Neutrophil‐to‐lymphocyte ratio and D‐dimer are biomarkers of death risk in severe COVID‐19: A retrospective observational study

BACKGROUND AND AIMS: Over 4 million deaths from coronavirus disease (COVID)‐19 have been reported in the world. Several biomarkers have been identified that predict disease severity, but there is still a need to identify biomarkers for death risk in severe COVID‐19. We aim to define amongst the biomarkers already identified those which are mostly associated with increased death rate in patients with severe COVID‐19. METHODS: In this retrospective study conducted in three public hospitals linked to the Medical School of Ribeirão Preto, Brazil, patients with severe COVID‐19 were evaluated regarding biomarkers (neutrophil‐to‐lymphocyte ratio‐NLR, D‐dimer, fibrinogen) of death risk, obtained before administration of corticosteroids. RESULTS: Thirty‐nine (32.8%) of the 119 patients included (104 [87.4%] on mechanical ventilation) died during hospitalization. Non‐survivor group had higher median (range) NLR (12.63 [2.6‐115] vs 7.43 [0.43‐31.8]; P = .001), D‐dimer (2.17 [0.27‐20.00] vs 1.57 [0.28‐20.00]; P = .03), but lower fibrinogen (631 [353‐1078] vs 705 [407‐1200]; P = .02). The group with NLR ≥ 10 and D‐dimer ≥ 2 μg/mL had a higher death risk than the group with NLR < 10 and D‐dimer < 2 μg/mL (OR: 5.39; CI 95%: 1.5‐19.42; P = .01). CONCLUSION: High NLR and D‐dimer, especially when combined, are predictors of death risk for patients with severe COVID‐19 and should be incorporated into their evaluation.