Vitamin D deficiency is associated with susceptibility to tuberculosis (TB) in HIV-uninfected people in Europe, but it is not known whether such an association exists among HIV-infected people in ...subtropical Africa. We conducted a cross-sectional study to determine whether vitamin D deficiency was associated with susceptibility to active TB in HIV-uninfected (n = 196) and HIV-infected (n = 174) black Africans in Cape Town, South Africa. We also investigated whether there was evidence of seasonal variation in vitamin D status and TB notifications in this setting over an 8-y period. Vitamin D deficiency (serum 25-hydroxyvitamin D 25(OH)D <50 nmol/L) was present in 232 (62.7%) of 370 participants and was associated with active TB in both HIV-uninfected (odds ratio = 5.2, 95% confidence interval: 2.8–9.7; P < 0.001) and HIV-infected (odds ratio = 5.6, 95% confidence interval: 2.7–11.6; P < 0.001) people. Vitamin D status varied according to season: The mean serum 25(OH)D concentration was highest in January through March and lowest in July through September (56.8 vs. 30.7 nmol/L, respectively; P < 0.001). Reciprocal seasonal variation in TB notifications was observed: The mean number of TB notifications per quarter for Cape Town in 2003 to 2010 was lowest in April through June and highest in October through December (4,222 vs. 5,080; P < 0.001). Vitamin D deficiency is highly prevalent among black Africans in Cape Town and is associated with susceptibility to active TB both in the presence and absence of HIV infection. Reciprocal seasonal variation in serum 25(OH)D concentration and TB notifications suggests that seasonal variations in vitamin D status and TB incidence in this setting are causally related.
Background. Paradoxical neurologic tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) is a potentially life-threatening condition that occurs within 3 months after starting ...combination antiretroviral therapy (ART). The reports in the published literature are anecdotal, and the prevalence and outcomes of neurologic TB-IRIS are unknown. Methods. We prospectively assessed patients with suspected TB-IRIS from June 2005 through October 2007 at our hospital in Cape Town, South Africa. We defined paradoxical TB-IRIS and paradoxical neurologic TB-IRIS with use of consensus clinical case definitions. We collected data on tuberculosis diagnosis, ART, details of TB-IRIS diagnosis, other opportunistic infections, corticosteroid use, and outcome. Results. We reviewed 279 patients with suspected TB-IRIS, 54 (19%) of whom had suspected neurologic TB-IRIS, and 225 (81%) of whom had suspected non-neurologic TB-IRIS. Paradoxical TB-IRIS was diagnosed in 190 patients; 23 (12%) of these 190 patients had neurologic TB-IRIS (95% confidence interval, 7%–17%). Eight had meningitis, 7 had tuberculoma, 5 had both tuberculoma and meningitis, and 3 had radiculomyelopathy. Twenty (87%) of the 23 patients with neurologic TB-IRIS required hospital admission (median duration, 12 days; interquartile range, 6–24 days), and 21 (91%) received corticosteroids (median duration, 58 days; interquartile range, 29–86 days). Outcomes 6 months after the initial assessment for neurologic deterioration were as follows: 16 (70%) of the patients were alive (10 of these patients had documented full physical and mental recovery), 3 (13%) were dead, and 4 (17%) were lost to follow-up. Conclusions. Paradoxical neurologic TB-IRIS accounts for 12% of paradoxical TB-IRIS cases. Neurologic TB-IRIS causes considerable short-term morbidity but has reasonable long-term outcomes. Further research is needed to devise optimal diagnostic and management strategies for patients with tuberculosis who experience neurologic deterioration after starting ART.
