Ch. 33 Immune Complex Small-Vessel Vasculitis: IgA Vasculitis (Henoch-Schönlein) and Hypersensitivity Vasculitis Flashcards
Leukocytoclasis is the predominant inflammatory reaction in which vasculitides
1) IgAV
2) Hypersensitivity vasculitis
3) Mixed cryoglobulinemia
Conditions associated with leukocytoclastic vasculitis
Box 33.1 (p.457)
MC systemic vasculitis of childhood
IgAV
Diagnostic triad of IgAV
1) Purpuric rash
2) Arthritis
3) Abn urinary sediments
2010 Classification Criteria for IgAV
Palpable purpura (mandatory) with LE predominance unrelated to thrombocytopenia + 1/4
1) Diffuse abdominal pain
2) Histopath: Skin (LCV) or kidney (proliferative GN with preominant IgA deposition)
3) Arthritis/arthralgias
4) Renal involvement (hematuria and/or proteinuria)
T/F Atypical distribution of purpura in suspected IgAV requires biopsy
T
T/F IgAV is more severe when it occurs in adults
T
IgAV most frequently occurs in what age group
3-12y
IgAV is rare in what age
<2y
IgAV is more common in what gender
M
T/F IgAV is often preceded by an URTI
T, 30-50%
T/F IgAV has been associated with exposure to pharmaceutical agents
T
T/F There is a strong causative association between vaccinations and vasculitides, including IgAV
F
Suggested pathogenesis of IgAV nephritis
Galactose-deficient IgA1 (Gd-IgA1) is recognized by antiglycan antibodies, leading to the formation of circulating immune complexes and their mesangial deposition
Most specific and sensitive criterion for IgAV
Histopath
Constitutional signs often present in IgAV
Low-grade fever or malaise
Presenting symptom in ~3/4 of patients with IgAV
Skin manifestations
T/F Ulcerations do not develop in IgAV
F, may occasionally develop in large ecchymotic areas
GI symptoms of IgAV usually appears ___
Within 1 week after onset of rash and almost always within 30 days
T/F Abdominal pain may precede all other manifestations of IgAV
T
Most frequently involved site of IgAV in the GI tract because of its predilection toward ischemic injury
Small bowel
MC surgical complication of IgAV
Intussusception
GN affects about ___ of children with IgAV and is potentially life-threatening in ___
1/3, <10%
T/F Renal disease in IgAV commonly precedes purpura
F, seldom
If serious renal disease develops in IgAV, it does so within
4-6 weeks of rash onset
risk factors for renal involvement in IgAV
Male
Older
Severe GI
Arthritis/arthralgia
Persistent purpura
Raised WBC and/or PC
Elevated ASO
Low C3
RElapse
Definitions of severity of IgAV nephritis (SHARE): Mild
Normal GFR and mild/moderate proteinuria
Definitions of severity of IgAV nephritis (SHARE): Moderate
<50% crescents
Impaired GFR OR severe presistent proteinuria
Definitions of severity of IgAV nephritis (SHARE): Severe
> 50% crescents
Impaired GFR OR presistent proteinuria
PErsistent proteinuria (UPCr)
> 250mg/mmol x 4 weeks
100 x 3 months
50 x 6 months
Mild proteinuria (UPCr)
<100mg/mmol
Moderate proteinuria (UPCr)
100-250mg/mmol
Severe proteinuria (UPCr)
> 250mg/mmol
ISKDC histologic classification of IgAV nephritis: Mild IgAV
Class I (minimal change) or II (mesangial change)
ISKDC histologic classification of IgAV nephritis: Moderate IgAV
Class III
ISKDC histologic classification of IgAV nephritis: Severe IgAV
Class IV or V
Indications for renal biopsy in IgAV nephritis
Impaired eGFR
Severe or persistent proteinuria
Consider in the ff:
RPGN, nephrotic synd, nephritic synd
T/F Re: arthralgia/arthritis in IgAV: Early in the disease
T
T/F Re: arthralgia/arthritis in IgAV: If it precedes symptoms, usually a week or 2
F, a day or 2
Arthralgia/arthritis in IgAV: MC affected joints
Knees and ankles
Arthralgia/arthritis in IgAV: Erosive
F
T/F Scrotal pain and swelling are relatively frequent in IgAV
T
Principal lesion in IgAV nephritis
Endocapillary proliferative GN with increase in endothelial mesangial cells;
Deposits of principally IgA accompanied by IgG, fibrin, C3, and properdin
T/F Absence of IgA in staining of skin lesions (histopath) excludes a diagnosis of IgAV
F
Indications for GC treatment in IgAV (4)
Orchitis
CNS vasculitis
Pulmo hem
Severe GI
Renal disease in IgAV, more common and severe in adults vs children
Adults
Joint manifestations in IgAV, more frequent in adults vs children
Chidlren
T/F NSAIDs are absolutely contraindicated in patients with IgAV and diffuse abdominal pain
Not contraindicated if renal fxn is normal
Biologic agent reported to be beneficial for severe life-threatening IgAV
Rituximab
SHARE guidelines for the mgt of IgAV nephritis
Pg 463, Fig 33.6
Duration of IgAV in majority of patients
4 weeks
Most exacerbations of IgAV take place within
First 6 weeks (up to 2 years from onset)
Associated with higher recurrence rate in IgAV
Severe course with GI and joint involvement
T/F Severity of LCV correlated with visceral organ involvement in IgAV
F
Significant morbidity and mort in IgAV, short term
GI
Significant morbidity and mort in IgAV, long term
renal
Worst renal outcome in IgAV is assoc with
Nephritic or nephrotic synd
Patients with IgAV clinical nephritis should be followed closely for at least how long
5 years
Criteria for dx of hypersensitivity vasculitis
Pg 465, T33.4
Tx for hypersensitivity vasculitis
Removal of precipitating agent - GC therapy if with severe cutaneous symptoms or systemic vasculitis
IgAV vs Hypersensitivity vasculitis
IgAV: More freq GI, renal, palpable purpura
HV: Milder renal, freq normal ESR
