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Macrophage Count in Dialysis Fluid (Manual Qualitative)

Published: August 9, 2026Updated: August 16, 2026

This test checks for the presence of macrophages, a type of white blood cell, in the fluid collected during dialysis. Macrophages can indicate inflammation or infection in the dialysis circuit.

Quick summary

["Macrophages in dialysis fluid may signal potential contamination or infection during treatment."]

Medically reviewed by WellAlly Editorial TeamLast reviewed August 16, 2026Editorial policy

Key facts at a glance

LOINC
51621-1
Short code
Macrophages NFr Dial fld Manual
Synonyms
Macrophages NFr Dial fld Manual
Category
chemistry
Sample
serum
Container
Red-top tube (SST)
Units
N/A
Fasting
false
Population
adult
Sex
all
Age range
18–65 years
Method
manual-count
Specimen volume
5 mL
Stability
Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
Hemolysis max
500
Lipemia max
1000
Icterus max
500
TAT
4–24 hours
Order
routine

Why Is This Test Done?

Healthcare providers may order this test if you experience symptoms like fever, unusual fluid buildup, or signs of infection after dialysis. It helps identify if macrophages are entering your bloodstream through the dialysis machine, which could be due to a malfunction or infection in the dialysis line.

What Does a Positive Result Mean?

A positive result (presence of macrophages) suggests there may be an issue with your dialysis setup, such as contamination from the dialysis fluid, equipment failure, or an infection in the access site. This isn’t always urgent but requires follow-up to address the cause.

What Does a Negative Result Mean?

A negative result means no macrophages were detected in the fluid, indicating no immediate signs of contamination or infection related to dialysis. However, ongoing monitoring is still important to prevent future issues.

What Does This Test Involve?

During dialysis, a small sample of the fluid used in your treatment is collected and examined under a microscope to look for macrophages. This is a manual (not automated) qualitative test, meaning the result is qualitative rather than a numerical value.

Clinical interpretation

How abnormal results are interpreted and what conditions they suggest.

Clinical Significance:

Short name

Macrophage Presence in Dialysis Fluid

Frequently asked questions

What Are the Possible Causes of a Positive Result?
Possible causes include contamination of dialysis fluid, bacterial or fungal infection in the dialysis line, or a malfunction in the dialysis machine. Macrophages can also appear if there’s an access site infection (e.g., from your fistula or shunt).
How Often Is This Test Done?
This test is typically done as part of routine dialysis monitoring, often weekly or biweekly, depending on your healthcare provider’s protocol. It helps track the safety and effectiveness of your dialysis treatment.
What Should I Do If My Test Comes Back Positive?
If macrophages are found, your dialysis team will investigate further. They may adjust your dialysis settings, check for equipment issues, or prescribe antibiotics if an infection is suspected. Follow their instructions closely to prevent complications.
  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 16, 2026. · Read our editorial policy