Immunofixation Result, Serum

The Immunofixation test is often used to diagnose multiple myeloma or Waldenstrom’s macroglobulinemia, when symptoms of the disorders are present. Both conditions produce abnormal Ig.

Clinical symptoms of multiple myeloma include:

- bone pain in the back or ribs
- weakness and fatigue
- weight loss
- broken bones
- recurrent infections
- weakness in the legs
- nausea and vomiting

Clinical symptoms of Waldenstrom’s macroglobulinemia include:

- weakness
- severe fatigue
- bleeding from the nose or gums
- weight loss
- bruises or other skin lesions
- blurred vision
- swelling of the lymph nodes, spleen, or liver

This test alone cannot be used to make a diagnosis. The test only indicates whether abnormal Ig is present.

Another test must be used to measure the amount of abnormal Ig in the blood. This test is called serum protein electrophoresis (SPEP) test. Your doctor can use it to confirm certain diagnoses.

Immunofixation can either reveal a normal pattern or identify a monoclonal protein or a polyclonal immunoglobulin pattern.

A normal result includes:

- a darker immunoglobulin G (IgG) lane,

- a lighter immunoglobulin A (IgA),

- an absent immunoglobulin M (IgM),

- and a denser kappa compared to lambda lane, with ratio of 2:1.

In a normal result, the lanes are broad and there is a gradual and smooth reduction in the color density toward the edges of the lane with no narrow dense band with sharp borders identified within the lane.

In some cases, all the lanes are homogeneously darkened to the same degree. This pattern represents the presence of polyclonal immunoglobulin. Again, the lanes are broad and the transition to the lane borders is smooth. In this case, the IgM lane, which is normally absent, is broad with smooth borders.

When a narrow band with sharp borders can be identified, it implies the presence of a monoclonal protein.