Introduction and Background of the Project

Introduction

Tuberculosis (TB), caused by Mycobacterium tuberculosis, is one of the most challenging infectious diseases, with ten million new cases and up to two million deaths reported worldwide every year. Control efforts have been hampered by limitations of available diagnostic tests, which are primarily performed on sputum samples. Sputum-based tests are inefficient and also cannot be used to diagnose extrapulmonary TB, and certain patient populations such as children and people living with HIV cannot produce sputum. There is an urgent need for non-sputum-based TB tests at the point of care (PoC), for all kinds of TB and in all patient populations.

Lipoarabinomannan (LAM) is an established TB biomarker that is present in urine of TB patients. Currently available LAM tests have poor sensitivity and can only be used in people living with HIV. An ultrasensitive PoC test for urine LAM could improve diagnostic accuracy and enable expansion of TB testing and thereby impact TB outcomes and reduce transmission.

Fluxus, Inc. (Sunnyvale, CA, USA) is an industry leader in optofluidics that develops and commercializes next-generation ultrasensitive analytical detection systems with an emphasis on single-molecule counting. Fluxus is developing an ultrasensitive urine TB test based on optofluidic technology that combines integrated optics and microfluidics on a single chip-based system.

Project objective

To develop a prototype portable PoC system and integrated ultrasensitive assay for detection of LAM in urine. The test will be benchmarked to a fully-validated ultrasensitive urine LAM assay being developed on Fluxus’ automated benchtop immunoassay analyzer.

Project design

The project objectives will be achieved by performing the following Specific Aims: 1) Complete development and validation of an ultrasensitive urine LAM assay on an existing benchtop immunoassay analyzer. This assay will be adapted and transferred to a stable and cost-effective PoC cartridge format. 2) Design and development of critical components for a portable, ultrasensitive PoC system, with functional cartridge and prototype PoC LAM assay.

How can your partnership (project) address global health challenges?

An estimated three million new TB cases are missed each year due to underdiagnosis and lack of accurate and accessible diagnostic. Currently available tests are hampered by poor sensitivity, high cost and complexity, long turnaround time, and/or infrastructure deficiencies, and sputum-based tests cannot be used in all patient populations or for all forms of TB. There is a great need for an ultrasensitive urine LAM PoC test, to expand the use and increase the diagnostic yield in TB, and thereby lead to improved clinical outcomes and reduced transmission.

What sort of innovation are you bringing in your project?

Fluxus’ optofluidic single-molecule counting technology has been successfully demonstrated on a benchtop analyzer, with ultrasensitivity achieved for a urine LAM prototype assay. The technology’s core concept is based on intersecting optical waveguides and microfluidic channels on a tiny microfabricated chip, enabling detection of individual fluorescent reporter molecules bound to LAM. As a key part of this project, Fluxus will draw on its expertise and experience in advanced photonics, hardware/software engineering, microfabrication, bioconjugation, and assay development to incorporate this same technology and performance into a small, robust, and portable device.

Role and Responsibility of Each Partner

Fluxus is the overall coordinator of the project and will be responsible for the development of the ultrasensitive LAM assay and the PoC-compatible system. Fujirebio will provide technical expertise and guidance. Stanford University and Health Care and the Rapid Research in Diagnostics Development for TB (R2D2) Network will provide access to clinical samples as well as expertise and guidance on clinical development.