Table 47.5

Suggested diagnostic criteria, polycythemia vera

A1 Increased RBC mass Men >36 cm3 / kg Women >32 cm3/kg

B1 Thrombocytosis, platelets >600,000/cells/mm3

A2 Arterial oxygen >92% B2 WBC count

>12,000/mm3 in absence of fever or infarction

A3 Splenomegaly

Leukocyte alkaline phosphatase score >100 Elevated serum vitamin B12 (>900 pg/mL) or elevated unsaturated vitamin B12-binding capacity >2200 pg/mL

The diagnosis is acceptable if A1, A2, and A3 are present:

(1) A + A2 + A3 or, in the absence of splenomegaly,

Until recently, the diagnosis of PV was made after all causes of secondary polycythemia had been excluded (Table 47.1). The most commonly used criteria for the diagnosis of PV had been those of the Polycythemia Vera Study Group (PVSG).11 These criteria were established for diagnosing patients with active polycythemia entering a therapeutic trial comparing the value of phlebotomy only, chloram-bucil, or P-32.11 For historical purposes, the PVSG diagnostic criteria are shown in Table 47.4. Note that the RBC mass determination was used both for establishing the existence of polycythemia per se and as a criterion for diagnosing PV. Categories B2, B3, and B4 all reflect an increase in WBCs and their progenitors. (Yet in our series, only 60% of patients had a leukocytosis).

There are many other limitations of these criteria, which were, in fact, appreciated by the PVSG. Nevertheless, in the ensuing 40 years they have been used, and/or cited in the literature, for diagnosing patients with PV at least 270 times.1118 Other limitations of the criteria include the following: (1) the increase in RBC mass should be used to establish whether or not a patient is polycythemic, and not as a diagnostic criterion; (2) the abnormalities seen on bone marrow biopsy characteristic of PV are not mentioned: these are panhyperplasia, absent iron stores, increased reticulin fibers, and morphologic abnormalities of the megakaryocytes19; (3) determination of the serum erythropoietin level is not required.

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