Uncovering the Bronchoalveolar Single-Cell Landscape of Patients With Pulmonary Tuberculosis With Human Immunodeficiency Virus Type 1 Coinfection.

BACKGROUND: Coinfection of human immunodeficiency virus type 1 (HIV-1) is the most significant risk factor for tuberculosis (TB). The immune responses of the lung are essential to restrict the growth of Mycobacterium tuberculosis and avoid the emergence of the disease. Nevertheless, there is still limited knowledge about the local immune response in people with HIV-1-TB coinfection. METHODS: We employed single-cell RNA sequencing (scRNA-seq) on bronchoalveolar lavage fluid from 9 individuals with HIV-1-TB coinfection and 10 with pulmonary TB. RESULTS: A total of 19 058 cells were grouped into 4 major cell types: myeloid cells, T/natural killer (NK) cells, B cells, and epithelial cells. The myeloid cells and T/NK cells were further divided into 10 and 11 subsets, respectively. The proportions of dendritic cell subsets, CD4+ T cells, and NK cells were lower in the HIV-1-TB coinfection group compared to the TB group, while the frequency of CD8+ T cells was higher. Additionally, we identified numerous differentially expressed genes between the CD4+ and CD8+ T-cell subsets between the 2 groups. CONCLUSIONS: HIV-1 infection not only affects the abundance of immune cells in the lungs but also alters their functions in patients with pulmonary TB.

Pooling sputum samples for the Xpert MTB/RIF assay: a practical screening strategy for highly infectious tuberculosis cases.

The Xpert MTB/RIF test (Xpert) can help in the accurate screening of tuberculosis, however, its widespread use is limited by its high cost and lack of accessibility. Pooling of sputum samples for testing is a strategy to cut expenses and enhance population coverage but may result in a decrease in detection sensitivity due to the dilution of Mycobacterium tuberculosis (Mtb) by sample mixing. We investigated how the mixing ratio affected the detection performance of Xpert. We used frozen sputum samples that had been kept after individual Xpert assays of the sputa from Mtb-confirmed TB patients and non-TB patients. Our results showed that the overall sensitivity of the Xpert pooling assay remained higher than 80% when the mixing ratio was between 1/2 and 1/8. When the mixing ratio was raised to 1/16, the positive detection rate fell to 69.0%. For patients with either a high sputum Mtb smear score ≥ 2+, a time-to-positive culture ≤ 10 days, or an Xpert test indicating a high or medium abundance of bacteria, the pooling assay positivity rates were 93.3%, 96.8%, and 100% respectively, even at a 1/16 mixing ratio. For participants with cavities and cough, the pooling assay positivity rates were 86.2% and 90.0% at a 1/8 ratio, higher than for those without these signs. Our results show that the Xpert pooled assay has a high overall sensitivity, especially for highly infectious patients. This pooling strategy with lower reagent and labor costs could support TB screening in communities with limited resources, thereby facilitating reductions in the community transmission and incidence of TB worldwide.

Sensitivity, Specificity, and Safety of a Novel ESAT6-CFP10 Skin Test for Tuberculosis Infection in China: 2 Randomized, Self-Controlled, Parallel-Group Phase 2b Trials.

