IgG Anticentromere (Kinetochore) Autoantibodies: Diagnosis of Autoimmune Diseases

The IgG anticentromere (kinetochore) autoantibody test is a laboratory test used to detect immunoglobulin G (IgG) class autoantibodies directed against centromere proteins (kinetochores) in the blood. The presence of these autoantibodies is an important marker for diagnosing certain systemic autoimmune diseases, especially limited systemic sclerosis (CREST syndrome).

What are centromeres (kinetochores) and autoantibodies?

The centromere is a part of a chromosome that plays a crucial role during cell division. The kinetochore is a protein complex that forms on the centromere and serves as the attachment site for microtubules, ensuring proper separation of chromosomes.

Anticentromere antibodies (ACA) are autoantibodies that mistakenly target these proteins. Their presence is strongly associated with limited systemic sclerosis, also known as CREST syndrome (Calcinosis, Raynaud’s phenomenon, Esophageal dysfunction, Sclerodactyly, Telangiectasias). This is a chronic autoimmune disease affecting the skin, blood vessels, gastrointestinal tract, and other organs.

Why is the IgG anticentromere (kinetochore) test performed?

This test is usually performed to:

• Diagnose limited systemic sclerosis (CREST syndrome): when symptoms such as Raynaud’s phenomenon (color changes in fingers due to cold), skin thickening, digestive issues, or telangiectasias (dilated capillaries) are present.
• Differentiate from other forms of systemic sclerosis: helps distinguish the limited form from diffuse systemic sclerosis.
• Assess disease course and prognosis: the presence of ACA is associated with slower disease progression and a better prognosis compared to other autoantibodies.
• Investigate unexplained Raynaud’s phenomenon: when an autoimmune cause is suspected.

Test procedure in a clinic

The IgG anticentromere (kinetochore) test is a simple blood test. A blood sample is taken from a vein, usually in the arm. Typically, no special preparation (such as fasting) is required, but it is always important to consult a healthcare provider for specific instructions.

Interpretation of results

Test results are interpreted based on reference ranges, the patient’s symptoms, medical history, and other diagnostic data:

• Positive result: indicates the presence of anticentromere autoantibodies, confirming an autoimmune process. It is a strong marker of limited systemic sclerosis (CREST syndrome).
• Negative result: indicates that autoantibodies were not detected.

It is important to emphasize that test results should always be evaluated by a qualified healthcare professional, taking into account the patient’s full medical history, symptoms, and other diagnostic findings.