Measurement of ANCA is an important adjunct to clinical findings in the evaluation of clinical sub-types within the systemic vasculitides spectrum. Two routine methods for the measurement of ANCA exist:

• Indirect immunofluorescence detecting ANCA against unspecified antigens and
• ELISA with MPO and PR-3 as antigens.

The presence of ANCA alone, in particular pANCA, as detected by indirect immunofluorescence, has a low specificity for vasculitides (137). ELISA are recommended as the superior method not only for detecting ANCA but also for the follow-up of disease activity after diagnosis and of the therapeutical efficacy (138), they should be preferably used. Nowadays cANCA (PR-3-ANCA) and pANCA (MPO-ANCA) are established as important clinical routine markers of the so-called "ANCA-associated vasculitides" (139, 140). As the clinical spectrum of ANCA-related diseases increases, and further target antigens are identified and characterized, the introduction of additional antigen-specific ELlSA using highly purified antigen extracts may play valuable role in the identification of clinical disease sub-types in the future.

Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) - Sample
Serum
Specimen stable at 4 °C for 1 week.

Methods:

Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) - Indirect immunofluorescence assay
See Antinuclear Antibodies – Indirect immunofluorescence assay.

Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) - Radioimmunoasay
See Appendix.

Perinuclear anti-neutrophil cytoplasmic antibodies (p-ANCA) - ELISA
See Antinuclear Antibodies - ELISA.