COVID-19 and the clinical hematology laboratory

Abstract

The ongoing COVID-19 pandemic originated in Wuhan, Hubei Province, China, in December 2019. The etiologic agent is a novel coronavirus of presumed zoonotic origin with structural similarity to the viruses responsible for severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). Like SARS and MERS, COVID-19 infection manifests most frequently with lower respiratory symptoms. A minority of patients progress to acute respiratory distress syndrome/ diffuse alveolar damage. In addition to its central role in the diagnosis of COVID-19 infection, the clinical laboratory provides critical information to clinicians regarding prognosis, disease course, and response to therapy. The purpose of this review is to (a) provide background context about the origins and course of the pandemic, (b) discuss the laboratory's role in the diagnosis of COVID-19 infection, (c) summarize the current state of biomarker analysis in COVID-19 infection, with an emphasis on markers derived from the hematology laboratory, (d) comment on the impact of COVID-19 on hematology laboratory safety, and (e) describe the impact the pandemic has had on organized national and international educational activities worldwide.

Keywords: COVID-19; hematology; virus.

FIGURE 1

Morphologic features of circulating cells from peripheral blood films of patients with COVID‐19 infection. Neutrophils show hyposegmented nuclei (A‐C), sometimes with pre‐apoptotic chromatin (B), and hypergranular cytoplasm, sometimes with hypogranular basophilic areas (C). Such dysmorphism appears related to the accelerated and disorderly granulopoiesis associated with hyperinflammation. Reactive lymphocytes with large amounts of pale blue cytoplasm (D), lymphoplasmocytoid cells, and large granular lymphocytes predominate in treated and recovering patients (May‐Grünwald‐Giemsa, original magnification ×1000)