CMAAO CORONA FACTS and MYTH BUSTER 100 Lab Parameters

CMAAO CORONA FACTS and MYTH BUSTER 100 Lab Parameters

Dr K K Aggarwal

President Confederation of Medical Associations of Asia and Oceania, HCFI, Past National President IMA, Chief Editor Medtalks

With inputs from Dr Monica Vasudev

889 What are common lab findings

Lymphopenia (83%) is the most common laboratory finding in hospitalized patients. Worsening lymphopenia is a bad sign.

Although procalcitonin is typically normal on admission, levels may increase among those admitted to the intensive care unit (ICU).

Findings associated with more illness severity: Lymphopenia, Neutrophilia, Elevated levels of serum alanine aminotransferase and aspartate aminotransferase, Elevated lactate dehydrogenase, High C-reactive protein (CRP) level and High ferritin levels

Elevated D-dimer (>1 mcg/mL), Elevated prothrombin time (PT), Elevated troponin, Elevated CPK, Acute kidney injury are linked to mortality.

Elevated D-dimer and lymphopenia have been associated with mortality.

Progressive decline in the lymphocyte count and rise in the D-dimer over time were observed in nonsurvivors compared with more stable levels in survivors

Markers of inflammation or coagulation (D-dimer level >1 microg/mL on admission, elevated fibrin degradation products, prolonged activated partial thromboplastin and prothrombin times) are linked to death.

890:  IL6 and D Dimer

Cohort drawn from two NewYork-Presbyterian hospitals: Estimated inflammation through interleukin-6 (IL-6) concentrations and thrombosis through D-dimer concentrations, found a 10% increased risk for death with every 10% increase of IL-6 (adjusted hazard ratio [aHR], 1.11; 95% confidence interval [CI], 1.02–1.20) or D-dimer concentration (aHR, 1.10; 95% CI, 1.01–1.19).

891: D Dimer cut off

D-dimer = 2.0 ug/ml (fourfold increase) on admission might be the optimum cutoff to predict in-hospital mortality.

[Zhenlu Zhang Laboratory Medicine, Wuhan Asia Heart Hospital. No.753 Jinghan Avenue, Wuhan, China, 430022].

892: Coagulation testing

Prothrombin time (PT) and aPTT normal or slightly prolonged

Platelet counts normal or increased (mean, 348,000/microL)

Fibrinogen increased (mean, 680 mg/dL; range 234 to 1344)

D-dimer increased (mean, 4877 ng/mL; range, 1197 to 16,954)

Other assays

Factor VIII activity increased (mean, 297 units/dL)

VWF antigen greatly increased (mean, 529; range 210 to 863), consistent with endothelial injury or perturbation

Minor changes in natural anticoagulants

-Small decreases in antithrombin and free protein S

-Small increase in protein C

TEG findings

Reaction time (R) shortened, consistent with increased early thrombin burst, in 50 percent of patients

Clot formation time (K) shortened, consistent with increased fibrin generation, in 83 percent

Maximum amplitude (MA) increased, consistent with greater clot strength, in 83 percent

Clot lysis at 30 minutes (LY30) reduced, consistent with reduced fibrinolysis, in 100 percent

893: Laboratory features associated with severe COVID-19^[1-6]

Abnormality	Possible threshold
Elevations in:
§  D-dimer	>1000 ng/mL (normal range: <500 ng/mL)
§  CRP	>100 mg/L (normal range: <8.0 mg/L)
§  LDH	>245 units/L (normal range: 110 to 210 units/L)
§  Troponin	>2× the upper limit of normal (normal range for troponin T high sensitivity: females 0 to 9 ng/L; males 0 to 14 ng/L)
§  Ferritin	>500 mcg/L (normal range: females 10 to 200 mcg/L; males 30 to 300 mcg/L)
§  CPK	>2× the upper limit of normal (normal range: 40 to 150 units/L)
Decrease in:
§  Absolute lymphocyte count	<800/microL (normal range for age ≥21 years: 1800 to 7700/microL)

Although these laboratory features are associated with severe disease in patients with COVID-19, they have not been clearly demonstrated to have prognostic value. We use the thresholds listed above to identify patients who may be at risk for severe disease; they are extrapolated from published cohort data and individualized to the reference values used at our laboratory. However, the specific thresholds are not well established and may not be applicable if laboratories use other reference values.

COVID-19: coronavirus disease 2019; CRP: C-reactive protein; LDH: lactate dehydrogenase; CPK: creatine phosphokinase.

References:

1.      Guan WY, Ni ZY, Hu Y, et al. Clinical characteristics of coronavirus disease 2019 in China. N Engl J Med 2020.

2.      Huang C, Wang Y, Li X, et al. Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China. Lancet 2020; 395:497.

3.      Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020; 395:1054.

4.      Wang D, Hu B, Hu C, et al. Clinical characteristics of 138 hospitalized patients with 2019 novel coronavirus-infected pneumonia in Wuhan, China. JAMA 2020.

5.      Wu Z, McGoogan JM. Characteristics of and important lessons from the coronavirus disease 2019 (COVID-19) outbreak in China: Summary of a report of 72,314 cases from the Chinese Center for Disease Control and Prevention. JAMA 2020.

6.      Ruan Q, Yang K, Wang W, et al. Clinical predictors of mortality due to COVID-19 based on an analysis of data of 150 patients from Wuhan, China. Intensive Care Med 2020.