Lecture 34 (Systemic Immunologic Disease)

what is the most common test used to HELP in the diagnosis of SLE?

ANA test (antinuclear antibodies)

autoimmune diseases that involve multiple organ systems are known as ___________ immune diseases or disorders

systemic

systemic immune diseases:

patients develop immune-complex deposition that leads to chronic __________ in multiple organs

-preferentially affects capillary beds

inflammation

what does SLE stand for?

systemic lupus erythematosus

what parts of the body does SLE affect?

-skin
-joints
-serous membranes
-renal system
-hematologic system
-neurologic system

SLE is clinically seen in what three animals?

-dogs
-cats
-horses

SLE is which hypersensitivity reaction classification type?

type III

pathogenesis of SLE:

_________ cells from affected patients are not cleared normally through phagocytosis

apoptotic

SLE:

________ light exposure of skin leads to accumulation of apoptotic cells and ultimate auto-antibody development against the skin

UV

what are the three laboratory tests that are supportive of diagnosing SLE?

-LE preps
-positive ANA antibody tests
-biopsy results

when conducting an ANA test, a positive result means the patient probably has SLE. we say only probably even though 97-100% of SLE patients test positive. why?

16-20% of control patients test positive for ANA too

what is an LE prep in simplest terms?

seeing if the phagocytes have consumed material

treatment for SLE works in which of the following:

a) horses
b) dogs

b) dogs

treatment for SLE

-steroids
-immunosuppressive therapy

what does DLE stand for?

discoid lupus erythematosus

DLE is a mild variant of ________ where only facial/skin lesions are seen

SLE

ANA/LE tests will be [positive/negative] in DLE

negative

treatment for DLE

oral steroids or topical steroids

why are ANA and LE tests negative in Discoid Lupus if they are positive in SLE?

there is not a systemic immune issue; the immune complexes are only depositing in the localized basement membrane

how do you differentiate SLE from DLE?

SLE is going to be systemic (affects kidney, joints, heart, etc.) while DLE affects the basal layer of the skin

in the context of autoimmune polyarthritis, which is more common in domestic animals?

a) erosive
b) non-erosive

b) non-erosive

this disease causes marked joint pathology and secondary systemic signs

*deposition of immunoglobulins or immune complexes within joints

autoimmune polyarthritis

autoimmune polyarthritis is separated into what two groups?

erosive polyarthritis (Rheumatoid arthritis) and non-erosive polyarthritis

-most important variant in humans
-characterized by erosion of joint cartilage, deformities, bony ankyloses, and soft tissue swelling

a) erosive polyarthritis
b) non-erosive polyarthritis

a) erosive polyarthritis

-most important variant in domestic species
-no joint cartilage erosion
-lesion confined to joint capsule and synovia

a) erosive polyarthritis
b) non-erosive polyarthritis

b) non-erosive polyarthritis

how do you diagnose Rheumatoid arthritis (erosive)

-presence of characteristic findings
-presence of RF antibodies
-negative ANA test to rule out SLE

what are RF antibodies?

an antibody against the Fc portion of IgG

what is Rheumatoid factor (RF)

antibody against IgG

treatment for Rheumatoid arthritis

-analgesics
-steroids
-monoclonal antibodies to TNF, CD4, IL-2
-joint fusion

what are the 3 types of Non-erosive autoimmune polyarthritis?

1. associated with SLE
2. associated with Myositis
3. idiopathic (Immune Mediated Poly-Arthritis - IMPA)

what is the most common type of non-erosive polyarthritis?

idiopathic polyarthrities (I.e. IMPA)

what are the 4 sub-types of Idiopathic IMPA?

1. truly idiopathic - no other diseases
2. associated w/ infectious lesion outside joints
3. associated with GI disease (overlaps with 2)
4. associated with a neoplasia remote from joints

what symptom would you not see in idiopathic IMPA:

a) stiffness
b) lameness
c) positive ANA
d) hypertrophy of mononuclear infiltrate

c) positive ANA

*if so, then you probably have PA from SLE

symptoms of idiopathic polyarthritis

-fever, lethargy, anorexia, lameness, muscle atrophy
-stiffness after rest
-stifle, elbow, and carpus most commonly affect
-no joint erosion
-significant soft tissue swelling & joint effusion

the prognosis for IMPA is generally:

a) good
b) bad

a) good

Rheumatoid arthritis is erosive or non-erosive?

erosive

how would you diagnose idiopathic polyarthritis?

-characteristic signs // history
-negative ANA and RF
-sterile joint fluid
-synovial biopsies show hypertrophy with mononuclear infiltrate

treatment of idiopathic polyarthritis

steroids

what disease is this?

-clinical syndrome of dermatitis & myositis

-humans, Collies, and Shelties

-normal at birth..develop skin lesions at 7-11 weeks and develop myositis at 12-23 weeks

-skin lesions are seen first

Dermatomyositis

Dermatomyositis:

disease onset and progression characterized by rise in circulating immune complexes and serum _____

IgG

treatment of Dermatomyositis

-steroids
-vitamin E
-pentoxy

what disease is this?

-affects beagles <2 years of age
-signs include episodic fever and cervical pain
-poor prognosis
-histologic changes include inflammatory cell infiltrates involving medium and small-sized arteries
-ultimately leads to fibrosis
-can progress to amyloidosis

Canine Juvenile Polyarteritis