WHO criteria for PV
| WHO PV criteria . | |
|---|---|
| Major criteria | |
| 1. Hemoglobin >16.5 g/dL in men | |
| Hemoglobin >16.0 g/dL in women | |
| or, | |
| Hematocrit >49% in men | |
| Hematocrit >48% in women | |
| or, | |
| increased red cell mass (RCM)* | |
| 2. BM biopsy showing hypercellularity for age with trilineage growth (panmyelosis) including prominent erythroid, granulocytic, and megakaryocytic proliferation with pleomorphic, mature megakaryocytes (differences in size) | |
| 3. Presence of JAK2V617F or JAK2 exon 12 mutation | |
| Minor criterion | |
| Subnormal serum erythropoietin level | |
| Diagnosis of PV requires meeting either all 3 major criteria, or the first 2 major criteria and the minor criterion† | |
| WHO PV criteria . | |
|---|---|
| Major criteria | |
| 1. Hemoglobin >16.5 g/dL in men | |
| Hemoglobin >16.0 g/dL in women | |
| or, | |
| Hematocrit >49% in men | |
| Hematocrit >48% in women | |
| or, | |
| increased red cell mass (RCM)* | |
| 2. BM biopsy showing hypercellularity for age with trilineage growth (panmyelosis) including prominent erythroid, granulocytic, and megakaryocytic proliferation with pleomorphic, mature megakaryocytes (differences in size) | |
| 3. Presence of JAK2V617F or JAK2 exon 12 mutation | |
| Minor criterion | |
| Subnormal serum erythropoietin level | |
| Diagnosis of PV requires meeting either all 3 major criteria, or the first 2 major criteria and the minor criterion† | |
More than 25% above mean normal predicted value.
Criterion number 2 (BM biopsy) may not be required in cases with sustained absolute erythrocytosis: hemoglobin levels >18.5 g/dL in men (hematocrit, 55.5%) or >16.5 g/dL in women (hematocrit, 49.5%) if major criterion 3 and the minor criterion are present. However, initial myelofibrosis (present in up to 20% of patients) can only be detected by performing a BM biopsy; this finding may predict a more rapid progression to overt myelofibrosis (post-PV MF).