Activity stages of ANCA-associated vasculitides (AAV) – EUVAS definition.
| Activity stage | Definition |
| Localized stage | Upper and/or lower respiratory tract without systemic manifestation, without B symptoms, not organ-threatening1 |
| Early systemic stage | All organ involvement possible, not life-threatening or organ-threatening2 |
| Generalization stage | Renal involvement (kidney involvement) or other organ-threatening manifestation (serum creatinine < 500 µmol/l (5.6 mg/dl))3 |
| Severe, vital-threatening generalization stage | Renal failure or other organ failure (creatinine > 500 µmol/l (5.6 mg/dl))3 |
| Refractory stage | Progressive disease, refractory to standard therapy (glucocorticoids, cyclophosphamide) |
Legend
- 1ANCA often negative
- 2ANCA negative or positive
- 3ANCA almost always positive
B symptomatology
- Unexplained, persistent or recurrent fever (> 38 °C).
- Night sweats (wet hair, soaked sleepwear).
- Unwanted weight loss (> 10% percent of body weight within 6 months).
Eosinophilic granulomatosis with polyangiitis (EGPA), formerly Churg-Strauss syndrome (CSS), can be classified according to the ACR criteria* :
| Bronchial asthma (>90% of cases). |
| Nonfixed pulmonary infiltrates on imaging study. |
| Pathologic paranasal sinuses/sinusitis (sinusitis). |
| Mono- and polyneuropathies (diseases of the peripheral nervous system) |
| Blood eosinophilia (>10% in differential blood count). |
| Evidence of extravascular eosinophilia (by biopsy (tissue sample)). |
If 4 of the 6 criteria are present, a diagnosis of eosinophilic granulomatosis with polyangiitis (EGPA), formerly Churg-Strauss syndrome (CSS), can be made.
* American College of Rheumatology (ACR)
