Define FANA, ANA and ENA, the staining patterns that may be observed in FANA, and the two specific ENAs that are diagnostic for Systemic Lupus Erythematosus (SLE or Lupus).
FANA: Fluorescent antinuclear antibody involves taking human epithelial cells fixed on a slide and introduced to patient serum, allowed to incubate, and then washed. Antihuman immunoglobulins tagged with fluorescent molecules are added to detect bound ANA. These results are interpreted based on titer and pattern of antibody binding.
Patterns Include: homogeneous, speckled, nucleolar, peripheral, and mixed.
ANA: Anti-nuclear antibodies; antibodies which attack nuclear substances such as DNA and chromatin.
ENA: Extractable Nuclear Antigen Tests are usually performed after positive
FANA. These tests isolate specific antibodies in the afflicted patient. Anti-dsDNA and Anti-Sm are two antibodies specific for SLE diagnosis.