The anti-centromere antibody rarely comes up in casual conversation. Even doctors are easily confounded by this antibody. Doctors can give confusing or mixed messages regarding a centromere antibody result and this can send even the most levelheaded into a tailspin.
What is a centromere?
We might need to return to high school biology to answer this. Stick with me as we do a quick refresher. The centromere is a piece of DNA that attaches to chromatids to form a chromosome. (!!!) We all have 46 chromosomes or 23 pairs. (Think of “23 and me”) The chromosome is a structure that houses all our DNA. We find this structure in the nucleus of our cells, making, by definition, the centromere antibody an anti-nuclear antibody, or ANA. The anti-centromere antibody, thus, can be positive in those with a positive ANA result. Remember, the ANA blood test is a general, non-specific anti-nuclear antibody blood test while the anti-centromere antibody test is a more specific type of ANA. This then would make a positive centromere antibody result with a negative ANA, very unlikely.
Why do we check it?
The two most common reasons are
- Raynaud’s phenomenon
Raynaud’s phenomenon is a condition of vasoconstriction of the blood vessels of the digits. This results in color changes of the fingertips (or toes) when exposed to cold or stress. The color changes can go from white to blue to red. In some cases, we discover lupus or scleroderma after the development of Raynaud’s. For this reason, doctors will check the anti-centromere antibody.
- The autoimmune lab panel
When a doctor has concerns for autoimmunity (rashes, fatigue, hair loss) it is common to check a full autoimmune panel. Most lab companies have various antibody panels available. Experts in the field put together these panels to streamline the autoimmune workup. They include antibodies commonly associated with a positive ANA. However, as thorough as these panels may be, they may not be specific to your situation. Most autoimmune panels includes the anti-centromere test and doctors commonly discover it through this testing.
CREST syndrome, otherwise known as limited scleroderma, is closely associated with a positive anti-centromere antibody result. If you have done your research into autoantibodies, like ANA or rheumatoid factor (RF), you know that they are imperfect. Many will ultimately have a “false positive.” A false positive simply means a positive lab result in an individual without the associated condition. The anti-centromere antibody doesn’t result in as many false positives as we see with the ANA or RF. However, not everyone with an anti-centromere antibody has CREST syndrome. In fact, the anti-centromere antibody is also seen with rheumatoid arthritis, lupus, Sjogren’s, amongst others. We must investigate all possible conditions when we find an anti-centromere antibody. Further complicating matters, some may develop an anti-centromere antibody years before any symptoms. As scary as this may sound, always remember, no patient is the same! Through a partnership with your doctor you can get answers.
Questions for you when faced with a + anti-centromere antibody:
1. Do you have Raynaud’s? Is this something you have had your whole life? Have you just noticed this symptom recently?
2. Have you noticed any skin changes? Are you getting new rashes? Are you having any discomfort or tightness in your skin?
3. Are you having any new or worsening heartburn?
4. Dig into your family history. Autoimmune begets autoimmune. Remember, family history does not need to be specific for the condition of concern. Any autoimmunity is important including often overlooked vitiligo and thyroid disease.
Questions for your doctor:
1. Do I have any signs or symptoms that make you worried about CREST syndrome? And if so, can you help me see them? Can you explain them to me?
2. If I don’t seem to have CREST syndrome, are there any other conditions this anti-centromere antibody could be related to? And if so, what other testing do we need to do to rule in or rule out these other conditions?
3. What are some red flag signs or symptoms I need to be on the lookout for?
4. How often do I need to be checking in with you? It is not uncommon for those with a positive anti-centromere antibody to check in with their rheumatologist or primary care doctor every 6 to 12 months.
The anti-centromere antibody is a very specific but often very confusing and anxiety producing lab result. Although it requires a comprehensive investigation into a possible autoimmune condition, it doesn’t have to be scary. When armed with the information regarding what to look out for any patient facing an anti-centromere antibody positive result can feel confident in moving forward.