Ashwin Kulkarni1, Divya Prabhu2, Likitesh A.B.3, T. Anil Kumar4, Varun Vinayak P. Rao5, Shaivya P. Murthy6
BACKGROUND
The infection caused due to novel coronavirus 2 can cause wide spectrum of
disease from asymptomatic mild disease to life threatening disease. The
widespread inflammation is most likely the cause of the adverse outcomes. There
are numerous markers of the inflammation which are used to identify the severity
and prognosis of the disease. Neutrophil lymphocyte ratio (NLR) is one such
marker which is easily available and feasible in all the hospital settings. This study
intended to evaluate the NLR as a marker of disease severity and prognosis, in
those with Covid-19.
METHODS
This was a retrospective study to determine the utility of NLR as a marker of
severity and prognosis among patients with Covid disease. Medical records of 60
patients admitted with mild to moderate Covid-19 disease were reviewed and
relevant data was retrieved. The NLR at admission and 72 hours later was noted.
High resolution computerised tomography was done and computerised
tomography severity score (CT-SS) was calculated. The outcomes of these patients
were noted.
RESULTS
Mean NLR at admission in mild disease was 5.6 and in moderate disease was 9.2.
This difference was found to be statistically significant. It was also seen that NLR
had a positive co-relation with CT severity score, duration of hospital stay, Creactive
protein (CRP) and D-dimer. For predicting mortality, NLR with cut off of
6.6 had a sensitivity of 100 % and a specificity of 66.07 %. CRP with cut off of 6.8
had sensitivity of 100 %, specificity of 76.79 %. D-dimer with cut off of 1.6 had
specificity of 78.58 %. For predicting severity, NLR with cut off of 6.6 had
sensitivity of 75 % and specificity of 80 %. CRP with cut off of 7.9 had sensitivity
of 65 % and specificity of 100 %. D-dimer with cut off of 1.3, had sensitivity of 90
% and specificity of 97.5 %.
CONCLUSIONS
The study shows that neutrophil–lymphocyte ratio is a good indicator of disease
severity and has prognostic significance in Covid-19. There is a positive correlation
with high-resolution computed tomography (HRCT) chest score and other markers
of inflammation among patients with Covid-19. Serial monitoring of NLR can be
utilised as a surrogate to HRCT chest to determine disease severity whenever the
latter is not available. This can ensure early intervention and help prevent
mortality.
