Interleukin-6 receptor inhibition with tocilizumab induces a selective and substantial increase in plasma IP-10 and MIP-1β in non-ST-elevation myocardial infarction.

Aim: To evaluate the effect of interleukin-6 inhibition with tocilizumab on the cytokine network in patients with acute non-ST-elevation myocardial infarction (NSTEMI).

Methods: 117 patients with acute NSTEMI were randomised to an intravenous infusion of 280 mg tocilizumab or placebo prior to coronary angiography. Blood samples were obtained at baseline, at 6 consecutive points in time during hospitalisation, and at follow-up after 3 and 6 months. Cytokines (n = 27) were analysed with a multiplex cytokine assay.

Results: Using a mixed between-within subjects analysis of variance, we observed a significant (p < 0.001) between-group difference in changes for interferon gamma-inducible protein (IP-10) and macrophage inflammatory protein-1β (MIP-1β), due to significant increases in the tocilizumab group during hospitalisation (i.e., IP-10 median change from baseline during hospitalisation (m), placebo: 3 (-60, 68) pg/ml vs tocilizumab: 209 (69, 335) pg/ml; MIP-1β m, placebo: 5 (-2, 12) pg/ml vs tocilizumab: 39 (24, 63) pg/ml). MIP-1β was inversely correlated to troponin T (r = -0.28, p < 0.05) and neutrophils (r = -0.32, p < 0.05) in the tocilizumab group. In contrast, tocilizumab had only modest or no effects on the other examined cytokines.

Conclusions: Tocilizumab led to a selective and substantial increase in IP-10 and MIP-1β during the acute phase of NSTEMI, with no or only minor effects on the other measured cytokines. ClinicalTrials.gov, NCT01491074.