Vitamin D-binding protein as a biomarker to confirm specific clinical diagnoses

ABSTRACT

Introduction: Vitamin D-binding protein (DBP) performs a variety of functions as a transporter for various ligands and takes part in a number of systemic and local physiological and pathological processes. The knowledge about the pathomechanisms of this protein involvement justifies its use as a biomarker to confirm specific clinical diagnoses suggested by nonspecific signs and symptoms.

Areas covered: DBP has properties of both systemic laboratory parameters measured in the blood plasma and specific parameters measured in variety of physiological fluids to assess local changes in specific body organs. Articles published in English between 1993 and 2019 were searched for in PubMed using terms DBP, vitamin D, and metabolites, inflammation. DBP is a transport protein and a regulator of immune and inflammatory processes.

Expert opinion: DBP capacity for transporting numerous ligands and co-involvement of DBP in immune and inflammatory processes suggest that DBP may be used in laboratory diagnostics as a specific parameter to confirm pathomechanisms of several systemic diseases and local conditions. Changes in the concentration of DBP present in a variety of clinical material may provide valuable information for use in assessing the severity and treatment of pathological processes.

KEYWORDS:

• Vitamin D-binding protein
• inflammation
• neutrophil chemotaxis
• acute phase proteins
• vitamin D

Article Highlights

• DBP has properties of both systemic laboratory parameter measured in the blood plasma and specific parameter measured in a variety of physiological fluids to assess local changes in specific body organs.

• DBP serves as a transporter for vitamin D and with different affinities vitamin D analogues, binds with high capacity actin and is a carrier of saturated and unsaturated free fatty acids.

• DBP is involved in immune and inflammatory processes through macrophage and osteoclast activation and via C5a-co-chemotactic activity.

• DBP is the most polymorphic protein known, and different DBP alleles can have a substantial impact on its biological functions.

• The variability of DBP concentrations in physiological fluids depends on Gc polymorphism, non-specific acute phase response, hormones which regulate DBP production and affinity of DBP to bind with multiple cell-surface ligands.

• DBP concentrations determined in various clinical materials (urine, cervicovaginal fluid, bronchoalveolar lavage, gingival crevicular fluid, fresh thrombotic cells, synovial fluid, sputum, cerebrospinal fluid) may provide useful information on the functioning of the specific organs.

Declaration of interest

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.

Reviewers Disclosure

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

Additional information

Funding

This work was supported by a grant ‘Research Project funded by the National Centre for Science, No DEC-2011/01/B/NZ7/00648’.