What a Positive Centromere Antibody Test Result Means

A positive centromere antibody (ACA) test means your immune system is producing antibodies against proteins in the centromere, a structural part of your chromosomes. The result is most strongly linked to limited cutaneous systemic sclerosis, a form of scleroderma that tends to affect the skin of the hands, face, and lower arms while also threatening internal organs over time. But the antibody can show up in other autoimmune conditions too, and its presence, its level, and the clinical picture around it all matter for what comes next.

What the Antibody Targets

Centromere antibodies are directed against proteins embedded in the kinetochore, the structure that helps chromosomes divide during cell division. The three main targets are CENP-A, CENP-B, and CENP-C, each a different-sized protein within the same complex.¹ Most commercial lab tests screen for antibodies to CENP-B because it is the most reliably detected, though some also test for CENP-A. The standard detection method uses a cell-based immunofluorescence assay, which produces a distinctive speckled pattern on the cell nuclei that is hard to confuse with other antibody patterns.

That said, ELISA tests targeting only one or two centromere proteins can occasionally miss cases that the cell-based assay catches, and vice versa. One comparison of the two methods found about 93% agreement, with the cell-based test picking up some antibodies the ELISA missed because it can detect responses to all centromere subcomponents at once.² Conversely, a large study of scleroderma patients found that a meaningful number of sera positive on CENP-B ELISA did not show the typical centromere pattern on immunofluorescence, suggesting a negative result on one platform does not completely rule out the antibody.³ If your doctor suspects limited scleroderma and the first test is negative, they may order the other format.

The Main Association: Limited Systemic Sclerosis

The condition most tightly linked to a positive centromere antibody is limited cutaneous systemic sclerosis, historically known by the acronym CREST (calcinosis, Raynaud’s phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasia). A pooled analysis of 30 studies found centromere antibodies in about 32% of all systemic sclerosis patients, but that figure jumped to roughly 57% among those with the limited cutaneous subtype.⁴ In a separate clinic-based study, the antibody was present in about 11% of a broad rheumatology population, and most of those positive patients had features of limited scleroderma or CREST, either alone or alongside primary biliary cholangitis. It was rarely found in patients with rapidly advancing or diffuse scleroderma.⁵

This distinction between limited and diffuse scleroderma matters a great deal. Diffuse scleroderma tends to progress faster, with widespread skin thickening and earlier internal organ involvement. Limited scleroderma, by contrast, typically progresses slowly, often over decades, with skin tightening restricted to the extremities and face. A positive centromere antibody in someone with early Raynaud’s or mild skin changes points toward the limited pattern rather than the more aggressive diffuse form. That carries real weight in how a rheumatologist plans monitoring and treatment.

Specificity is also high. Fewer than 1% of healthy individuals carry the antibody, and only about 5% of patients with other connective tissue diseases test positive.⁴ So a positive result is a meaningful finding, not an artifact that shows up in everyone with vague autoimmune symptoms.

What It Tells You About Lung Risk

One of the most clinically important things a positive centromere antibody signals is an elevated risk for pulmonary arterial hypertension (PAH), a dangerous rise in blood pressure within the arteries of the lungs. In systemic sclerosis, PAH without accompanying lung scarring was more than twice as common among patients with centromere antibodies compared to those with anti-Scl-70 antibodies (roughly 13% versus 5%).⁶ Older age at diagnosis compounds this risk. One study found that both older age and positive centromere antibodies were associated with a faster rise in estimated pulmonary artery pressure over time, meaning PAH could be caught earlier with regular echocardiographic screening in these patients.⁷

More recent work suggests the level of the antibody, not just its presence, matters for PAH risk. In a cohort of ACA-positive scleroderma patients, those who developed PAH had anti-CENP-B concentrations roughly three times higher than those who did not. Patients above a specific cutoff had more than six times the odds of PAH compared to those below it.⁸ This is an area of active research, and quantitative antibody measurement is not yet standard practice everywhere, but it is moving in that direction.

