Investigation and diagnosis cont

• Serum U&E: to screen for renal impairment.

• Urinalysis: haematuria or proteinuria should prompt further renal investigations.

• LFTs: to screen for liver disease.

• Abdominal USS: for hepatosplenomegaly, renal or pelvic abnormalities.

• CXR to screen for pulmonary disease (plus pulmonary function tests if indicated) and congenital cardiac abnormalities.

• Serum erythropoietin: assays not yet part of routine laboratory investigation in UK: serum Epo 5 in PV and 4 in SE; may also be low in RE and idiopathic erythrocytosis.

• BM examination: trephine may be diagnostic in PV. Typical features include hypercellularity and trilineage hyperplasia with abnormal megakaryocytes (clustering with giant forms and increased ploidy). Increased fibrosis may be present. Normal BM histology does not

242 exclude PV but is more usual in SE.

• Cytogenetics: not routine; ~30% have abnormalities, typically 20q-. 8+, 9+ and 13q-.

• BFU-E culture: not routine; PV progenitors show increased sensitivity to growth factors and develop 'endogenous erythroid colonies' without added Epo.

Proposed diagnostic criteria for PV

A1 Raised RCM (>25% above mean normal predicted value)

or Hct >0.60 in 9or 0.56 in 9 A2 Absence of cause of secondary erythrocytosis

A3 Palpable splenomegaly

A4 Clonality marker, i.e. acquired abnormal BM karyotype

B1 Thrombocytosis (platelet count >400 x 109/L)

B2 Neutrophil leucocytosis (neutrophils >10 x 109/L; >12.5 x 109/L

in smokers)

B3 Splenomegaly demonstrated on isotope or ultrasound scan

B4 Characteristic BFU-E growth or reduced serum erythropoietin

A1 + A2 + A3 or A4 establishes PV A1 + A2 + two of B establishes PV

Pearson, T.C. & Messinezy, M. (1996) The diagnostic criteria of polycythaemia rubra vera. Leuk Lymphoma, 22 Suppl 1, 87-93.

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