| Localized |
Upper and/or lower respiratory tract disease without any other Systemic involvement or constitutional symptoms |
| Early systemic |
Any, without organ-threatening or life-threatening disease |
| Generalized |
Renal or other organ threatening disease, serum creatinine ,500 mmol/ litre (5.6 mg/dl) |
| Severe |
Renal or other vital organ failure, serum creatinine .500 mmol/litre (5.6 mg/dl) |
| Refractory |
Progressive disease unresponsive to glucocorticoids and Cyclophosphamide |