BACKGROUND: Diagnostics to identify tuberculosis infection are limited. We aimed to assess the diagnostic accuracy and safety of ESAT6-CFP10 (EC) skin test for tuberculosis infection in Chinese adults. METHODS: We conducted 2 randomized, parallel-group clinical trials in healthy participants and tuberculosis patients. All participants were tested with the T-SPOT.TB test, then received an EC skin test and tuberculin skin test (TST). The diameter of skin indurations and/or redness at injection sites were measured at different time periods. A bacillus Calmette Guerin (BCG) model was established to assess the diagnosis of tuberculosis infection using an EC skin test. RESULTS: In total, 777 healthy participants and 96 tuberculosis patients were allocated to receive EC skin test at 1.0 µg/0.1 mL or 0.5 µg/0.1 mL. The area under the curve was 0.95 (95% confidence interval [CI], .91-.97) for the EC skin test at 1.0 µg/0.1 mL at 24-72 hours. Compared with the T-SPOT.TB test, the EC skin test demonstrated similar sensitivity (87.5, 95% CI, 77.8-97.2 vs 86.5, 95% CI, 79.5-93.4) and specificity (98.9, 95% CI, 96.0-99.9 vs 96.1, 95% CI, 93.5-97.8). Among BCG vaccinated participants, the EC skin test had high consistency with the T-SPOT.TB test (96.3, 95% CI, 92.0-100.0). No serious adverse events related to the EC skin test were observed. CONCLUSIONS: The EC skin test demonstrated both high specificity and sensitivity at a dose of 1.0 µg/0.1 mL, comparable to the T-SPOT.TB test. The diagnostic accuracy of the EC skin test was not impacted by BCG vaccination. CLINICAL TRIALS REGISTRATION: NCT02389322 and NCT02336542.

Untargeted metabolomics analysis reveals Mycobacterium tuberculosis strain H37Rv specifically induces tryptophan metabolism in human macrophages.

BACKGROUND: Tuberculosis (TB) caused by Mycobacterium tuberculosis (M. tb) remains a global health issue. The characterized virulent M. tb H37Rv, avirulent M. tb H37Ra and BCG strains are widely used as reference strains to investigate the mechanism of TB pathogenicity. Here, we attempted to determine metabolomic signatures associated with the Mycobacterial virulence in human macrophages through comparison of metabolite profile in THP-1-derived macrophages following exposure to the M. tb H37Rv, M. tb H37Ra and BCG strains. RESULTS: Our findings revealed remarkably changed metabolites in infected macrophages compared to uninfected macrophages. H37Rv infection specifically induced 247 differentially changed metabolites compared to H37Ra or BCG infection. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed H37Rv specifically induces tryptophan metabolism. Moreover, quantitative PCR (qPCR) results showed that indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase 2 (TDO2) which converts the tryptophan to a series of biologically second metabolites were up-regulated in H37Rv-infected macrophages compared to H37Ra- or BCG-infected macrophages, confirming the result of enhanced tryptophan metabolism induced by H37Rv infection. These findings indicated that targeting tryptophan (Trp) metabolism may be a potential therapeutic strategy for pulmonary TB. CONCLUSIONS: We identified a number of differentially changed metabolites that specifically induced in H37Rv infected macrophages. These signatures may be associated with the Mycobacterial virulence in human macrophages. The present findings provide a better understanding of the host response associated with the virulence of the Mtb strain.

Safety of a Novel ESAT6-CFP10 skin test compared with tuberculin skin test in a double-blind, randomized, controlled study.

BACKGROUND: ESAT6-CFP10 (EC) skin test has been reported accurate and safe in identifying tuberculosis infection. We aimed to demonstrate the safety of EC skin test compared with tuberculin skin test (TST) in university freshmen. METHODS: We conducted a double-blind, randomized, controlled clinical study in a university freshmen population with 16,680 participates in China, and finally 14,579 completed the study. About a half received an EC skin test and the others received TST. Adverse reactions were evaluated. RESULTS: Out of the 14,579 participants, 48.2% (7029/14,579) were males. The average age was 18.1 ± 0.8 years and the average BMI was 20.9 ± 3.1 kg/m2. 50.4% (7351/14,579) participants received EC skin test and 49.6% (7228/14,579) received TST. The EC group had significantly less adverse reactions compared with the TST group (21.3%, 1565/7351 vs. 34.6%, 2499/7228, P = 0.000). The most common adverse reactions for EC were bleeding (5.63%, 414), dermatodyschroia (4.27%, 314), induration (3.90%, 287), swelling (2.49%, 183), pain (1.59%, 117) and pruritus (1.48%, 109). Bleeding, dermatodyschroia, swelling and erythema were significantly less in EC group (P < 0.05), while others were similar to those of TST. CONCLUSION: the EC skin test was safe in our cohort. And its incidence of total adverse drug reactions (ADRs) is less than that of TST. Most adverse reactions were mild or moderate, lasting less than 48 h and self-limiting. Considering the satisfactory diagnostic accuracy in identifying tuberculosis infection, the cost and safety, the EC skin test might be a potential candidate for replacing TST in high burden countries or those with routine BCG vaccination. CLINICAL TRIALS REGISTRATION: ChiCTR2000038622, Safety of the EC skin test to screen tuberculosis infection in two universities, compared with the tuberculin skin test: a double-blind, randomized, controlled trial. registered on 26/09/2020 at http://www.chictr.org.cn .

