CRP thresholds inform success of dexamethasone, tocilizumab against COVID-19 mortality

Using C-reactive protein (CRP) levels as indicators for early treatment with tocilizumab and dexamethasone can help reduce mortality in hospitalized patients with the coronavirus disease 2019 (COVID-19), a recent study has found.

Researchers conducted a retrospective analysis of 3,128 hospitalized COVID-19 patients (median age 66 years, 58.9 percent men) who required anti-inflammatory therapy. CRP levels within 24 hours of admission were retrieved from medical records. The primary outcome of interest was 30-day mortality.

A total of 381 patients died, yielding a global 30-day mortality rate of 11.8 percent. In patients treated with dexamethasone, deaths were numerically higher when CRP was ≤3.50 mg/dL and lower when CRP was >13.75 mg/dL (p=0.06 and p=0.08, respectively). In tocilizumab-treated patients, mortality was lower when CRP was >3.50 mg/dL, an effect that reached significance when CRP was >13.75 mg/dL (p=0.004).

Multivariate analysis confirmed that tocilizumab treatment in patients with CRP >3.5 mg/dL significantly protected against 30-day mortality, reducing such likelihood by 35 percent (odds ratio [OR], 0.65, 95 percent confidence interval [CI], 0.44–0.95; p=0.029). Similarly, the interaction between dexamethasone and CRP >13.75 mg/dL showed a significant and inverse correlation with 30-day mortality (OR, 0.57, 95 percent CI, 0.37–0.89; p=0.014).

“Our results suggest that anti-inflammatory therapy with dexamethasone and tocilizumab are associated with a reduction in mortality when prescribed to patients with a certain inflammatory activity as assessed by CRP, a cheap and widely available biomarker,” the researchers said.