Immunoglobulin Subclass IGG4

• Test Name: Immunoglobulin Subclass IGG4 Test
• Test Type: Immunology test
• Specimen Required: Blood sample (serum)
• Methodology: Quantitative immunoassay, such as enzyme-linked immunosorbent assay (ELISA) or nephelometry
• Purpose: Measures the concentration of the IGG4 subclass of immunoglobulins in the blood to evaluate immune function and diagnose conditions associated with abnormal IGG4 levels.

• Diagnosis: Helps diagnose conditions such as IGG4-related disease (IGG4-RD), a group of disorders characterized by tissue infiltration by IGG4-positive plasma cells.
• Evaluation of Immune Disorders: Assesses immune function in patients with suspected primary or secondary immunodeficiencies, particularly those affecting the IGG4 subclass.
• Monitoring: Monitors the response to treatment in patients with IGG4-RD or other conditions associated with elevated IGG4 levels.
• Allergy Assessment: This can be used to evaluate allergic conditions where IGG4 levels may be elevated, although it is not a primary allergy test.

• Components:
  • Collection of a blood sample from the patient.
  • Quantitative measurement of IGG4 levels in the serum using an immunoassay technique.
  • Calibration with standard controls to ensure accurate and reliable results.
  • Reporting of IGG4 concentration in milligrams per deciliter (mg/dL) or grams per liter (g/L)
     
• Procedure:
  • A blood sample is drawn from a vein in the patient’s arm.
  • The serum is separated and analyzed in the laboratory using specific antibodies to detect and quantify IGG4 levels.
  • Results are compared to reference ranges to determine if IGG4 levels are normal or abnormal.

• Normal Findings: IGG4 levels fall within the normal reference range, indicating typical immune function.
• Elevated Levels: High IGG4 levels may indicate IGG4-related disease (e.g., autoimmune pancreatitis, retroperitoneal fibrosis) or allergic conditions.
• Low Levels: Low IGG4 levels may suggest an immune deficiency, particularly if other IGG subclasses are also affected.
• Clinical Correlation: IGG4 levels should be interpreted in the context of clinical symptoms, other laboratory findings, and the patient’s medical history for an accurate diagnosis.

• Qualitative and Quantitative: Provides a quantitative measurement of IGG4 levels in the serum.
• Interpretation: Results are interpreted based on reference ranges and clinical context.
• Report: A detailed report includes the measured IGG4 concentration and its clinical significance.
• Turnaround Time: Typically 1-3 days, depending on the laboratory.

Q. What is the Immunoglobulin Subclass IGG4 Test?
This test measures the levels of IGG4, a subclass of immunoglobulins, in the blood to evaluate immune function and diagnose certain conditions like IGG4-related disease
 

Q. Why is the IGG4 Test ordered?
It is ordered to diagnose or monitor conditions such as IGG4-related disease, evaluate immune function, and assess potential allergic or inflammatory conditions
 

Q. How is the IGG4 Test performed?
A blood sample is drawn and analyzed in the lab using immunoassay techniques to quantify the level of IGG4 in the serum
 

Q. What do high IGG4 levels indicate?
Elevated IGG4 levels may suggest the presence of IGG4-related disease, certain allergic conditions, or chronic inflammatory disorders
 

Q. What do low IGG4 levels indicate?
Low IGG4 levels could be indicative of an immune deficiency, particularly if other immunoglobulin subclasses are also low
 

Q. Do I need to prepare for the IGG4 Test?
Generally, no special preparation is needed for this test. However, follow any specific instructions provided by your healthcare provider
 

Q. How long does it take to get the results of the IGG4 Test?
Results are typically available within 1-3 days after the blood sample is collected and analyzed.