170 likes | 342 Views
CLS 1113 Introduction to Clinical Laboratory Practices. Autoimmunity Chapter 12. Auto Immune Processes. Immune recognition and reaction against the individual’s own cells Body establishes self-tolerance mechanisms to distinguish between self and non-self determinants:
E N D
CLS 1113Introduction to Clinical Laboratory Practices Autoimmunity Chapter 12
Auto Immune Processes • Immune recognition and reaction against the individual’s own cells • Body establishes self-tolerance mechanisms to distinguish between self and non-self determinants: • Autoimmunity is the breakdown of these mechanisms.
Systemic Lupus Erythematosus • Chronic Systemic inflammatory disease • Multiple system autoimmune disorder • Complement fixing complexes of antibody with DNA, etc. are deposited in the kidney, skin, joints and choroid plexus • Cause is unknown • Possible: genetic, hormonal, environmental, and drug-induced
Incidence of SLE • 1 in every 2000 • Females: 1 in 700 • Black females: 1 in 245 • 20-40 years of age • Disease can go in and out of remission
Signs and Symptoms • Disease of acute and chronic inflammation • Life-threatening renal, cardiac, respiratory, or central nervous system involvement • The disease is highly variable • Periods of disease and remission • Person to person
Signs and Symptoms • Arthritis • Joint pain • Sensitivity to opportunistic infections • Swollen Lymph Nodes • Renal Involvement • Caused by high levels of immune complexes in the blood that are deposited into renal tissue. • Acute/Chronic Glomerulonephritis
Signs and Symptoms • Pregnancy • Increased incidence of premature delivery and spontaneous abortion • Passive antibody transfer • Cardiac Involvement • Pericarditis • Tachycardia • Ventricular enlargement
Signs and Symptoms • Photosensitive rash • Any skin exposed to ultraviolet light • 30-40% of patients • “Lupus” (wolf-like)
SLE: Immunologic Theories • Polyclonal B cell activation • B cells stimulated in a non-specific fashion • Specifically B cells with the CD5 marker • Increase in number and become activated • System is stimulated directly by specific antigens • Estrogens enhance B-cell activation • There appears to be a decrease in the number of T cells and complement levels
Laboratory Findings • Presence of antinuclear antibodies • Antibody to nuclear antigens: DNA, histones, etc. • 28 different autoantibodies • Formation of Immune complexes • Deposition of immune complexes in tissues • Decreased levels of Complement
Common Laboratory Tests Antinuclear Antibodies • Screening Test • Fluorescent Antinuclear Antibodies - FANA • Very sensitive • NOT very specific • 5% • 10-30% • 2%
Antinuclear Antibodies • The antibodies react with the whole nucleus or just part. • Define pattern • They are nonspecific enough that they can react with human DNA and other animal tissues
Examples of Antinuclear Antibodies • Anti-ds-DNA: Double-stranded DNA • Anti-ss-DNA: Single-stranded DNA • Anti-nucleolar: Nucleolar Protein • Anti-Sm: RNA nuclear antigen • Anti-SS-A Ro: Protein complex • Anti-RNP: Nuclear RNA
Fluorescent Antinuclear Antibody Test • Human or animal cells are fixed to the slide
Common Laboratory Tests • Double diffusion patterns with a mixture of antigens in the central well
Treatment • For fever and arthritis: anti-inflammatory drugs • For skin ailments: topical steroids • For systemic disorders: corticosteroids (Prednisone) • Steroids are lymphotoxic to B cells and T cells.