Table 2.
Major and Minor Criteria for Diagnosis of Polycythemia Vera *
| Major criteria (A) |
|---|
| A1: Erythrocyte mass greater than 36 mL/kg in men or greater than 32 mL/kg in women or packed cell volume > 0.51 in men and > 0.48 in women |
| A2: Splenomegaly |
| A3: Oxygen saturation greater than 92% |
| Minor criteria (B) |
| B1: Platelet count higher than 400,000/mm3 |
| B2: Leukocyte count higher than 12,000/mm3 (no fever or infection) |
| B3: Leukocyte alkaline phosphatase score higher than 100 |
| B4: Vitamin B12 level higher than 900 pg/mL or unsaturated vitamin B12-binding capacity higher than 2200 pg/mL |
Diagnosis requires the presence of all three major criteria or two major criteria (excluding splenomegaly) and two minor criteria; for example, A1 + A2 + A3 or A1 + A3 + any two B.