Interleukin 33 in premenopausal women with rheumatoid arthritis: Is it related to generalized bone loss?

Abstract

Aim The aim was to study the role of interleukin (IL)-33 in rheumatoid arthritis (RA)-induced generalized bone loss in premenopausal women and its relation to general disease activity and various laboratory markers. Patients and methods A total of 60 premenopausal women with RA were enrolled in this work as a study group and 30 age-matched healthy women as a control group. The participants were subjected to full clinical, radiological, and laboratory assessments. The following were assessed in patients and controls by enzyme-linked immunosorbent assay technique: serum level of IL-33, 25-hydroxyvitamin D3 [25(OH) D3], and bone turnover markers, osteocalcin and C-terminal telopeptide of type I collagen. Bone mineral density was assessed using dual-energy X-ray absorptiometry. Results IL-33 was higher in patients with RA than controls (33.445 ± 10.07 vs 13.713 ± 0.70 pg/ml, P < 0.001). In patients with RA, serum level of IL-33 was found to be positively correlated with clinical and laboratory makers of disease activity (disease activity score 28 and C-reactive protein), anticyclic citrullinated peptide antibodies titer (P < 0.001), and bone erosions using Larsen's score (P = 0.026), in addition to serum level of C-terminal telopeptide of type I collagen (P = 0.023). No correlations were detected between serum level of IL-33 and osteocalcin, 25(OH) D3, or bone mineral density. Conclusion High serum level of IL-33 in patients with RA was found to be positively correlated with disease activity, bone erosions, and marker of bone resorption, suggesting its possible role in local and generalized bone loss in this disease, but larger studies are needed to ensure this effect.

Keywords

• interleukin-33
• osteoporosis
• rheumatoid arthritis