Demographic and Clinical Characteristics of Non-severe Patients at Admission
Thirteen COVID-19 patients who presented with non-severe disease upon admission were enrolled in the study. The demographic and clinical characteristics of the 12 non-severe patients are shown in Table 1. The demographic and clinical characteristics of the single patient who developed to severe COVID-19 during hospitalization are described separately. The average age of the 12 non-severe patients was 40±13 years, ranging from 22 to 89 years. Seven (58.33%) patients were male. No patient had a history of direct contact with wildlife, while 10 (83.33%) patients were local residents of Wuhan, or had been to Wuhan, or had contact with people from Wuhan. There were four groups of family clusters (two families, each with three patients, and two families, each with two patients). Most of the patients (11/12, 91.67%) presented with fever, while two thirds (8/12, 66.67%) presented with dry cough. The median days from illness onset to admission or diagnosis was 2 (IQR, 1–3) and 2 (IQR, 1–4), respectively.
Here: Table 1. Demographics and Clinical Characteristics of Non-severe Patients at Admission
Laboratory and Radiologic Findings of Non-severe Patients at Admission
Among the twelve non-severe patients, 11 (91.7%) of them showed normal or decreased white blood cell (WBC) count. Six patients (50%) had lymphopenia, two (16.7%) had decreased platelet count, four (33.33%) demonstrated elevated C-reactive protein (CRP) and five (41.67%) showed elevated interleukin-6 (IL-6). All patients had normal levels of procalcitonin, but three had elevated alanine transaminase (ALT) and aspartate aminotransferase (AST) at admission.
Chest CT imaging of all patients showed multiple GGO under the pleura of both lungs, which were consistent with the early manifestations of COVID-19 (Table 2).
Here: Table 2. Laboratory and Radiographic Findings of Non-severe Patients at Admission
Clinical Characteristics Following Progression to Severe COVID-19 During Hospitalization
A 54-year-old woman was admitted to hospital after 2 days of fever and dry cough with a history of contact with people from Wuhan within 7 days preceding illness onset. She had no underlying diseases. Her body temperature was slightly elevated (37.6°C) and other vital signs were stable. Laboratory examination showed lymphopenia (0.99×109/L), and other laboratory findings were normal. She was diagnosed with COVID-19 (non-severe) at admission. However, following the 10th day of hospitalization, she experienced obvious shortness of breath both at rest and upon exercising. Her diagnosis was revised to COVID-19 (severe) because of increased respiration rate (31bpm), decreased pulse oxygen saturation without oxygen (90%) and progressive pulmonary opacities found at repeat chest CT on day 12 of hospitalization. After several days of high flow oxygen therapy through a nasal catheter and symptomatic treatment, she recovered gradually with relief of respiratory symptoms and improvement of pulse oxygen saturation. Repeat chest CT also showed improvement (Figure 1).
Figure 1. Dynamic change in chest CT images in a severe COVID-19 patient during hospitalization.
(A) Day 1. A small region of subpleural GGO in the left lower lobe (white arrow). (B–E) Days 3–13, diffuse GGO in the lower lobe of both lungs. (F) GGO obviously absorbed, which then develop into linear opacities and subsequent consolidation.
Dynamic Change in Lymphocyte Count During Hospitalization
Lymphocyte count changed significantly in the non-severe patients over time (P=0.012). There were no significant differences in lymphocyte count between admission and day 5 of hospitalization (P=0.69). However, lymphocyte count increased gradually from day 5 post-admission (hospitalization day 5 vs day 15, P<0.001; Figure 2A). Conversely, the lymphocyte count of the severe COVID-19 patient fluctuated throughout the 15 day period, and even decreased within the first 12 days after hospitalization, before increasing gradually (Figure 2B).
Figure 2. Dynamic change in lymphocyte count during hospitalization.
(A) Dynamic change in lymphocyte count in non-severe COVID-19 patients; (B) Dynamic change in lymphocyte count in the severe COVID-19 patient.
Dynamic Change in Chest CT Score During Hospitalization
Chest CT scores of nine (75%) non-severe COVID-19 patients on day 5 of hospitalization were significantly higher than those obtained at time of admission; however, they decreased gradually from day 5 until day 15 post-hospitalization (admission vs hospitalization day 5, P<0.001; hospitalization day 5 vs day 15, P=0.004). Conversely, in the severe patient, the CT score continued to increase over the 2-week post-admission period before decreasing gradually (Figure 3).
Figure 3. Dynamic change in chest CT score during hospitalization.
(A) Dynamic change in CT score in non-severe COVID-19 patients; (B) Dynamic change in CT score in the severe COVID-19 patient.
Subgroup Analysis of Dynamic Change in Chest CT Score During Hospitalization
The non-severe patients were divided into two subgroups (group 1, patients with normal lymphocyte count at admission; group 2, patients with lymphocyte count below normal at admission). CT scores of the patients in group 2 appeared to be higher than counterparts in group 1 during hospitalization. Furthermore, CT scores of the patients in group 2 on day 5 after admission were significantly higher than those observed at time of admission, but decreased gradually from day 5 of hospitalization (admission vs hospitalization day 5, P=0.008, hospitalization day 5 vs day 15, P=0.044). Conversely, CT scores of the patients in group 1 did not show significant changes over time (Figure 4).
Figure 4. Dynamic change in CT score according to lymphocyte count at admission
Group1, patients with normal lymphocyte count at admission; Group 2, patients with lymphocyte count below normal at admission.