The effect of new Mycobacterium tuberculosis infection on the sensitivity of prognostic TB signatures

2021 ◽  
Vol 25 (12) ◽  
pp. 1001-1005
Author(s):  
T. Sumner ◽  
A. Fiore-Gartland ◽  
M. Hatherill ◽  
R. M. G. J. Houben ◽  
T. J. Scriba ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Intervention Study ◽  
Preventive Therapy ◽  
Mycobacterium Tuberculosis Infection ◽  
Transmission Setting ◽  
Product Profile ◽  
Transcriptomic Signature ◽  
Time Of Infection ◽  
Minimum Sensitivity ◽  
Minimum Criteria

BACKGROUND: Tests that identify individuals at greatest risk of TB will allow more efficient targeting of preventive therapy. The WHO target product profile for such tests defines optimal sensitivity of 90% and minimum sensitivity of 75% for predicting incident TB. The CORTIS (Correlate of Risk Targeted Intervention Study) evaluated a blood transcriptomic signature (RISK11) for predicting incident TB in a high transmission setting. RISK11 is able to predict TB disease progression but optimal prognostic performance was limited to a 6-month horizon.METHODS: Using a mathematical model, we estimated how subsequent Mycobacterium tuberculosis (MTB) infection may have contributed to the decline in sensitivity of RISK11. We calculated the effect at different RISK11 thresholds (60% and 26%) and for different assumptions about the risk of MTB infection.RESULTS: Modelled sensitivity over 15 months, excluding new infection, was 28.7% (95% CI 12.3–74.1) compared to 25.0% (95% CI 12.7–45.9) observed in the trial. Modelled sensitivity exceeded the minimum criteria (>75%) over a 9-month horizon at the 60% threshold and over 12 months at the 26% threshold.CONCLUSIONS: The effect of new infection on prognostic signature performance is likely to be small. Signatures such as RISK11 may be most useful in individuals, such as household contacts, where probable time of infection is known.

scholarly journals A Randomized Controlled Trial of Isoniazid to Prevent Mycobacterium tuberculosis Infection in Kenyan Human Immunodeficiency Virus–Exposed Uninfected Infants

2020 ◽  
Author(s):  
Sylvia M LaCourse ◽  
Barbra A Richardson ◽  
John Kinuthia ◽  
A J Warr ◽  
Elizabeth Maleche-Obimbo ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
Mycobacterium Tuberculosis ◽  
High Risk ◽  
Adverse Events ◽  
Controlled Trial ◽  
Preventive Therapy ◽  
Infection Prevalence ◽  
Mycobacterium Tuberculosis Infection ◽  
Immunodeficiency Virus ◽  
Exposed Uninfected

Abstract Background Human immunodeficiency virus (HIV)–exposed uninfected (HEU) infants in endemic settings are at high risk of tuberculosis (TB). For infants, progression from primary Mycobacterium tuberculosis (Mtb) infection to TB disease can be rapid. We assessed whether isoniazid (INH) prevents primary Mtb infection. Methods We conducted a randomized nonblinded controlled trial enrolling HEU infants 6 weeks of age without known TB exposure in Kenya. Participants were randomized (1:1) to 12 months of daily INH (10 mg/kg) vs no INH. Primary endpoint was Mtb infection at end of 12 months, assessed by interferon-γ release assay (QuantiFERON-TB Gold Plus) and/or tuberculin skin test (TST, added 6 months after first participant exit). Results Between 15 August 2016 and 6 June 2018, 416 infants were screened, with 300 (72%) randomized to INH or no INH (150 per arm); 2 were excluded due to HIV infection. Among 298 randomized HEU infants, 12-month retention was 96.3% (287/298), and 88.9% (265/298) had primary outcome data. Mtb infection prevalence at 12-month follow-up was 10.6% (28/265); 7.6% (10/132) in the INH arm and 13.5% (18/133) in the no INH arm (7.0 vs 13.4 per 100 person-years; hazard ratio, 0.53 [95% confidence interval {CI}, .24–1.14]; P = .11]), and driven primarily by TST positivity (8.6% [8/93] in INH and 18.1% [17/94] in no INH; relative risk, 0.48 [95% CI, .22–1.05]; P = .07). Frequency of severe adverse events was similar between arms (INH, 14.0% [21/150] vs no INH, 10.7% [16/150]; P = .38), with no INH-related adverse events. Conclusions Further studies evaluating TB preventive therapy to prevent or delay primary Mtb infection in HEU and other high-risk infants are warranted. Clinical Trials Registration NCT02613169.

