return to P index

return to index page


Test Directory - PR3 antibodies


Serine proteinase 3

Clinical Indications

Autoimmune vasculitides including:
Wegener's granulomatosis
Microscopic polyangiitis
Crescentic glomerulonephritis
Churg-Strauss syndrome
Please note: All samples found to be ANCA IIF positive or to have an interfering ANA will be tested for the presence of MPO and PR3 antibodies. 
The assay should not be considered diagnostic and a definitive diagnosis should not be based on the results of this assay alone

Test Includes

ANCA positive samples have a pattern reported, and have MPO and PR3 antibodies measured.

Part of Profile


Request Form

Combined Pathology Blood form (Yellow/Black)


Referral test: Analysed by Immunology, Southend Hospital.

Specific Criteria

Positive ANCA pattern, monitoring known positive.

Turnaround Time

Two weeks




2 ml


Yellow top (SST) tube or

Paediatric orange top (lithium-heparin)

Causes for Rejection

Assay within previous month

Reference Range

0 - 2 U/mL



PR3 directed c-ANCA is present in 80-90% of granulomatosis with polyangiitis, 20-40% of microscopic polyangiitis, 20-40% of pauciimmune cresentric glomerulonephritis and 35% of Churg-Strauss syndrome.

Lab. Handling

Processing: Aliquot (MPA) and store at 4C in separating fridge (CB39), Southend Immunology rack.
: ANCA and send or IMDUP and track at 4C in cold room (CB23).

 Version 1.0 / July 2014                                                                                                           Approved by: Consultant Biochemist