Blood-based diagnosis of pediatric tuberculosis: A prospective cohort study in South Africa and Dominican Republic.

Summary

In two prospective cohorts (n=258), a serum MAP-TB assay diagnosed pediatric TB—including unconfirmed and extrapulmonary cases—and tracked treatment response. Sensitivity was comparable to culture/Xpert for confirmed TB, though specificity declined when infants <1 year were included.

Key Findings

• MAP-TB sensitivity for confirmed/unconfirmed pediatric TB was comparable to culture/Xpert for confirmed TB.
• Specificity was age-dependent and declined from 98.1% to 78.4% when including children <1 year.
• MAP-TB values decreased by six months after treatment initiation in children with clinical improvement, supporting response monitoring.

Clinical Implications

Serum MAP-TB could reduce reliance on invasive respiratory sampling in children, support earlier diagnosis—including extrapulmonary disease—and provide a tool for monitoring treatment response.

Limitations

• Specificity falls in infants <1 year, which may necessitate age-tailored thresholds.
• Exact operating characteristics by TB phenotype and HIV status are not detailed in the abstract.

Future Directions

Head-to-head implementation studies versus Xpert Ultra and host transcriptomic assays, age-specific threshold optimization, and evaluation in high-HIV-burden settings.