Background Significant advances in the treatment of rheumatoid arthritis (RA) with biological treatments have led to the search for new biomarkers and has become an important area of research in RA, analyzing new molecules and parameters for better diagnosis, assessment of severity/disease activity and degree of response to treatment.

Objectives In this preliminary study was intended to describe the variation of the serum levels of various cytokines and analyze its relationship with clinical features, genetics and response to treatment with infliximab - a blocking of the action of TNF alpha - in patients with RA.

Methods We included patients with definite RA (ACR criteria 1987) with active disease (defined by DAS28>3.2) despite treatment with methotrexate and had started treatment with infliximab iv at a dose of 3 mg/kg at 0, 2, 6, 14, 22 and 30 weeks. We collected peripheral blood samples for DNA isolation (identification of genetic polymorphisms of HLA-DRB1 and TNF (-238A/G and-308A/G) and make the determination of levels of TNF alpha, IL1 beta, IL6, IL8, IL10, IL12 and nitric oxide at weeks 0th (baseline) and 30th. Cytokines were determined by flow cytometry using the cytometric Multiplex Bead ArrayKit. Demographic, clinical and laboratory caractheristics were recorded. Functional disability index (HAQ) and disease activity (DAS 28) at baseline and 30th week also. We divided patients into 2 groups according response to treatment and their time course of the disease more and less than 10 years. Statistical analysis was performed using SPSS 17.0. (chi square, Student’s t test and Mann-Whitney U-test).

Results We included 26 patients with RA, 22 (84.6%) women, with age at diagnosis of 39.4 years (SD10.9), duration of illness 11.0 years (SD 7.6), presence of rheumatoid factor 21 patients (80.8%),erosions in 19 (73.1%) and nodules in 6 (23.1%). Fifteen patients (57.7%) met EULARresponsecriteria at 30th week (reduction of DAS28>1.2) and 11patientsnot, with a decrease in DAS28 at 30th week of 2.50 (0.84) in responders and 0.25 (0.73) in non-responders (p<0.0001). The reduction of serum levels of cytokines from baseline to30th was significant for IL6 (p 0.001),IL1beta

(p 0.025),IL8 (p0,007) and nitric oxide (p 0.041) but did not correlate with the activity of disease and response to treatment. Differences were observed in serum levels of IL6 in patients with less than 10 years history of RA (n=14) but did not differ according to the EULARresponse to treatment (see table).

Conclusions Almost all patients reached decreases of all cytokines mainly IL6, IL1beta, IL8 and nitric oxide after treatment 30 weeks with infliximab. Nevertheless, in this preliminary study only IL6 presented decreases most significant in those patients whose disease had an evolution of less than 10 years.

Disclosure of Interest None Declared