Julie Huynh

Background: Early diagnosis of tuberculous meningitis (TBM) is critical to favorable outcomes. We investigated whether a 3-gene host response signature in whole blood can distinguish TBM from symptomatic controls in children. Methods: Whole-blood RNA sequencing was performed in children with TBM and controls. Expression of the 3-gene signature, [guanylate-binding protein (GBP5), dual specificity phosphatase 3 (DUSP3) and Krupple-like factor 2 (KLF2)] was quantified and a tuberculosis (TB) score was calculated using (GBP5+DUSP3)/2-KLF2. Discriminatory performance was obtained using receiver-operator characteristic curve analysis against microbiologic and composite reference standards. TB score and 3-gene expression in children were compared against adults with TBM. In parallel, an exploratory transcriptome-wide analysis was performed, applying bootstrapped least absolute shrinkage and selection operator regression to identify additional genes associated with TBM. Results: Forty-two children had TBM and 41 were controls. KLF2 was upregulated in TBM compared to controls ( P = 0.043); while GBP5, DUSP3 and TB score showed no difference. The diagnostic performance of GBP5 alone (area under the curves: 0.64; 95% confidence interval: 0.46–0.83) and TB score (area under the curves: 0.59; 95% confidence interval: 0.41–0.77) was poor against the reference standard of definite TBM. GBP5 in children with TBM was lower than in adults without HIV (median 13.04; interquartile ranges: 11.91–14.29 vs. median 13.72; interquartile ranges: 12.58–14.53, P = 0.036), and expression was nonlinear across the age spectrum; lowest in young children. Exploratory transcriptomic analysis suggests that novel genes may contribute a discriminatory signal. Conclusion: The 3-gene host response signature does not discriminate TBM from controls in children and was much less discriminative compared to adults. An alternative set of pediatric-specific signatures may exist, but further discovery and validation are required.

Background: Diagnosing extrapulmonary tuberculosis (EPTB) in children is challenging due to nonspecific presentations and poor diagnostic yield from conventional microbiologic tests. Host gene expression signatures offer a non-sputum-based diagnostic alternative. This systematic review evaluates their diagnostic performance in pediatric EPTB. Methods: We systematically reviewed host-based gene expression diagnostics for pediatric EPTB. PubMed, Embase and Cochrane Library (January 1965–May 2025) were searched for studies in children (0–18 years) with EPTB. Exclusions were adult-only studies, mixed data on pulmonary TB and EPTB without disaggregation, pulmonary TB-only studies, reviews and abstracts. Two reviewers screened data, resolving disagreements by discussion. Results: Of 830 records, 2 studies met the inclusion criteria: Pan et al. (2017) and Olbrich et al. (2024), both in low and middle-income countries, enrolling a total of 891 children under 15 years. Olbrich et al.’s 3-gene MTB-HR prototype showed 59.8% sensitivity against a strict culture-confirmed reference standard and 50.0% in isolated EPTB with a low risk of bias. Using a microbiologic, clinical and radiologic composite standard, Pan et al.’s miRNA-29a assay achieved 67.2% sensitivity, 88.5% specificity in peripheral blood mononuclear cells; 81.1% sensitivity, 90.0% specificity in cerebrospinal fluid; 84.4% sensitivity, 95.4% specificity in combined peripheral blood mononuclear cell/cerebrospinal fluid with a high risk of bias. Conclusions: Evidence for host gene expression diagnostics in pediatric EPTB is limited by few studies, small sample sizes, bias and lack of disaggregated data, with accuracy falling short of the World Health Organization targets.

We characterized cerebral infarction in children with tuberculous meningitis and explored its relationship with systemic inflammatory mediators using targeted transcriptomic analysis. Children with tuberculous meningitis had baseline magnetic resonance imaging scans and whole blood RNA sequencing for matrix metalloproteinases (MMP-8, MMP-9, TIMP-1), cytokines (IL-10, IL-1β, TNF-α, IFN-γ), and growth factors (VEGF). Overall 22 (73%) children had mild disease and 19 (63%) had cerebral infarctions, which were commonly acute (n = 9, 47%), multiple (n = 14, 74%), and bilateral (n = 12, 63%), occurring in cerebral hemispheres (n = 12, 59%), basal ganglia (n = 10, 53%), and thalamus (n = 5, 26%). Children with infarctions had significantly higher cerebrospinal fluid protein, lower cerebrospinal fluid glucose, and higher systemic MMP-8 expression.

Tuberculous meningitis (TBM) is the most severe form of tuberculosis, disproportionately affecting vulnerable populations such as young children and people living with human immunodeficiency virus (HIV). Major challenges to accurate and early diagnosis of TBM are the non-specific clinical features which overlap with other infectious syndromes and the lack of adequately sensitive tests to detect Mycobacterium tuberculosis in the cerebrospinal fluid (CSF). Diagnosis is, therefore, still dependent on clinical suspicion along with clinical features, cerebrospinal fluid (CSF) characteristics and, where facilities are available, neuroimaging. Typical neuroimaging features of TBM include hydrocephalus, infarcts, tuberculomas and basal exudates; however, less well described are very rare features such as cytotoxic lesion of the corpus callosum (CLOCC), otherwise known as transient splenic lesion. We describe the first case report of a child with confirmed TBM who had a very rare presentation of CLOCC with complete recovery and present a literature review on the pathophysiology and alternative aetiologies where CLOCC is more commonly seen.