The past, present and future of tuberculosis treatment.

Tuberculosis (TB) is an ancient infectious disease. Before the availability of effective drug therapy, it had high morbidity and mortality. In the past 100 years, the discovery of revolutionary anti-TB drugs such as streptomycin, isoniazid, pyrazinamide, ethambutol and rifampicin, along with drug combination treatment, has greatly improved TB control globally. As anti-TB drugs were widely used, multidrug-resistant (MDR) and extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis emerged due to acquired genetic mutations, and this now presents a major problem for effective treatment. Genes associated with drug resistance have been identified, including katG mutations in isoniazid resistance, rpoB mutations in rifampin resistance, pncA mutations in pyrazinamide resistance, and gyrA mutations in quinolone resistance. The major mechanisms of drug resistance include loss of enzyme activity in prodrug activation, drug target alteration, overexpression of drug target, and overexpression of the efflux pump. During the disease process, Mycobacterium tuberculosis may reside in different microenvironments where it is expose to acidic pH, low oxygen, reactive oxygen species and anti-TB drugs, which can facilitate the development of non-replicating persisters and promote bacterial survival. The mechanisms of persister formation may include toxin-antitoxin (TA) modules, DNA protection and repair, protein degradation such as trans-translation, efflux, and altered metabolism. In recent years, the use of new anti-TB drugs, repurposed drugs, and their drug combinations has greatly improved treatment outcomes in patients with both drug-susceptible TB and MDR/XDR-TB. The importance of developing more effective drugs targeting persisters of Mycobacterium tuberculosis is emphasized. In addition, host-directed therapeutics using both conventional drugs and herbal medicines for more effective TB treatment should also be explored. In this article, we review historical aspects of the research on anti-TB drugs and discuss the current understanding and treatments of drug resistant and persistent tuberculosis to inform future therapeutic development.

A Niemann-pick C1 disease child with BCG-itis: a case report and analysis.

BACKGROUND: Niemann-Pick C disease is a rare autosomal recessive lysosomal lipid storage disorder. Some primary immunodeficiency diseases patients developed regional disease or disseminated disease after vaccinating BCG. It is unclear whether NPC gene deficiency is associated with Mycobacteria infection. CASE PRESENTATION: We report and discuss a case of a child who presented at the age of 6 months with NPC1 and BCG-itis. The patient was treated with Miglustat and the symptom of lymphadenopathy was improved. CONCLUSIONS: We reasonably speculate that NPC1 is a susceptibility gene of Mtb infection and mainly affects innate immunity. Once diagnosed, the infant should not be vaccinated with BCG and early treated.

Induration or erythema diameter not less than 5 mm as results of recombinant fusion protein ESAT6-CFP10 skin test for detecting M. tuberculosis infection.

