Table 3:
Bloodwork abnormalities in pseudo-thrombotic microangiopathy (TMA) from vitamin B12 deficiency, compared with thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC)
| Pseudo-TMA from vitamin B12 deficiency (± DIC) | TTP | DIC | |
|---|---|---|---|
| Hemoglobin | ↓↓ | ↓ | ↓ |
| MCV | ↑ | –/↑ | – |
| Platelets | ↓ | ↓ | ↓ |
| Leukocytes | ↓ | – | – |
| Reticulocytes | –/↓ | ↑ | ↑ |
| Peripheral blood film | Hypersegmented neutrophils, schistocytes (few), dacrocytes | Schistocytes | Schistocytes (few) |
| INR | –/↑ | − | ↑ |
| aPTT | –/↑ | – | ↑ |
| Fibrinogen | –/↓ | – | ↓ |
| Creatinine | – | –/↑ | –/↑ |
| Unconjugated bilirubin | ↑ | ↑↑ | ↑ |
| Direct antiglobulin test | Negative | Negative | Negative |
| Lactate dehydrogenase | ↑↑ | ↑ | –/↑ |
| Haptoglobin | ↓ | ↓ | ↓ |
| d-dimer, ng/mL | –/↑ | – | ↑↑ |
| ADAMTS13, % | > 10 | < 10 | > 10 |
| Vitamin B12 level | ↓↓ | − | − |
Note: aPTT = activated partial thromboplastin time, ADAMTS13 = a disintegrin and metalloproteinase with thrombospondin motifs 13, INR = international normalized ratio, MCV = mean corpuscular volume.