Myeloid Flashcards
What is pancytopenia?
Reduction in WBC, RBC and platelets
How is pancytopenia treated?
Blood transfusion
What are the types of proliferative disorders?
Myeloproliferative neoplasms and lymphoproliferative
What are myeloid progenitors?
RBC, Platelets and WBC (Specifically, granulocytes and monocytes and dendritic cells)
WHat are the myeloproliferative neoplasms?
Disorder in the myeloid progenitors affecting the number of RBC, Platelets and WBC (Specifically, granulocytes and monocytes).
What is JAK2 receptors?
EPO/TPO binds to receptor which stimulates dimerisation. Janus activated kinase (JAKS) proteins are then activated which cross phosphorylate the adjacent subunit of tyrosine residues on the intracellular catalyctic domain to activate it. STATS are signal transducer activator of transcription. They bind to the phosphorylated residues of the intracellular catalyctic domain and undergo tyrosine phosphorylation by JAKS. They dimersie and translocate to the nucleus to increase RBC/platelet production
What are examples of myeloproliferative neoplasms?
Polycythaemia vera, essential thrombocythemia, myelofibrosis and myeloid leukemia.
What is primary myelofibrosis?
Mutation in JAK2 of haematopoietic stem cells leads to excess production of EPO and TPO and production of megakaryocytes. Megakaryocytes produce cytokines which attract fibroblasts in the bone marrow prior to forming platelets. Fibroblasts lay down collagen and replaces the haematopoietic stem cells. This causes scar tissue to form and reduciton of RBC, WBC and platelets.
What is secondary myelofibrosis?
Cuased by polycythaemia or essential thrombocythaemia. Excess platelets and RBC attract fibroblasts to lay down collagen in bone marrow
What is the indication of primary myelofibrosis?
Immature nucleated RBC, immature WBC, platelets and abnormal RBC.
Patinet has splenomegaly, itchiness after shower, redness, blurred vision, sweating
Polycythaemia
What causes itchiness in polycythaemia vera?
Increased levels of basophils and mast cells produce excess histamine.
What is acute myeloid leukemia?
Myeloproliferative neoplasm- it is a cnacer of the bone marrow affecting the myeloid lineage of haematopoietic stem cells. It results in production of immature myeloid cells called myeloblasts. It reduces RBC, WBC and platelets numbers and causes increased infection risk, frequent bleeding and paleness and breathlessness.
What is a myeloblast?
Immature myeloid which is dysfunctional and continues to divide in leukemia
What is essential thrombocythaemia?
Excess platelets caused by mutation in the AK2V617F. Generally asymptomatic but extreme symtpoms are haeorrage, thrombosis and progression into myelofibrosis or leukemia.
