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If anti-CENP-B (anti-centromere protein B) shows up on your lab results, it means your immune system is producing antibodies against one of your own proteins, specifically a structural protein found in every cell's chromosome machinery. This is not a routine screening test. It is ordered when there is a clinical suspicion that your immune system has begun attacking your own tissues, particularly in the context of Raynaud's phenomenon (fingers or toes turning white or blue in response to cold), unexplained skin tightening, or difficulty swallowing.
The single most important thing this test tells you is whether your body is making a specific autoimmune signature most closely tied to a condition called limited cutaneous systemic sclerosis, sometimes referred to by its older name, CREST syndrome. This is a form of scleroderma, a disease in which the immune system drives excess collagen production, gradually thickening and hardening the skin and sometimes affecting internal organs. Among the different autoantibody patterns seen in scleroderma, anti-CENP-B is the one associated with the most limited, slowest-progressing form of the disease.
A positive result does not automatically mean you have scleroderma. But it dramatically narrows the diagnostic picture and tells your clinician exactly which organs to watch and how urgently to follow up.
The test measures antibodies in your blood directed against a protein called CENP-B, an 80-kilodalton protein that sits in the centromere, the structural hub that holds the two halves of a chromosome together during cell division. CENP-B is found in virtually every cell in your body, but for reasons that are still not fully understood, some people's immune systems begin treating it as a foreign invader and produce antibodies against it.
Anti-CENP-B is the most reliably detected of the anticentromere antibodies. When labs run an immunofluorescence test on your blood, a positive result shows a characteristic pattern of discrete speckles across the cell nucleus. The antibody can also be measured more precisely using a technique called ELISA, which uses a lab-made version of the CENP-B protein to quantify how much antibody is circulating.
Most people who test positive for anti-CENP-B also carry antibodies against two related centromere proteins, CENP-A and CENP-C, with overlap rates exceeding 90%. For clinical purposes, anti-CENP-B is the workhorse marker because it is the most consistently present and the most widely tested.
Anti-CENP-B is not a one-disease marker, but it has a short list of strong associations. Its diagnostic specificity for systemic sclerosis exceeds 96% when compared against other autoimmune diseases, meaning a positive result in the right clinical setting is a powerful signal.
The conditions most strongly linked to a positive anti-CENP-B result fall into a few groups:
Anti-CENP-B can occasionally be found in people with systemic lupus erythematosus or rheumatoid arthritis, though these are less common. It can also be detected at low levels in apparently healthy individuals, though this is uncommon and typically at much lower concentrations than in people with established autoimmune disease.
If you test positive for anti-CENP-B in the context of scleroderma, the news is relatively reassuring compared to other autoantibody patterns. People with anti-CENP-B-positive limited cutaneous systemic sclerosis have the most favorable prognosis among all scleroderma subsets, with 20-year survival rates of approximately 65% and significantly lower mortality compared to other autoantibody groups.
By contrast, a different scleroderma-associated antibody called anti-topoisomerase I (also known as anti-Scl-70) is linked to more aggressive disease, more skin involvement, and worse survival. Anti-CENP-B and anti-Scl-70 almost never appear together in the same person, and they map onto very different disease trajectories.
The specific organ risks associated with anti-CENP-B positivity have a distinct pattern:
| Complication | What to Know |
|---|---|
| Pulmonary arterial hypertension (high blood pressure in the lung arteries) | This is the most characteristic serious complication. It can develop even without significant lung scarring and requires annual screening with echocardiography. |
| Interstitial lung disease (scarring in the lung tissue) | Significantly lower risk than with other scleroderma antibodies. Only about 8.5% of people with anti-CENP-B-positive limited scleroderma develop clinically significant lung scarring over 20 years. |
| Scleroderma renal crisis (sudden severe kidney failure) | Very rare at 0.3% over 20 years in limited cutaneous disease. |
| Heart involvement | Uncommon at 4.9% over 20 years. |
| Digital ulcers (sores on the fingertips from poor blood flow) | Can occur but tend to be less severe than in diffuse scleroderma. |
Sources: Nihtyanova et al. (2020); Hamaguchi (2010).
What this means for you: if you are anti-CENP-B positive with limited scleroderma, your primary surveillance concern is your lungs, specifically the blood pressure in your lung arteries rather than lung scarring. Annual echocardiograms are the key monitoring tool. The low rates of kidney and heart involvement mean these are less likely to be your primary risk, but they should still be checked at baseline.
One important nuance: anti-CENP-B level, not just positivity, carries information. Among people with very early signs of scleroderma (Raynaud's, puffy fingers, or abnormal nail fold capillaries, but not yet meeting full diagnostic criteria), higher baseline IgG anti-CENP-B levels were associated with 4.3-fold increased odds of progressing to definite scleroderma. Overall, 42% of people with very early disease progressed within 5 years.
That said, a recent systematic review found that the evidence for anticentromere antibodies independently predicting better survival is not as consistent as once thought. Only 5 of 19 studies found that anticentromere antibody positivity was independently associated with improved survival. The antibody is a strong diagnostic and phenotyping tool, but its value as a standalone survival predictor is more nuanced.
Some people discover a positive anti-CENP-B result before they have been diagnosed with any connective tissue disease, often in the workup for Raynaud's phenomenon or unexplained joint pain. If this describes you, the result should not be ignored, but it also should not cause panic. What matters most is the company the antibody keeps: what other signs and symptoms are present alongside it.
Your risk of eventually developing scleroderma depends heavily on what additional findings are present. A simple procedure called nailfold capillaroscopy, in which a clinician examines the tiny blood vessels at the base of your fingernails under magnification, is one of the most powerful risk-stratification tools available.
| Who Was Studied | What Was Compared | What They Found |
|---|---|---|
| People with Raynaud's plus a scleroderma-specific antibody and abnormal nail fold capillaries | Progression to definite scleroderma over time | About 66% developed scleroderma at 5 years and 73% at 10 years |
| People with Raynaud's plus puffy fingers and a positive antinuclear antibody | Progression to definite scleroderma at 5 years | About 94% progressed |
| People with Raynaud's plus abnormal capillaroscopy and a positive antinuclear antibody | Progression to definite scleroderma at 5 years | About 82% progressed |
| People with Raynaud's but no scleroderma capillaroscopy pattern and no scleroderma-specific antibody | Progression to definite scleroderma at 5 years | Only about 1% progressed |
Sources: Volkmann et al. (2023); Bellando-Randone et al. (2021).
What this means for you: a positive anti-CENP-B with Raynaud's phenomenon puts you in a higher-risk category, but the combination with abnormal capillaroscopy or puffy fingers is what truly escalates the concern. If you have anti-CENP-B with Raynaud's alone and normal capillaroscopy, your near-term risk is substantially lower. Regardless, follow-up every 6 to 12 months with a rheumatologist is reasonable.
A comprehensive initial workup should also screen for primary biliary cholangitis (through liver function tests and anti-mitochondrial antibodies) and Sjogren's syndrome (through symptom assessment and tear production testing), since both conditions are common co-travelers with anti-CENP-B positivity.