Introduction
Coronavirus disease‐2019 (COVID‐19), caused by the severe acute
respiratory syndrome‐coronavirus 2 (SARS‐CoV‐2) is cause of illness and
death of millions since December 2019. It is a highly contagious disease
that spreads via contact and aerosol transmission. There are much more
cases than reported because many are asymptomatic but infectious. Gold
standart diagnostic tool is testing nasopharyngeal swab samples by
real‐time reverse‐transcription polymerase chain reaction (PCR). But PCR
is not available in every health-care institution due to its cost and
working technique, elsemore getting results takes time. Computed
tomography (CT) of the chest is indicated in those patients suspicious
of pneumonia with a prior chest x-ray that is undiagnostic. CT is
expensive, not available in every healthcare institution and patients
are exposed to radiation. There is a need for fast diagnostic parameters
to assist doctors in the diagnostic phase and to help differentiating
patients with Covid-19 pneumonia than those without. Comlpete blood
parameters are studied in many patients at admittion in Covid-19
clinics. Biomarkers of inflammation derived from the peripheral blood,
hemogram parameters such as white blood cell (WBC) count, neutrophil
lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) have been
investigated as independent predictors for prognosis of systematic
inflammatory diseases 1. Monocyte-macrophage
activation markers are increased and correlate with other inflammatory
markers in SARS-CoV-2 infection, in association to hospital admission.
The red blood cell distribution width (RDW) is a measure of the
variation of red blood cell volume. There are recent studies focusing on
RDW 2. Mean platelet volume (MPV) is one of the
platelet function indices which reflects the platelet production rate
and stimulation 3. Platelet distribution width (PDW)
is a direct measure of platelet size variation and a marker of platelet
activation. High levels of PDW have been associated with Covid-19
mortality 4. All above mentioned parameters are
studied by routine complete blood count test that might be overlooked by
clinicians. The major difficulty for physicians is to translate the
recommended guidelines into clinical practice. In this study we aimed to
determine wheather monocyte levels, eosinophil levels, MPV, PDW, RDW,
NRL, MLR and PLR can be used as biomarkers in the early diagnosis of
laboratory-confirmed COVID-19 patients as well as to explore the most
useful diagnostic biomarkers and optimal cut-off values. Else more to
investigate if these parameters can be used in differentiation of
Covid-19 patients with pneumonia than those without and healthy
controls. To the best of our knowledge this is the first study
investigating above mentioned parameters in previously totally healthy
Covid-19 patients.