Which serological tests are most useful for confirming a diagnosis of systemic sclerosis?

The most useful serological tests for confirming a diagnosis of systemic sclerosis are those detecting specific autoantibodies, primarily anticentromere antibodies (ACA) and anti-topoisomerase I (also known as anti-Scl-70) antibodies. These autoantibodies are highly associated with systemic sclerosis and help differentiate clinical subsets of the disease. Testing for ACA is particularly linked with limited cutaneous systemic sclerosis, while anti-topoisomerase I antibodies are more common in diffuse cutaneous systemic sclerosis and are associated with more severe disease manifestations.

Additional serological markers that may be tested include anti-RNA polymerase III antibodies, which are also specific for systemic sclerosis and can indicate a higher risk of renal crisis. The presence of these autoantibodies supports the diagnosis in the appropriate clinical context and can guide prognosis and management.

Routine serological testing for systemic sclerosis should therefore include assays for anticentromere antibodies, anti-topoisomerase I antibodies, and anti-RNA polymerase III antibodies to confirm diagnosis and assist in clinical evaluation.

This approach aligns with UK clinical practice guidelines emphasizing the role of autoantibody testing in systemic sclerosis diagnosis and is supported by peer-reviewed literature highlighting the diagnostic and prognostic value of these autoantibodies (Dick et al., 2002; Grassegger et al., 2008).