Anticentromere antibodies (ACA) directed to restricted regions of chromosomes are found in 80 – 90% of patients with the limited cutaneous (CREST) variant of systemic sclerosis (74). Recombinant CENP-B ELISA are reported to be more sensitive in identifying ACA than IFA (75). Another antibody, anti-Scl-70 antibody, is found in 40 – 70% of patients with systemic sclerosis. However, ACA are also seen in patients with systemic sclerosis up to 48% (76) and anti-Scl-70 in some patients with the CREST syndrome. ACA are present in 5% and anti-Scl-70 antibodies in 2% of patients with other connective tissue diseases, but fewer than 1% of disease free controls are reported to have one of these both antibodies (77).
As individual diagnostic tests in systemic sclerosis, both ACA and anti-Scl-70 antibodies are highly specific. Clinicians can rely on a positive test result as being specific in the detection of disease, but 40% of systemic sclerosis patients are likely to have neither antibody present, and a negative result does not exclude the diagnosis (77). Measurement of these antibodies should be considered secondary to the clinical features when making a diagnosis of systemic sclerosis.
But also in patients with SLE the presence of ACA is apparently more frequent than previously believed. Patients with SLE with ACA may be a distinct subgroup (78).

Material Pattern: ACA (Anti-centromere antibodies) Substrate: Hep-2 cells Description This is a speckled pattern; in mitotic cells centromeres and chromosomes show a typical disposition. Method Indirect immunofluorescence method.