Laboratory parameters of 1st order – obligatory laboratory tests.
- Small blood count [leukocytosis and thrombocytosis/increased white blood cell (leukocyte) and platelet (thrombocyte) counts]
- Inflammatory parameters – ESR (erythrocyte sedimentation rate) [moderately increased] or CRP (C-reactive protein) [moderately increased].
- Granulocyte cytoplasmic antibody (ANCA).
- Antinuclear antibodies (ANA)
- Detection of circulating immune complexes.
- Complement levels often elevated initially [IgA ↑]
- Urine status (rapid test for: nitrite, protein, hemoglobin, erythrocytes, leukocytes) incl. sediment, if necessary urine culture (pathogen detection and resistogram, that is, testing of suitable antibiotics for sensitivity / resistance) [proteinuria (increased excretion of protein with the urine)]
- Renal parameters – urea, creatinine, cystatin C or creatinine clearance, if necessary.
- 24-h urine volume – to determine creatinine clearance and proteinuria differentiation.
- Serum protein (total protein in serum), albumin.
- Biopsy or histology of skin lesions.
- Perivascular leukocyte subsets
- Vascular IgA deposits
- For abdominal pain
- Test for occult (non-visible) blood in stool.
- Determination of coagulation factor XIII