BACKGROUND: Recombinant fusion protein ESAT6-CFP10 (EC) is a newly developed skin test reagent for detecting Mycobacterium tuberculosis (M. tuberculosis) infection. In this study, we evaluated whether induration and erythema could be used as diagnostic indicators for EC skin test to detect M. tuberculosis infection. METHODS: A total of 743 tuberculosis patients and 1514 healthy volunteers underwent an EC skin test. The diameters of induration and erythema were measured with Vernier caliper, 24 h, 48 h, and 72 h after skin testing. Related indicators of EC reagent diagnostic test were tested, and the diagnostic effects of the four diagnostic indicators for EC skin test were compared. RESULTS: The sensitivity of induration / erythema measurement was lower at 24 h after EC skin test than at 48 h or 72 h (P<0.01). There was no difference in consistency (P = 0.16) between induration with clinical diagnosis, and erythema with clinical diagnosis at 48 h (88.88 and 90.16%, Kappa value was 0.75 and 0.78, respectively). In patients, the sensitivity of erythema measurement was higher than induration measurement (P<0.01). In healthy volunteers, the specificity of erythema measurement was lower than induration at 24 h after skin test, but there was no difference at 48 h after skin test (P = 0.22). In BCG vaccination volunteers, the specificity of induration and erythema were higher than 90%. In addition, there was a high consistency of induration and erythema. When induration or erythema was used as a positive diagnostic indicator, the sensitivity of the EC skin test was improved, and was no different from the other three indicators in terms of specificity and consistency with clinical diagnosis. CONCLUSIONS: Induration or erythema diameter not less than 5 mm could be used as a diagnostic indicator for detecting M. tuberculosis infection. TRIAL REGISTRATION: Phase III clinical trial of recombinant Mycobacterium tuberculosis ESAT6-CFP10 allergen; CTR20150695 ; registered in December 16, 2015.

The Role of KLRG1 in Human CD4+ T-Cell Immunity Against Tuberculosis.

Background: KLRG1 is a marker of terminally differentiated CD8+ T cells in viral infection, but its role in human Mycobacterium tuberculosis infection remains elusive. Methods: A set of cohorts of patients with tuberculosis was designed, and the expression profiles and functions of KLRG1+CD4+ T cells were determined with and without antibody blocking. Results: KLRG1 expression on CD4+ T cells was significantly increased in patients with active tuberculosis, compared with healthy controls and patients without tuberculosis. Upon M. tuberculosis-specific stimulation, the ability to secrete interferon γ, interleukin 2, and tumor necrosis factor α was significantly greater in KLRG1-expressing CD4+ T cells than in their KLRG-negative counterparts and was accompanied by a decreased proportion of regulatory T cells and increased Akt signaling. However, KLRG1-expressing CD4+ T cells had a shorter life-span, which was associated with a higher apoptosis rate but a similar proliferative response. Blockade of KLRG1 signaling significantly enhanced interferon γ and interleukin 2 secretion without affecting either cell apoptosis or multiplication. Addition of a specific Akt inhibitor prevented this increased cytokine response, implicating the Akt signaling pathway. Conclusions: Our study delineated the profile of KLRG1+CD4+ T cells in patients with tuberculosis and suggests that M. tuberculosis infection drives CD4+ T cells to acquire increased effector function in a terminally differentiated state, which is restrained by KLRG1 via KLRG1/Akt signaling pathway.

Sendai Virus Mucosal Vaccination Establishes Lung-Resident Memory CD8 T Cell Immunity and Boosts BCG-Primed Protection against TB in Mice.

Accumulating evidence has shown the protective role of CD8+ T cells in vaccine-induced immunity against Mycobacterium tuberculosis (Mtb) despite controversy over their role in natural immunity. However, the current vaccine BCG is unable to induce sufficient CD8+ T cell responses, especially in the lung. Sendai virus, a respiratory RNA virus, is here engineered firstly as a novel recombinant anti-TB vaccine (SeV85AB) that encodes Mtb immuno-dominant antigens, Ag85A and Ag85B. A single mucosal vaccination elicited potent antigen-specific T cell responses and a degree of protection against Mtb challenge similar to the effect of BCG in mice. Depletion of CD8+ T cells abrogated the protective immunity afforded by SeV85AB vaccination. Interestingly, only SeV85AB vaccination induced high levels of lung-resident memory CD8+ T (TRM) cells, and this led to a rapid and strong recall of antigen-specific CD8+ T cell responses against Mtb challenge infection. Furthermore, when used in a BCG prime-SeV85AB boost strategy, SeV85AB vaccine significantly enhanced protection above that seen after BCG vaccination alone. Our findings suggest that CD8+ TRM cells that arise in lungs responding to this mucosal vaccination might help to protect against TB, and SeV85AB holds notable promise to improve BCG's protective efficacy in a prime-boost immunization regimen.

