SLE

Question 1

what type of disease is Systemic Lupus Erythematosis? (2)

Answer 1

• inflammatory
• systemic

Question 2

What is the main pathology of SLE?

Answer 2

small vessel vasculitis mediated by the deposition of immune complexes containing autoantibodies (gammaglobulin), fibrin, and complement

Question 3

What dictates the clinical complaints?

Answer 3

The nature of the autoantibodies produced

Question 4

what is important to note about autoantibodies in SLE in terms of onset of the disease?

Answer 4

They may be present for YEARS before the onset of clinical complaints.

Question 5

Describe the the type autoantibodies present in SLE

Answer 5

non-organ specific, ANTI NUCLEAR ANTIBODIES (ANA)

Question 6

Pathogenesis of SLE (4 factors)

Answer 6

1) Genetic
2) Environmental
3) Hormonal
4) Neuro-endocrine

Question 7

what type of genetic disease is SLE?

Answer 7

polygenetic: about 30 susceptibility loci that can predispose to development of SLE. Some of the SLE risk loci are involved in: immune-complex processing, immune signal transduction, TLR and IFN-1 pathways

Question 8

what are 4 pieces of evidence for the effect of genetic factors in SLE?

Answer 8

1. deficiency in the early components of complement (C1q, C4, C2)
2. associated with HLA antigens
3. Apoptosis is abnormal
4. Metabolism of xenobiotic agents

Question 9

Important environmental factor in susceptible individuals

Answer 9

susceptible individuals are frequently slow acetylators

Question 10

What antibodies are found in 40% of SLE pts and 60% of sjogrens?

Answer 10

Anti Ro antibodies

Question 11

importance of INFa

• normal function and importance
• problem in SLE pts
• associations with what facotrs

Answer 11

• INFa influences dendritic cells, these cells are vital in controlling immune response
• SLE pts have an abnormal production if IFNa, correlates with disease activity
• INFa is produced in response to various viral infections, which is why viral infections are an important environmental factor

Question 12

gold standard for m easuring ANAs

Answer 12

Immunofluorescence

• 98% of pts with SLE produce ANA’s
• the ANA test is the m ost sensitive for SLE but it is not very specific

Question 13

What is important about the peripheral pattern of one type of ANA antibody?

Answer 13

Antibodies to double stranded DNA, and associated with SLE. Very specific antibody for SLE. Antibodies to dsDNA correlate with renal disease.

note: pts who develop drug induced SLe usually produce antihistone antibodies and do not develops dsDNA antibodies so they usually do not develop renal disease.

Question 14

dsDNA is very specific for SLE but can also be found in Syphilis, parasitic infections, and bacterial carditis. What is the most specific test and why can other tests give you false positives?

Answer 14

Crithidia Test: other tests give you FP because of cross reactivity with s-DNA and histones.

Question 15

ds-DNA auto antibodies are associated with what type of kidney problem?

Answer 15

Lupus nephritis

Question 16

Anti Ro is associated with these 3 things

Answer 16

1. Photosensitivity in SLE pts
2. Sjogren’s syndrome
3. The Neonatal Lupus Syndrome

Question 17

Neonatal Lupus Syndrome

Answer 17

• consequence of the tranplacental passage of maternal antibody
• associated with the presence of maternal antibody to ribonuclear protein Ro
• px with transient photosensitive rash, congenital complete heart block, hemolytic anemia, thrombocytopenia, leukopenia, myocarditis and hepatitis.

Question 18

Criteria for SLE

Answer 18

definite diagnosis requires 4/11 criteria to be fulfilled

these 11 criteria address many clinicla manifestations known to be associated with SLE

Question 19

Pathology of the chronic skin lesions

Epidermis:

Dermal/Epidermal junction:

Dermis:

Answer 19

Epidermis: Hyperkeratosis and follicular plugging

Dermal/Epidermal junction: liquefaction of the basal layer

Dermis: Perivascular dermal infiltrates with lymphocytes and plasma cells

immunofluorescence shows deposition of gamma globulin and complemetn along the dermal/epidermal junction

Question 20

subacute lesions may present in these two classical ways: describe

Answer 20

1) papulosquamous: look exactly like psoriasis
2) annular skin lesions with central clearing: often in pts who are very photosensitive and have antibodies to Ro.

Question 21

List 4 examples of how acute skin lesions may present in SLE

Answer 21

1) vasculitis
2) bullae
3) periungal erythema (surrounding the nails)
4) malar blush w. naseo-labial fold sparing