One of the advantages to using the HEp-2000® substrate is the ability to identify the presence of anti-SSA/Ro antibodies during the ANA screen.
In this sample we see the homogeneous ANA pattern, smooth staining in the interphase cells and smooth staining of the chromosomal area of the mitotics (a) along with the hyperexpressing cells demonstrating the SSA/Ro pattern (b).
In cases of mixed homogeneous and SSA/Ro, follow-up testing for anti-dsDNA and anti-ENA antibodies is necessary.
When mixed patterns are titered, the endpoint for each pattern is reported.
This pattern is reported as ANA positive, Homogeneous and SSA/Ro pattern, anti-SSA/Ro antibodies present; titering is necessary.
Homogeneous and SSA/Ro:
Interphase cells
- Smooth staining of the entire nucleus (homogeneous)
- Hyperexpressing SS-A/Ro pattern in 10-15%
Metaphase mitotic cells
- Smooth staining of the chromosome region
- Region outside of chromosome area may stain
