Blood-based biomarkers of chronic inflammation

ABSTRACT

Introduction

Diseases related to chronic persisting inflammation are amongst the largest sources of morbidity and health costs, yet biomarkers for early diagnosis, prognosis, and treatment response are not sufficiently effective.

Areas covered

This narrative review discusses how inflammation concepts have evolved from ancient times to the present, and places in perspective the use of blood-based biomarkers to assess chronic inflammatory diseases. From reviews of biomarkers in specific diseases, emerging biomarker classifiers and their clinical utility is discussed. Biomarkers representative of systemic inflammatory response such as C Reactive Protein are distinguished from local tissue inflammation markers such as cell membrane components and molecules involved in matrix degradation. The application of newer methodologies such as gene signatures, non-coding RNA, and artificial intelligence/machine-learning techniques is highlighted.

Expert opinion

The dearth of novel biomarkers for chronic inflammatory diseases can be ascribed in part to the lack of basic understanding about non-resolving inflammation, and in part by fragmentation of effort whereby individual diseases are studied but their pathophysiologic commonalities and differences are neglected. Finding better blood biomarkers for chronic inflammatory diseases may be best addressed by studying cell and tissue products of local inflammation, augmenting data interpretation by artificial intelligence techniques.

KEYWORDS:

• Artificial intelligence
• axial spondyloarthritis
• biomarkers
• chronic inflammation
• inflammatory bowel disease
• inflammation pattern
• laboratory diagnostics
• non-resolving inflammation

Article highlights

• Inflammation concepts are reviewed with emphasis on concepts of non-resolving chronic inflammation.

• Historical and current inflammation classifications are discussed with emphasis on the interrelationships of inflammatory and immune reactions.

• Blood-based biomarkers for inflammation are reviewed with focus on clinical utility, biomarker types, and distinction between biomarkers for systemic inflammation and those for local tissue inflammation.

• C Reactive Protein, the current standard blood protein inflammation biomarker, is discussed from perspective of clinical utility for systemic inflammation.

• The prospects for better blood biomarkers indicative of local tissue inflammation are discussed, as well as the future application of artificial intelligence/machine-learning techniques to inflammation biomarkers.

Declaration of interest

Kenneth Pritzker is affiliated with and has financial interests in KeyIntel Medical Inc.

Reviewers disclosure

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded.