Abstract:
Objective :
To investigate the causes of early COVID-19 complicated with
platelets(PLT) abnormality, and to analyze the possible mechanisms.
Methods: The case datum of early COVID-19 complicated with PLT
increase or decrease was collected. (125-350) ×109/L
defined as the normal level of PLT(Group C),
<125×109/L was defined as the PLT decrease
group (Group A), >350×109/L defined as
the PLT increase group (Group B) . The data were analyzed after
collected.
Results: Our statistical results showed that the incidence of
COVID-19 combined PLT decreased was about 11.94% and the incidence of
combined PLT increased was about 9.33% at admission. Compared with
Group B and C, Group A showed a significant decrease in white blood
cell, neutrophil and CD4 (P<0.05). The
lymphocyte in Group A and C decreased significantly, but not find in
Group B (P<0.05). Compared with Group A and C, IL-4 was
increased in Group B, but lymphocyte decline was not significant
(P>0.05).
Conclusion: PLT abnormalities occur in all patients with
different types of COVID-19. It may be related to the severity of
inflammation and infection, immune regulation and megakaryocyte
function, etc.
Keywords: COVID-19, PLT, Megakaryocyte
The interaction between PLT and endothelial cells has been shown to play
a role in the formation of acute lung injury caused by influenza
virus(Rommel et al.,2019). Study have reported that PLT reduction in
COVID-19 patient(Huang et al.,2020). We found that PLT was not only
decreased, but also increased in many COVID-19 patients. In this paper,
COVID-19 complicated with PLT abnormality cases at admission were
collected and analyzed.
1. Research objects and test methods
Retrospective study COVID-19 patients are admitted to the Tumor Center
affiliated to Tongji Medical College of Huazhong University of Science
and Technology. PLT abnormality case datum was gathered. Indicators
including WBC, RBC, hemoglobin, neutrophils, lymphocytes and T
lymphocyte subsets, cytokines (IL2, 4, 6, 8, 10, TNF -α, IFN -γ), CRP
and PCT. and according to the PLT clinical reference range divide 3
groups, (125-350) ×109/L defined as the normal level
of PLT(Group C), <125×109/L was defined as
the PLT decrease group (Group A),
>350×109/L defined as the PLT increase
group (Group B). Comparing the above indicators between each group.
Exclusion criteria: prior to COVID-19, there were underlying diseases or
drugs that caused PLT abnormalities, pregnant women,and so on.
COVID-19 diagnostic criteria: Refer to the COVID-19 Diagnosis and
Treatment Protocol (Trial version 6). Novel Coronavirus nucleic acid
positive(test by real-time FLUORESCENCE RT-PCR). Clinical
classification: critical, severe and normal (including light in
article)type. All patients were treated in the same way after admission,
including regular CT, nucleic acid test, oral antiviral,
anti-inflammatory,etc.
2. Statistical methods
Data were analyzed by SPSS22.0 software and checked by T-test,
chi-square test or Fisher’s exact probability test. P<0.05 was
considered statistically significant.
3.Results
3.1 In our study, we had investigated 268 COVID-19 patients and found 32
cases (11.94%) PLT decreased patients at admission, including 22 males
and 10 females. The age ranged from 29 to 84 years old. most of them
were≥60 years old. the PLT value were between (15-124
)×109/L, but only 8 cases were lower than 100
×109/L. Among them, 2 case were critically severe
type, 16 were heavy type, and 14 were normal type. 25 patients
( 9.33% ) PLT increased been found at admission, including 16 males
and 9 females. The age ranged from 23 to 83 years old, and the PLT value
were between (351-541) ×109/L, of which only 1 case
was critical heavy type, 13 cases were heavy type, and 11 cases were
normal type.
3.2 There was no statistically significant difference between the three
groups in terms of RBC and hemoglobin at admission
(P>0.05), as shown in table 1. Compared with Group B and C,
there was a decrease in WBC in Group A (P<0.05). The
lymphocyte in Group A and C decreased significantly compared with Group
B (P<0.05). The absolute value/percentage of neutrophils and
the percentage of lymphocytes were not significantly different
(P>0.05), as shown in table 1-2.
3.3 Among the 57 patients with abnormal PLT, except for one in group A,
the values of PCT of the other 56 patients were in the normal range;
IFN-γ was normal too; Only one case patient,s NF-α was
elevated in each group. There was no significant difference in the
comparison of CD3, IL2, IL4, and IL10 among patients in the three groups
at admission (P> 0.05), but CD4 in Group A was lower than
that in Group B and C(P<0.05), as shown Table 3-4.
IL-6 was increased in all patients, but the range of IL-6 values
fluctuated widely. There were more cases of IL-6 value ≥ 50 pg / ml
in Group A, while B and C Group have no significant
difference(P> 0.05); CRP was not statistically significant
in the number of cases (P> 0.05), but values ≥50mg / L,
Group A was more than Group B (P <0.05). IL-4 value in Group B
was significantly higher than that in Group C(P <0.05), but
there was no significant difference between Group A and C.