Anti-Gliadin antibodies

Healthcare practitioners order this test to assess the prevalence of gluten sensitivity in a person. This test is also done along with some other tests to check if a person has coeliac disease. 

Our body produces two types of antibodies/immunoglobulins against gliadin - IgA and IgG. Generally, the AGA-IgA test is suggested to check the occurrence of the coeliac disease. However, your doctor may order an IgG test if you have a deficiency of IgA. 

The following are the symptoms of celiac disease:

• Bloody stools
• Greasy and foul-smelling stools
• Chronic diarrhoea and constipation
• Vomiting
• Abdominal pain and swelling
• Bone pain and joint pain
• Iron deficiency anaemia
• Defects in dental enamel 

An anti-gliadin antibody test is also used to check for celiac disease in gluten-sensitive individuals who suffer from irritable bowel syndrome. These individuals usually get negative results with other diagnostic tests.

Additionally, a doctor may order this test if you have a family history of gluten allergy.

You need not do any preparation for this test if you already have the symptoms of AGA in the body. However, to check if you are sensitive to gliadin, your healthcare practitioner may request you to eat gluten-rich food for several weeks. Fasting is not required for this test. If you are consuming any prescribed, non-prescribed, legal or illicit medications, inform your doctor before the test.

A lab technician will withdraw a small amount of blood from a vein in your arm. When the needle is inserted, you may experience mild pain. Other risks associated with this test are: 

• Fainting
• Blood accumulation under the skin
• Excessive bleeding
• Multiple punctures to locate veins

Normal results:

Normal results are usually indicated as negative. It shows that a person is not allergic to gliadin, or does not have coeliac disease. However, to check for coeliac disease, other tests may also be ordered along with the AGA test. The normal value for gliadin IgA and IgG antibodies is:

• Negative: less than 20 U/mL

Abnormal results:

An abnormal result for AGA test is written as either weakly positive or moderate to strong positive. They indicate that you have anti-gliadin antibodies in your blood, which can be either due to coeliac disease or non-coeliac gluten sensitivity. The abnormal values for gliadin IgG and IgA antibodies are as follows:

• Weak positive: 20-30 U/mL
• Moderate to strong positive: >30 U/mL

Some other conditions in which the AGA test shows positive results are as follows: 

• Rheumatoid arthritis
• Sjogren’s syndrome (an autoimmune disease affecting the glands of tear and saliva causing dry eyes and dry mouth)
• Systemic lupus erythematosus (an autoimmune disease affecting the healthy tissues)
• Sarcoidosis (an inflammatory disease affecting lungs and lymph glands)
• Type 1 diabetes
• IgA nephropathy

A false-positive result can be observed in case of Crohn’s disease - a type of inflammatory bowel disease that leads to abdominal cramps and diarrhoea. 

Disclaimer: All results must be clinically correlated with the patient’s complaints to make a complete and accurate diagnosis. The above information is provided from a purely educational point of view and is in no way a substitute for medical advice by a qualified doctor.