scholarly journals Antibody-Secreting Cells To Diagnose Mycobacterium tuberculosis Infection in Children in Pakistan

mSphere ◽  
2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Najeeha Talat Iqbal ◽  
Kumail Ahmed ◽  
Farah N. Qamar ◽  
Fariha Shaheen ◽  
Aisha Mehnaz ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Serum Antibody ◽  
Preventive Therapy ◽  
Case Definition ◽  
Major Advance ◽  
Mycobacterium Tuberculosis Infection ◽  
Secreting Cell ◽  
Content Type ◽  
Antibody Secreting Cell ◽  
Pediatric Tuberculosis

ABSTRACT Reliance on microbiologic methods to diagnose Mycobacterium tuberculosis infection is a suboptimal approach for children due in part to the paucibacillary nature of the disease. A blood-based biomarker assay, such as the mycobacterial-antibody-secreting cell (MASC) assay, could be a major advance for the field of study of pediatric tuberculosis (TB). Children <15 years of age with clinical concern for TB and age-matched children with no concern for TB were enrolled from outpatient clinics in Karachi, Pakistan. MASC, ferritin, and C-reactive protein (CRP) assays were performed, and results were compared among cases and controls, as well as among children with a case definition of “confirmed TB,” “probable TB,” or “possible TB.” MASC responses were significantly higher among children with TB than among controls (0.41 optical density [OD] versus 0.28 OD, respectively, P < 0.001), and the differences were largely driven by the data from children with confirmed TB (P = 0.002). Ferritin and CRP values were significantly higher among those with confirmed TB than among those with the other disease states and controls (P = 0.004 and P = 0.019, respectively). The use of the MASC assay as a blood-based biomarker for TB disease shows some promise among children with microbiologically confirmed disease; however, the performance characteristics for the majority of young children with unconfirmed TB were suboptimal in this cohort. IMPORTANCE Tuberculosis (TB) in children represents a missed opportunity for diagnosis and preventive therapy. The magnitude or burden of disease in children is not fully understood due to our limitations with respect to exploring sensitive diagnostic algorithms. In a setting of TB endemicity in Pakistan, we carried out a proof-of-concept study to evaluate for the first time the performance of B cell analyses by the use of well-defined diagnostic criteria and NIH consensus guidelines as “culture-confirmed,” “probable,” and “possible” TB groups. In contrast to detection of serum antibody, we focused on mycobacterial-antibody-secreting cell (MASC) detection as a marker of active disease in children with a strong suspicion of TB. Further work exploring a larger panel of inflammatory biomarkers and enrichment of B cells with the objective of increasing the sensitivity of the current MASC assay would lead to the development of a field-friendly assay for timely diagnosis of childhood TB.

scholarly journals Acute inflammation, mediated by lung neutrophils, confers enhanced protection against Mycobacterium tuberculosis infection in mice

2021 ◽  
Author(s):  
Tucker J. Piergallini ◽  
Julia M. Scordo ◽  
Paula A. Pino ◽  
Jordi B. Torrelles ◽  
Joanne Turner
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Acute Inflammation ◽  
Mycobacterium Tuberculosis Infection ◽  
Positive Role ◽  
Innate Capacity ◽  
Time Of Infection ◽  
Lps Treatment ◽  
Partial Depletion

AbstractInflammation plays a crucial role in the control of Mycobacterium tuberculosis (M.tb) infection. In this study, we demonstrate that an inflammatory pulmonary environment at the time of infection mediated by liposaccharide (LPS) treatment in mice confers enhanced protection against M.tb for up to 6 months post infection. This transient protective inflammatory environment was associated with a neutrophil and monocyte/macrophage influx as well as increased inflammatory cytokines. In vitro infection of neutrophils from LPS treated mice demonstrated that LPS neutrophils exhibited increased recognition of M.tb, and had a greater innate capacity for killing M.tb. Finally, partial depletion of neutrophils in LPS treated mice showed an increase in M.tb burden, suggesting neutrophils conferred the enhanced protection observed in LPS treated mice. These results indicate a positive role of an inflammatory environment during initial M.tb infection, and suggests that acute inflammation at the time of M.tb infection can positively alter disease outcome.

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