Decreased eosinophil counts and elevated lactate dehydrogenase predict
severe COVID-19 patients with underlying chronic airway diseases
Abstract
Background: Several predictors for the severity of coronavirus disease
2019 (COVID-19) have been reported. However, chronic airway inflammation
characterized by accumulated lymphocytes or eosinophils may affect the
pathogenesis of COVID-19. Methods: In this retrospective cohort study,
we reviewed medical records of all laboratory confirmed COVID-19
patients with chronic bronchitis, chronic obstructive pulmonary disease
(COPD) and asthma admitted in Sino-French New City Branch of Tongji
Hospital, a large regional hospital in Wuhan, China, from January 26th
to April 3rd. The Tongji Hospital ethics committee approved this study.
Results: There were 59 patients with underlying chronic airway
inflammation including chronic bronchitis, COPD and asthma. When
compared with non-severe patients, severe patients were more likely to
have decreased lymphocyte counts (0.6vs.1.1×10⁹/L, p<0.001),
eosinopenia (<0.02×10⁹/L, 73%vs.24%, p<0.001),
increased lactate dehydrogenase (LDH) (471.0vs.230.0 U/L,
p<0.001) and elevated IL-6 level (47.4vs.5.7 pg/ml, p=0.002)
on admission. Eosinopenia and elevated LDH were significantly associated
with disease severity in both univariate and multivariate regression
models included the above variables. Eosinopenia was also an independent
risk factor for mortality of this cohort in a multivariate model
included the above variables. Moreover, eosinophil counts and LDH levels
tended to return to normal range over time in both groups after
treatment and severe patients recovered slower than non-severe patients,
especially eosinophil counts. Conclusions: Eosinopenia and elevated LDH
are potential predictors of disease severity in COVID-19 patients with
underlying chronic airway diseases. Theses predictors may help
clinicians identify the severe COVID-19 patients with chronic
bronchitis, COPD and asthma.