Which ANA pattern is associated with high titers of antibodies to Sm antigen?

Which ANA pattern is associated with high titers of antibodies to Sm antigen?

• A. Homogenous
• B. Peripheral
• C. Speckled
• D. Centromere

Answer: (C)

When you look at ANA testing, the pattern seen under indirect immunofluorescence on HEp-2 cells points to the types of nuclear antibodies present. Antibodies to Sm antigen are part of the group that targets RNA-associated nuclear components, and they characteristically produce a speckled staining pattern. Sm antibodies are highly specific for systemic lupus erythematosus, so a speckled pattern that’s present at a measurable titer aligns with anti-Sm testing. In contrast, homogeneous patterns often link to dsDNA or histones, rim/peripheral patterns to dsDNA, and centromere patterns to anticentromere antibodies. Therefore, high-titer anti-Sm antibodies are most commonly associated with a speckled ANA pattern.

When you look at ANA testing, the pattern seen under indirect immunofluorescence on HEp-2 cells points to the types of nuclear antibodies present. Antibodies to Sm antigen are part of the group that targets RNA-associated nuclear components, and they characteristically produce a speckled staining pattern. Sm antibodies are highly specific for systemic lupus erythematosus, so a speckled pattern that’s present at a measurable titer aligns with anti-Sm testing. In contrast, homogeneous patterns often link to dsDNA or histones, rim/peripheral patterns to dsDNA, and centromere patterns to anticentromere antibodies. Therefore, high-titer anti-Sm antibodies are most commonly associated with a speckled ANA pattern.