CLE (ECVD videos) Flashcards
Which breeds develop VCLE
*Shelties
*Rough Collies
*Border collies
Which body regions develop VCLE
*Sparsely haired skin (ventral abdomen, medial thighs, flanks)
*Mucocutaneous junctions, less (lipfolds, periocular, anus)
Histopath pattern for VCLE
*Lymphocyte-rich interface dermatitis with keratinocyte vacuolation
*Confluent. vacuolation leading to intrabasal vesiculation
Lymphocytes kill keratinocytes via 1) apoptosis or 2) cell lysis and necrosis, which leads to hydropic degeneration, which leads to vacuolation
Chronicity of VCLE (acute, subacute, chronic)
Subacute
(all other forms of CLE are chronic. No acute CLE in dogs)
Which T cells are present in VCLE
CD4 and CD8
Clinical signs of canine juvenile dermatomyositis
*Scarring alopecia w/ depigmentation and focal ulcers
*Facial predominant, ear tips, tail tips, joints
NOT THE SAME AS VCLE, just the same breeds!
*Interface dermatitis but CELL POOR
*ISCHEMIC FOLLICULAR ATROPHY
Factor that can aggravate VCLE
UV light
Flares during summer, sunshine
Where is IgG deposited in VCLE?
*Epidermal BMZ
*Vessel BMZ (possible vasculitic component)
*Intracytoplasmic basal cell (because IgG is attacking a part of basal cell, cytotoxic T cells also attack this antigen on basal keratinocyte –> induce vesiculation)
What percent of dogs with VCLE have positive IgG against ANA in their skin?
0%
Cannot find ANA
What are the targets of IgG in VCLE on basal keratinocytes
Different nuclear antigens:
*SSA, SSB (also SLE in humans!)
Also
*Sm/RNP
*Jo1
*Scl70
*Sm
Treatment for VCLE
BEST DRUG = CYCLOSPORINE (active on T cells!, which attack basal keratinocytes)
*Sun avoidance
*+/- Glucocorticoids tapered for 1 month
*+/- azathioprine if still unresponsive
PENTOXI IS NOT ENOUGH, because not related to dermatomyositis
Prognosis VCLE
Complete remission in 100% with cyclosporine +/- GC
CR within 2 months in 73%
T or F: Most dogs need GC in addition to cyclosporine to keep their VCLE in remission
FALSE. 100% of dogs could be on cyclosporine alone to maintain remission of VCLE
Which disease causes macular and figurate erythema with superficial sloughing and erosions on lightly-haired body regions?
VCLE
What is the lupus band test?
Positive IgG +/- complement against epidermal BMZ, vessel BMZ, and basal keratinocytes
Which nuclear antigens are IgG targeting in VCLE
*Ro-SSA/SSB
*Other nuclear antibodies too
Which version of canine CLE is most similar to human SCLE
VCLE is a close homologue of human (vesicular) SCLE
Breeds ECLE
*German shorthaired pointers
*Vizsla
Chronicity of ECLE (acute, subacute, chronic)
Chronic
(VCLE is only subacute form; all others are chronic)
Sex overrepresented for ECLE
Females (2.1:1)
Age for ECLE
Young! 10 month median
Lesion distribution ECLE
Start on head, move to the back
Muzzle, pinnae, head –> dorsum
Lesion type ECLE
Erythema, scaling (follicular casts), alopecia
Mode of inheritance of ECLE
Autosomal recessive
Gene associated with ECLE
UNC93B1 on chromosome 18
Function of UNC93B1
Function: Chaperone/Repressor for many TLRs
With ECLE mutation: Continuous activation of TLRs by self and exogenous nucleic acids!
Hyperactivation of innate immune system –> IFN –> autoimmunity
When syntenin-1 is bound to UNC93B1, what is the state of Myd88?
Myd88 is inactive when syntenin-1 is bound (from UNC93B1)
When syntenin-1 is ABSENT from UNC93B1, what is the state of Myd88?
Persistent activation of Myd88 –> hyperactive innate immune system. Self activation of TLR7/Myd88 –> autoimmunity
Which signaling pathways are increased in ECLE? (3)
*JAK-STAT
*Interferon signaling
*Innate immune response
Why does Apoquel work for ECLE?
Because increased JAK-STAT pathway signaling in ECLE
T or F: Sebaceous adenitis in vizsla may actually be a manifestation of ECLE
True
Erythema, alopecia, scale, follicular casts
What are the concurrent systemic signs seen in ECLE? (6)
*Thrombocytopenia
*Pain/lameness
*Hunch back
*Infections
*Infertility
*Lymphadenopathy
Which cells are targeted by T cells in ECLE
*Basal keratinocytes
*Sebaceous glands
Which form of CLE has an associated sebaceous adenitis
ECLE
Which type of T cell is present in ECLE
Cytotoxic γδ T cells
Where can you find IgG in ECLE
*Epidermal BMZ
*Hair follicle membrane
*Sebaceous gland membrane
Is ECLE a true SLE?
YES, with time
Develop + ANA with AGE
Prognosis ECLE
Poor. 44% euthanized, 31% achieve CR
Most effective ECLE therapy
High dose glucocorticoids + cytotoxic drug combo to induce remission
Other reported tx: mycophenolate
Which genes are overexpressed in ECLE
IFNg
Decreases with successful therapy
Types of CLE that responds to Apoquel (oclacitinib)
*MCLE (100%)
*ECLE (100%)
*FDLE (75%)
0.45mg/kg BID
Breed MCLE
*GSD
*Belgian Shepherd
Sex MCLE
Females
Female:Male
1.7:1
Age MCLE
Median 6 years
Clinical lesions MCLE
*Erosions, ulcers (perianal, perigenital)
*Pain (+/- pruritus?)
