The leukemoid reaction

NEET PG Pathology
#1

Persistent leukocytosis above 50,000 cells/mm3 when the cause is other than leukemia defines a leukemoid reaction.
major causes of leukemoid reactions are
• severe infections,
• intoxications
• malignancies,
• severe hemorrhage
• acute hemolysis.
• Trisomy 21 ( down syndrome)
• Asplenia
• Diabetic ketoacidosis

  1. CLINICALLY organomegaly seen in CML but not in leukemoid reactions.

  2. The peripheral blood smear may show myelocytes, metamyelocytes, promyelocytes, and rarely myeloblasts;( significant increase in early neutrophil precursors) however, there is a mix of early mature neutrophil precursors, IN CONTRAST TO THE IMMATURE FORMS TYPICALLY SEEN IN ACUTE LEUKEMIA.

  3. Serum leukocyte alkaline phosphatase is elevated in leukemoid reaction (DEPRESSED IN CHRONIC MYELOGENOUS LEUKEMIA.)

  4. Basophilia ,eosinophilia and thrombocytosis favors .CHRONIC MYELOID LEUKEMIA but these are absent in LEUKEMOID REACTIONS