Table 1.
Frequent haematological changes in patients with COVID-19.
| Parameter | Common finding in COVID-19 | Significance |
|---|---|---|
| d-dimer | Frequent and persistent elevation (4–6 times normal range) |
Increase possibly due to microvascular thrombosis Prognosis: associated with mortality |
| Plasma fibrinogen | Frequent and persistent elevation (greater than 5 g/l) |
Unclear May decrease in late stages (from 14 days) |
| Prothrombin time | Moderate prolongation (about 15 s) |
Prognosis: some studies relate it to mortality |
| Activated partial thromboplastin time | Minimal irregular variations | No relationship with prognosis or mortality found |
| Platelet count | Variable, normal or decreased, especially in critically ill patients | Questionable relationship with prognosis or mortality found |
| Antithrombin | Moderate decrease (about 80% activity) |
No relationship with prognosis or mortality found |
| Ferritin | Frequent and persistent elevation (4–6 times normal range) |
No relationship with prognosis or mortality found |
| Lymphocyte count | Very frequent and persistent elevation (70–80% < 1500 lymph/µl) |
Severe lymphopenia and LDH increase related to evolution severity |