*Dyschezia
*Dysuria
Lesion distribution MCLE
*Perianal
*Perigenital
*Perioral
Less common:
*Periocular
*Perinasal
MOST DOGS have lesions at 2-3 MC regions
Do MCLE lesions typically scar?
NO
MCLE vs MMP similarities
*Both affect GSD, near MC junctions
MCLE vs MMP differences
*MMP affects lip, but not surrounding skin
*MCLE affects perioral skin, but not lip mucosa itself
*MCLE: erosions/exudation
*MMP: ulcers, scars, blister formation
Histopath MCLE
*Lymphocyte-rich interface dermatitis
*Thick, irregular BMZ (immune complex deposition)
What type of Ig do you find at BMZ in MCLE
Mostly IgG (83%) –> Positive “lupus band test”
Also IgM (44%), C3 (33%), IgA (17%)
Treatments MCLE
*Oral glucocorticoid
*Cyclosporine
*Doxy/niacinamide
Prognosis MCLE
Good!
CR within 3 months
T or F: spontaneous remission can occur in MCLE
False.
Usually, need lifelong meds
Treatment with fastest time to CR in MCLE
Oral glucocorticoids
(1 month vs 2 months w/o)
How do you differentiate MCLE from mucocutaneous pyoderma
No response to topical/oral antibiotics
T or F: recurrence/relapses are common in MCLE if you taper immunosuppressive medication
True
Clinical signs of FDLE
*Depigmentation
*Erythema
*Scarring
*Loss of architecture
*Crusting
*Alopecia
Main differential diagnosis for FDLE
MMP
(Can affect nose, cause scarring)
(Less likely, nasal PV)
Histopath for FDLE
*Lymphocytic interface dermatitis w/BMZ thickening, keratinocyte damage
Lymphocytes and plasma cells are NORMAL in mucosa, which are not present on haired skin. Can make lymphocytic interface and basal cell apoptosis harder to see
T or F: lymphoplasmacytic lichenoid dermatitis is specific to FDLE
FALSE.
NONSPECIFIC lesion of mucosal and MC inflammation!!!
Treatment FDLE
*Doxy/niacinamide
*Partial improvement with tacrolimus
Overrepresented breeds GDLE
*Chinese crested dogs (lack of hair, more UV light exposure)
*Labrador retrievers
Sex GDLE
Equal M:F
Age GDLE
Older. 9 year median
Body distribution GDLE
*Lateral thorax
*Dorsum
*Neck
*Abdomen
*Proximal limbs
Clinical lesions GDLE
*Polycyclic plaques with central atrophic scarring
*Pigmentation changes
*Variable scaling
*Reticulated hyperpigmentation (raised if active, flat if inactive)
*MC junction involvement
Less common:
*Deep erosions, ulcers
*Hypertrophic crusting, scaling
*Scarring alopecia
Histopath GDLE
Lymphocyte rich interface dermatitis
Which Ig are present at Dermo-Epidermal junction for GDLE
*IgG (90%)
*IgA (80%)
What is UNIQUE about GDLE deposits of immunoreagents
IgG AND IgA!!
Can GDLE become SLE?
Yes, reported in 1 dog
Does GDLE have + ANA in serum?
Yes, 88% dogs
But most dogs do NOT progress to SLE
Which forms of CLE have reported SLE later?
ECLE
GDLE (not typical though!!)
Does GDLE have spontaneous remission reported
No
Treatment GDLE
*Glucocorticoids + Cyclosporine (PR)
*Doxycycline/Niacinamide (n=1, but CR)
*Tacrolimus + hydroxychloroquine
Do lesions usually recur with medication taper for GDLE?
Yes
What is unique about the immunopathology of GDLE?
*Positive low titers of ANA, without progression to SLE
*IgG and IgA antibodies
Which form of CLE is reported in cats
GDLE
*DLE
Which form of CLE is reported in donkeys
GDLE
What species have GDLE been reported in
Dogs
Humans
Cats
Donkeys
Which form of canine CLE is most similar to human DDLE
GDLE. Plaques, scarring, dyspigmentation
(more similar than FDLE)
What are the lupus-nonspecific skin diseases?
*Vasculitis (lupus panniculitis?)
*Autoimmune BM disease (BSLE-1)
Skin clinical signs of SLE
*Skin lesions (50-60%)
*MC ulcers + basal cell vacuolation = vasculitis?
*oral ulcers
*Hyperkeratotic paw pads
Bullous SLE Type 1
SLE + EBA
Clinical signs of SLE
*Fever
*Non-erosive Polyarthritis
*Proteinuria
*IMHA
*Leukopenia
*Thrombocytopenia
*Mouth ulcers
*Skin lesions (crusts, ulcers, scars)
*Internal organ involvement: thyroid gland, spleen, or kidneys.
UV-A vs UV-B differences
(relevant bc UV radiation can trigger lupus)
UV-A = longer waves, affects dermis, causes reactive oxygen species
UV-B = shorter waves, affects epidermis, causes DNA breakage
Both damage basal keratinocytes