Diagnostic criteria for polycythaemia vera

Polycythaemia vera is a myeloproliferative neoplasm known to be associated with dysregulated signalling of the Janus associated kinases JAK1 and JAK2.

Recommended diagnostic criteria for PV

JAK2-positive polycythaemia vera (requires both criteria)

• A1 High haematocrit (> 0.52 in men, > 0.48 in women) OR raised red cell mass (>25% above predicted)
• A2 Mutation in JAK2

JAK2-negative polycythaemia vera (requires A1- A4 plus another A or two B criteria) *

• A1 Raised red cell mass (>25% above predicted) OR haematocrit >=0.60 in men, >=0.56 in women
• A2 Absence of mutation in JAK2
• A3 No cause of secondary erythrocytosis
• A4 Bone marrow histology consistent with polycythaemia vera
• A5 Palpable splenomegaly
• A6 Presence of an acquired genetic abnormality (excluding BCR-ABL1) in the haematopoietic cells
• B1 Thrombocytosis (platelet count >450 x 10^9/l)
• B2 Neutrophil leucocytosis (neutrophil count >10 x 10^9/l in non-smokers, >=12.5 x 10^9/l in smokers)
• B3 Radiological evidence of splenomegaly
• B4 Low serum erythropoietin

*This is a very rare clinical entity

Reference:

McMullin MF et al. A guideline for the diagnosis and management of polycythaemia vera. A British Society for Haematology Guideline.British Journal of Haematology, 2019, 184, 176-191