Introduction Childhood tuberculous meningitis (TBM) is a devastating disease. The long-standing WHO recommendation for treatment is 2 months of intensive phase with isoniazid (H), rifampicin (R), pyrazinamide (Z) and ethambutol (E), followed by 10 months of isoniazid and rifampicin. In 2022, WHO released a conditional recommendation that 6 months of intensified antituberculosis therapy (ATT) could be used as an alternative for drug-susceptible TBM. However, this has never been evaluated in a randomised clinical trial. Trials evaluating ATT shortening regimens using high-dose rifampicin and drugs with better central nervous system penetration alongside adjuvant anti-inflammatory therapy are needed to improve outcomes. Methods and analysis The Shortened Intensive Therapy for Children with Tuberculous Meningitis (SURE) trial is a phase 3, randomised, partially blinded, factorial trial being conducted in Asia (India and Vietnam) and Africa (Uganda, Zambia and Zimbabwe). It is coordinated by the Medical Research Council Clinical Trial Unit at University College London (MRCCTU at UCL). 400 children (aged 29 days to Ethics and dissemination Local ethics committees at all participating study sites and respective regulators approved the SURE protocol. Ethics approval was also obtained from UCL, UK (14935/001). Informed consent from parents/carers and assent from age-appropriate children are required for all participants. Results will be published in international peer-reviewed journals, and appropriate media will be used to summarise results for patients and their families and policymakers. Trial registration ISRCTN40829906 (registered 13 November 2018).

Tuberculous meningitis (TBM) is the most severe form of tuberculosis, disproportionately affecting vulnerable populations such as young children and people living with human immunodeficiency virus (HIV). Major challenges to accurate and early diagnosis of TBM are the non-specific clinical features which overlap with other infectious syndromes and the lack of adequately sensitive tests to detect Mycobacterium Tuberculosis in the cerebrospinal fluid (CSF). Diagnosis is therefore still dependent on clinical suspicion along with clinical features, cerebrospinal fluid (CSF) characteristics and where facilities are available, neuroimaging. Typical neuroimaging features of TBM include hydrocephalus, infarcts, tuberculomas and basal exudates, however less well described are very rare features such as cytotoxic lesion of the corpus callosum (CLOCC) otherwise known as transient splenic lesion. We describe the first case report of a child with confirmed TBM who had a very rare presentation of CLOCC, present a literature review on the pathophysiology and alternative aetiologies where CLOCC is more commonly seen.

Tuberculous meningitis (TBM) is difficult to diagnose. We investigated whether a 3-gene host response signature in blood can distinguish TBM from other brain infections. The expression of 3 genes (dual specificity phosphatase 3 [DUSP3], guanylate-binding protein [GBP5], krupple-like factor 2 [KLF2]) was analyzed by RNA sequencing of archived whole blood from 4 cohorts of Vietnamese adults: 281 with TBM, 279 with pulmonary tuberculosis, 50 with other brain infections, and 30 healthy controls. Tuberculosis scores (combined 3-gene expression) were calculated following published methodology and discriminatory performance compared using area under a receiver operator characteristic curve (AUC). GBP5 was upregulated in TBM compared to other brain infections (P < .001), with no difference in DUSP3 and KLF2 expression. The diagnostic performance of GBP5 alone (AUC, 0.74; 95% confidence interval [CI], .67–.81) was slightly better than the 3-gene tuberculosis score (AUC, 0.66; 95% CI, .58–.73) in TBM. Both GBP5 expression and tuberculosis score were higher in participants with human immunodeficiency virus (HIV; P < .001), with good diagnostic performance of GBP5 alone (AUC, 0.86; 95% CI, .80–.93). The 3-gene host signature in whole blood has the ability to discriminate TBM from other brain infections, including in individuals with HIV. Validation in large prospective diagnostic study is now required.

The USP19 deubiquitinase is found in a locus associated with Parkinson’s Disease (PD), interacts with chaperonins, and promotes secretion of α-synuclein (α-syn) through the misfolding-associated protein secretion (MAPS) pathway. Since these processes might modulate the processing of α-syn aggregates in PD, we inactivated USP19 (KO) in mice expressing the A53T mutation of α-syn and in whom α-syn preformed fibrils (PFF) had been injected in the striatum. Compared to WT, KO brains showed decreased accumulation of phospho-synuclein (pSyn) positive aggregates. This improvement was associated with less activation of microglia and improved performance in a tail-suspension test. Exposure of primary neurons from WT and KO mice to PFF in vitro also led to decreased accumulation of pSyn aggregates. KO did not affect uptake of PFF nor propagation of aggregates in the cultured neurons. We conclude that USP19 instead modulates intracellular dynamics of aggregates. At an early time following PFF injection when the number of pSyn-positive neurons were similar in WT and KO brains, the KO neurons contained less aggregates. KO brain aggregates stained more intensely with anti-ubiquitin antibodies. Immunoprecipitation of soluble proteins from WT and KO brains with antibodies to pSyn showed higher levels of ubiquitinated oligomeric species in the KO samples. We propose that the improved pathology in USP19 KO brains may arise from decreased formation or enhanced clearance of the more ubiquitinated aggregates and/or enhanced disassembly towards more soluble oligomeric species. USP19 inhibition may represent a novel therapeutic approach that targets the intracellular dynamics of α-syn complexes.