Eosinophil counts and LDH levels tend to return to normal range
over time in non-severe patients
We further analyzed the eosinophil counts and LDH levels in non-severe
and severe COVID-19 patients with chronic bronchitis, COPD, and asthma,
respectively. We found that there was a significant difference in
eosinophil counts and LDH levels between severe and non-severe patients
with chronic bronchitis and COPD whereas not in patients with asthma
(Figure 1). To observe the dynamic changes of eosinophil counts and LDH
levels over time, we collected the eosinophil counts and LDH levels on
the 5th, 10th,
15th, 20th, 25th,
and 30th day after admission. We found that eosinophil
counts increased over time both in severe and non-severe patients.
Meanwhile, LDH decreased over time (Figure 2). Severe patients showed a
slower recovery rate than non-severe patients, especially eosinophil
counts. Of note, both eosinophil counts and LDH levels recovered more
slowly in severe patients with COPD than those in severe patients with
chronic bronchitis and asthma. Our data suggest that, as the disease
improved, eosinophil counts and LDH levels tend to return to normal
range both in severe and non-severe patients, indicating a good
therapeutic effect of patients with chronic airway diseases in COVID-19
treatment.
We further performed multivariate analysis for mortality in COVID-19
patients with chronic airway inflammation using the above four variables
and found that eosinophil counts < 0.02×10⁹/L (odds ratio per
1 unit increase, 18.000 [95% CI 1.929-167.986], p = 0.011)
was the only independent risk factor for mortality (Supplementary Table
1). Moreover, Kaplan-Meier survival curves indicated that COVID-19
patients with eosinopenia or elevated LDH had worse survival probability
(p < 0.05) (Supplementary Figure 1). This suggests that
eosinopenia and elevated LDH are also potential predictors for the
mortality of COVID-19 patients with underlying chronic airway diseases.