Use of Nitroblue Tetrazolium Test: Revisited in Context of COVID-19.

Coronavirus disease 2019 (COVID-19) is a pandemic caused by β coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-COV2) in which the virus binds to host cells via angiotensin-converting enzyme receptor, and the primary T cell immune response leads to recovery in asymptomatic/ mild infections. 1,2 However, in severe and critical type of illness, SARS-COV2 elicits an aberrant immune response involving interplay of events such as oxidative stress, lym-phocytic cytolysis, release of cytokines, chemotaxis, neutro-philia, and formation of neutrophil extracellular traps (NETs). 3 Increased levels of circulating NETs indicate neutrophil activity. The viral pathogenicity and altered immune response together led to deleterious series of events culmi-nating in acute respiratory distress syndrome (ARDS) and coagulopathy. is de fi