18 results
Pathophysiology of Hypocomplementemic Urticarial Vasculitis

C1q/anti-C1q antibiody ->
Immune Complex Formation - Complement Pathway Activation (C3a and C5a)
Pathophysiology of Hypocomplementemic ... Urticarial Vasculitis ... Complex Formation - Complement ... Formation -> Vasculitis ... TerrierBen #Hypocomplementemic
IgG4-Related Disease
Clinical history:  Man, 60 years, multiorgan involvement, unique or multiple inflammatory pseudotumor
4 phenotypes:
 •
IgG4-Related Disease ... node), high serum IgG4 ... rheumatoid factor), ± hypocomplementemia ... No necrosis, No vasculitis ... management #phenotypes #workup
Vasculitis and Vasculitides - Differential Diagnosis Framework

When to Consider Vasculitis:
 • Purpura, ischemic skin lesions
 •
Vasculitis and Vasculitides ... When to Consider Vasculitis ... often involved • Hypocomplementemic ... Urticaria and hypocomplementemia ... against MPO • Complement
IGG-4 RELATED DISEASE

WHAT?
 • A chronic, immune-mediated fibroinflammatory disease with tumefactive infiltration of IgG4+ plasma cells
IGG-4 RELATED DISEASE ... infiltration of IgG4 ... lesions - IgG4 ... aortitis, mimics vasculitis ... - ↑ IgE, ↓ complement
Hypersensitivity Types and Their Mechanisms
Type I - lgE - Soluble antigen
 - Allergen-specific lgE antibodies bind
antigen, leading to complement ... IgG can also mediate ... Type Ill - IgG and ... Complement activation ... Diagnosis #Reactions #Table
Highlighted Conditions With Arteritis or Periarteritis of the Coronaries
Takayasu's arteritis:
 - Onset < 40 yrs
 -
multiplex ANCA vasculitis ... Leukocytoclastic vasculitis ... arterial thrombosis IgG4 ... Diagnosis #Cardiology #Table
Summary table of types of hypersensitivity reactions. 
Type 1
 - Mediators: lgE
 - Antigen Form: Soluble
Summary table of ... - Mediators: IgG ... Mechanism of Action: IgG ... they activate complement ... types #allergy #table
Drug Induced Lupus vs SLE
Drug Induced Lupus (DIL):
 • Epidemiology: -10% of all lupus cases, drug-dependent,
• Immunologic Workup ... - ANA > 95% (IgG ... 90% - Low complement ... • Immunologic Workup ... sle #comparison #table
Causes of ileitis beyond Crohn’s disease and infections include systemic disorders -spondyloarthropathies, vasculitides, ischemia, and amyloidosis
spondyloarthropathies, vasculitides ... See below for table ... helpful paper complements ... #Differential #Table
Commonly Used Diagnostic Tests for Celiac Disease

Tissue transglutaminase (tTG) IgA antibodies
 - Most reliable noninvasive test
transglutaminase (tTG) IgG ... antibody test IgG ... Tests #Diagnosis #Workup ... #Table