Autoimmune

Anti-Centromere Antibody (ACA) — What Your Blood Test Result Means

ScanHealth Learn Autoimmune Anti-Centromere Antibody (ACA)

The Limited Scleroderma Marker

Anti-centromere antibodies target the centromere region of chromosomes and are highly specific for limited cutaneous systemic sclerosis (also called CREST syndrome: Calcinosis, Raynaud, Esophageal dysmotility, Sclerodactyly, Telangiectasia). If you have anti-centromere antibodies with Raynaud phenomenon, scleroderma is the likely diagnosis.

What is Anti-Centromere Antibody (ACA)?

Anti-centromere antibodies target centromere proteins (CENP-A, B, C). Produce a distinctive centromere (discrete speckled) pattern on ANA immunofluorescence. >90% specific for limited systemic sclerosis. Present in 50-90% of limited SSc and 10-15% of PBC patients.

What High Anti-Centromere Antibody (ACA) Means

Positive: strong association with limited systemic sclerosis (CREST). Also associated with primary biliary cholangitis (PBC). Better prognosis than anti-Scl-70 positive diffuse scleroderma.

Common symptoms:

Raynaud phenomenon (fingers turn white → blue → red with cold) · Sclerodactyly (tight, shiny skin on fingers) · Telangiectasias (spider veins on face/hands) · Dysphagia (esophageal dysmotility) · Calcinosis (calcium deposits under skin)

What Low Anti-Centromere Antibody (ACA) Means

Negative: doesn't exclude scleroderma (check anti-Scl-70 for diffuse type).

Common symptoms:

Negative = no symptoms from this marker

Why It Matters

When normal:

Highly specific for limited systemic sclerosis (CREST)

Distinguishes limited from diffuse scleroderma

Predicts better prognosis than diffuse SSc

Also associated with primary biliary cholangitis

Risks if abnormal:

Limited SSc: pulmonary arterial hypertension (main cause of death)

CREST: Raynaud can cause digital ulcers

Monitor for PAH with annual echocardiogram

What Can Cause Abnormal Levels?

Limited Systemic Sclerosis (CREST)

70% likely

Limited skin involvement (distal to elbows/knees + face). Higher PAH risk. Better overall survival than diffuse.

Primary Biliary Cholangitis

15% likely

10-15% of PBC patients are anti-centromere positive.

Raynaud Phenomenon (isolated)

Anti-centromere positive Raynaud has high progression risk to scleroderma.

What You Can Do

If positive with Raynaud: full scleroderma workup (nailfold capillaroscopy, PFTs, echo)

Impact: Early detection of organ involvement \u00B7 Timeline: At diagnosis

Annual echocardiogram for pulmonary arterial hypertension screening

Impact: PAH is the leading cause of death in limited SSc \u00B7 Timeline: Annual

If lifestyle changes aren't enough:

Raynaud management: calcium channel blockers (nifedipine), keep warm

Impact: Prevents digital ischemia and ulcers \u00B7 Timeline: Ongoing

Recommended retest: One-time diagnostic; does not need serial monitoring

Related Markers

ana esr complement_c3 complement_c4 alkaline_phosphatase
Medical Disclaimer: This information is for educational purposes only and is not a substitute for professional medical advice. Always consult your doctor for diagnosis and treatment.

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