Summary The immune reconstitution inflammatory syndrome (IRIS) has emerged as an important early complication of antiretroviral therapy (ART) in resource-limited settings, especially in patients with ...tuberculosis. However, there are no consensus case definitions for IRIS or tuberculosis-associated IRIS. Moreover, previously proposed case definitions are not readily applicable in settings where laboratory resources are limited. As a result, existing studies on tuberculosis-associated IRIS have used a variety of non-standardised general case definitions. To rectify this problem, around 100 researchers, including microbiologists, immunologists, clinicians, epidemiologists, clinical trialists, and public-health specialists from 16 countries met in Kampala, Uganda, in November, 2006. At this meeting, consensus case definitions for paradoxical tuberculosis-associated IRIS, ART-associated tuberculosis, and unmasking tuberculosis-associated IRIS were derived, which can be used in high-income and resource-limited settings. It is envisaged that these definitions could be used by clinicians and researchers in a variety of settings to promote standardisation and comparability of data.
Purpose of review
Tuberculous meningitis (TBM) is a global health problem. In this review, we systematically evaluate the evidence for current and emerging antimicrobials, host-directed therapies and ...supportive managements.
Recent findings
Current antimicrobial regimes do not factor the differing ability of drugs to cross the blood-brain barrier. Rifampicin may be more effective at higher doses yet the most recent clinical trial failed to demonstrate survival benefit at 15 mg/kg/day. Dose finding studies suggest that higher doses still may be safe and more effective. Fluoroquinolones are currently listed as important second-line agents in drug-resistant TBM; however, a survival benefit as a first-line agent has yet to be shown. Linezolid may be a promising antimicrobial with good central nervous system penetrance. Dexamethasone reduces mortality in HIV-uninfected individuals yet evidence for its use in HIV co-infection is lacking. Aspirin has anti-inflammatory and anti-thrombotic properties. Small studies have demonstrated efficacy in reducing stroke but further research is required to better understand its effect on controlling the host inflammatory response. Discovery of genetic polymorphisms may direct individualized immune therapies and mediators of the innate immune response may provide targets for the development of novel therapies. There is at present no significant evidence base to guide management of hydrocephalus in HIV co-infection.
Summary
Further clinical trial data is required to improve treatment outcomes in TBM in particularly in regard to the value of high-dose rifampicin, newer antimicrobials with improved central nervous system penetration and host-directed therapies. Supportive measures in particular the management of hydrocephalus in HIV co-infection should be an area for future research.
Tuberculosis (TB), caused by infection with Mycobacterium tuberculosis, is a major cause of morbidity and mortality worldwide. Efforts to control it are hampered by difficulties with diagnosis, ...prevention and treatment. Most people infected with M. tuberculosis remain asymptomatic, termed latent TB, with a 10% lifetime risk of developing active TB disease. Current tests, however, cannot identify which individuals will develop disease. The immune response to M. tuberculosis is complex and incompletely characterized, hindering development of new diagnostics, therapies and vaccines. Here we identify a whole-blood 393 transcript signature for active TB in intermediate and high-burden settings, correlating with radiological extent of disease and reverting to that of healthy controls after treatment. A subset of patients with latent TB had signatures similar to those in patients with active TB. We also identify a specific 86-transcript signature that discriminates active TB from other inflammatory and infectious diseases. Modular and pathway analysis revealed that the TB signature was dominated by a neutrophil-driven interferon (IFN)-inducible gene profile, consisting of both IFN- and type I IFN- signalling. Comparison with transcriptional signatures in purified cells and flow cytometric analysis suggest that this TB signature reflects changes in cellular composition and altered gene expression. Although an IFN-inducible signature was also observed in whole blood of patients with systemic lupus erythematosus (SLE), their complete modular signature differed from TB, with increased abundance of plasma cell transcripts. Our studies demonstrate a hitherto underappreciated role of type I IFN- signalling in the pathogenesis of TB, which has implications for vaccine and therapeutic development. Our study also provides a broad range of transcriptional biomarkers with potential as diagnostic and prognostic tools to combat the TB epidemic.
