TTP – Lab Tests
British Committee for Standards in Haematology clinical practice guideline recommends the following tests in patients with a suspected diagnosis of TTP:
| Test | Comment |
|---|---|
| Complete blood count | Anaemia, thrombocytopenia |
| Peripheral smear | Schistocytes |
| Reticulocyte count | Increased |
| Haptoglobin | Reduced |
| Clotting screen including fibrinogen | Normal |
| Urea and electrolytes | +/- Renal impairment |
| Troponin T/Troponin I | For cardiac involvement |
| Liver function tests | Usually normal |
| Calcium | May reduce with TPE |
| Lactate dehydrogenase (LDH) | Increased |
| Direct antiglobulin test | Negative |
| Blood group and antibody screen | To allow provision of blood products |
| Pregnancy test | In women of child-bearing age |
| ADAMTS 13 assay ((activity/antigen and inhibitor/antibody in specialized laboratory) | Do not wait for result before starting treatment in suspected TTP |
| Electrocardiogram/Echocardiogram | To document/monitor cardiac damage |
| CT/MRI brain | To determine neurological involvement |