SARS-CoV-2 infection induces soluble platelet activation markers and PAI-1 in the early moderate stage of COVID-19

Introduction

Coagulation dysfunction and thromboembolism emerge as strong comorbidity factors in severe COVID‐19. However, it is unclear when particularly platelet activation markers and coagulation factors dysregulated during the pathogenesis of COVID‐19. Here, we sought to assess the levels of coagulation and platelet activation markers at moderate and severe stages of COVID‐19 to understand the pathogenesis.

Methods

To understand this, hospitalized COVID‐19 patients with (severe cases that required intensive care) or without pneumonia (moderate cases) were recruited. Phenotypic and molecular characterizations were performed employing basic coagulation tests including prothrombin time (PT), activated partial thromboplastin time (APTT), D‐Dimer, and tissue factor pathway inhibitor (TFPI). The flow cytometry‐based multiplex assays were performed to assess FXI, anti‐thrombin, prothrombin, fibrinogen, FXIII, P‐selectin, sCD40L, plasminogen, tissue plasminogen activator (tPA), plasminogen activator inhibitor‐1 (PAI‐1), and D‐Dimer.

Results

The investigations revealed induction of plasma P‐selectin and CD40 ligand (sCD40L) in moderate COVID‐19 cases, which were significantly abolished with the progression of COVID‐19 severity. Moreover, a profound reduction in plasma tissue factor pathway inhibitor (TFPI) and FXIII were identified particularly in the severe COVID‐19. Further analysis revealed fibrinogen induction in both moderate and severe patients. Interestingly, an elevated PAI‐1 more prominently in moderate, and tPA particularly in severe COVID‐19 cases were observed. Particularly, the levels of fibrinogen and tPA directly correlated with the severity of the disease.

Conclusions

In summary, induction of soluble P‐selectin, sCD40L, fibrinogen, and PAI‐1 suggests the activation of platelets and coagulation system at the moderate stage before COVID‐19 patients require intensive care. These findings would help in designing better thromboprophylaxis to limit the COVID‐19 severity.

1255 Crowdedness and Consequences of Long Waiting Time in Public and Private Health Centers Among Patients in Khartoum State, Sudan - 2016

Aim

Waiting time (WT) reflects quality of services delivered by Primary health care level. Long waiting time is due to various causes, among which crowdedness is a main cause. This prolonged time has negative impacts on PHC services utilization as well as patients’ outcomes. The aim of this study is to measure the total WT, assess the crowdedness in PHC centers, and to determine the possible consequences of this long waiting time.

Method

Descriptive cross sectional– health institution-based study done in 40 Health centres across Khartoum state using randomized multi-stage sampling. Patients, doctors and lab technicians were interviewed using three different pre-tested structured questionnaires.

Results

A total of 477 patients were included in the study. The average waiting time was found to be 168 minutes. Crowdedness was one of the main causes of delay in waiting time. The lab was the most perceived crowded service (74.4% of the respondents). This long WT had health consequences on patients, ranging from backache, joint pain, and headaches to hypoglycemic symptoms. These symptoms affected patients' willingness to return to the same center. 36.4% of the affected patients were unwilling to revisit the same center.

Conclusions

WT in this study is longer compared to studies from other countries. Crowdedness is one of the main causes of long WT. Due to this prolonged time, patients experienced physical symptoms. It also affected their future attitude regarding PHC centers utilization. There is a need to understand the underlying causes of this issue and address them appropriately.

Abstract P357: Induction Of Soluble P-selectin And CD40 Ligand And, FXIII Deficiency Promote Aberrant Coagulation And Thromboembolism In Severe COVID-19

Coagulation dysfunction and thromboembolism emerge as strong comorbidity factors in severe COVID-19. However, the underlying pathomechanisms are largely undefined. Here, we sought to identify the potential underlying molecular mechanisms of SARS-CoV-2 mediated coagulopathy and thromboembolism. In this series, 30 hospitalized COVID-19 patients presenting elevated D-dimer with (severe cases that required intensive care) or without pneumonia (moderate cases) were included in the study. Patients with anticoagulant/ antiplatelet therapy or with a history of cardiovascular diseases were excluded. Phenotypic and molecular characterizations were carried out employing basic coagulation tests, flow cytometry-based multiplex assays, and ELISA. The findings revealed slightly higher prothrombin and activated partial thromboplastin times (aPTT) with normal platelet counts. Elevated levels of plasma P-selectin and CD40 ligand (CD40L), markers of platelet activation, were observed in the moderate COVID-19 cases which were significantly abolished with the progression of COVID-19 severity. Moreover, analysis of the coagulation pathways revealed comparable FIX, prothrombin, and anti-thrombin levels, and a significantly higher level of fibrinogen was observed in both the moderate and severe patients vs. control group. Interestingly, the levels of plasma tissue factor pathway inhibitor (TFPI) and FXIII, a regulator of stable thrombus formation, were significantly lower particularly in the severe COVID-19 cases. Moreover, a dysregulated fibrinolysis was indicated by elevated tissue plasminogen activator (tPA), plasminogen activator inhibitor (PAI), and D-dimer levels in COVID-19 cases. In summary, SARS-CoV-2 infection-mediated endothelial cell lining damage potentially enhances soluble P-selectin and CD40L levels inducing platelet activation. Furthermore, in severe COVID-19, a decreased level of TFPI possibly contributes to additional thrombin generation through activation of the TF pathway and provides positive feedback to platelet activation and thrombus formation. FXIII deficiency plays a key role in thrombus instability which most likely promotes thromboembolism in the severe COVID-19.

