title: Vitamin K homologs as potential biomarkers for disease activity in patients with rheumatoid arthritis.
abstract: The aim of this study was to evaluate the possible role of vitamin K homologs as potential biomarkers for disease activity in patients with rheumatoid arthritis (RA). In this study, 42 patients with RA and 40 healthy controls were enrolled. Serum levels of vitamin K homologs were measured using a high-performance liquid chromatography-fluorescence method. Different biochemical and clinical markers for disease activity were measured and correlated with serum levels of vitamin K homologs. There were no significant differences between RA patients and healthy subjects in demographic data. Patients with RA showed significantly higher levels of biochemical markers compared with healthy subjects (p < 0.001). These markers included rheumatoid factor (RF), anticyclic citrullinated polypeptide (anti-CCP), undercarboxylated osteocalcin (ucOC), matrix metalloproteinase (MMP-3), C-reactive protein (CRP), and disease activity score assessing 28 joints with erythrocyte sedimentation rate (DAS28-ESR). In addition, serum levels of vitamin K homologs were reduced in RA patients, and the levels of menaquinone-4 (MK-4) and menaquinone-7 (MK-7) were moderately to strongly inversely correlated with the clinical articular features in RA patients, whereas phylloquinone (PK) levels were weakly correlated. Serum levels of MK-4, MK-7 and PK were strongly inversely correlated with ucOC, MMP-3 and DAS28-ESR in RA patients. In contrast, serum levels of MK-4, MK-7 and PK were weakly correlated with CRP, RF and anti-CCP. These results suggest that serum levels of vitamin K homologs may be considered as potential biomarkers for disease activity. In addition, the results confirm the role of vitamin K deficiency in the etiology of RA.
authors.affiliation: Department of Clinical and Hospital Pharmacy, College of Pharmacy, Taibah University, Al Madinah AlMunawarah, Saudi Arabia. hkhojah@taibahu.edu.sa.
authors.forename: Hani M
authors.initials: HM
authors.lastname: Khojah
authors.affiliation: Department of Pharmacognosy and Pharmaceutical Chemistry, College of Pharmacy, Taibah University, Al Madinah AlMunawarah, Saudi Arabia.
authors.forename: Sameh
authors.initials: S
authors.lastname: Ahmed
authors.affiliation: Department of Pharmacology and Toxicology, College of Pharmacy, Taibah University, Al Madinah AlMunawarah, Saudi Arabia.|Department of Pharmacology, Faculty of Medicine, Assiut University, Assiut, Egypt.
authors.forename: Mahran S
authors.initials: MS
authors.lastname: Abdel-Rahman
authors.affiliation: Department of Rheumatology, King Fahd Hospital, Al Madinah AlMunawarah, Saudi Arabia.
authors.forename: Khaled M
authors.initials: KM
authors.lastname: Alkhalil
authors.affiliation: Department of Rheumatology, King Fahd Hospital, Al Madinah AlMunawarah, Saudi Arabia.
authors.forename: Al-Badr
authors.initials: AB
authors.lastname: Hamza
keywords: Biomarkers; DAS28-ESR; Matrix metalloproteinase; Rheumatoid arthritis; Vitamin K homologs