Compared with healthy controls, patients with rheumatoid arthritis (RA) demonstrated higher serum concentrations of galectin-3 and interleukin-7 (IL-7), especially with increased disease activity, suggesting their potential use as RA biomarkers, according to study findings published in The Egyptian Rheumatologist.
Researchers assessed the relationship between galectin-3 and IL-7 serum concentrations and disease activity in 66 patients with RA treated at outpatient rheumatology clinics at Cairo University Hospitals compared with 20 age- and sex-matched healthy control participants. Age of the study participants ranged from 17 to 78 years, and 92.4% of the patients with RA were women.
Following a thorough clinical evaluation, the researchers obtained 8 mL of venous blood samples from each participant and used an enzyme-linked immunosorbent assay (ELISA) to determine galectin-3 and IL-7 serum concentration levels. Disease activity was measured using the disease activity score (DAS28).
Among the patients with RA, the average number of tender joints was 8.1 ± 8.6, the average number of swollen joints was 3.6 ± 4.7, and the average DAS28 score was 4.72 ± 1.77.
Other symptoms and diagnoses included dry eyes (31.8%), dry mouth (25.8%), fibromyalgia (21.2%), subcutaneous nodules (19.7%), fever (6.1%), carpal tunnel syndrome (6.1%), hepatitis C virus (6.1%), weight loss (4.5%), peripheral neuritis (4.5%), interstitial lung disease (4.5%), pleural effusion (1.5%), and pulmonary nodules (1.5%).
Patients with RA had higher serum galectin-3 and IL-7 concentration levels compared with control participants (P <.001 for both). The concentration levels of both markers significantly correlated with RA clinical characteristics as well as heightened RA disease activity as indicated by the DAS28.
Serum galectin-3 demonstrated 84.8% sensitivity and 100% specificity as a diagnostic biomarker for RA (95% CI, 0.927-0.997; P <.001), while serum IL-7 demonstrated a 92.4% sensitivity and 95% specificity (95% CI, 0.932-1.006; P <.001).
A limitation of the study included the small sample size, which may require future larger scale studies to confirm the diagnostic and prognostic potential of galectin-3 and IL-7.
The study authors concluded, “[S]erum levels of galectin-3 and IL-7 were considerably greater in [patients with] RA than in controls and both were elevated in high disease activity making them promising markers. Both serum galectin-3 and IL-7 showed high diagnostic power for RA… [and] may provide further understanding of RA pathogenesis and suggest new therapeutic interventions.”
Abdel Baki NM, Elgengehy FT, Zahran AM, et al. Galectin-3 and interleukin-7 as potential serologic markers in rheumatoid arthritis patients. Egypt Rheumatol. 2022;44(4):319-324. doi:10.1016/j.ejr.2022.04.003