AB1247 ELEVATED SERUM COMPLEMENT (C3/C4) LEVEL AS AN INFLAMMATORY MARKER FOR INFECTION IN PATIENTS WITH FEVER: A RETROSPECTIVE STUDY

Background:

The functions of the complement system are to protect the host against infection, clearance of immune complexes, and regulate adaptive immunity after activation by C-reactive protein (CRP) or foreign cells.1C3 and C4 may increase up to 50 percent of baseline values as part of the acute-phase response, which is an expected host response for infection and injury.2

Objectives:

We aimed to examine the correlation between elevated C3/C4 levels and the underlying causes (infectious vs. non-infectious) of fever (subjective and/or objective) in adults admitted to Community Regional Medical Center (CRMC).

Methods:

This is a retrospective study of C3/C4 level that was ordered in adult patients who were admitted to CRMC in April 1st, 2018 to September 30th, 2018 with fever. This was also analyzed in comparison to elevated lactic acid, erythrocyte sedimentation rate (ESR), and CRP level.

Results:

Complement levels were ordered in 210 patients admitted to CRMC medicine or intensive care units. Among these patients, 28.09% (59/210) were diagnosed with various infectious diseases confirmed by gold standard methods (cultures, serology tests, computerized tomography, or magnetic resonance imaging), regardless of fever status during admission.

About 26.6% (56/210) had subjective or objective (temperature greater than100.4 F or above), and52of them had complement levels (C3/C4) ordered with resulted in either normal or elevated. Within these52patients, lactic acid, ESR, and CRP were ordered in33,28,25of them respectively.

Table 1.

Elevated C3/C4 level vs. normal C3/C4 level in detecting infection in fever patients when tested against gold standards.

Patients with infectious disease diagnosisPatients without infectious disease diagnosisElevated C3 or C4 or both (screen test +)137Positive predictive value (PPV)=13/20=65%Both normal C3 and C4 (screen test -)824Negative predictive value (NPV)=15/32=48.9%Sensitivity=13/21=61.9%Specificity=24/31=77.4%Table 2.

Sensitivity, specificity, PPV, NPV, likelihood ratio positive (LR+), and likelihood ratio negative (LR-) among C3/C4, lactic acid, ESR, CRPI/CRPH in detecting infection in patient with fever

C3/C4 (N=52)Lactic Acid(N=33)ESR(N=28)CRPI/CRPH(N=25)Sensitivity61.9%50%90%100%Specificity77.4%91.3%11.1%11.8%PPV65%71.4%36%34.8%NPV48.9%80.8%66.6%100%LR+2.75.71.01.1LR -0.490.550.90

Conclusion:

Complement levels can be used as a rapid screening test to guide infection consideration as it correctly identified 61.9 % of febrile patients with infection, and 77.4% who didn’t have an infection. A positive screening test in itself still requires further investigation in the causes of fever to confirm the diagnosis since the PPV is 65%. With the NPV of 48.9%, a negative screening test is still not reassuring that the febrile patient doesn’t have an infection. Our study demonstrated the potential utilization of the elevated complement level as an inflammatory marker for infectious etiology of fever, as it has better LR+ when compares to ESR and CRP with similar turnaround time.

This study helps educate providers to acknowledge the fact that complement level does not have to be limited to be used on autoimmune related disorders only. Further large pool studies will be necessary to further investigate the role of complement levels as part of the screening test in a patient with fever.

References:

[1]Walport. MJ. Complement. Second of two parts. N Engl J Med.2001 Apr 12; 344(15):1140-4. DOI: 10.1056/NEJM200104123441506

[2]Wen L, Atkinson JP, Giclas PC. Clinical and laboratory evaluation of complement deficiency. J Allergy Clin Immunol. 2004;113(4):585. DOI: 10.1016/j.jaci.2004.02.003

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Disclosure of Interests:

None declared

Solitary thyroid nodule in Khartoum

Ninety four patients with solitary and significantly dominant thyroid nodules were studied. Inadequate sampling was reported in 5 patients (5.9%). In the remaining 89 patients, 64 had simple goitre (72%), 12 follicular adenoma (13.5%), 12 were malignant nodules (6 follicular, 5 papillary and one anaplastic) (13.5%) and one patient had Hashimoto's thyroiditis. The incidence of malignancy in the clinically solitary nodules was 14% (10/70) compared to 10% (2/19) for the dominant nodules which increased to 16% (8/49) versus 10% (4/40) respectively after ultrasonography and histopathological confirmation of the nature of the gland. There is a low positive predictive value for follicular neoplasm with fine needle aspiration cytology (FNAC) (44%). This is due to the fact that reports of suspicious follicular pattern is agreed not to imply definite malignancy, however total lobectomy was done for those patients whereas terms like "not suspicious" and "highly suspicious" are considered to mean, benign and malignant respectively and in those latter groups the prediction was 100%. The study stresses the importance of FNAC techniques in reducing the surgical load with minimal false negative results, increasing the yield of carcinoma and projecting the importance of a significantly dominant nodule in endemic areas.