Dr. Ron’s Research Review – February 26, 2014

© 2014

This week’s research review focuses on the neutrophil-lymphocyte ratio (NLR).

Neutrophilia and lymphocytopenia are well-established markers of severe bacterial infection. The neutrophil-lymphocyte ratio (NLR) has been shown to be a sensitive predictor of bacterial infection. (de Jager, van Wijk et al. 2010)

NLR is an indicator of systemic inflammation and may have predictive power in prognosis, severity, and mortality rates of atherosclerosis and cardiovascular diseases. (Imtiaz, Shafique et al. 2012) (Gokhan, Ozhasenekler et al. 2013)

A recent study showed a correlation of NLR with different grades of glucose intolerance and insulin resistance. NLR can be used as an adjuvant prognostic marker for macro- and microvascular complications in patients with glucose intolerance. (Shiny, Bibin et al. 2014)

Dr. Ron


Articles

Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit

         (de Jager, van Wijk et al. 2010) Download

INTRODUCTION: Absolute lymphocytopenia has been reported as a predictor of bacteremia in medical emergencies. Likewise, the neutrophil-lymphocyte count ratio (NLCR) has been shown a simple promising method to evaluate systemic inflammation in critically ill patients. METHODS: We retrospectively evaluated the ability of conventional infection markers, lymphocyte count and NLCR to predict bacteremia in adult patients admitted to the Emergency Department with suspected community-acquired bacteremia. The C-reactive protein (CRP) level, white blood cell (WBC) count, neutrophil count, lymphocyte count and NLCR were compared between patients with positive blood cultures (n = 92) and age-matched and gender-matched patients with negative blood cultures (n = 92) obtained upon Emergency Department admission. RESULTS: Significant differences between patients with positive and negative blood cultures were detected with respect to the CRP level (mean +/- standard deviation 176 +/- 138 mg/l vs. 116 +/- 103 mg/l; P = 0.042), lymphocyte count (0.8 +/- 0.5 x 109/l vs. 1.2 +/- 0.7 x 109/l; P < 0.0001) and NLCR (20.9 +/- 13.3 vs. 13.2 +/- 14.1; P < 0.0001) but not regarding WBC count and neutrophil count. Sensitivity, specificity, positive and negative predictive values were highest for the NLCR (77.2%, 63.0%, 67.6% and 73.4%, respectively). The area under the receiver operating characteristic curve was highest for the lymphocyte count (0.73; confidence interval: 0.66 to 0.80) and the NLCR (0.73; 0.66 to 0.81). CONCLUSIONS: In an emergency care setting, both lymphocytopenia and NLCR are better predictors of bacteremia than routine parameters like CRP level, WBC count and neutrophil count. Attention to these markers is easy to integrate in daily practice and without extra costs.


Neutrophil lymphocyte ratios in stroke subtypes and transient ischemic attack

         (Gokhan, Ozhasenekler et al. 2013) Download

OBJECTIVES: This investigation was conducted to test the value of Neutrophil Lymphocyte Ratio (NLR), which has been shown in some recent studies to be a prognostically important and an easy-to-measure inflammatory marker, in patients presenting to Emergency Service with stroke (ischemic and hemorrhagic) and transient ischemic attack. MATERIALS AND METHODS: A total of 868 patients were enrolled, who presented to our Emergency Service with cerebrovascular accident (stroke and transient ischemic attack) and admitted to Neurology Clinic. Demographic characteristics and comorbidities of patients were recorded. The patients were divided into 3 groups as acute ischemic stroke (AIS), acute hemorrhagic stroke (AHS) and transient ischemic attack (TIA). Patients with AIS were classified into subgroups in terms of TOAST (trial of 10172 stroke treatment) criteria. Admission NLR levels were compared across all groups. RESULTS: A total of 868 patients were enrolled, 51.6% of which were male and 48.4% were female. AIS rate was 75.3%, AHS rate was 14.3% and TIA rate was 10.7%. In all of patients, mortality rate was 10.7%. NLR was significantly higher in patients who died (p < 0.001). NLR level in patients with TIA was significantly lower than those of AIS and AHS groups (p < 0.001). Among AIS subgroups, NLR level was significantly higher in group with great artery atherosclerosis or atherothrombosis compared to other groups (p < 0.001). CONCLUSIONS: NLR may be used as a simple and easy-to-measure marker for prediction of short-term prognosis and in-hospital mortality in both ischemic and hemorrhagic stroke patients.

