> See also: > - [[Antinuclear Antibody Tests]] # Systemic Autoimmune Rheumatic Diseases (SARDs) **Antinuclear antibodies (ANAs)** are self-reacting antibodies (*autoantibodies*) that are specific for nuclear components of human cells. Commonly associated with [[Autoimmunity]], specifically a group known as **systemic Autoimmune Rheumatic Diseases (SARDs): - Rheumatoid Arthritis (RA) - Systemic Lupus Erythematosus (SLE) (+ other lupus subsets) - Sjorgen Syndrome (SjS) - Systemic Sclerosis (SSc)/Scleroderma --- *ANA testing* can be used to [[Screening vs Diagnostic Testing|screen]] (but not diagnose) specific SARDs - SLE, SjS, and SSc are associated with a positive ANA test - ### Lupus Lupus is a chronic inflammatory autoimmune disease Can cause disease of the skin, hearts, lungs, kidneys, joints, and/or nervous system. - **Discoid Lupus:** When only skin is involved with lupus - **Systemic Lupus Erythematosus (SLE):** When internal organs are involved (i.e. lungs, kidneys, etc) **Demographics** - Both discord & SLE more common in women - Average onset age between 20-40 > [!danger] Types of ANAs > **ds-DNA antibodies (Anti-DNA)** are the *most specific for SLE* > - Seen in 40-70% of patients > - Produce a homogeneous staining pattern in [[Immunofluorescence]] > - Produce a *homogeneous* pattern > > **Anti-Sm (Smith) Antibodies** are *highly specific* but less than anti-DNA > - Seen in 20-40% of patients > - Produce a coarsely *speckled* pattern in indirect immunofluorescent testing **Screening for ANAs** is the first step in diagnosis process (*~95% of patients* with SLE show positive results) - Low diagnostic specificity due to other autoimmune diseases being associated with ANAs (could lead to false positives if not lupus) d > [!abstract]- 11 Criteria for SLE Diagnosis > Meeting **4 or more** of criteria strongly suggests SLE: > > 1. *Malar "Butterfly" Rash* > 2. Discoid Skin Rash > 3. *Photosensitivity* > 4. Mucus Membrane Ulcers > 5. *Arthritis* > 6. Pleuritis/Pericarditis > 7. Kidney Abnormalities > 8. Neurological Disorders > 9. Blood Count Abnormalities > 10. *Immunological Disorder (anti-DNA or anti-Sm)* > 11. *Antinuclear Antibodies* ### Sjorgen's Syndrome Inflammation in the glands of the body, specifically those that produce moisture (lacrimal & salivary glands). - Inflammation of **lacrimal glands** - Inflammation of **salivary glands** can lead to ### Scleroderma Autoimmune disease of the connective tissue - Characterized by the formation of scar tissue (*fibrosis*) in the skin and organs of the body **Demographics** - Women are affected four times more than men - Can affect any age (including children), most common age range is 30-50 *Nucleolar pattern* in indirect immunofluorescence often indicators Scleroderma