How to Calculate ANC | Absolute Neutrophil Count: The Ultimate Guide

To understand How to Calculate ANC, let’s understand what is ANC. The neutrophil is the most abundant type of white blood cell and plays a crucial role in your body. They fight bacteria and other pathogens by releasing chemical weapons, so-called leukocytes. In return, they are also attacked by other types of cells. If you are keeping track of your blood values, you’ve probably come across the absolute neutrophil count (ANC) more than once.

This article will provide you with everything you need to know about How to Calculate ANC: why it’s important, how to measure it, what its significance means, and which conditions might be associated with an elevated or depressed count.

What is an ANC?

The ANC is an indicator of the number of neutrophils in a sample of blood. The sample is usually taken from a vein. For this reason, it is also called “vascular neutrophil count”. While the number and the function of neutrophils are relatively constant in healthy people, infections or certain medications (such as cytotoxic drugs) can alter the results, which makes ANC a good predictor of the course of an infection. The ANC itself is an absolute value.

This means that it does not depend on the other values in your blood sample, such as for example the hemoglobin or the platelet count. While it can be used as an indicator for other values, though, the interpretation of the ANC is only possible if the results are compared to others. Let’s read more on How to Calculate ANC.

How to Calculate an ANC

The ANC is calculated by multiplying the number of neutrophils by 9. For instance, if the ANC is 500,000, you can calculate the number of neutrophils as 500/9 = 45. However, there are some differences in how different laboratories measure the ANC. Because neutrophils are usually measured by blood sampling, it can be affected by various factors, such as the amount of blood in the vessel. Therefore, the amount of blood in the vessel should be counted too. You can do this by taking a blood sample from the other arm. Another thing that should be taken into account is the variation in how aggressively your body releases the sample. Therefore, it is important to figure out the best time of day to take the sample.

ANC = WBC (cells/uL) x [percent (PMNs + bands) ÷ 100]

Let’s try an example. If the WBC count is 6.3 thousand/uL, and neutrophils are 56.1% and bands are 3%, what is the ANC?

ANC = WBC (cells/uL) x [percent (PMNs + bands) ÷ 100]
ANC = 6,300 cells/uL x [(56.1%+3%) ÷ 100]
ANC = 6,300 cells/uL x (59.1% ÷ 100)
ANC = 6,300 cells/uL x 0.591
ANC = 3,720 cells/uL

So, what does this mean?

An ANC of less than 1,500 cells/uL is usually considered as neutropenia ( decreased neutrophils) in an adult and can be classified as mild, moderate, or severe.

Conditions That Are Affected by Neutrophil Count

The neutrophil count is frequently elevated in people with bacterial infections such as bronchitis, pneumonia and urinary tract infections. It’s not very common to see an elevated count during viral infections, such as the common cold. Furthermore, certain types of cancer, such as lymphoma, may also result in an elevated count. As a rule of thumb, if the ANC is elevated in relation to other values, it is important to get checked for the underlying cause.

Example #2

JD is a 42-year-old who presents with progressive fatigue. Physical examination is notable for splenomegaly and lymphadenopathy. Results from his CBC with differential are:

White Blood Cells           1.2 THO/uL
Hemoglobin                    10.7 g/dL
Hematocrit                      31 %
Platelets                          262 THO/uL
% Neutrophils                 70.1 %
% Lymphocytes              30.8 %
% Monocytes                  9.5 %
% Eosinophils                 2.4 %
% Basophils                    1.2 %
% Bands                          3%

Based on these results, let’s calculate JD’s ANC.

ANC = WBC (cells/uL) x [percent (PMNs + bands) ÷ 100]
ANC = 1,200 cells/uL x [(70.1%+3%) ÷ 100]
ANC = 1,200 cells/uL x (73.1% ÷ 100)
ANC = 1,200 cells/uL x 0.731
ANC = 877.2 cells/uL

Because JD has neutropenia, further evaluation is required to discover the cause.

Significance of the Absolute Neutrophil Count

A high ANC may indicate an infection, cancer or even an autoimmune disease. If a high ANC is found together with other signs of infection, it can help your doctor to diagnose the cause of your symptoms more easily. In rare cases, it can be a sign of an autoimmune disease, in which your immune system targets certain cells in your body and releases chemicals to kill them. This may cause pain, redness or swelling. Many chronic conditions can also be associated with an elevated count.

Summing up

If you have a blood test that measures the absolute neutrophil count, you can calculate the count by dividing the number of neutrophils by 9. This is an important indicator of the health of your immune system. A high count can be an indicator of an infection, cancer or autoimmune disease. This article has been designed to give you a better understanding of the absolute neutrophil count and how to calculate it.

Knowing how to perform a granular leukocyte count (GLC) is essential for anyone working in the medical field, whether it be as a medical student or a physician. Understanding the granular leukocyte count is crucial for many reasons, including helping you determine your risk of infection and other diseases, such as anemia and infections. With that being said, knowing how to calculate the absolute neutrophil count is also important because it helps you differentiate between types of neutrophils in the GLC.