Nitro Blue Tetrazolium (NBT)

• Test Name: Nitro Blue Tetrazolium (NBT) Test
• Test Type: Diagnostic functional test for neutrophils
• Specimen Required: Whole blood sample
• Methodology: Reduction of nitroblue tetrazolium dye by neutrophils
• Purpose: Evaluate the oxidative burst activity of neutrophils, specifically assessing their ability to produce reactive oxygen species (ROS) to fight infections.

• Diagnosis of Chronic Granulomatous Disease (CGD): Primarily used to diagnose CGD, a genetic disorder where neutrophils fail to produce reactive oxygen species, leading to recurrent bacterial and fungal infections.
• Assessment of Immune Function: Helps evaluate the functional capacity of neutrophils in patients with suspected immune deficiencies.
• Monitoring: This may be used to monitor patients with CGD to assess the effectiveness of treatment or bone marrow transplantation.

• Components:
  • Collection of a whole blood sample from the patient.
  • Incubation of blood cells with nitroblue tetrazolium (NBT) dye.
  • Evaluation of the reduction of NBT to a blue formazan product by neutrophils, indicating normal oxidative burst activity.
  • Microscopic examination or flow cytometry to quantify the percentage of neutrophils that reduce NBT.
• Procedure:
  • Blood is drawn from the patient.
  • The sample is mixed with NBT and incubated.
  • The presence of blue-stained cells indicates normal neutrophil function, while the absence suggests a defect.

• Normal Findings: A high percentage of neutrophils successfully reduce NBT to formazan, indicating normal oxidative burst function.
• Abnormal Findings: Low or absent reduction of NBT by neutrophils suggests a defect in the oxidative burst, consistent with chronic granulomatous disease (CGD) or other neutrophil dysfunctions.
• Clinical Correlation: Test results should be correlated with clinical findings and other diagnostic tests to confirm the diagnosis of CGD or other related disorders.

• Qualitative and Quantitative: The test provides both a qualitative and quantitative assessment of neutrophil function.
• Interpretation: Results are interpreted based on the percentage of neutrophils that reduce NBT, with lower percentages indicating potential immune deficiencies.
• Report: A report detailing the percentage of neutrophils that reduce NBT, along with clinical interpretation, is provided.
• Turnaround Time: Typically 1-2 days, depending on the laboratory.

Q. What is the Nitro Blue Tetrazolium (NBT) Test?
The NBT test is a diagnostic test that measures the ability of neutrophils to produce reactive oxygen species (ROS), which are critical for fighting infections
 

Q. Why is the Nitro Blue Tetrazolium (NBT) Test performed?
It is primarily performed to diagnose chronic granulomatous disease (CGD), a condition where neutrophils cannot effectively kill bacteria and fungi due to defective ROS production
 

Q. How is the Nitro Blue Tetrazolium (NBT) Test conducted?
A blood sample is taken and mixed with NBT dye. The test then measures the ability of neutrophils to reduce the dye, which indicates their functional capacity
 

Q. What do the results of the Nitro Blue Tetrazolium (NBT) Test mean?
If a high percentage of neutrophils reduce NBT, it indicates normal function. Low or no reduction suggests a problem, such as CGD, where neutrophils are unable to produce ROS effectively
 

Q. Who should consider getting the Nitro Blue Tetrazolium (NBT) Test?
Individuals with recurrent bacterial or fungal infections, particularly those suspected of having chronic granulomatous disease (CGD), should consider this test
 

Q. Are there any risks or preparations required for the Nitro Blue Tetrazolium (NBT) Test?
The test is low-risk, involving a simple blood draw. No special preparation is needed
 

Q. How long does it take to get results from the Nitro Blue Tetrazolium (NBT) Test?
Results are typically available within 1-2 days after the sample is collected, depending on the laboratory