KRAS mutant pancreatic ductal adenocarcinoma (PDAC) is characterized by a desmoplastic response that promotes hypovascularity, immunosuppression, and resistance to chemo- and immunotherapies. We show ...that a combination of MEK and CDK4/6 inhibitors that target KRAS-directed oncogenic signaling can suppress PDAC proliferation through induction of retinoblastoma (RB) protein-mediated senescence. In preclinical mouse models of PDAC, this senescence-inducing therapy produces a senescence-associated secretory phenotype (SASP) that includes pro-angiogenic factors that promote tumor vascularization, which in turn enhances drug delivery and efficacy of cytotoxic gemcitabine chemotherapy. In addition, SASP-mediated endothelial cell activation stimulates the accumulation of CD8+ T cells into otherwise immunologically “cold” tumors, sensitizing tumors to PD-1 checkpoint blockade. Therefore, in PDAC models, therapy-induced senescence can establish emergent susceptibilities to otherwise ineffective chemo- and immunotherapies through SASP-dependent effects on the tumor vasculature and immune system.
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•Therapy-induced senescence in PDAC triggers SASP-dependent vascular remodeling•SASP-mediated vascularization facilitates chemotherapy uptake and efficacy•SASP-mediated endothelial activation drives T cell infiltration into PDAC lesions•Senescence-inducing treatment potentiates PD-1 blockade in PDAC models
In mouse models of KRAS mutant pancreatic ductal adenocarcinoma, tumor cell senescence following MEK and CDK4/6 inhibition promotes vascular remodeling through induction of a pro-angiogenic senescence-associated secretory phenotype, leading to enhanced drug delivery and T cell infiltration that sensitizes these tumors to chemotherapy and immune checkpoint blockade.
Patients with cancer are currently prioritized in coronavirus disease 2019 (COVID-19) vaccination programs globally, which includes administration of mRNA vaccines. Cytokine release syndrome (CRS) ...has not been reported with mRNA vaccines and is an extremely rare immune-related adverse event of immune checkpoint inhibitors. We present a case of CRS that occurred 5 d after vaccination with BTN162b2 (tozinameran)-the Pfizer-BioNTech mRNA COVID-19 vaccine-in a patient with colorectal cancer on long-standing anti-PD-1 monotherapy. The CRS was evidenced by raised inflammatory markers, thrombocytopenia, elevated cytokine levels (IFN-γ/IL-2R/IL-18/IL-16/IL-10) and steroid responsiveness. The close temporal association of vaccination and diagnosis of CRS in this case suggests that CRS was a vaccine-related adverse event; with anti-PD1 blockade as a potential contributor. Overall, further prospective pharmacovigillence data are needed in patients with cancer, but the benefit-risk profile remains strongly in favor of COVID-19 vaccination in this population.
Background. Tuberculosis immune reconstitution inflammatory syndrome (IRIS) is a common cause of deterioration in human immunodeficiency virus (HIV)—infected patients receiving tuberculosis treatment ...after starting antiretroviral therapy (ART). Potentially life-threatening neurological involvement occurs frequently and has been suggested as a reason to defer ART. Methods. We conducted a prospective study of HIV-infected, ART-naive patients with tuberculous meningitis (TBM). At presentation, patients started tuberculosis treatment and prednisone; ART was initiated 2 weeks later. Clinical and laboratory findings were compared between patients who developed TBM-IRIS (TBM-IRIS patients) and those who did not (non-TBM-IRIS patients). A logistic regression model was developed to predict TBM-IRIS. Results. Forty-seven percent (16/34) of TBM patients developed TBM-IRIS, which manifested with severe features of inflammation. At TBM diagnosis, TBM-IRIS patients had higher cerebrospinal fluid (CSF) neutrophil counts compared with non-TBM-IRIS patients (median, 50 vs 3 cells ×10 6 /L, P = .02). Mycobacterium tuberculosis was cultured from CSF of 15 TBM-IRIS patients (94%) compared with 6 non-TBM-IRIS patients (33%) at time of TBM diagnosis; relative risk of developing TBM-IRIS if CSF was Mycobacterium tuberculosis culture positive = 9.3 (95% confidence interval CI, 1.4–62.2). The combination of high CSF tumor necrosis factor (TNF)-α and low interferon (IFN)-γ at TBM diagnosis predicted TBM-IRIS (area under the curve = 0.91 95% CI, .53–.99). Conclusions. TBM-IRIS is a frequent, severe complication of ART in HIV-associated TBM and is characterized by high CSF neutrophil counts and Mycobacterium tuberculosis culture positivity at TBM presentation. The combination of CSF IFN-γ and TNF-α concentrations may predict TBM-IRIS and thereby be a means to individualize patients to early or deferred ART.
