Association of IL-6 and autoantibody levels with the number and phenotype of infiltrating neutrophils in inflamed joints of patients with rheumatoid arthritis

GORLINO CV; BLAS R; DÍAZ-GABUTTI MS; MUNARRIZ A; TAMASHIRO H; PARDO-HIDALGO RA; PISTORESI-PALENCIA MC; DI GENARO MS

Mar del Plata

Congreso; LXIV Reunión Anual de la Sociedad Argentina de Inmunología; 2016

SAI

Background/Purpose. In Rheumatoid arthritis (RA), neutrophils are recruited into inflamed joints enhancing tissue injure. Accumulated evidence has demonstrated that interleukin (IL)-6 modulates neutrophil influx at sites of inflammation and promotes humoral immunity. Among the numerous autoantibodies associated with RA, anti-cyclic citrullinated peptide antibodies (ACPA) are recognized the most disease-specific. The aim of this study was to investigate the association among ACPA, neutrophil influx and IL-6 in the inflamed joints of RA patients. Methods. Synovial fluid (SF) samples were obtained from 60 RA patients. All patients gave informed consent and the study was approved by the ethic board from IBYME. Cytokine and ACPA levels were measured by ELISA and the expression of CD16, CD62L, CXCR1, and CD66b were assessed by flow cytometry. Results. We showed that in SF of ACPA-positive patients, IL-6 levels positively correlated with neutrophil counts (p=0.009) and with IL-8 (p=0.04). Moreover, in SF of patients with high ACPA levels (ACPA-high SF: >200 U/ml) IL-6 was significantly increased (p