We read the article “Can neutrophil–lymphocyte ratio (NLR) be independent risk factor for predicting acute kidney injury (AKI) in patients with severe sepsis?” by Yilmaz et al.Citation1 They aimed to assess whether NLR is a predictor of AKI in patients with septic shock. They concluded that the NLR is superior to C-reactive protein (CRP), and white blood cells (WBCs) for predicting the development of AKI in patients with severe sepsis.
A complete blood count is an easy examination technique that gives us information about the patient’s formed blood contents. It includes the total WBC count and its subtypes as an indicator of systemic inflammation.Citation2 Accordingly, the NLR can be easily calculated from the differential WBC count, which is widely available and routinely performed.Citation3 The NLR can easily be calculated.Citation4 This calculation is very simple and cheap when compared with the other inflammatory markers like CRP. Furthermore, the NLR has been demonstrated to have a predictive power for cardiac and non-cardiac diseases.Citation5,Citation6 Recently, the NLR has been widely used to determination the severity of inflammation in cardiovascular disease,Citation7 malignancies, diabetes mellitus, hypertension.Citation8 Furthermore, the NLR was studied in auto inflammatory diseases. For example, in one study, the NLR was higher in patients with familial Mediterranean fever than controls.Citation9 In another study, the NLR was found to be higher in patients with active ulcerative colitis compared with controls and inactive patients.Citation10 Behçet’s disease (BD) could lead to dysfunction in varying degrees, depending on the severity of the disease and the affected organ. For them, the NLR may use activity marker for BD patients. We have shown that NLR levels were significantly higher in active BD patients compared with inactive patients.Citation11 This ratio is significantly altered by many conditions (e.g. dehydration, over-hydration, diluted blood specimens, in vitro blood specimen handling). For example, several types of cancer and their progression have been linked to the NLR. Cancer is a common condition that may co-exist with CVD. Cancer itself may be associated with an increased risk of thrombosis. In addition, some medications may affect the NLR. The NLR significantly decreased after statin therapy. Antihypertensive therapy like nebivolol, valsartan and amlodipine significantly lowered the NLR.Citation8,Citation12 In this context, medication should be considered, when the NLR is assessed.
We believe that these findings will elucidate further studies about NLR as a surrogate marker of prognosis in AKI patients. Finally, NLR itself alone without other inflammatory markers may not give information to clinicians about the chronic endothelial inflammatory condition of the patient.Citation13 So, we think that it should be evaluated together with other serum inflammatory markers.
Declaration of interest
There is no conflict of interest.
References:
- Yilmaz H, Cakmak M, Inan O, Darcin T, Akcay A. Can neutrophil–lymphocyte ratio be independent risk factor for predicting acute kidney injury in patients with severe sepsis? Ren Fail. 2015;37(2):225–229
- Zahorec R. Ratio of neutrophil to lymphocyte counts – rapid and simple parameter of systemic inflammation and stress in critically ill. Bratisl Lek Listy. 2001;102(1):5–14
- Balta S, Celik T, Mikhailidis DP, et al. The relation between atherosclerosis and the neutrophil–lymphocyte ratio. Clin Appl Thromb Hemost. 2015. [Epub ahead of print]. doi: 10.1177/1076029615569568
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- Horne BD, Anderson JL, John JM, et al. Which white blood cell subtypes predict increased cardiovascular risk? J Am Coll Cardiol. 2005;45:1638–1643
- Balta S, Demirkol S, Celik T, et al. Association between coronary artery ectasia and neutrophil–lymphocyte ratio. Angiology. 2013;64(8):627–632
- Sarli B, Baktir AO, Saglam H, et al. Neutrophil-to-lymphocyte ratio is associated with severity of coronary artery ectasia. Angiology. 2014;65(2):147–151
- Fici F, Celik T, Balta S, et al. Comparative effects of nebivolol and metoprolol on red cell distribution width and neutrophil/lymphocyte ratio in patients with newly diagnosed essential hypertension. J Cardiovasc Pharmacol. 2013;62(4):388–393
- Ahsen A, Ulu MS, Yuksel S, et al. As a new inflammatory marker for familial mediterranean fever: neutrophil-to-lymphocyte ratio. Inflammation. 2013;36(6):1357–1362
- Celikbilek M, Dogan S, Ozbakır O, et al. Neutrophil–lymphocyte ratio as a predictor of disease severity in ulcerative colitis. J Clin Lab Anal. 2013;27(1):72–76
- Ozturk C, Balta S, Balta I, et al. Neutrophil–lymphocyte ratio and carotid-intima media thickness in patients with Behcet disease without cardiovascular involvement. Angiology. 2015;66(3):291–296
- Karaman M, Balta S, Ay SA, et al. The comparative effects of valsartan and amlodipine on vWf levels and N/L ratio in patients with newly diagnosed hypertension. Clin Exp Hypertens. 2013;35(7):516–522
- Balta S, Demirkol S, Cakar M, Arslan Z, Unlu M, Celik T. Other inflammatory markers should not be forgetten when assessing the neutrophil-to-lymphocyte ratio. Clin Appl Thromb Hemost. 2013;19(6):693–694