Serum Human IgG 4

Specimen Required

3-5cc Clotted Blood or Serum

Fasting Required

Purpose of the Test

This test is ordered when a healthcare provider suspects an autoimmune disorder or an allergic reaction, especially if the patient presents with symptoms such as swelling, itching, or hives. IgG4 levels are frequently associated with allergic reactions and inflammation, so a high level of IgG4 antibodies may indicate the presence of an autoimmune disease or an allergic reaction.

When this test is required

The serum human IgG4 test is requested when a healthcare provider suspects an autoimmune disorder or an allergic reaction. The test may be ordered if a patient has symptoms such as swelling, itching, or hives that suggest an allergic reaction. Additionally, the test may be ordered if a patient has symptoms that suggest an autoimmune disorder, such as joint pain, fatigue, or unexplained weight loss.

What the Test Detects

The serum human IgG4 test measures the levels of IgG4 antibodies in the blood. Immunoglobulin G (IgG) is a type of antibody that plays a crucial role in the immune system’s response to infections and diseases. IgG4 is a subclass of IgG that is involved in allergic reactions and autoimmune disorders.

Preparation for the Test

No specific test preparation is needed. However, it is essential to inform the healthcare provider about any medications the patient is taking, including over-the-counter drugs and supplements, as they can affect the test results. It is also important to follow the healthcare provider’s instructions regarding fasting, if required, and to inform them if the patient has a bleeding disorder or if they are taking blood-thinning medications.

Sample Requirements

The serum human IgG4 test is a blood test, and a blood sample is required. During the test, a healthcare professional will insert a needle into a vein in the arm, and a small amount of blood will be drawn into a test tube.

Additional Notes

It is important to note that a high level of IgG4 antibodies does not necessarily mean that a patient has an autoimmune disorder or an allergic reaction. Other conditions, such as infections, can also cause elevated IgG4 levels. Additionally, some individuals naturally have higher levels of IgG4 antibodies than others, so healthcare providers consider many factors when interpreting the test results. If a healthcare provider suspects that a patient has an autoimmune disorder or an allergic reaction, they will use the serum human IgG4 test in combination with other tests and assessments to determine the best course of treatment.

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