Response Criteria for Megaloblastic Anemia

Hematologic Parameters Indicating Response

The American Society of Hematology defines major response as a hemoglobin increase of >2 g/dL from baseline for patients with pretreatment hemoglobin <11 g/dL, with a strength of evidence based on multiple studies 1, 2
The American Society of Hematology defines minor response as a hemoglobin increase of 1-2 g/dL from baseline, with a strength of evidence based on multiple studies 1, 2
For transfusion-dependent patients, achieving transfusion independence indicates major response, according to the American Society of Hematology 1, 2
The National Comprehensive Cancer Network recommends that neutrophil count increase is defined as at least 100% increase or absolute increase >500/mm³ for patients with baseline absolute neutrophil count <1500/mm³, with a strength of evidence based on multiple studies 1, 2
The American Society of Hematology defines platelet count increase as an absolute increase of ≥30,000/mm³ for patients with pretreatment platelet count <100,000/mm³, with a strength of evidence based on multiple studies 1, 2

Mild megaloblastoid changes may persist during treatment and should not be interpreted as treatment failure, as these can be consistent with treatment effect, according to the American Society of Hematology 1, 3, 4, 5
Response criteria require confirmation on at least 2 successive determinations at least 1 week apart after an appropriate period following therapy, typically 1 month or longer, as recommended by the National Comprehensive Cancer Network 1, 3, 4, 5
Improvements must last at least 2 months to qualify as a durable response in formal response criteria, according to the American Society of Hematology 1, 2, 3, 4, 5