Autoimmune diseases

Question 1

Autoimmunity

Answer 1

condition in which the body’s own antigenic structures stimulate an immune response & react with self Ag in a manner similar to the destruction of foreign Ag
MAY cause an autoimmune disorder

Question 2

Autoantibody

Answer 2

an immunoglobulin (IgG or IgM) produced against a self antigen

Question 3

Autoimmune disorder

Answer 3

clinical presentation that results from the immune system attacking the body’s own tissues bc of failure to recognize self
significantly higher incidence in women

Question 4

Autoimmune disorder diagnosis

Answer 4

relies on clinical presentation & lab testing (detecting autoantibodies)

Question 5

Classifications of Autoimmune diseases

Answer 5

1. systemic

2. organ-specific

Question 6

SLE (systemic Lupus Erythematosus)

Answer 6

generalized dysregulation of the immune system

immune complexes travel through the body & are deposited in tissues which cause an inflammatory response

Question 7

Clinical Features of SLE

Answer 7

20-40 yrs
9x more common in women
reddening of the face
renal disorder
etc etc
Anti-Sm (smith), speckled & homogenous ANA

Question 8

Antinuclear Antibodies

Answer 8

group of autoantibodies directed against contents of cell nucleus

Question 9

ANA lab tests

Answer 9

1. ELISA

2. Fluorescent antinuclear antibody (FANA) - gold standard for ANA testing

Question 10

FANA

Answer 10

fluorescent anti-nuclear antibody test that uses HEp-2 cells as substrates
detects different patterns which can reflect certain diseases

Question 11

Homogenous ANA pattern

Answer 11

most common pattern
antibody against dsDNA (mitotic cells are positive)
suggestive of SLE

Question 12

Speckled ANA pattern

Answer 12

antibody against nuclear proteins (mitotic cells are negative)
suggestive of SLE, Sjogren’s Syndrome & Sclerosis

Question 13

Sjogren’s Syndrome

Answer 13

autoimmune disorder in which the body attacks glands that produce moisture
speckled ANA

Question 14

Nucleolar ANA pattern

Answer 14

antibody against nucleolar RNA

suggestive of SLE & Scleroderma

Question 15

Scleroderma - Systemic

Answer 15

‘hard skin’

90% have positive nucleolar ANA

Question 16

Centromere ANA pattern

Answer 16

antibody against centrioles (46 dots in interphase)

suggestive of Systemic Sclerosis

Question 17

Sclerosis - Systemic

Answer 17

connective tissue disease

fibroblasts are activated - collagen crosslinks are formed affecting all organs

Question 18

ANA confirmation

Answer 18

1. indirect fluorescent assay w/ more specific substrate (crithidia luciliae for dsDNA)
2. ELISA w/ specific substrate

Question 19

SLE treatment

Answer 19

no known cure

decrease clinical manifestation - anti-inflammatory drugs, cytotoxic drugs, avoid sunlight, renal transplant

Question 20

Rheumatoid Arthritis (RA)

Answer 20

chronic disease w/ inflammation & destruction of joints - immune complexes in joints binds complement & attracts segs & macrophages

Question 21

RF antibody

Answer 21

75% of RA patients have the rheumatoid factor antibody (RF)

IgM against IgG - resulting in a type 3 hypersensitivity reaction

Question 22

Clinical features of RA

Answer 22

most common rheumatic disease
30-50 yrs
2-3x more likely in women

Question 23

RA diagnosis

Answer 23

serology : RF & ACPA
joint involvement
duration of symptoms
ESR

Question 24

Anti-Citrullinated Peptide (ACP) antibodies

Answer 24

more reliable indicator of RA than RF test

occurs during inflammation