1 INTRODUCTION
The new coronavirus disease 2019 (COVID-19), caused by severe acute
respiratory syndrome coronavirus 2 (SARS-CoV-2), is a highly
communicable infectious disease. It has rapidly and widely spread
worldwide,1 and was declared a pandemic in March 2020
by World Health Organization.2 As of
27th August 2020, the cumulative number of confirmed
cases in Pakistan is 294,193 with 8,987 active cases and 6,267
deaths.3
Despite significant advancements in medicine and science, we are still
in the age of infancy regarding COVID-19 infection and its management.
COVID-19 infection can be categorized as asymptomatic, mild, moderate,
or severe disease. Moderate and severe COVID-19 infections have been
associated with long hospital stays, difficult clinical management and
high mortality rate.4 Clinically, if early warning
signs of severe COVID-19 infection can be identified, timely
intervention and treatment may help reduce the mortality, improve the
cure rate, shorten the hospital stay and reduce the consumption of
resources.
Different immunity parameters in the human body have been identified to
combat the disease.5,6 These tests are often expensive
and time delay occurs in the results of these tests, jeopardizing the
patient’s treatment. Therefore, we ought to have a clinical indicator or
marker that is inexpensive, has a rapid turnaround time, and is
simultaneously specific and sensitive. One such marker is a complete
blood count (CBC) profile, out of which neutrophils and lymphocytes are
especially important. The neutrophils are increased in bacterial
infection, and lymphocytes are reduced during viremia. Examining these
two parameters can greatly help assess the COVID-19 infection.
A recent systematic review and metanalysis by Feng et al.regarding immune-inflammatory parameters in COVID-19 infection concluded
that neutrophil/lymphocyte ratio (NLR) is associated with the
progression of the infection and can be utilized by the physicians to
identify high risk or deteriorating patients at an early
stage.7 Several other studies have reported their
findings that NLR can be used as an early warning signal of severe
COVID-19 infection,8 and cohnsidered as an independent
marker for poor clinical outcomes and mortality in COVID-19
infection.9-13 However, the majority of these studies
have been reported from China and some from European countries. To our
knowledge, no study has been conducted in this regard in the South-Asian
population. Our study aimed to prospectively analyze the clinical data
of COVID-19 patients admitted to the high dependency unit/intensive care
unit (HDU/ICU) at District Headquarter (DHQ), Faisalabad (Pakistan) in
order to determine the risk factors and markers, with particular focus
on NLR, associated with severity of COVID-19 infection in the
South-Asian population.