Angiopoietin-like 4 (cANGPTL4) as a Novel Biomarker for Rapid Diagnosis and Prediction of Severity of Acute Pneumonia

Abstract/Technology Overview

There is an urgent need to develop more efficient diagnosis for acute pneumonia especially at early stages. By using cANGPTL4-centered biomarker, rapid diagnosis of pneumonia can be achieved from relatively non-invasive samples such as serum, sputum, and broncho-alveolar lavage fluid (BALF). In conjuction with local and overseas collaborators, samples from acute pneumonia patients were analyzed and matched with controls. By constructing a cANGPTL4 isoform-specific enzyme immunoassay (ELISA) diagnostic kit, the cANGPTL4 profiles in pneumonia patient samples were evaluated (concurrently with several established biomarkers) and correlated these with pneumonia severity and other parameters.

The technology’s first cANGPTL4 isoform-specific ELISA kit will focus on the lung injury status of the patient instead of only on the pathogen which most existing diagnostic kits identify. By combining other robust biomarkers and incorporating relevant diagnostic kit standards, the kit can potentially provide an accurate reflection of pneumonia severity to facilitate prompt clinical judgment and management. Moreover, this kit can potentially aid clinicians to triage acute pneumonia patients to prioritize them for antimicrobial therapy. Thus, the diagnostic kit can contribute to more efficient, timely and targeted pneumonia treatment to improve patient outcomes, especially in this era of ever-increasing multi-drug resistant bacterial strains. Currently, the anti-cANGPTL4 antibody have been validated in both Western blot and ELISA formats and the ELISA kit is being optimised for clinical application on patient samples.

Technology Features, Specifications and Advantages

The technology includes the development of novel diagnostic biomarkers to facilitate rapid and reliable pneumonia diagnosis. Angiopoietin-like 4 (ANGPTL4) is a multi-faceted protein involved in energy homeostasis, wound repair, tumorigenesis, angiogenesis, modulation of blood vessel permeability, and redox regulation. Studies showed that the C-terminal portion of ANGPTL4 (cANGPTL4) is significantly over-expressed during pneumonia induced by influenza infection in an animal model and in clinical lung biopsy samples, which is associated with the modulation of lung tissue permeability. This discovery has resulted in a patent filing, and has been reported in the media in various countries including Singapore, US, China, UK, Spain, and India.

The solution is based on a novel biomarker (cANGPTL4) that is directly associated with infection-induced immune responses such as cytokine production and activation of the inflammatory pathway. Expression of this biomarker coincides and co-localizes with damaged lung tissue in acute pneumonia, thus offering high specificity for detection of acute pneumonia. For technical development of the diagnostic assay, the widely-used, high-throughput ELISA approach is adopted based on a proprietary patented monoclonal antibody for cANGPTL4 detection, thus promising convenient application in the healthcare setting.

Potential Applications

According to the World Health Organization, lower respiratory tract infections are the leading cause of deaths in lower and middle income countries. As a major outcome of respiratory tract infections, pneumonia is ranked second of all the principal causes of death in Singapore, contributing to about 20% of all deaths. Pneumonia is also the leading cause of childhood mortality, accounting for 15% of all deaths of children below five years of age. Thus, effective diagnosis and treatment of pneumonia is critical in reducing mortality and morbidity caused by respiratory tract infections.

However, current techniques for the diagnosis of pneumonia are limited, and cannot provide sufficiently specific information for effective triage and monitoring of disease progression, which partly contributes to case fatality. Only about 30% of children with pneumonia receive appropriate therapy, despite over US$100 million spent annually on the diagnosis and treatment of pneumonia. Current diagnostic methods also have limitations for reflecting pneumonia severity in real-time, and for detecting lung tissue damage at the early stage of pneumonia. The technology offers a rapid diagnostic kit based on reliable biomarkers for infection-induced acute pneumonia.

Customer Benefit

In contrast to existing commercial kits for pneumonia detection, cANGPTL4 is a novel biomarker that reflects host lung tissue damage specifically, rather than being pathogen-centric. For example, the DiaPlexQTM PneumoPatho 13 detection kit can identify 13 types of common pneumonia-related pathogens, thus focusing on the etiologic agent rather than on the status of host lung damage or recovery which ultimately determines the patient’s lung function. Moreover, current diagnostic techniques (such as chest X-ray) to assess lung tissue integrity are not suitable for frequent use to reflect the disease status and treatment effect in real-time. The level of cANGPTL4 specifically correlates with pulmonary tissue damage during pneumonia in a spatio-temporal manner, thus enabling rapid diagnosis and evaluation of host lung tissue integrity. Our proposed diagnostic kit uses relatively non-invasively collected samples such as serum, sputum, ventilator aspirate or BALF, so that the clinician is alerted of the status of lung tissue injury or recovery in a timely manner. This will facilitate the objective and efficient judgment of the efficacy of current treatment strategies, as well as to tailor the therapy according to patient response.

Technology Owner

Tim Ang


National Health Innovation Centre Singapore

Technology Category
  • Diagnostics
  • Biotech Research Reagents & Tools
Technology Status
  • Available for Licensing
Technology Readiness Level
  • TRL 7