Early hypercytokinemia is associated with interferon-induced transmembrane protein-3 dysfunction and predictive of fatal H7N9 infection.

A unique avian-origin A/H7N9 influenza virus has so far caused 134 cases with 44 deaths. Probing the host factors contributing to disease severity, we found that lower levels of plasma inflammatory cytokines on hospital admission correlated with faster recovery in 18 patients with A/H7N9 influenza virus, whereas high concentrations of (in particular) IL-6, IL-8, and macrophage inflammatory protein-1ß were predictive of a less favorable or fatal outcome. Analysis of bronchoalveolar lavage samples showed up to 1,000-fold greater cytokine/chemokine levels relative to plasma. Furthermore, patients with the rs12252-C/C IFN-induced transmembrane protein-3 (IFITM3) genotype had more rapid disease progression and were less likely to survive. Compared with patients with the rs12252-T/T or rs12252-T/C genotype of IFITM3, patients with the C/C genotype had a shorter time from disease onset to the time point when they sought medical aid (hospital admission or antiviral therapy) and a shorter interval to development of the acute respiratory distress syndrome stage (reflected by shorter intervals between clinical onset and methylprednisolone treatments and higher rates of mechanical ventilator use), as well as experiencing elevated/prolonged lung virus titers and cytokine production and higher mortality. The present analysis provides reported data on the H7N9 influenza-induced "cytokine storm" at the site of infection in humans and identifies the rs12252-C genotype that compromises IFITM3 function as a primary genetic correlate of severe H7N9 pneumonia. Together with rs12252 sequencing, early monitoring of plasma cytokines is thus of prognostic value for the treatment and management of severe influenza pneumonia.

Clinical findings in 111 cases of influenza A (H7N9) virus infection.

BACKGROUND: During the spring of 2013, a novel avian-origin influenza A (H7N9) virus emerged and spread among humans in China. Data were lacking on the clinical characteristics of the infections caused by this virus. METHODS: Using medical charts, we collected data on 111 patients with laboratory-confirmed avian-origin influenza A (H7N9) infection through May 10, 2013. RESULTS: Of the 111 patients we studied, 76.6% were admitted to an intensive care unit (ICU), and 27.0% died. The median age was 61 years, and 42.3% were 65 years of age or older; 31.5% were female. A total of 61.3% of the patients had at least one underlying medical condition. Fever and cough were the most common presenting symptoms. On admission, 108 patients (97.3%) had findings consistent with pneumonia. Bilateral ground-glass opacities and consolidation were the typical radiologic findings. Lymphocytopenia was observed in 88.3% of patients, and thrombocytopenia in 73.0%. Treatment with antiviral drugs was initiated in 108 patients (97.3%) at a median of 7 days after the onset of illness. The median times from the onset of illness and from the initiation of antiviral therapy to a negative viral test result on real-time reverse-transcriptase-polymerase-chain-reaction assay were 11 days (interquartile range, 9 to 16) and 6 days (interquartile range, 4 to 7), respectively. Multivariate analysis revealed that the presence of a coexisting medical condition was the only independent risk factor for the acute respiratory distress syndrome (ARDS) (odds ratio, 3.42; 95% confidence interval, 1.21 to 9.70; P=0.02). CONCLUSIONS: During the evaluation period, the novel H7N9 virus caused severe illness, including pneumonia and ARDS, with high rates of ICU admission and death. (Funded by the National Natural Science Foundation of China and others.).

Association between adverse clinical outcome in human disease caused by novel influenza A H7N9 virus and sustained viral shedding and emergence of antiviral resistance.