On the flip side, centromere antibody positivity is associated with a lower risk of interstitial lung disease (ILD), the other major lung complication in scleroderma. ILD involves scarring of lung tissue and is more common in patients with diffuse scleroderma and anti-Scl-70 antibodies.⁹ Among centromere-antibody-positive patients who did develop ILD, lung function declined more slowly than in the broader scleroderma-ILD population.¹⁰ So while no one is immune to lung scarring, the centromere antibody profile tends to carry a more favorable ILD trajectory.

When You Do Not Have Scleroderma

Not everyone with a positive centromere antibody will be diagnosed with systemic sclerosis. The antibody turns up in several other conditions, and interpreting what it means depends heavily on the rest of the clinical picture.

Primary biliary cholangitis (PBC), an autoimmune liver disease, is one well-known association. Some patients with PBC carry centromere antibodies, sometimes overlapping with scleroderma and sometimes not. Recent work has found that ACA-positive PBC patients may be at higher risk for portal hypertension and gastroesophageal varices even before reaching full cirrhosis.¹¹

Sjögren’s syndrome is another. About 6 to 13% of Sjögren’s patients carry centromere antibodies, depending on the population studied.¹²¹³ These patients tend to look different from typical Sjögren’s patients: they are less likely to carry the classic Sjögren’s antibodies (anti-SSA and anti-SSB) but more likely to have severe dry mouth and dry eyes, with worse gland function on objective testing.¹² They are also more likely to have Raynaud’s phenomenon and features that overlap with scleroderma, which sometimes makes the diagnostic boundary blurry.¹³

In a study of 33 ACA-positive patients, 21 had CREST and two had scleroderma, but the remaining 10 included patients with lupus, aggressive inflammatory arthritis, and isolated Raynaud’s. The authors concluded that a positive centromere antibody without scleroderma often signals another serious rheumatic or connective tissue condition.¹⁴ This is not an antibody to dismiss casually when no clear diagnosis is in hand.

Raynaud’s and the Question of Progression

Many people first encounter a centromere antibody result during a workup for Raynaud’s phenomenon, a condition where fingers (and sometimes toes) turn white or blue in response to cold or stress. Most people with Raynaud’s never develop a systemic autoimmune disease, but a subset do, and the centromere antibody is one of the strongest predictors of that progression.

A prospective study following Raynaud’s patients over time found that those who were initially ACA-positive were dramatically more likely to develop signs of connective tissue disease, with odds roughly 63 times higher than ACA-negative patients.¹⁵ The antibody was also associated with the development of telangiectasias, the small dilated blood vessels on the skin that are a hallmark of CREST. So if you have Raynaud’s and your centromere antibody comes back positive, your doctor will likely want closer monitoring for emerging scleroderma features, even if you feel fine right now.

Centromere antibodies, once they appear, tend to stick around. A long-term longitudinal study found that with a single exception, every ACA-positive patient remained positive over prolonged follow-up, and the antibodies were consistently of the IgG class with no clear trend in titer over time.¹⁶ This persistence is part of what makes the antibody useful as a marker: it doesn’t flicker on and off, and a single positive result is generally informative for years to come.

Antibody Levels and Disease Stage

While the simple yes-or-no result of a centromere antibody test carries the most weight in day-to-day practice, the actual concentration of the antibody adds another layer of information. Research comparing patients at different stages of disease found that people with very early scleroderma (sometimes just Raynaud’s and a few suggestive features) had significantly lower IgG and IgM centromere antibody levels than those with established disease. Higher IgG levels were associated with more than double the odds of having definite scleroderma versus very early disease.¹⁷

One older study noted that patients who denied Raynaud’s symptoms all had antibody titers below a certain threshold, and in one case a 16-fold rise in titer coincided with the onset of Raynaud’s 12 years later.¹⁸ Combined with the PAH data showing higher CENP-B levels in patients who develop pulmonary hypertension, a picture is forming: the antibody level may eventually serve as a graded risk indicator rather than a simple binary. Most labs still report it qualitatively (positive or negative), but quantitative reporting is gaining ground.

