Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (350 page)

Complete Hematologic Response

   Complete normalization of peripheral blood counts with leukocytes <10,000/μL

   Platelet count <450,000/μL

   No immature cells in peripheral blood

Cytogenetic Response

   Complete: no translocation detected in a minimum of 20 metaphases

   Major: 0–30% positive metaphases

   Minor: 35–90% positive metaphases

Molecular Response

   Defined by the magnitude of reduction in BCR-ABL transcripts from a standard value.

   
Complete
molecular response:
BCR-ABL1
mRNA undetectable by RT-PCR.

   
Major
molecular response: >3-log reduction of
BCR-ABL1
mRNA; it correlates well with survival. No patient who achieved complete cytogenetic response and a major molecular response at 18 months progressed to accelerated or blast phase at 60 months.

Suggested Readings

Luatti S, Castagnetti F, Marzocchi G, et al. Additional chromosomal abnormalities in Philadelphia-positive clone: adverse prognostic influence on frontline imtinib therapy: a GIMEMA Working Party on CML analysis.
Blood.
2012;120:761–767.

Branford S. Monitoring after successful therapy for chronic myeloid leukemia.
Hematology Am Soc Hematol Educ Program.
2012;2012:105–110.

POLYCYTHEMIA VERA (PV)

   Definition

PV is the most common chronic myeloproliferative neoplasm (MPN). It is characterized by overproduction of morphologically normal erythroid cells, leading to an elevated red cell mass (RCM), as reflected by high hemoglobin and hematocrit. An increased RCM alone is insufficient to establish the diagnosis, because the RCM may be increased in secondary polycythemias, such as conditions associated with hypoxia, or with tumors secreting erythropoietin, or in congenital conditions.

   Classification

   The revised 2008 WHO criteria for the diagnosis of PV are presented: