Table 1.

Monitoring treatment response in chronic myelogenous leukemia (CML).

Complete hematologic remission	Cytogenetic remission				Molecular response
1. Normalization of peripheral counts and differential*	Karyotype analysis of metaphases from bone marrow				Quantitative PCR (RT-PCR)
2. Disappearance of all signs and symptoms of CML$		Major cytogenetic response (0–34% Ph+)			Complete molecular response	Major molecular response
Optimal response (3 months)	Complete cytogenetic response	Partial cytogenetic response	Minor cytogenetic response	No cytogenetic response	Undetectable BCR–ABL transcripts	BCR–ABL/ABL ratio of <0.1% (international scale)
	(0% Ph+)	1–35% Ph+	36–95% Ph+	>95% Ph+
Optimal response-3m	12 months	6 months	3 months	–		18 months

^*Normalization of peripheral counts is defined through platelet count less than 450 × 10⁹, white blood cell count less than 10 × 10⁹, the absence of immature granulocytes and less than 5% basophils on differential.

^$Includes resolution of splenomegaly.

Ph, Philadelphia; RT-PCR, real-time polymerase chain reaction.