Haematology Flashcards
Tell me the key facts about acute promyelocytic leukaemia.
A subtype of AML. Chromosomes 15 and 17 (exchange of material). Formation of PML-RAR alpha fusion gene. Cells formed commonly have Auer rods. Is a medical emergency you get coagulopathy (anticoagulation). Treatment is immediate all-transretinoic acid (ATRA) and then for 3 months after.
Which cell type produces platelets
Megakaryocyte
Where are blood cells made at the different stages of development?
Following conception - yolk sac
~12 weeks foetus - liver and spleen
Baby born- bone marrow primary responsible
In adults the bone marrow production is confined to the axial skeleton whereas in children the long bones also contribute
What is the classic site for bone marrow biopsy
Posterior superior iliac crest
What the ‘influencing’ factors for blood cell production i.e. production of granulocytes, platelets and red blood cells and where are they released from?
G-CSF which is most specific for neutrophils is released by the endothelium and macrophages
EPO- production of red blood cells- produced by kidneys in response to hypoxia or anaemia
TPO- production of platelets- produced by the liver
What are the values corresponding to microcytic, normocytic and macrocyctic anaemia?
Microcytic is <80
Normocytic is 80-100
Macrocytic is >100
If a blood film has lots of reticulocytes (young red cells) what is the term used to describe the blood film?
Polychromasia meaning ‘many colours’- reticulocytes are larger and more blue than normal cells
What is one of the first investigations done after discovering that a patient has an abnormal blood cell count?
Peripheral blood film
General features of acute leukaemia
Proliferation of immature cells. Differentiation block (stops the bone marrow from being able to produce normal healthy blood cells). Present with symptoms of marrow failure. Anaemia, thrombocytopenia (bleeding), neutropenia (infection). Patients have a very short history and are often unwell. An aggressive type of cancer.
General features of chronic leukaemia
Mature cells, less acute, often present with increased WCC. CML = chronic myeloid leukaemia (myeloproliferative): granulocytes. CLL = chronic lymphocytic leukaemia (lymphoproliferative): lymphocytes
Give the names of the other myeloproliferative neoplasms (other than CML).
Polycythaemia rubra Vera = raised red cells/ increased Hb and Hct
Essential thrombocythaemia = increased platelets only
Primary myelofibrosis = bone marrow fibrosis
What is the commonest mutation causing the myeloproliferative neoplasms?
JAK2
What age group does Hodgkin’s lymphoma more commonly occur?
Young adults
General difference between leukaemia and lymphoma?
Lymphoma is mainly in the lymph nodes, leukaemia is mainly in the blood and bone marrow
Which age group is ALL most common in?
Children
Which age group is CLL most common in?
The elderly
Myeloma can cause CRABI. Name the components
HyperCalcaemia Renal dysfunction Anaemia Bone (lytic lesions, osteoporosis, fractures) Infections
What is the classic bruising pattern seen in thrombocytopenia?
Petechiae (pin-prick bruises) is classic platelet type bleeding
What is the lifespan of platelets, neutrophils and RBCs?
Platelets= 7 days Neutrophils = 24 hrs RBCs= 120 days
What may be the only sign of neutropenia?
Fever (severely neutropenic patients cant form pus in the same way).
Which industrial chemical is an important cause of AML?
Benzene
Is AML or ALL more common and what age group does AML present in?
AML is More common than ALL.
AML is more common in adults- increasing incidence with age.
What findings aid a diagnosis of AML?
FBC- low Hb, low platelets, low granulocyte count, high blast count
Blood film- lots of blasts (high nuclear:cytoplasmic ratio)
Bone marrow histology- blasts must be >20% of nucleated cells
Flow cytometry- CD13+ and CD33+
Cytogenetics- t(15;17) prognosis = good unless you catch it too late, t(8;21), inv16 = good prognosis. Monosomy 7, abnormalities chromosome 5, chromosome 1 and complex cytogenetics = poor prognosis
What is the treatment for AML?
(Most recent addition in Tx is the antibody Mylotarg (Gemtuzumab ozogamicin) which is a CD33 antibody).
Combination chemotherapy- important drugs include cytarabine (aka. Cytosine arabinoside) and daunorubicin. Total of 4-6 months of Tx, Tx induces profound bone marrow suppression and pancytopenia so need supportive care incl: transfusion of RBCs and platelets, antiseptic mouthwashes, clean diet, oral prophylactic anti-fungal agents and quinolones.