Tuberculous meningitis (TBM) is a frequent cause of meningitis in individuals with human immunodeficiency virus (HIV) infection, resulting in death in approximately 40% of affected patients. A severe ...complication of antiretroviral therapy (ART) in these patients is neurological tuberculosis–immune reconstitution inflammatory syndrome (IRIS), but its underlying cause remains poorly understood. To investigate the pathogenesis of TBM-IRIS, we performed longitudinal whole-blood microarray analysis of HIV-infected patients with TBM and reflected the findings at the protein level. Patients in whom TBM-IRIS eventually developed had significantly more abundant neutrophil-associated transcripts, from before development of TBM-IRIS through IRIS symptom onset. After ART initiation, a significantly higher abundance of transcripts associated with canonical and noncanonical inflammasomes was detected in patients with TBM-IRIS than in non-IRIS controls. Whole-blood transcriptome findings complement protein measurement from the site of disease, which together suggest a dominant role for the innate immune system in the pathogenesis of TBM-IRIS.
Drug resistance is a challenge for the global control of tuberculosis. We examined mortality in patients with tuberculosis from high-burden countries, according to concordance or discordance of ...results from drug susceptibility testing done locally and in a reference laboratory.
This multicentre cohort study was done in Côte d'Ivoire, Democratic Republic of the Congo, Kenya, Nigeria, South Africa, Peru, and Thailand. We collected Mycobacterium tuberculosis isolates and clinical data from adult patients aged 16 years or older. Patients were stratified by HIV status and tuberculosis drug resistance. Molecular or phenotypic drug susceptibility testing was done locally and at the Swiss National Center for Mycobacteria, Zurich, Switzerland. We examined mortality during treatment according to drug susceptibility test results and treatment adequacy in multivariable logistic regression models adjusting for sex, age, sputum microscopy, and HIV status.
We obtained M tuberculosis isolates from 871 patients diagnosed between 2013 and 2016. After exclusion of 237 patients, 634 patients with tuberculosis were included in this analysis; the median age was 33·2 years (IQR 26·9–42·5), 239 (38%) were women, 272 (43%) were HIV-positive, and 69 (11%) patients died. Based on the reference laboratory drug susceptibility test, 394 (62%) strains were pan-susceptible, 45 (7%) monoresistant, 163 (26%) multidrug-resistant (MDR), and 30 (5%) had pre-extensively or extensively drug resistant (pre-XDR or XDR) tuberculosis. Results of reference and local laboratories were concordant for 513 (81%) of 634 patients and discordant for 121 (19%) of 634. Overall, sensitivity to detect any resistance was 90·8% (95% CI 86·5–94·2) and specificity 84·3% (80·3–87·7). Mortality ranged from 6% (20 of 336) in patients with pan-susceptible tuberculosis treated according to WHO guidelines to 57% (eight of 14) in patients with resistant strains who were under-treated. In logistic regression models, compared with concordant drug susceptibility test results, the adjusted odds ratio of death was 7·33 (95% CI 2·70–19·95) for patients with discordant results potentially leading to under-treatment.
Inaccurate drug susceptibility testing by comparison with a reference standard leads to under-treatment of drug-resistant tuberculosis and increased mortality. Rapid molecular drug susceptibility test of first-line and second-line drugs at diagnosis is required to improve outcomes in patients with MDR tuberculosis and pre-XDR or XDR tuberculosis.
National Institutes of Allergy and Infectious Diseases, Swiss National Science Foundation, Swiss National Center for Mycobacteria.
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