Quantitative immunoglobulins -... Health Article

What abnormal results mean

Increased levels of IgG may indicate the following:

• Chronic infection or inflammation
• Hyperimmunization
• IgG multiple myeloma
• Liver disease
• Rheumatic fever
• Rheumatoid arthritis

Decreased levels of IgG may indicate the following:

• Agammaglobulinemia (very rare)
• Amyloidosis
• Leukemia
• Myeloma
• Preeclampsia

Increased levels of IgM may indicate the following:

• Early HIV infection
• Infectious mononucleosis
• Lymphoma
• Macroglobulinemia
• Myeloma
• Rheumatoid arthritis

Decreased levels of IgM may indicate the following:

• Agammaglobulinemia (very rare)
• Amyloidosis
• Leukemia
• Myeloma

Increased levels of IgA may indicate the following:

• Chronic infections, especially involving the gastrointestinal tract
• Inflammatory bowel disease
• Myeloma
• Rheumatic fever

Decreased levels of IgA may indicate the following:

• Agammaglobulinemia (very rare)
• Hereditary IgA deficiency
• Myeloma
• Protein-losing gastroenteropathy

What the risks are

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling lightheaded
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Special considerations

Nephelometry determines the total amount of each immunoglobulin but cannot distinguish antibodies. Other tests such as immunoelectrophoresis or immunofixation can be used to make these distinctions.

References

McPherson RA and Pincus MR. Henry's Clinical Diagnosis and Management by Laboratory Methods. 21st ed. Philadelphia, Pa: WB Saunders; 2007:40-41.

Adkinson Jr. NF, Yunginger JW, Busse WW, et al., eds. Middleton's Allergy: Principles and Practice. 6th ed. Philadelphia, Pa: Mosby; 2003:615-616.