Presenting Characteristics
Table 1 lists the characteristics of all discharged patients. The median age for moderate symptom patients was 40 years (range, 1-78 years), while 19 years for mild-symptom patients (range, 7-39 years), as well as 63 years (range, 32-69) for critical patients (one-way ANOVA, p<0.0001). Approximately 48 patients (51%) were the patients aged ≤40 years, including 2 children under 3 years. Overall, 15 patients had one or two types of chronic cardiovascular diseases, including coronary heart disease (CHD), hypertension (HBP) or diabetes (T2DM). 79 of them had resided in Hubei province, while another 13 had the history of contact with Hubei residents. But none of them were exposed to the Huanan seafood market. According to our research, 36 of the 94 patients (38%) were associated with familial clusters. There was no significant difference among mild, moderate or severe group of patients by their epidemiology history. However, three groups of patients indeed presented significantly different illness onset on the most common symptoms like fever (one-way ANOVA, p=0.0089), fatigue (one-way ANOVA, p=0.0001) and diarrhea (one-way ANOVA, p=0.0486), but not pharyngalgia or dry cough (Table 1). Besides, the average length of hospital stay and interferon treatment duration of moderate group were 14.12 (13.34~14.90) days and 14.24 (13.45~15.03) days, respectively. While those of the severe group took average 2.08 days and 1.44 days longer than total average levels.
Differences on Laboratory Parameters
Figure 1 showed the outcomes of blood cell counting. On admission, only the amount of platelets (Figure. 1D) exhibited obvious differences among three groups (p=0.006, one way ANOVA; p<0.05, severe group vs moderate group). For the following 6 days, there was no significant difference on numbers of immune cell types until Day 9, when the increased white blood cell (WBC) and neutrophil cell numbers significantly higher in severe group comparing with moderate group (Figure 1A and 1B). Shown in Figure 1C with quite distinguishable difference on cell accounts among three group, the lymphocyte number in severe group remained lower within the first week of hospitalization (p<0.05, vs moderate group on day 3 and 6, respectively). From then on, the lymphocyte number increased in severe group and turned to as similar level as other patients.
Figure 2 showed the blood biochemical test at different time points. Among the first 6-9 days of hospitalization, patients in severe group showed significantly higher levels of serum interleukin 6 (IL-6) and LDH than those in moderate group (Figure 2B and 2C). Except for mild group, there was a fluctuation around day 3 on hospital in serum C-reactive protein (CRP) and IL-6 levels, which then dramatically dropped down around Day 6 to 9 in both moderate and severe group of patients (Figure 2A and 2B). Besides, the CK concentration declined rapidly in severe group (Figure 2D). In contrast, the changes of serum LDH concentration slipped smoother during hospital stay and the differences remained significance among three groups until day 12, approaching similar level after that (Figure 2C).
Correlations between PCR negative conversion rate and serum LDH or CK level
PCR negative conversion rate was calculated by the rate of PCR negative to all undischarged patients by PCR detection of viral mRNA. The results indicated that the PCR negative conversion rate was over 50% since Day 6 (59.46%) and kept increasing up to 95.45% on Day 15 (Table 2). Linear regression analysis was used to study the relationships between serum LDH or CK concentrations and PCR negative conversion rate. Figure 3A and 3B showed that there existed a significant inverse correlation between PCR negative conversion rate and average CK level (r square=0.822, p=0.0337) instead of LDH level (r square=0.696, p=0.079). Further revised average LDH and CK concentrations in PCR positive patients were all inversely correlated with the negative conversion rate (r square=0.843, p= 0.0279 and r square=0.890, p= 0.0161) (Figure 3C and 3D).
Relationship between lengths of hospital stay and PCR negative conversion times in different antiviral treatments
There were 46 patient treated with IFN-α + lopinavir/ritonavir. Another 21 patient were treated with IFN-α + lopinavir/ritonavir combined with ribavirin. As Figure 4A and 4B shown, there was no significant different on average lengths of hospital stay or PCR negative conversion times among different antivirus treatment groups. On the other hand, correlation analysis (Figure. 4C and 4D) indicated that the lengths of hospital stay were significantly correlated with PCR negative conversion times in IFN-α + lopinavir/ritonavir + ribavirin group (p= 0.0215), as well as IFN-α + lopinavir/ritonavir group (p=0.012).