B cell depletion in patients with rheumatoid arthritis is associated with reduced IL-1β in GCF

Objectives: We evaluated the effect of B cell depletion on the clinical periodontal findings and IL-1β and MMP-8 levels of the gingival crevicular (GCF) fluid in patients with rheumatoid arthritis (RA).

Materials and methods: Seventy patients were included in this case-control study. Twenty patients with RA were undergoing B-cell depletion treatment. The second group of RA patients (n = 20) were undergoing non-B-cell depletion treatment with Disease-Modifying Anti-Rheumatic Drugs (DMARD). Control group, with no RA, consisted of 30 individuals. Periodontal parameters including probing depth (PD), clinical attachment level (CAL), bleeding on probing (BOP), gingival index (GI), and plaque index (PI) were recorded. IL-1β and MMP-8 levels in GCF were determined using enzyme-linked immunosorbent assay. Rheumatological parameters including Disease Activity Score-28 (DAS-28), rheumatoid factor levels (RF), and anti-cyclic citrullinated peptide levels were included in the data analyses.

Results: All groups were similar in PD, CAL, BOP, GI, and PI measures. GCF IL-1β levels were 1.85 ± 1.67 pg in the B-cell depletion group, 10.50 ± 13.16 pg in the DMARD group, and 34.12 ± 29.45 pg in the control group (p < 0.001). MMP-8 levels were 21.00 ± 4.23 pg in the B-cell depletion group, 8.16 ± 6.94 pg in the DMARD group, and 21.45 ± 8.67 pg in the control group (p < 0.001). DAS 28, RF, and anti-CCP were similar in RA groups.

Conclusions: GCF IL-1β levels were significantly lower in B cell depletion group, and MMP-8 levels were significantly lower in DMARD group, suggesting that rheumatoid arthritis treatments may modify biochemical parameters of GCF.

Clinical relevance: This study suggests that host modulation therapies in RA can reduce local production of IL-1β and MMP-8. Reduction of these inflammatory cytokines and enzymes may have a beneficial effect in controlling periodontal tissue destruction.