Point-of-care diagnostics, a major opportunity for change in traditional diagnostic approaches: potential and limitations

Abstract

‘Point-of-care’ (POC) diagnostics are a powerful emerging healthcare approach. They can rapidly provide statistically significant results, are simple to use, do not require specialized equipment and are cost-effective. For these reasons, they have the potential to play a major role in revolutionizing the diagnosis, initiation and monitoring of treatment of major global diseases. This review focuses on antibody-based POC devices that target four major global diseases: cardiovascular diseases, prostate cancer, HIV infection and tuberculosis. The key statistics and pathology of each disease is described in detail, followed by an in-depth discussion on emerging POC devices that target each disease, highlighting their potential and limitations.

Keywords::

• acute myocardial infarction
• antibody
• biosensor
• cardiovascular disease
• HIV
• mHealth
• POC
• prostate cancer
• TB

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Erratum

Financial & competing interests disclosure

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending or royalties.

No writing assistance was utilized in the production of this manuscript.

Key issues

• A plethora of acute myocardial infarction (AMI) biomarkers are available, each with its own advantages and clinical utility, but no definitive evidence as to the ideal biomarker of choice is available. The multiplex measurement of AMI biomarkers appears to be the most viable means to improve the case for AMI diagnosis, as a significant increase in clinical accuracy was observed using this approach. However, it has still not been evaluated as to which biomarker combination can decisively diagnose AMI with high accuracy and confidence. While point-of-care tests (POCTs) are available for multi-marker detection, the critical flaw of inappropriate/suboptimal biomarkers identifications hampers performance.

• An overreliance on prostate-specific antigen, a non-prostate cancer (PCa)-specific biomarker, for PCa diagnosis can often lead to overdiagnosis and overtreatment. New emerging biomarker assays and measurements, such as prostate cancer antigen 3 and Prostate Health Index, are improving the case for discriminating between benign and cancerous diseases, however, the issue of lack of specificity has persisted. As with AMI, there is a requirement for determining a biomarker combination that can improve the overall clinical performance and for the approval of new biomarkers. Once this has been determined, POCTs can be developed, as currently there is a reliance on laboratory-based testing, which can have a long turnaround time and are considerably more expensive to perform. POCT in PCa diagnosis could have profound impact on large-scale disease monitoring, monitoring of disease state during treatment and providing a cost-effective alternative to laboratory-based testing.

• POCT is currently providing effective means for diagnosing patients with later-stage HIV in ‘resource-limited’ and outreach settings. However, POCT is lacking in the diagnosis of acute HIV infection (AHI) phase HIV patients, due to a lack of sensitivity to AHI biomarkers. Efforts to introduce laboratory-based issue with laboratory-based tests is the high cost associated and immunoassays into the POC may address the immediate need for more sensitive AHI diagnosis, but the issue of cost will persist. Thus, there is a requirement for the identification of AHI-specific biomarkers and the development of highly sensitive, low-cost assays that can detect such biomarkers in resource-limited settings.

• Tuberculosis (TB) biomarkers are emerging and are demonstrating significant potential in improving TB case detection and diagnosis. Promising biomarkers such as IFN-γ-inducible protein-10 and monocyte chemotactic protein-2 are claimed to significantly increase TB case detection, however, they are unable to discriminate latent and active disease. Other emerging biomarkers such as Mtb-specific TNF-α may address this need, but regulatory approval must first be acquired before such biomarkers can be put to use. At the time of writing, the case for approved immunological TB POCTs was poor, as these assays were severely deficient of sensitivity and specificity. The area of mHealth is showing potential for the identification of microorganisms in human samples and may be able to address the need for improved TB case detection; however, no data have emerged as to the clinical utility of such testing.

Notes