Anti-centromere antibodies (ACA) occur in CREST syndrome and occasionally in systemic scleroderma. They are very rare in other rheumatic conditions and in healthy persons.

Anti-centromere antibodies are found in approximately 60% of patients with CREST and in 15% of those with scleroderma. The specificity of this test is >98%. Thus, a positive anticentromere antibody finding is strongly indicative of CREST or scleroderma. Anti-centromere antibodies present early in the course of disease is notably predictive of limited cutaneous involvement and a decreased likelihood of interstitial lung disease.When present in primary biliary cirrhosis, ACA are prognostic of portal hypertension.