Evaluation of Neutrophil to Lymphocyte ratio (NLR) and its utility as a
prognostic marker in COVID-19 patients
Abstract
Introduction COVID-19 has presented an unprecedented situation to the
medical world. With the high infectivity rate, the search for ideal
prognostic tests is on. Neutrophil lymphocyte ratio (NLR) has been used
as a prognostic marker in several infectious, inflammatory and malignant
conditions. We aim to assess the utility of NLR as a prognostic marker
in COVID-19. Materials and methods: 142 confirmed COVID-19 patients were
included in the study. A detailed clinical Performa was filled. Complete
blood count and coagulation parameters were done in each patient. Based
on the clinical criteria, the patients were classified as asymptomatic
(100) and symptomatic (42). The symptomatic patients were subjected to
CT chest examination and were assigned a CT severity index. Using
clinical presentation, organ dysfunction, oxygen requirement and CT
severity index the patients were classified as mild and severe COVID-19
groups. NLR, coagulation parameters and CT severity index were compared.
Results: 46.4 % of males and 17.8 % of females had neutrophilia.
37(38.1 %) males had 14 (31.1 %) females had lymphopenia. NLR was
between 1-3.5 in 83 (58.45%) cases and 59 cases (41.5%) had NLR
>3.5.Of these 59 cases, 50 had a deranged FDP/D-dimer
levels. The Receiver Operating Characteristics (ROC) curve analysis was
carried out to indicate the sensivity and specifity of NLR and its
respective optimal cut-off value for predicting severity in COVID. NLR
>3.5 helped in predicting severity of COVID with a
sensitivity of 60% and specificity of 70%. Conclusion: High NLR
(>3.5) indicates a severe form of disease. ’What is already
known about this topic? Covid 19 is an emerging pandemic and researchers
are trying to find the various diagnostic and prognostic parameters.
What does this article add? This article tries to assess a new
prognostic marker for covid 19