science

Neutrophil to lymphocyte ratio

Neutrophil to lymphocyte ratio is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Neutrophil to lymphocyte ratio rather than just read about it. In short: The neutrophil to lymphocyte ratio (NLR) reflects systemic inflammation, which plays an important role in the process of treating ischemic strokes. In medicine neutrophil to lymphocyte ratio (NLR) is used to show there is inflammation in the body.

Key takeaways

Neutrophil to lymphocyte ratio belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Neutrophil to lymphocyte ratio to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Neutrophil to lymphocyte ratio from memory before moving on to harder problems.

Reference excerpt

The neutrophil to lymphocyte ratio (NLR) reflects systemic inflammation, which plays an important role in the process of treating ischemic strokes. In medicine neutrophil to lymphocyte ratio (NLR) is used to show there is inflammation in the body. It is calculated by dividing the number of neutrophils by number of lymphocytes, usually from peripheral blood sample, but sometimes also from cells that infiltrate tissue, such as tumor. Recently Lymphocyte Monocyte ratio (LMR) has also been studied as a marker of inflammation including tuberculosis and various cancers.

Uses

Prognostic biomarker in acute ischemic stroke (AIS) The NLR is associated with stroke severity, unfavorable functional outcomes and mortality in AIS.

Prognosis of cardiovascular diseases Higher NLR contributes to predicting mortality rates (prognostic marker) in patients undergoing certain medical procedures, such as angiography or cardiac revascularization.

Prognostic marker in cancer Increased NLR is associated with poor prognosis of various cancers, such as esophageal, liver, ovarian, pancreatic, prostate and stomach cancer.

Prognostic marker in COVID-19 NLR can be used as a prognostic marker for COVID-19 given the significant difference of NLR between those died and recovered from COVID-19.

Reference values A 2017 study found that the normal NLR range for healthy adults is between 0.78 and 3.53.

History Neutrophil to Lymphocyte ratio was first demonstrated as useful parameter after a correlation of a relationship between the neutrophil lymphocyte ratio to reactions of the immune response was noted. A study in 2001 was conducted by the Department of Anaesthesiology and Intensive Care Medicine, St. Elizabeth Cancer Institute in Bratislava by Zahorec which suggested the routine use of the ratio as a stress factor in clinical ICU practice in intervals of 6-12 and 24 hours. The first study to demonstrate that pre-therapeutic NLR can be used as a predictor of chemotherapy sensitivity to thoracic esophageal cancer was demonstrated by Hiroshi Sato, Yasuhiro Tsubosa, and Tatsuyuki Kawano in a 2012 study published in the World Journal of Surgery.

References

Further reading Socorro Faria, Sara; Fernandes Jr, Paulo César; Barbosa Silva, Marcelo José; Lima, Vladmir C; Fontes, Wagner; Freitas-Junior, Ruffo; Eterovic, Agda Karina; Forget, Patrice (12 December 2016). "The neutrophil-to-lymphocyte ratio: a narrative review". ecancermedicalscience. 10: 702. doi:10.3332/ecancer.2016.702. PMC 5221645. PMID 28105073. for risk stratification for breast cancer Tang, Xingxing; Du, Peng; Yang, Yong (27 July 2017). "The clinical use of neutrophil-to-lymphocyte ratio in bladder cancer patients: a systematic review and meta-analysis". International Journal of Clinical Oncology. 22 (5): 817–825. doi:10.1007/s10147-017-1171-5. PMID 28752351. S2CID 4910519. Huang, Qi-tao; Zhou, Lin; Zeng, Wen-juan; Ma, Qian-qian; Wang, Wei; Zhong, Mei; Yu, Yan-hong (2017). "Prognostic Significance of Neutrophil-to-Lymphocyte Ratio in Ovarian Cancer: A Systematic Review and Meta-Analysis of Observational Studies". Cellular Physiology and Biochemistry. 41 (6): 2411–2418. doi:10.1159/000475911. PMID 28467978. Yin, Xiaotao; Xiao, Yi; Li, Fanglong; Qi, Siyong; Yin, Zhaoyang; Gao, Jiangping (January 2016). "Prognostic Role of Neutrophil-to-Lymphocyte Ratio in Prostate Cancer". Medicine. 95 (3) e2544. doi:10.1097/MD.0000000000002544. PMC 4998274. PMID 26817900. Azab, Basem; Camacho-Rivera, Marlene; Taioli, Emanuela; Zhang, Jian (6 November 2014). "Average Values and Racial Differences of Neutrophil Lymphocyte Ratio among a Nationally Representative Sample of United States Subjects". PLOS ONE. 9 (11) e112361. Bibcode:2014PLoSO...9k2361A. doi:10.1371/journal.pone.0112361. PMC 4223021. PMID 25375150.

Worked examples

Example 1 — a first encounter with Neutrophil to lymphocyte ratio

Start with the simplest possible case. Write down what Neutrophil to lymphocyte ratio claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Neutrophil to lymphocyte ratio before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Neutrophil to lymphocyte ratio ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Neutrophil to lymphocyte ratio

In research: Neutrophil to lymphocyte ratio appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Neutrophil to lymphocyte ratio in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Neutrophil to lymphocyte ratio is common in secondary-school and first-year university syllabi. It links to neighbouring topics Immunologic tests, so understanding it makes those chapters shorter.
In everyday life: Look for Neutrophil to lymphocyte ratio outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Neutrophil to lymphocyte ratio in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Neutrophil to lymphocyte ratio means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
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Frequently asked questions

What is Neutrophil to lymphocyte ratio in simple terms?

Why does Neutrophil to lymphocyte ratio matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Neutrophil to lymphocyte ratio?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Neutrophil to lymphocyte ratio.