Evaluation of the prognostic role of NLR, LMR, PLR, and LCR ratio in COVID‐19 patients

Abstract

We aimed to find the most useful biomarker by examining the prognostic effect of neutrophil‐lymphocyte ratio (NLR), lymphocyte‐monocyte ratio (LMR), platelet‐lymphocyte ratio (PLR), and lymphocyte‐C reactive protein ratio (LCR) in patients with coronavirus disease 2019 (COVID‐19). Three hundred and four patients diagnosed with COVID‐19 infection in our hospital within 5 months (April–August 2020) were examined. Laboratory values and demographic findings of the patients were analyzed retrospectively. Thirty‐six patients were diagnosed with severe cases. The ratio of NLR, LMR, PLR, and LCR of patients with severe and those with nonsevere clinical symptoms were statistically analyzed. The NLR and PLR ratios of those with severe clinical symptoms were significantly higher ( p < 0.001), the LCR rate was significantly lower ( p < 0.001), and there was no significant difference in the LMR rate ( p = 0.199). When we examined other peripheral blood parameters, we found that CRP was high, lymphocyte and monocyte were low ( p < 0.001), but neutrophil ( p = 0.416) and platelet ( p = 0.998) were not statistically different between the groups. According to the results, routine blood values are abnormal in patients with COVID‐19. NLR, PLR, and LCR ratios can be used as more significant biomarkers than other values in predicting the prognosis of patients.

Evaluation of individual and combined NLR, LMR and CLR ratio for prognosis disease severity and outcomes in patients with COVID-19

“…Unlike NLR, declined LMR was maintained at last day of hospitalization in patients with a fatal outcome compared to those who survived in ICU. In line with our finding, previous study revealed that decreased LMR value as an indicator of increased chances of mortality among patients suffering from COVID-19 disease in ICU [46] , [47] .…”

“…Importantly, it was observed in the current study that CLR in the deceased group remained high, while these values returned to normal more quickly in survivor’s patients. Similar results were documented in another study, which showed that the LCR is able to distinguish COVID-19 infected patients of different severity (mild/moderate, severe and critically ill) [47] , [48] . Erdogan A. et al [47] , [48] demonstrated that the LCR was significantly decreased in severe cases, suggesting that this marker could reflect the severity of COVID-19 disease.…”

“…Previous reports have revealed decreased LMR value among patients of ICU thus rendering declined ratio of LMR as an indicator of poor prognosis [46] , [47] . However, our findings argue against the involvement of LMR as an indicator of severe COVID-19 outcome.…”

“…Since the SARS-CoV2 viral load has been highly correlated with CRP value and lymphocyte count [38] , [15] , we hypothesized that CLR could help predict of disease severity. Few previous studies have been carried out to evaluate the feasibility of (lymphocyte-to-C-reactive protein ratio) LCR to assess COVID-19 disease severity [47] , [48] . By contrast, this study aimed to determine CLR and not LCR whether or not could be useful in the discrimination of COVID 19 cases with different levels of severity.…”

Clinical Features of Early Stage COVID-19 in a Primary Care Setting

“…There are a few reports regarding these scores pertaining to COVID-19 diagnosis. There are several other diagnostic scores for COVID-19, such as neutrophile-to-lymphocyte ratio, lymphocyte-to-monocyte ratio, and platelet-to-lymphocyte ratio (22,24,26,(53)(54)(55)(56). Prior to the COVID-19 pandemic, these scores were used in the evaluation of malignant tumors (57,58).…”