BACKGROUND: On March 30, a novel influenza A subtype H7N9 virus (A/H7N9) was detected in patients with severe respiratory disease in eastern China. Virological factors associated with a poor clinical outcome for this virus remain unclear. We quantified the viral load and analysed antiviral resistance mutations in specimens from patients with A/H7N9. METHODS: We studied 14 patients with A/H7N9 disease admitted to the Shanghai Public Health Clinical Centre (SPHCC), China, between April 4, and April 20, 2013, who were given antiviral treatment (oseltamivir or peramivir) for less than 2 days before admission. We investigated the viral load in throat, stool, serum, and urine specimens obtained sequentially from these patients. We also sequenced viral RNA from these specimens to study the mutations associated with resistance to neuraminidase inhibitors and their association with disease outcome. FINDINGS: All patients developed pneumonia, seven of them required mechanical ventilation, and three of them further deteriorated to become dependent on extracorporeal membrane oxygenation (ECMO), two of whom died. Antiviral treatment was associated with a reduction of viral load in throat swab specimens in 11 surviving patients. Three patients with persistently high viral load in the throat in spite of antiviral therapy became ECMO dependent. An Arg292Lys mutation in the virus neuraminidase (NA) gene known to confer resistance to both zanamivir and oseltamivir was identified in two of these patients, both also received corticosteroid treatment. In one of them, wild-type sequence Arg292 was noted 2 days after start of antiviral treatment, and the resistant mutant Lys292 dominated 9 days after start of treatment. INTERPRETATION: Reduction of viral load following antiviral treatment correlated with improved outcome. Emergence of NA Arg292Lys mutation in two patients who also received corticosteroid treatment led to treatment failure and a poor clinical outcome. The emergence of antiviral resistance in A/H7N9 viruses, especially in patients receiving corticosteroid therapy, is concerning, needs to be closely monitored, and considered in pandemic preparedness planning. FUNDING: National Megaprojects of China for Infectious Diseases, Shanghai Municipal Health and Family Planning Commission, the National Key Basic Research Program of China, Ministry of Science and Technology, and National Natural Science Foundation of China.

A nursing report on a corneal contact lens wearer receiving keratoplasty due to corneal ulcer and perforation caused by Pythium insidiosum infection: A case report.

BACKGROUND: To report the nursing experience of a case of corneal contact lens wearer receiving the 2nd keratoplasty due to corneal ulcer and perforation caused by Pythium insidiosum infection. METHODS: A 30-year-old female patient had blurred vision after deep anterior lamellar keratoplasty for a right corneal ulcer. At the 5th week, the right eye appeared the symptoms, such as redness and pain. The anterior segment photography was performed on the eye, and the result showed that the epithelium was missing in the right eye lesion area, and a large number of longitudinal and transversal streaks were visible from the epithelium to the stroma, with fungus filaments to be discharged. Upon macro-genome sequencing of the corneal secretion, a P. insidiosum infection was observed. Then, the patient underwent the keratoplasty, and 3 weeks later, the corneal implant showed a tendency to dissolve, the sutures were partially loosened, and the eye was almost blind. Subsequently, the patient was admitted to our hospital and subject to the 2nd penetrating keratoplasty of the right eye (allograft). After surgery, linezolid and azithromycin injections were given through intravenous drip and local drip of the eye for anti-inflammation, and tacrolimus eye drops for antirejection. RESULTS: Postoperatively, the patient showed signs of recovery with slight corneal edema and visible pupil, leading to discharge with improved vision. The corneal implant was normal 1 week after surgery and the vision of the right eye was hand move/before eye at the 6th month of follow-up. Continuous care and removal of sutures 3 months post-surgery contributed to a successful outcome, with the patient achieving hand motion vision 6 months after the procedure. CONCLUSION: Corneal ulcer caused by P. insidiosum infection not only needs timely and effective keratoplasty intervention, but also requires perfect nursing measures.

A retrospective study on intracranial mixed infection with tuberculous meningitis in Shenzhen, China.

