Multiplex Flow Immunoassay
Useful diagnostic and prognostic information can be gained in ANA positive patients by knowing the specificity of the autoantibodies that are detected. Ideally, collagen vascular disease diagnosis is based on a combination of clinical symptoms and laboratory testing. It is not cost effective to follow up every positive ANA with assays for all 10 possible detectable antibody specificities. MLabs promotes a more cost effective strategy an ENA 5 Antibody Panel (includes SS-A, SS-B, Sm, RNP, and SmRNP) (order code ENA5). These antibodies will account for the vast majority of significant positive results. Other ENA antigens such as Scl-70, Centromere B, Jo-1, and Ribosomal P should not be routinely screened for, but ordered as individual tests as the differential diagnosis dictates. The laboratory recommends either anti-dsDNA (order code ADNA) or crithidia DNAIFA (order code DNAIF) to detect and quantify anti-dsDNA.
See Extractable Nuclear Antibody Testing.available online at http://www.pathology.med.umich.edu/handbook/Tables/ANA-ENA-08.pdf. ENA5 Panel includes SS-A (Ro), SS-B (La), Smith, SmRNP, and RNP. ENA7 Panel includes SS-A (Ro), SS-B (La), Smith, SmRNP, RNP, Jo-1, and Scleroderma (Scl-70). ENA10 Panel includes SS-A (Ro), SS-B (La), Smith, SmRNP, RNP, Jo-1, Scleroderma (Scl-70), Centromere B, Chromatin, and Ribosomal P. The following antibodies may also be ordered individually: Centromere B (CENT B), Jo-1 (JO-1), Ribosomal P (RIBO P), RNP (RNP), Scleroderma (SCL-70), Smith (SMITH), SS-A (SS-A), and SS-B (SS-B).