Pathology: Autoimmune Disorders

Question 1

What is Systemic Lupus Erythematosus? What type of hypersensitivities can occur to cause it?

Answer 1

Systemic autoimmune disease

• Antibodies versus host damage multiple tissues

Type II: Cytotoxic

Type III: Antigen-anibody complex

Question 2

What are the clinical features of SLE?

Answer 2

• Fever and weight loss
• Malar “butterfly” rash, especially on exposure to sunlight
• Arthritis
• Pleuritis and pericarditis
• CNS psychosis
• Renal damage - Diffuse proliferative glomerulonephritis is most common
• Endocarditis, myocarditis, or pericarditis (all 3 layers)
• -> Libman-sacks endocarditis (thrombotic vegetations on both sides of the mitral valve)
• Anemia, thrombocytopenia or leukopenia

Question 3

What are common causes of death in SLE patients?

Answer 3

Renal failure
(due to diffuse proliferative glomerulonephritis)

Infection
(due to destruction and decreased # of WBC)

Question 4

What antibodies are used for screening and diagnosis of SLE?

Answer 4

Screening: Anti-nuclear Antibody

Diagnosis: anti-dsDNA antibody
(specific to SLE)

Anti-histone antibody (specific to drug-induced lupus)

Question 5

What are common causes of drug-induced Lupus?

Answer 5

Hydralazine

Procainamide

Isoniazid

Question 6

What is anti-phospholipid syndrome?

Answer 6

Autoantibody against proteins bound to phospholipids are produced in SLE patients

Antibodies include: Anticardiolipin and Lupus antiboagulant
- Leads to false-positive syphilis tests and falsely-elevated PTT lab studies, respectively

–> Syndrome can actually cause a hypercoagulable state (which is opposite to what the elevated PTT suggests)

Question 7

What are clinical features of Anti-phospholipid syndrome?

Answer 7

Results in arterial and venous thrombosis

–> DVT
hepatic vein thrombosis (cause Budd-Chiari syndrome)
Placental thrombosis (recurrent miscarriages)
Stroke

• Requires lifelong anticoagulation

Question 8

What is Sjogren syndrome? What type of hypersensitivity is it?

Answer 8

Autoimmune destruction of lacrimal and salivary glands

• Lymphocyte-mediated damage (Type IV HSR) with fibrosis

Question 9

What are clinical features of Sjogren’s syndrome?

Answer 9

- Dry Eyes

- Dry mouth

- Recurrent dental carries in older woman

“Can’t chew a cracker; dirt in my eyes”

• *- Increased risk for B-cell Lymphoma**
• -> unilateral growth of one of the already enlarged parotid glands late in disease course suggests lymphoma

Question 10

What antibodies are associated with Sjogren’s Syndrome?

Answer 10

Anti-ribonucleotide protein:

Anti-SS-A
Anti-SS-B
(SS = Sjogren syndrome)

Question 11

What other autoimmune disorder is most often associated with Sjogren’s disease?

Answer 11

Rheumatoid Arthritis

Question 12

What is scleroderma?

Answer 12

Autoimmune tissue damage with activation of fibroblasts and deposition of collagen (fibrosis)

–> divided into diffuse and localized

Question 13

What antibodies are associated with Scleroderma?

Answer 13

ANA

anti-DNA topoisomerase I
(AKA Scl-70) antibody

Question 14

What is the localized type of scleroderma?

Answer 14

CREST syndrome

• *Calcinosis / anti-C**entromere antibodies
• *R**aynaud phenomenon
• *E**sophageal dysmotility
• *S**clerodactyly
• *T**elangiectasias of skin

Question 15

What is mixed connective tissue disease? What antibody is it associated with?

Answer 15

Autoimmune-mediated tissue damage with mixed features of SLE, systemic sclerosis, and polymyositis

–> characteriezd by serum atnibodies against U1 Ribonucleoprotein