Cell-bound complement activation products as lupus biomarkers: diagnosis, monitoring and stratification

ABSTRACT

Introduction: Cell-bound complement activation products (CB-CAPs) were first reported in 2004, since which time multiple laboratories have demonstrated their value as biomarkers for diagnosis, monitoring, and stratification of patients with systemic lupus erythematosus.

Areas covered: This review summarizes the highlights of these 14 years of CB-CAPs discovery and validation, concluding with a view toward their future potential for precision medicine.

Expert commentary: The practice of medicine is both art and science and each physician can be considered both artist and scientist with a variable blend of the two skill sets. There is arguably no disease that presents a greater challenge, nor a greater opportunity, for implementation of precision medicine, as does lupus. The physician who is presented with diagnosis and/or management of a patient suspected of having lupus will need to augment artistic skills with scientific guidance, and that science will be delivered in the form of biomarkers. Ultimately, we will likely have a ‘lupus liquid biopsy’ that will be 100% sensitive and 100% specific for a diagnosis of lupus. This will undoubtedly be a panel of biomarkers rather than an individual laboratory test. Such a liquid biopsy could transform lupus diagnosis to an entirely scientific process.

KEYWORDS:

• Biomarker
• CB-CAPs
• complement
• diagnosis
• lupus
• monitoring
• SLE
• precision medicine

Declaration of interest

J Ahearn and S Manzi are inventors of CB-CAPs (Royalties received from University of Pittsburgh), and consultants for Exagen Diagnostics, which holds exclusive license to CB-CAPs technology. CC Liu is an inventor of CB-CAPs (Royalties received from University of Pittsburgh). The authors have no other 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 apart from those disclosed.

Additional information

Funding

This article was supported by Pennsylvania Department of Health SAP# 4100073189.