Rare Complications Worth Knowing About

Scleroderma renal crisis, a sudden and dangerous spike in blood pressure with rapid kidney failure, is classically associated with diffuse scleroderma and anti-RNA polymerase III antibodies, not with centromere antibodies. But rare case reports have documented it in ACA-positive patients with limited scleroderma, and the kidney outcomes in those cases were poor.¹⁹²⁰ The clinical takeaway is that while the antibody generally predicts a milder disease course than diffuse scleroderma, it does not guarantee immunity from serious organ events. Providers should remain alert to unusual presentations rather than assuming the limited-disease label means the kidneys are safe.

Genetic Roots of the Antibody Response

Why some people make centromere antibodies and others do not has a genetic component, rooted in the immune system’s cell-surface molecules that present fragments of proteins to immune cells. Specific variants in the HLA gene region have been linked to ACA positivity in different ethnic populations. In European Americans, the HLA-DRB1*07:01 allele was more strongly associated with the centromere-antibody-positive subtype of scleroderma than with scleroderma overall, suggesting the genetic predisposition is to making this particular antibody, not just to getting the disease.²¹ In Japanese patients, a different set of alleles was implicated, and certain HLA types were associated with high versus low antibody titers and with whether the antibody targeted CENP-C as well as CENP-B.²²

Intriguingly, the same research group that mapped the HLA associations discovered that the centromere protein fragments most likely to be presented by those HLA molecules resemble sequences from certain large DNA viruses. This raises the possibility that the antibody response starts as a misdirected immune reaction to a viral infection, though this remains speculative and has not been proven in clinical studies.²¹

Centromere Antibodies and Fertility

An underappreciated area of concern for ACA-positive patients is reproduction. A study of patients undergoing in vitro fertilization found that those with positive centromere antibodies had significantly lower embryo implantation rates and clinical pregnancy rates compared to ACA-negative patients, even though the number of embryos transferred was similar. Miscarriage rates, however, were not significantly different between the two groups.²³ This suggests the antibody may affect the ability to become pregnant rather than the ability to sustain a pregnancy once it is established.

A separate study looking at birth outcomes in ACA-positive patients treated with assisted reproduction found no significant difference in birth parameters like weight or gestational age compared to ACA-negative patients. The authors concluded that the antibody strongly affects maternal fertility but does not appear to harm the baby once pregnancy is achieved.²⁴ If you are ACA-positive and planning pregnancy, this is worth discussing with both a rheumatologist and a reproductive specialist, since the centromere proteins the antibody targets are integral to cell division and could plausibly interfere with the rapid cell division of early embryonic development.

How the Diagnosis Typically Unfolds

In most cases, a centromere antibody test is not ordered out of the blue. It usually comes back as part of an antinuclear antibody (ANA) panel prompted by symptoms like Raynaud’s, unexplained skin tightening, persistent dry eyes and mouth, or abnormal blood tests hinting at autoimmunity. When the ANA test shows the distinctive discrete-speckled pattern associated with centromere antibodies, the lab often reflexes to a specific centromere antibody confirmation.

Once confirmed positive, your doctor will piece together the result alongside your symptoms, physical exam, and other bloodwork. A positive centromere antibody in someone with Raynaud’s and puffy fingers points toward early scleroderma and triggers a monitoring protocol: baseline lung function tests, an echocardiogram to screen for pulmonary hypertension, and potentially a specialized nail fold capillaroscopy to look for tiny blood-vessel changes in the fingers. In someone without obvious scleroderma features, the workup branches out to look for the other conditions discussed above.

Because the antibody persists over time and its clinical significance can evolve, a single positive test often leads to periodic reassessment even when things seem stable. Many patients live for years, even decades, with a positive centromere antibody and only mild symptoms. Others progress to significant organ involvement. The antibody result itself does not determine your fate, but it reshapes the monitoring plan in ways that can catch problems early.