Laboratory parameters of 1st order – obligatory laboratory tests.
- Small blood count [possibly leukocytosis (increase in white blood cells: > 10-12,000/μl), thrombocytosis (increase in platelets)]
- Inflammatory parameters – CRP (C-reactive protein), ESR (erythrocyte sedimentation rate) [often ↑]
- Urine status (rapid test for: Nitrite, protein, hemoglobin, erythrocytes [erythrocyturia; if confirmed, a urine sediment should be done, for example, to detect glomerulonephritis early], leukocytes) including sediment.
- Renal parameters – urea, creatinine [↑], cystatin C or creatinine clearance if necessary.
- Biopsies (tissue samples) from:
- Nasopharynx (nasopharynx).
- Lungs
- Possibly kidneys
- Histological triad: granulomas, necrotizing vasculitis, glomerulonephritis.
- Granulocyte cytoplasmic antibody
- Antineutrophil cytoplasmic antibodies with cytoplasmic fluorescence pattern (cANCA), usually with the target antigen proteinase 3 (anti-proteinase 3 antibody (PR3-ANCA)): in the initial stage in 50% of cases, in the generalization stage in 95% of cases.
- Anti-myeloperoxidase antibodies (anti-MPO) [often].
