# A Novel Point-of-Care Assay for Diagnosing TB from Blood using Exosomes

> **NIH NIH R56** · UNIVERSITY OF CALIFORNIA, SAN DIEGO · 2022 · $754,249

## Abstract

Project Summary
Tuberculosis (TB) is the leading infectious disease killer globally, causing 1.5 million deaths annually, and
because most TB diagnoses currently rely on sputum-based tests that are complex or have low sensitivity, TB
is massively underdiagnosed leading to poor outcomes worldwide. Assays that detect Mycobacterium
tuberculosis (Mtb) antigens in blood could revolutionize TB diagnostics, because blood is easy to collect and
can detect TB not limited to the lungs; yet blood-base assays remain elusive due to ultra-low antigen
concentrations and cross-reacting elements present in blood. The objective of this proposal is to develop and
evaluate a highly innovative, blood-based point-of-care (POC) assay for rapid diagnosis of active TB
disease (ATB) based on detection of exosome-bound Mtb antigens in blood. We will exploit Alternating
Current Electrophoresis (ACE) on a POC platform to isolate and concentrate exosome-bound Mtb antigens in
unprocessed patient blood samples to diagnose active TB with accuracy that meets or exceeds World Health
Organization’s Target Product Profile (TPP) performance criteria for a TB triage assay (sensitivity >95%,
specificity >80%). This groundbreaking assay, originally developed for cancer diagnoses, uses ACE
technology to capture small (~0.1 to 1 micron) biomolecules such as exosomes from blood to concentrate Mtb
Ag while excluding potential inhibitors allowing them to be imaged using fluorescent antibody probes. This
study aims to: 1) evaluate the proof-of-concept Mtb Ag microchip assay on the ExoVerita Flex platform against
200 archived serum samples from patients with culture-confirmed ATB, LTBI, and culture-negative control
patients to quantify assay performance drivers and identify opportunities for optimizing assay performance,
potentially with additional Mtb antigens; 2) transfer the optimized Mtb Ag microchip assay from the ExoVerita
Flex platform to the OmniVerita-M POC reader using the same 200 archived serum samples from UCSD’s
biobank and characterizing the assay’s POC performance using prospectively collected whole blood (n=100);
and 3) determine the clinical sensitivity and specificity of the optimized assay on the POC reader in a field-
based study with prospectively collected blood samples from patients at risk for TB in settings with high
(Pakistan), medium (Mexico) and low (U.S.) TB burden (n=1,500). We will evaluate and optimize the Mtb Ag
assay using serum samples from a well-characterized Biobank and whole blood from patients with suspected
ATB (n=100) at the University of California, San Diego, and then assess its performance compared to standard
Mtb bacteriological confirmatory methods among patients with suspected ATB in field settings with a high
(Pakistan), medium (Mexico) and low (U.S.) TB burden (n=1,500). The proposed work is highly innovative in
that isolation of exosome-bound Mtb antigens in whole blood is a first-of-its-kind approach for TB diagnosis,
which may also be able ...

## Key facts

- **NIH application ID:** 10596302
- **Project number:** 1R56AI161826-01A1
- **Recipient organization:** UNIVERSITY OF CALIFORNIA, SAN DIEGO
- **Principal Investigator:** Richard S Garfein
- **Activity code:** R56 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $754,249
- **Award type:** 1
- **Project period:** 2022-05-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10596302

## Citation

> US National Institutes of Health, RePORTER application 10596302, A Novel Point-of-Care Assay for Diagnosing TB from Blood using Exosomes (1R56AI161826-01A1). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10596302. Licensed CC0.

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