Increased Neutrophil Activation, Cell Death in Rheumatoid Arthritis

In patients with rheumatoid arthritis (RA), neutrophils undergo increased activation and cell death, according to study results published in Arthritis & Rheumatology. The results also indicated that neutrophil biomarkers can be used for monitoring and prognosis in patients with RA.

The study included 3 cross-sectional RA cohorts and healthy participants. The researchers used ELISA to analyze markers of neutrophil activation (calprotectin) and cell death (neutrophil extracellular traps) in plasma. They used a longitudinal inception cohort (n=247) for predictive analyses. The patients were followed for a median of 8 years. Compared with healthy individuals, patients with RA had increased markers of neutrophil activation and cell death (P <.0001).

The researchers found that calprotectin levels were associated with the Clinical Disease Activity Index score (r=.53; P <.0001). Patients with active RA and patients in remission could be determined by levels of calprotectin, which is an effect not seen with C-reactive protein.

The results indicated that a biomarker panel of anticitrullinated protein antibodies and calprotectin could predict erosive disease (odds ratio [OR], 7.5; P <.0001) and joint space narrowing (OR, 4.9; P =.001). The levels of neutrophil extracellular traps correlated with higher levels of cell-free citrulline (P =.02) and inflammation (P =.0002). In addition to a neutrophil activation signature biomarker panel, neutrophil extracellular traps had good predictive value for identifying patients with RA developing extra-articular nodules (OR, 5.6; P =.006).

“Future studies are needed to validate our findings in larger cohorts, as well as evaluate whether early identification of these patients would lead to effective preventative treatment strategies,” the researchers wrote.

Reference

Bach M, Moon J, Moore R, et al. A neutrophil activation biomarker panel in prognosis and monitoring of patients with rheumatoid arthritis [published online July 28, 2019]. Arthritis Rheumatol. doi:10.1002/art.41062