Criteria for the diagnosis of PPV-MF by the IWG-MRT75
| . | Criteria . |
|---|---|
| Required criteria | Documentation of a previous diagnosis of PV as defined by the WHO criteria; and BM fibrosis grade 2 to 3 (on 0-3 scale) or grade 3 to 4 (on 0-4 scale)* |
| Additional criteria | Anemia† or sustained loss of requirement for either phlebotomy (in the absence of cytoreductive therapy) or cytoreductive treatment of erythrocytosis; a leukoerythroblastic peripheral blood picture; increasing splenomegaly, defined as either an increase in palpable splenomegaly of ≥5 cm (distance of tip of the spleen from LCM) or the appearance of a newly palpable splenomegaly; and development of ≥1 of 3 constitutional symptoms: >10% weight loss in 6 months, night sweats, and unexplained fever (>37.5°C) |
| . | Criteria . |
|---|---|
| Required criteria | Documentation of a previous diagnosis of PV as defined by the WHO criteria; and BM fibrosis grade 2 to 3 (on 0-3 scale) or grade 3 to 4 (on 0-4 scale)* |
| Additional criteria | Anemia† or sustained loss of requirement for either phlebotomy (in the absence of cytoreductive therapy) or cytoreductive treatment of erythrocytosis; a leukoerythroblastic peripheral blood picture; increasing splenomegaly, defined as either an increase in palpable splenomegaly of ≥5 cm (distance of tip of the spleen from LCM) or the appearance of a newly palpable splenomegaly; and development of ≥1 of 3 constitutional symptoms: >10% weight loss in 6 months, night sweats, and unexplained fever (>37.5°C) |
Diagnosis of PPV-MF requires ≥2 additional criteria beyond the 2 main criteria.
According to the European classification, grade 2 or 3 fibrosis is a diffuse, often coarse, network of fibers with no evidence of collagen formation by trichrome stain or a diffuse coarse fiber network with areas of collagen deposition stained positive by the trichrome staining.76 According to the standard classification, grade 3 or 4 fibrosis is a diffuse and dense increase in reticulin fibers with extensive intersections, with only occasional focal bundles of collagen and/or focal osteosclerosis or diffuse and dense increase in reticulin fibers with extensive intersections with coarse bundles of collagen, often associated with significant osteosclerosis.77
Below the reference range for appropriate age, gender, and altitude considerations.