The earliest manifestation of megaloblastic anemia is

Peripheral blood pictureBone marrow picture1.Macrocytosis (| MCV, MCH. Normal MCHC)2.Peripheral smearMacroovalocytes Few nucleated RBCsEvidence of dyserythropoiesis like--Basophilic stippling-Cabot ring-Howell- Jolly bodies3.| Hb4.| Hematocrit 5.Reticulocyte count - Normal or mild decrease6.White cells- Leucopenia7.Hypersegmented neutrophils/ Macropolycytes- First manifestation 8.| Platelets9.Pancytopenia (10-20%)Lab investigations:10.Serum iron, ferritin - | in pure VitB12/ Folate defect11.Serum bilirubin & LDH |- due to hemolytic component12.Schillings test: Used to assess status of intrinsic factor (IF) & Vit B12 to distinguish pernicious anemia from other causes of Vit.B12 deficiency.1.Moderate- marked hypercellularity2.Erythroid hyperplasia3.M:E ratio reversal4.Ehropoiesis- Megaloblastic5.Giant metamyelocytes6.Mildly reduced megakaryocytes7.BM iron moderately increased in pure Vit B12/ Folate defects.(Ref: Harrison 18/e p866, 17/e p645-646, Tejinder Singh 2/e p54-61)