights into the genetic etiology of TB.Genetic risk loci for tuberculosis (TB) have so far been identified in African and Russian populations. Here, the authors perform a three-stage GWAS for TB in Han Chinese populations and find two risk loci near ESRRB and TGM6 and further demonstrate that tgm6 protects mice from Mtb infection.

MicroRNA-27a controls the intracellular survival of Mycobacterium tuberculosis by regulating calcium-associated autophagy

Tuberculosis (TB) caused by Mycobacterium tuberculosis (Mtb) kills millions every year, and there is urgent need to develop novel anti-TB agents due to the fast-growing of drug-resistant TB. Although autophagy regulates the intracellular survival of Mtb, the role of calcium (Ca2+) signaling in modulating autophagy during Mtb infection remains largely unknown. Here, we show that microRNA miR-27a is abundantly expressed in active TB patients, Mtb-infected mice and macrophages. The target of miR-27a is the ER-located Ca2+ transporter CACNA2D3. Targeting of this transporter leads to the downregulation of Ca2+ signaling, thus inhibiting autophagosome formation and promoting the intracellular survival of Mtb. Mice lacking of miR-27a and mice treated with an antagomir to miR-27a are more resistant to Mtb infection. Our findings reveal a strategy for Mtb to increase intracellular survival by manipulating the Ca2+-associated autophagy, and may also support the development of host-directed anti-TB therapeutic approaches.How Mycobacterium tuberculosis (Mtb) escapes autophagy-mediated clearance is poorly understood. Here, Liu et al. show that Mtb-induced MicroRNA-27a targets the ER-associated calcium transporter CACNA2D3, leading to suppression of antimicrobial autophagy and to enhanced intracellular survival of Mtb.