Tuberculous meningitis (TBM) is a prevalent global intracranial infection and the most lethal and disabling form of tuberculosis. TBM with mixed intracranial infections is clinically rare but has a higher mortality rate. To investigate the clinical characteristics of TBM with mixed intracranial infections, demographic and clinical data of TBM and pulmonary tuberculosis (PTB) patients admitted to Shenzhen Third People's Hospital between January 2015 and October 2022 were collected anonymously. A total of 207 cases of TBM were diagnosed, of which 16 cases (7.73%) were TBM with mixed intracranial infections. The overall mortality rate of TBM cases was 16.4%, while the mortality rate of TBM cases with mixed intracranial infections was as high as 35.7%. Compared to simple TBM cases, TBM cases with mixed intracranial infections had severer clinical symptoms. The percentage of human immune deficiency virus (HIV)-positive TBM cases with mixed intracranial infections reached up to 68.8%. HIV co-infection, CD4+/CD8+ T-cell counts less than 1, cranial nerve impairment, paralysis, cerebral infarction, PRO less than 450 mg/L, WBC less than 10 × 106 /L, and CL more than 120 mmol/L were risk factors for TBM cases with mixed intracranial infections. Compared to PTB, HIV co-infection, CD4+ T cell less than 550 /uL, and age less than 45 years were risk factors for TBM, and TBM was associated with higher mortality rates. Our study provides additional data to better understand single TBM and TBM with mixed intracranial infections. More than two-thirds of TBM cases with mixed intracranial infections were HIV-positive. Clinicians should consider the possibility of multiple infections in people with TBM/HIV co-infection. IMPORTANCE: TBM can cause severe neurological damage and death, and TBM with mixed intracranial infections can exacerbate the damage and poor prognosis of the disease. TBM with mixed intracranial infections is a rare disease, which has led to an incomplete understanding of its clinical features. This study investigated the clinical features of TBM and its associated factors by comparing the characteristics of TBM with mixed intracranial infections, single TBM and pulmonary tuberculosis. This information will help to improve the understanding of TBM, diagnostic accuracy and treatment outcomes.

The impact of Mycobacterium tuberculosis on the macrophage cholesterol metabolism pathway.

Mycobacterium tuberculosis (Mtb) is an intracellular pathogen capable of adapting and surviving within macrophages, utilizing host nutrients for its growth and replication. Cholesterol is the main carbon source during the infection process of Mtb. Cholesterol metabolism in macrophages is tightly associated with cell functions such as phagocytosis of pathogens, antigen presentation, inflammatory responses, and tissue repair. Research has shown that Mtb infection increases the uptake of low-density lipoprotein (LDL) and cholesterol by macrophages, and enhances de novo cholesterol synthesis in macrophages. Excessive cholesterol is converted into cholesterol esters, while the degradation of cholesterol esters in macrophages is inhibited by Mtb. Furthermore, Mtb infection suppresses the expression of ATP-binding cassette (ABC) transporters in macrophages, impeding cholesterol efflux. These alterations result in the massive accumulation of cholesterol in macrophages, promoting the formation of lipid droplets and foam cells, which ultimately facilitates the persistent survival of Mtb and the progression of tuberculosis (TB), including granuloma formation, tissue cavitation, and systemic dissemination. Mtb infection may also promote the conversion of cholesterol into oxidized cholesterol within macrophages, with the oxidized cholesterol exhibiting anti-Mtb activity. Recent drug development has discovered that reducing cholesterol levels in macrophages can inhibit the invasion of Mtb into macrophages and increase the permeability of anti-tuberculosis drugs. The development of drugs targeting cholesterol metabolic pathways in macrophages, as well as the modification of existing drugs, holds promise for the development of more efficient anti-tuberculosis medications.

Interactions between CNS and immune cells in tuberculous meningitis.

The central nervous system (CNS) harbors its own special immune system composed of microglia in the parenchyma, CNS-associated macrophages (CAMs), dendritic cells, monocytes, and the barrier systems within the brain. Recently, advances in the immune cells in the CNS provided new insights to understand the development of tuberculous meningitis (TBM), which is the predominant form of Mycobacterium tuberculosis (M.tb) infection in the CNS and accompanied with high mortality and disability. The development of the CNS requires the protection of immune cells, including macrophages and microglia, during embryogenesis to ensure the accurate development of the CNS and immune response following pathogenic invasion. In this review, we summarize the current understanding on the CNS immune cells during the initiation and development of the TBM. We also explore the interactions of immune cells with the CNS in TBM. In the future, the combination of modern techniques should be applied to explore the role of immune cells of CNS in TBM.