Neutrophil-to-Lymphocyte Ratio (NLR)

The neutrophil-to-lymphocyte ratio (NLR) is a value calculated as the ratio of the number of neutrophils to the number of lymphocytes in the blood. This index is widely used in clinical practice as a simple and accessible marker of inflammation and immune status.
What are neutrophils and lymphocytes?
  • Neutrophils are a type of white blood cells that play a key role in protecting the body from bacterial infections and participate in the initial inflammatory response.
  • Lymphocytes are immune system cells responsible for specific immunity, including protection against viruses and the formation of immune memory.

The significance of NLR:
  • Elevated NLR indicates systemic inflammation, stress, or infection, as neutrophil count increases and lymphocyte count decreases.
  • Low or normal NLR usually suggests the absence of a pronounced inflammatory process.

Applications in medicine:
  • Diagnosis and monitoring of inflammatory diseases.
  • Predicting the severity of infectious processes, including pneumonia, COVID-19, and other viral and bacterial infections.
  • Assessment of immune status in chronic diseases and oncological conditions.
  • Used as an additional marker for cardiovascular disease risk assessment.

Advantages of NLR analysis:
  • Accessibility and simplicity of calculation — based on a complete blood count.
  • High informativeness when combined with other clinical data.
  • Allows quick evaluation of patient condition and assists in decision-making regarding further diagnostics or treatment.

How NLR is calculated:

NLR = number of neutrophils / number of lymphocytes (usually absolute values obtained from a complete blood count).

Conclusion:

The neutrophil-to-lymphocyte ratio is an important and easy-to-use marker of inflammation and immune response, helping physicians evaluate patient condition and predict the course of various diseases.




Types of Tests