Immunity and infection prevention

How to read neutrophils and ANC

The main article (“What is neutropenia?”) explains the blood count as a whole. This topic looks closely at one value, the absolute neutrophil count (ANC): how it is calculated, what it shows and what it does not.

Last updated: ~1 min read
Two matching puzzle pieces.
Figure 1.The ANC is calculated from two pieces.

01Short answer

A blood count reports the total number of white cells and how they divide by type (the differential). The neutrophil share may be given as a percentage, but infection risk is reflected by the absolute number, the ANC, not the percentage. The ANC is calculated by multiplying the total white count by the share of neutrophils (segmented and band forms); many laboratories report it directly. Units can be written differently from lab to lab, so read your own report with your team. The trend matters more than one number: is it falling, at its lowest, or rising?

02Simple explanation

ANC: absolute neutrophil count.

Not the percentage but the absolute number.

The trend matters more than one number.

03Scientific explanation

Calculation: ANC = total white count × (share of segmented + band neutrophils).

A trap: in acute leukaemia the white count can be high while the ANC is very low, because most cells are blasts.

04What happens in the body?

Two pieces

The ANC comes from two facts: the total white count and the neutrophil share.

Sorting the cells

The differential divides white cells into five types.

White cells in five trays.
Figure 2.The differential sorts cells by type.

The trend

Results from several days together tell you more.

A rising line above calendar pages.
Figure 3.Several results show a trend.

05Reading the ANC

Four steps.

Sample — Blood is taken.1SampleBlood is taken.
Count — Total white cells.2CountTotal white cells.
Share — The neutrophil share.3ShareThe neutrophil share.
Compare — Look at the trend.4CompareLook at the trend.

06What to look for on the report

LineWhat it tells you
White cells (WBC)Total white cells
Neutrophils, %A share; does not show risk alone
Neutrophils, absolute (ANC)The main marker of infection risk
BlastsLeukaemia cells present
MonocytesMay be an early sign of recovery

07Key terms

ANC
Absolute neutrophil count.
Differential
The split of white cells by type.
Segmented
Mature neutrophils.
Band
Slightly younger neutrophils.
Reference range
The laboratory normal range.

08Key points

  • The ANC reflects infection risk.
  • A percentage is not enough.
  • A high white count can come with a low ANC.
  • Units differ between labs.
  • Watch the trend.
  • Read the report with your team.

09Frequently asked questions

My report has no ANC; what should I do?

Ask the lab or your doctor; it can be calculated from the differential.

My ANC is low; what should I do?

Follow protection advice and seek help at once if you get a fever (“Fever in a patient”).

When will my ANC rise?

It depends on treatment; rising monocytes are sometimes an early sign.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. My report has no ANC; what should I do?

  2. My ANC is low; what should I do?

  3. When will my ANC rise?

My questions

12Sources

  1. MedlinePlus (U.S. National Library of Medicine). Blood Differential
  2. MedlinePlus (U.S. National Library of Medicine). White Blood Count (WBC)
  3. National Cancer Institute (NCI). Definition: neutropenia
  4. American Red Cross. Blood Types Explained – A, B, AB and O
  5. The Lancet Infectious Diseases (ECIL 7), 2019. Vaccination of haemopoietic stem cell transplant recipients: guidelines of the 2017 European Conference on Infections in Leukaemia (ECIL 7)
  6. Clinical Infectious Diseases (IDSA), 2011. Clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer: 2010 update by the Infectious Diseases Society of America
  7. Journal of Clinical Oncology (ASCO and IDSA), 2018. Outpatient Management of Fever and Neutropenia in Adults Treated for Malignancy: ASCO and IDSA Clinical Practice Guideline Update
  8. Centers for Disease Control and Prevention (CDC). About C. diff
  9. MedlinePlus (U.S. National Library of Medicine). Aspergillosis
  10. Clinical Infectious Diseases (IDSA), 2016. Practice Guidelines for the Diagnosis and Management of Aspergillosis: 2016 Update by the IDSA
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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