Skip to content

Neutrophil Count (Absolute) with Differential Analysis (Serum/Plasma)

Published: August 9, 2026Updated: August 15, 2026

This test measures the number of neutrophils in your blood and evaluates the proportion of different neutrophil subtypes, which can help identify infections, immune responses, or other blood disorders.

Quick summary

["Neutrophils are key white blood cells that fight infections; this test helps assess their role in your health."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 15, 2026Editorial policy

Key facts at a glance

LOINC
101447-1
Short code
CNTN1NF155
Synonyms
CASPR1 IgG + NF155 IgG4 pnl SerPl
Category
chemistry
Sample
serum
Container
Serum separator tube (SST) or red-top tube; plasma collected in EDTA or heparin tube is acceptable
Units
N/A
Ref low
0
Ref high
1
Fasting
false
Population
adult
Sex
all
Age range
0–120 years
Method
Cell-based indirect immunofluorescence assay (CBA) using transfected HEK293 cells expressing human Contactin-associated protein 1 (CNTN1) and Neurofascin155 (NF155) antigens, with IgG or IgG4-specific secondary detection
CPT
86255 (with possible add-on 86256 for IgG4 subclass)
SNOMED
444068003
Specimen volume
1-2 mL of serum or plasma; minimum 0.5 mL
Stability
Serum stable at 2-8°C for 14 days; frozen at -20°C or lower for long-term storage (up to 6 months). Avoid repeated freeze-thaw cycles.
Hemolysis max
100
Lipemia max
100
Icterus max
50
TAT
72–168 hours
Order
routine

What Neutrophils Do in Your Body

Neutrophils are a type of white blood cell that play a critical role in fighting bacterial infections. They are among the first responders to areas of inflammation or infection in your body. The test measures their absolute count and the distribution of their subtypes, which can vary based on your immune response or underlying health conditions.

Why This Test Might Be Ordered

Your healthcare provider may order this test to diagnose or monitor conditions such as infections (e.g., bacterial), inflammatory diseases, blood disorders (e.g., leukemia), or to evaluate how your immune system is responding to treatment.

How the Test Works

Blood is drawn and processed to separate the different types of white blood cells. The test uses microscopic or automated methods to count neutrophils and classify their subtypes (e.g., band neutrophils, segmented neutrophils) based on their appearance and function.

What to Expect Before the Test

There are no special preparations needed for this test. You may have a small bruise or slight discomfort at the needle insertion site, but this is normal. Avoid strenuous activity or eating heavy meals before the blood draw if instructed by your provider.

Reference range

Negative (titer <1:10 for CNTN1 IgG; titer <1:10 for NF155 IgG4). Positive results reported with endpoint titer.N/A

Specimen: serum

No special preparation required. Patient should be informed about the autoimmune nature of testing. Clinical correlation with neurological examination, nerve conduction studies, and MRI findings is recommended.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Elevated neutrophil counts may indicate acute infections, inflammation, or stress responses. A low neutrophil count could signal immune deficiencies, certain cancers, or autoimmune disorders. Changes in the neutrophil differential (e.g., high band neutrophils) can also signal ongoing infection or poor immune function. Always discuss results with your healthcare provider for personalized interpretation.

Short name

Neutrophil Differential Profile

Frequently asked questions

When Might I See This Test Result?
You may receive this test result shortly after your blood draw, often within a few hours to a couple of days, depending on lab processing. Your healthcare provider will review the results with you during your follow-up visit or appointment.
What Does a High or Low Neutrophil Count Mean?
A high neutrophil count often points to an active infection, inflammation, or other conditions like rheumatoid arthritis or certain cancers. A low neutrophil count can indicate a weakened immune system, which may require further evaluation to determine the cause, such as medications, chronic illnesses, or genetic conditions.
Can Diet or Exercise Affect Neutrophil Counts?
Diet and exercise generally do not directly affect neutrophil counts, but they can influence overall immune health. Avoiding excessive stress, staying hydrated, and maintaining a balanced diet may support your immune system, but this test specifically measures the absolute count and subtype distribution of neutrophils in your blood.
  1. 1
    MedlinePlus — Laboratory TestsSource
  2. 2
    Lab Tests OnlineSource
  3. 3
    Mayo Clinic — Tests & ProceduresSource

Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.

This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.

Medical Disclaimer

This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.

If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.

Medically reviewed by WellAlly Editorial Team Last reviewed August 15, 2026. · Read our editorial policy