Autoimmune blistering Flashcards
Associations of EBA
IBD (esp crohns), myeloma, SLE, RA, thyroiditis, dermatomyositis, amyloidosis, lymphoma, carcinoma, drug induced.
Types of EBA
1) classic - acral with alopecia and nail dystrophy
2) BP like (no milia or scarring): widespread with accentuation in skin folds
3) mucous membrane including bursting-perry with scarring alopecia. oesophageal strictures, laryngeal stenosis, ocular scarring, blindness.
DIF of EBA
SSS
Continuous, linear, IgG at BMZ, can have C3, IgA or M
SSS: dermal side.
EBA can occur at any age
T
EBA is more common in asians
T
Antibodies in EBA
alpha-chain 290kDa NC1 domain (collagen VII) 145kDa
Where is the blister in EBA
sublamina densa
PMN predominant
BP antigens
BPAg1 230kDa
BPag2 NC16A 180kDa
BP IF
Linear C3 and IgG at BMZ
IgG4>G1
Drugs associated with BP
Fluid Sores Caused by Prescription
Frusemide, Spironolactone/sulphasalazine, Captopril, Betablockers, PCN, penicillamine.
Potential associations with BP
Psoriasis, LP, parkinsons, dementia, stroke, MS
Triggers for BP
trauma, burns, radiotherapy, UV irradiation
BP oral cavity in %
30%
Eosinophilia in BP %
50%
Gender predominance in BP
M>F
BP in children - where
acral and vulvar
EM in BP where is the blister
Lamina lucida blister
Variants of BP
Localised variants: pretibial, vulva, peristomal, umbilical, distal end of amputated limb, sites of radiotherapy, burns
Unusual: palmo/plantar, vegetans, nodularis, vesicular TEN like, papular, eczematous, erythrodermic, LP pemphigoides
Drugs associated with MMP
penicillamine, clonidine
Antibodies and MMP
Group 1 = laminin332=5, laminin 6
Group 2= just ocular: integrin beta4
Group 3: mucosa + skin BPAG2/BP/collagen XVII/BP230
Group 4: heterogenous. variable mucosa, no skin
% of oral mucosa in MMP
85%
skin involvement in MMP
25-30%
Associations with MMP
Anti-laminin 5 (332) and adenocarcinoma,
autoimmune disease: LS
DIF MMP
linear deposits of immunoglobulins and/or complement along epithelial BMZ. Linear IgG and C3 at BMZ
Mucosa 50-90% > skin 20-50%
SSS MMP
epidermal roof mostly
but anti-laminin 5 (332): dermal
histo MMP
blister in lamina lucida with mixed infiltrate: may have plasma cells, Eos, PMNs
Ddx of cicatricial pemphigoid
PV, erosive LP, ocular pseudopemphigoid, SJS/TEN, BP, EBA, linear IgA
Herpes gestationis DIF
linear C3 at BMZ
Associations with pemphigus gestationis
Graves, hydatidiform mole, choriocarcinoma.
Pemphigus gestationis antigens
BPAg2 NC16A
Pemphigus gestationis DIF
linear C3 at BMZ
Pemphigus gestationis - mucosal involvement?
No
Pemphigus gestationis - when
4 weeks to 5 weeks post part
Pemphigus gestationis who
father more often HLA-DR2
50% 1st pregnancy, 8% of subsequent pregnancies are spared.
Pemphigus gestationis flares
post partum, menstruation, OCP
Pemphigus gestationis more likely to be prolonged if:
older age, multiparity, mucosal involvement
Pemphigus gestationis fetal prognosis
worse when early onset. Risk of low birth weight and premature
neonatal PG in 3%
SSS MMP
Epidermal (roof) except anti-laminin 5 (332): floor
MMP antigens
BPAg2 - NC16A, BPAg1, Laminin 5, type VII collagen, alpha 6integrin beta 4
MMP M>F
F
DIF MMP
Linear IgG +/- complement along epithelial BMZ (mucosa >skin). Less commonly IgA and IgM
%+ve IIF MMP
20-30% usually IgG +/-IgA
What gives a worse prognosis in children with MMP
IgA
Associations with MMP
LS
antiliminin 5 - adenoca
Drugs: penicillamine, clonidine, NSAIDS
Which HLA is MMP associated with
HLA DQ7, DQB1*0301
MMP H&E vs BP
MMP: subepidermal blister with usually fewer eosinophils in the cutaneous lymphochistiocytic infiltrate than in bullous pemphigoid. Later stage: fibrosis
All patients with MMP will have +ve DIF
false
Most commonly +ve DIF site for MMP
Conjunctiva
T/F in mmp SSS increases sensitivity of autoantibodies and is more likely to detect IgA
T
MMP - genitals involved in half of female patients
t
2 types of skin lesions in MMP `
Generalised blistering (looks like BP) or localised blisters on an erythematous plaque