Ex-vivo Cell-based Assay for Assessment of Response to TNF Inhibitors in Patients with Rheumatic Diseases.

OBJECTIVE: TNF inhibitors (TNFi) comprise 5 products whose structure and signalling differ. An individual patient with a rheumatic disease may respond to one TNFi but not to another. In addition, 30-40% of the patients respond inadequately to TNFi. The different TNFi downstream signalling may lead to their clinical efficacy. Several reports showed that TNFi exhibited differential effects on Th17 cells. We analyzed the different TNFi effects on IL-17A expression in the peripheral blood mononuclear cells (PBMCs) of patients with rheumatic diseases in order to evaluate the predictive capability of responses in an ex-vivo setting. METHODS: PBMCs were co-cultured with the different TNFi or medium (control), and IL-17A mRNA levels were analyzed by qPCR. IL-17A expression levels in response to 4 TNFi (except certolizumab pegol) were compared with control. IL-17A expression in the assay was correlated to the clinical responses. Assay sensitivity and specificity for distinguishing responders from non-responders was calculated by receiver-operating characteristic (ROC) analysis. RESULTS: The results of a retrospective cohort of patients with rheumatic diseases (n = 82) correlated with their therapeutic responses to the different TNFi with 89.5% accuracy. The assay predicted the responses of a prospective cohort (n = 54) to specific TNFi with 79% accuracy. CONCLUSION: This functional assay could assist in predicting the odds for response to TNFi therapy, indicating whether a given patient is likely to respond to a specific TNFi.

Synovial monocytes from psoriatic and rheumatoid arthritis patients are modulated differently by TNF inhibitors and glucocorticoids: an ex-vivo study.

OBJECTIVES: Synovial monocytes (expressing CD14+CD16+) affect pro-inflammatory responses in the synovium microenvironment of psoriatic arthritis (PsA) and rheumatoid arthritis (RA). The effect of various drugs on those cells was evaluated. METHODS: Synovial fluid mononuclear cells (SFMCs) from PsA (n=29) and RA (n=11) patients were cultured with biologics or glucocorticoids (GCs). CD14+CD16+ cells were analysed by flow cytometry. TNF secretion was assessed by ELISA and changes in cytokine and matrix metalloproteinase-9 (MMP-9) mRNA by qPCR. RESULTS: TNF inhibitors (i) [adalimumab (ADA) and infliximab (IFX)] significantly reduced the %CD14+CD16+ cells (p<0.04 and p<0.02, respectively) compared to IL-17Ai, IL-12/23i, and GCs in PsA patients' SFMCs. Similarly, those TNFi reduced the %CD14+CD16+ cells (p<0.05 and p<0.02, respectively) compared to IL-6Ri, CD20i and GCs in RA patients' SFMCs. TNFi (ADA p<0.01, IFX p=0.0003), and GCs (p<0.05) reduced TNF levels in PsA patients SFMCs supernatants. IFX down-regulated IL-1ß mRNA (p<0.005) while GCs betamethasone (BET) (p<0.01) and methylprednisolone acetate (MPA) (p<0.005) led to IL-1ß up-regulation. IFX down-regulated IL-8 and MMP-9 (p<0.01) and up-regulated IL-10 (p<0.005), and GCs did so to a greater extent (for IL-8, BET p<0.0001 and MPA p<0.005, for MMP-9, BET and MPA p<0.0001 and for IL-10, BET and MPA p<0.0001). CONCLUSIONS: TNFi but not GCs reduced the inflammatory monocytes. Both TNFi and GCs inhibited TNF secretion but differently modulated IL-1ß, IL-8, MMP-9 and IL-10 gene expression. Our data point to TNFi as a modulator of synovial monocytes.