IL-6 receptor antagonists benefit COVID-19 patients with high baseline death risk

Interleukin (IL-6) receptor antagonists provide significant clinical benefit in coronavirus disease 2019 (COVID-19) patients with high baseline mortality risk, a recent study has found. In contrast, such agents pose considerable threat when baseline mortality risk is low.

Drawing from the online databases of PubMed, Medline, WHO COVID-19 Database, Embase, PubMed Central, the Cochrane Library, Web of Science, Emcare, and Academic Search Premier, the researchers retrieved 71 studies eligible for meta-analysis. The cumulative sample included 29,495 patients, of whom 8,652 had been treated with IL-6 receptor antagonists.

Pooled analysis of 63 studies showed that IL-6 suppressed mortality risk overall (risk ratio [RR], 0.75, 95 percent confidence interval [CI], 0.65–0.86), with a corresponding 7.4-percent risk difference.

Due to substantial heterogeneity, the researchers conducted subsequent analyses, which showed that baseline mortality risk modified the effect of IL-6 use on mortality outcome. Indeed, they found that IL-6 receptor antagonists exerted significant beneficial effects on patients with high baseline mortality risks.

Similarly, IL-6 receptor antagonists suppressed the risk of mechanical ventilation (RR, 0.78, 95 percent CI, 0.62–0.96) and of the composite between mortality and mechanical ventilation (RR, 0.66, 95 percent CI, 0.54–0.82). No such effect was reported for admission into the intensive care unit.

Potential side effects included neutropaenia, impaired liver function, and secondary infections, all of which occurred more frequently in patients treated with IL-6 receptor antagonists.