Anti-neutrophil Cytoplasmic Antibodies (ANCA)

The anti-neutrophil cytoplasmic antibody called ANCA (anti-neutrophil cytoplasmic for antibodies) are autoantibodies recognizing antigens neutrophil cytoplasmic. They are found in systemic vasculitis, particularly in Wegener’s granulomatosis or Wegener’s granulomatosis (WG).
They are of two types:
• inducing ANCA by indirect immunofluorescence (IIF), a diffuse cytoplasmic staining (c-ANCA);
• perinuclear ANCA fluorescence (p-ANCA).

Indications:

Finding a GW before a drawling rhinosinusitis or pulmonary infection resistant to antibiotic therapy, or repeated epistaxis, hemoptysis.

Sample:

Venous blood collected in a dry tube.

Typical values:

IIF:
negative if <1/20
The antibodies are sought IFIs. If this search is positive specificity (pANCA or cANCA) is determined by Elisa.

Interpretation:

ANCA were found in systemic necrotizing vasculitis affecting small caliber vessels, such as GW (90% of cases) or Churg-Strauss syndrome (30%).

Wegener’s granulomatosis (WG):
GW is revealed by rhinitis, sinusitis drawling, epistaxis or pulmonary symptoms: dyspnea, chest pain, hemoptysis. The X-ray shows pulmonary nodules with thick walls, excavated, infiltrates the disease is complicated by glomerulonephritis Extracapillary croissant (lung-kidney syndrome) may evolve towards a rapidly progressive renal failure. C-ANCA-type antibodies are present in 90% of cases likely to disappear under the influence of treatment and reappear in case of relapse.

In the Churg-Strauss syndrome (CSS) – that characterize a late asthma, eosinophilia> 1000 / mL and fever with poor general condition – the antibodies are p-ANCA-type (70% of cases) .
ANCA are rapidly progressive glomerulonephritis specific focal necrosis with the tuft no deposit of immunoglobulin called pauci-immune.