2. What is Vasculitis?
The term vasculitis means inflammation of the
wall of blood vessels.
Various sizes of blood vessels may be involved.
The inflammatory exudates may vary and be
mononuclear, eosinophilic or neutrophilic.
3. How Common is Vasculitis in
Children?
Vasculitis in children appears to have an
incidence of about 50 cases per 100,000
children per year.
Henoch Schonlein purpura (HSP) and Kawasaki
disease (KD) are more common in children (75–
125 per 100,000 in Japanese children and 9 per
100,000 in Caucasian children of USA.)
4. How is Vasculitis Classified in
Children?
The aorta and its main branches are termed
large vessels;
The first branches of the aorta e.g., renal,
mesenteric, coronary vessels are regarded as
mid-sized;
Arterioles, capillaries and venules are regarded
as small-sized.
Small vessel vasculitis (SVV) is sub-categorized
into granulomatous and non-granulomatous
varieties.
12. What is the Investigative Approach for a Child
with Vasculitis with Regards to Radiology,
Histopathology and Serology?
Radiology:
Digital Subtraction Angiography (DSA)
In large vessel vasculitis, conventional DSA is
useful in demonstrating vessel stenoses or
aneurysms.
The major limitations of DSA
1. Invasiveness,
2. High contrast load,
3. High-dose radiation exposure,
4. Complications at the arterial injection site.
5. Inability to delineate the arterial wall anatomy.
14. MR Angiogram (MRA)
MR angiography :
1. Detects of early signs of large-vessel disease,
and
2. It has the added advantage of potentially
revealing evidence of ongoing large arterial wall
inflammation.
Disadvantage :
1. Its relative insensitivity to slow flow or in-plane
flow because of saturation of the MR imaging
signal intensity.
2. This can lead to overestimation of the severity of
the stenosis or to a false diagnosis of vascular
occlusion .
15. Computerised Tomography (CT) and
Ultrasonography
(USG)
USG provides a very good image of the following compared
to CT or MRI.
1. Carotid.
2. Axillary.
3. Brachial.
4. Femoral arteries.
Major advantages are
1. Non invasiveness,
2. No radiation,
3. Wide availability and
4. Low cost.
5. Blood flow characteristics, wall elasticity, and plaques can be
delineated.
16. Relative Disadvantages : The image of the
subclavian, iliofemoral, renal, superior and
inferior mesenteric arteries, the celiac trunk, and
the abdominal aorta is moderate.
The assessment of thoracic aorta requires
transesophageal USG.
17. CT, Electron beam tomography and CT
angiogram (CTA) have been reported as useful
tools for assessing the aorta and its main
branches.
However, poor visualisation of the more distal
branches and a high radiation exposure are
possible disadvantages.
18. Studies comparing Color Doppler Flow Imaging
(CDFI) with MRA and conventional angiography
have shown a high degree of correlation in
delineating the extent of stenosis in the carotids
and subclavian vessels.
Positron emission tomography (PET) scanning
with radioactive-labelled 18-fluorodeoxyglucose
(FDG) has been shown to be useful in
monitoring disease activity (by its extreme
sensitivity to pick inflamed vessels) and
response to treatment in preliminary studies.
19. 2 D Echocardiogram
Helps in detecting or excluding coronary artery
aneurysms, intraluminal or mural thrombi,
regurgitant cardiac valves, myocardial
dysfunction, or pericardial effusion.
20. Histology
The choice of tissue is guided by the clinical
setting using the most accessible involved organ
or tissue.
Various organs biopsied include the skin, lungs
and kidney (pulmonary-renal syndrome), sural
nerve, and muscle.
21. Skin is the most commonly biopsied area.
A deep punch biopsy (to diagnose changes in the
deeper vessels at the dermal level) is ideal.
Cutaneous vasculitis is mostly characterized by
involvement of the post-capillary venules with
endothelial cell swelling, neutrophilic invasion of
blood vessel walls, presence of disrupted
neutrophils (leukocytoclasia), extravasation of red
blood cells, and fibrinoid necrosis of the blood
vessels walls.
22. These features are termed cutaneous
necrotizing vasculitis (CNV), which refers to
leukocytoclastic vasculitis affecting the small
and medium vessels supplying nutrients to the
skin .
23. Along with leukocytoclasia, the biopsy may
reveal areas of panniculitis, particularly in PAN.
Samples should be subjected to
immunofluorescence particularly for possible
HSP (IgA deposits), ANCA associated vasculitis
(pauci-immune necrotising vasculitis) or
secondary vasculitis like SLE (immunoglobulins
and complement deposits at the dermo-
epidermal junction).
24. Renal biopsies are carried out if clinical features
and urinalysis suggest renal involvement.
Various changes from focal to segmental
glomerulonephritis can be seen.
Subepithelial deposits can be seen on electron
microscopy
25. As the yield from tissues like sinuses, nose,
ears, and trachea is low (<50%), invasive
procedures such as open or thoracoscopic lung
biopsies or renal biopsies are often used to
diagnose Wegeners granulomatosis (WG).
26. Serology
ANCA are present with a high specificity of up to
98% in the specific group of AAV.
Two staining patterns for ANCA are detected by
ELISA.
1. Cytoplasmic ANCA (C-ANCA) representing
antibody to proteinase 3 is present in 90% of
patients with active diffuse WG i.e., with high
specificity.
2. Perinuclear ANCA (P-ANCA) caused by
antimyeloperoxidase antibody is suggestive of
involvement of small to medium sized arteries in
conditions such as microscopic polyangiitis.
27. The presence of Von Willebrand factor antigen
is a surrogate marker for SVV.
Elevated IgA levels may be found in 50–70% of
HSP.
Anti-streptolysin O titres may be elevated with
cutaneous polyarteritis (C- PAN).
Serology for Hepatitis B and C are relevant in
cases of polyarteritis nodosa (PAN).
30. What is the Prognosis of the Various Vasculitides?
The majority of children with HSP make a full
and uneventful recovery with no evidence of
ongoing significant renal disease.
Mortality is around 1–2% with severe
gastrointestinal or renal involvement.
Renal involvement is the most serious long-term
complication of HSP and occurs in 5%.
31. KD has a good prognosis, with 1–2% acute
mortality rate due to myocardial infarction,
having been reduced further to less than 1%
due to increasing awareness of clinicians and
prompt treatment.
32. Ozen et al reported in a retrospective series of
childhood PAN an improved outcome compared
to that reported in adults with only one (1.1%)
death and two (2.2%) patients with end-stage
renal disease among 110 patients.
C-PAN has a good prognosis, albeit with
recurrent relapses and remissions.
33. The AAV carry considerable disease-related
morbidity and mortality mainly due to
progressive renal failure or aggressive
respiratory involvement.
For Churg-Strauss syndrome (CSS) in children,
the most recent series reports mortality of 18%,
attributable to disease rather than to therapy.
The risk of organ damage is related to the
duration of active disease.
34. With proper treatment, clinical remission is often
achieved within the first year.
The remission may be life-long, but long-term
maintenance therapy is frequently required.
Periods of disease remission may be interrupted
with relapses requiring more intensive therapy.