Neutrophil lymphocyte ratio as a measure of systemic inflammation in prevalent chronic diseases in Asian population

         (Imtiaz, Shafique et al. 2012) Download

BACKGROUND: Preliminary evidence has suggested the role of inflammation in development and prognosis of cardiovascular diseases and cancers. Most of the prognostic studies failed to account for the effects of co-morbid conditions as these might have raised the systemic inflammation. We used neutrophil lymphocyte ratio (NLR) as a measure of systemic inflammation and investigated its association with prevalent chronic conditions. METHODS: Present study is a cross sectional study conducted on population of Karachi, Pakistan. A detailed questionnaire about the demographic details of all subjects was filled and an informed consent obtained for blood sampling. Multinomial regression analyses were carried out to investigate the relationship between NLR and prevalent chronic conditions. RESULTS: 1070 apparently healthy individuals participated in the study. Proportion of individuals with hypertension was higher in middle and highest tertile of NLR as compared to the lowest tertile (18.2% & 16.1% compared to 11.8%). Individuals with hypertension were 43% (RRR = 1.43, 95% CI 0.94-2.20) and 66% (RRR = 1.69, 95% CI 1.09-2.54) more likely to be in the middle and highest tertile of NLR respectively compared to the baseline group. Similarly, individuals with diabetes mellitus were 53% (RRR = 1.53, 95% CI 0.93-2.51) and 65% (RRR = 1.65, 95% CI 1.01-2.71) more likely to be in the middle or highest tertile of NLR as compared to the baseline NLR group. CONCLUSIONS: Systemic inflammation measured by NLR has a significant association with prevalent chronic conditions. Future research is needed to investigate this relationship with longitudinal data to establish the temporal association between these variables.

Association of Neutrophil-Lymphocyte Ratio with Glucose Intolerance: An Indicator of Systemic Inflammation in Patients with Type 2 Diabetes

         (Shiny, Bibin et al. 2014) Download

Abstract Background: The neutrophil-lymphocyte ratio (NLR) has been demonstrated to be a better risk factor than total white blood cell count in the prediction of adverse outcomes in various medical conditions. This study analyzed the association of NLR with different grades of glucose tolerance and insulin resistance in Asian Indians. Subjects and Methods: Study subjects were recruited from Phase 3 of the Chennai Urban Rural Epidemiology Study (CURES). For this cross-sectional analysis, subjects with normal glucose tolerance (NGT) (n=237), impaired glucose tolerance (IGT) (n=63), and type 2 diabetes mellitus (DM) (n=286) were selected. The hemogram was done in all subjects using a five-part hematology analyzer (model SF-3000; Sysmex, Kobe, Japan). The NLR was calculated as the ratio between counts for neutrophils and total lymphocytes. Fasting insulin was measured by enzyme-linked immunosorbent assay, and insulin resistance was calculated using the homeostasis model assessment (HOMA-IR). Results: Subjects with DM showed a significantly higher NLR (2.2+/-1.12) compared with IGT subjects (1.82+/-0.63), who in turn had a higher ratio than NGT subjects (1.5+/-0.41) (P<0.01). Pearson correlation analysis showed a significant positive correlation of NLR with glycated hemoglobin (r=0.411), fasting plasma glucose (r=0.378), and HOMA-IR (r=0.233) (P<0.001). Regression analysis showed a linear increase in NLR with increasing severity of glucose intolerance even after adjusting for age, waist circumference, blood pressure, triglycerides, and smoking. Conclusions: This is the first report on the correlation of NLR with different grades of glucose intolerance and insulin resistance. NLR can be used as an adjuvant prognostic marker for macro- and microvascular complications in patients with glucose intolerance.

References

de Jager, C. P., P. T. van Wijk, et al. (2010). "Lymphocytopenia and neutrophil-lymphocyte count ratio predict bacteremia better than conventional infection markers in an emergency care unit." Crit Care 14(5): R192. [PMID: 21034463]

Gokhan, S., A. Ozhasenekler, et al. (2013). "Neutrophil lymphocyte ratios in stroke subtypes and transient ischemic attack." Eur Rev Med Pharmacol Sci 17(5): 653-7. [PMID: 23543449]

Imtiaz, F., K. Shafique, et al. (2012). "Neutrophil lymphocyte ratio as a measure of systemic inflammation in prevalent chronic diseases in Asian population." Int Arch Med 5(1): 2. [PMID: 22281066]

Shiny, A., Y. S. Bibin, et al. (2014). "Association of Neutrophil-Lymphocyte Ratio with Glucose Intolerance: An Indicator of Systemic Inflammation in Patients with Type 2 Diabetes." Diabetes Technol Ther. [PMID: 24455985]