Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ CONNECTIVE TISSUE DISEASES ++ Group of systemic autoimmune diseases Screening Antinuclear antibody (ANA): performed using indirect immunofluorescence (IF) Varying concentrations of patient serum are incubated with a tissue substrate (usually human epithelial tumor line HEp-2), and any autoantibodies to nuclear antigens present in the serum bind to the substrate A fluoresceinated antibody is added, and the tissue is observed under fluorescent microscopy to check for a specific staining pattern Results reported as Titer: level of antinuclear antibodies significant enough to be defined as a positive ANA. The standard definition is the titer exceeding that found in 95% of normal individuals (5% of normal individuals can be ANA-positive, with titers usually ≥1:320 and a speckled or homogeneous pattern) Pattern: corresponds to the presence of a specific antibody. A certain pattern may indicate the presence of various rheumatologic diseases A positive ANA is seen in Systemic lupus erythematosus (SLE): 99% Systemic sclerosis (SSc) patients: 97% Dermatomyositis (DM) patients: 40 to 80% ANA patterns and their corresponding antibodies Homogeneous pattern (Fig. 22-1): complete nuclear fluorescence; specific for SLE – Double-stranded DNA (dsDNA) or native DNA: 70% SLE, associated with lupus nephritis – Histone: 50 to 70% SLE; also the antibody found in drug-induced SLE (but not in drug-induced subacute cutaneous lupus erythematosus) Rim pattern: fluorescence at edges of nucleus, anti-DNA, antihistone and antilaminin antibodies: SLE (most specific) but also may be seen in chronic active hepatitis Speckled pattern (Fig. 22-2): – SS-A/Ro: 30 to 40% SLE; often with subacute cutaneous lupus erythematosus (SCLE), drug-induced SCLE, and neonatal LE; also seen in Sjögren syndrome (SS), DM – SS-B/La: 15% SLE often with SCLE, drug-induced SCLE, neonatal LE – Antiribonucleoprotein (RNP): 30% SLE; associated with mixed connective tissue disease (MCTD) – Anti-Smith (Sm): 20 to 30% SLE; very specific Extractable nuclear antigens (ENAs) Soluble cytoplasmic and nuclear components that are bound by autoantibodies Antibodies include Ro, La, Sm, RNP, Scl-70, and Jo-1 ENA-4 test – Identifies Ro, La, RNP, and Sm – Used to diagnose SLE, MCTD, and SS Nucleolar pattern (homogeneous, speckled, or clumpy staining of nucleolus) – RNA polymerase I (RNA pol 1): 4 to 23% SSc – U3-RNP/fibrillarin: SSc – Topoisomerase I (Scl-70): 22 to 40% of SSc, associated with diffuse SSc – PM-Scl: SSc-polymyositis overlap Centromere pattern (antibodies to kinetochore proteins) – Approximately 22 to 36% of SSc patients – Approximately 60 to 90% of limited SSc patients (e.g., CREST syndrome [calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangiectasia]) ++ FIGURE 22-1 Homogeneous pattern. (Used with permission from Dr. Robert Jordon.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++ FIGURE 22-2 Speckled pattern. (Used with permission from Dr. Robert Jordon.) Graphic Jump LocationView Full Size|Favorite Figure|Download Slide (.ppt) ++ Lupus Erythematosus ++ Autoimmune disorder with a spectrum of presentations; may be cutaneous and/or systemic Cutaneous lupus subsets... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. Access My Subscription GET ACCESS TO THIS RESOURCE Subscription Options Pay Per View Timed Access to all of AccessDermatologyDxRx 24 Hour $34.95 (USD) Buy Now 48 Hour $54.95 (USD) Buy Now Best Value AccessDermatologyDxRx Full Site: One-Year Individual Subscription $995 USD Buy Now View All Subscription Options