Anti Jo-I antibody Test

Your doctor will order an anti-Jo-1 antibody test if you have symptoms suggestive of an autoimmune disorder. Several tests may be done to differentiate between autoimmune disorders and identify the exact disorder depending on the autoantibodies found in your body. 

The following symptoms prompt a doctor to recommend this test:

• Skin rashes
• Persistent low-grade fever
• Pain in the muscles
• Hair loss
• Anaemia
• Joint pain
• Swelling in the joints

These are the most typical symptoms of autoimmune disorders. 

The doctor will also order this test to monitor the progression or status of the autoimmune disorder (if already diagnosed). 

Anti Jo-1 antibody is mainly associated with two disorders – polymyositis and pulmonary fibrosis. Polymyositis is a disease which causes inflammation of the muscles as a result of an autoimmune reaction. It presents with the following symptoms:

• Joint pain
• Stiffness in the joints 
• Muscular pain and weakness 
• Irregular heartbeat (in extreme cases)

Pulmonary fibrosis refers to the scarring of lungs and is associated with symptoms such as:

• Shortness of breath
• Shallow breathing
• Tiredness
• Persistent dry cough
• Pain in the joints

No specific preparations are required before this test. 

In order to conduct this test, only a small amount of blood is needed. A doctor or laboratory technician will withdraw the blood sample from a vein in your arm by inserting a sterile needle. You may feel no pain from the needle or just a quick sting or pinch.

Some risks associated with taking a blood sample are. 

• Difficulty in obtaining the sample
• Excessive bleeding at the site from where the blood is drawn
• Fainting 
• Haematoma (accumulation of blood under the skin)
• Infection at the site where the needle is inserted

Typically, the immunoglobulin G (IgG) type anti Jo-1 antibody levels are checked in this test. It’s one of the antibodies that are abundantly present in the blood and can hence be easily identified. Results are given in terms of Units.

Normal results:

A value of < 1.0 U is considered negative. Negative test results mean that there are no anti-Jo-1 antibodies present in your blood and the symptoms you are experiencing are not due to an autoimmune disease.

Abnormal results:

A value of ≥ 1.0 U is considered to be an abnormal or positive result. This indicates that you may be suffering from polymyositis or pulmonary fibrosis. Your doctor will conduct more tests to evaluate your condition further and establish the diagnosis.

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.