---

- Discussion:
    - serves as screening test for collagen vascular dz and lupus;
    - fluorescent antinu-clear antibody test: (FANA)
          - indirect immunofluorescence assay is the initial screening test used to detect ANAs;
    - testing for specific auto-antibodies:
          - if the FANA test is positive, then there is secondary testing for specific autoantibodies;
          - recognized patterns:
                - speckled: lupus, drug induced lupus, and Sjögren’s
                - rim: lupus;
                - homogeneous: lupus;
                - centromere
                      - CREST syndrome (calcinosis, raynaud’s phenomenon, esophageal problems, sclerodactyly, telangiectasias);
                - nucleolar: scleroderma
                - antibodies to dsDNA and/or Sm (Smith): Lupus
    - positive result: (diff dx)
          - low levels of ANA (titers 1:20 to 1:40) may be present in about 4% of normal individuals and up to 38% in persons older than 60 years;
          - SLE: ANA is almost always present in patients w/ SLE (95% to 98%);
          - medication induced lupus like syndrome (procainamide);
          - scleroderma
          - RA
          - Sjogren's syndrome
          - polymyositis
    - false positive result:
          - Graves’ disease
          - Hashimoto’s thyroiditis