Hematology Flashcards
(163 cards)
Virchows triad for thrombosis?
blood
vessel wall - antithrombotic normally, secretes anticoagulants and antiplatelet factors. inflammation and injury makes it Prothrombotic
blood flow - stasis:
Immobility = Surgery, Paraparesis Travel
Compression = Tumour, pregnancy
Viscosity = Polycythaemia, Paraprotein
Congenital vascular abnormalities
state immediate anticoagulant therapies and their mechanisms
Eg heparin mechanism and how to reverse
heparin - potentiates antithrombin. reverse with protamine
direct Xa inhibitors and IIa inhibitors
acute leukemia features?
rapid onset
blast cells (immature cells) - high nucleus:cytoplasm ratio
bone marrow failure ->anemia, neutropenia (infections), thrombocytopenia (bleeding)
mutation in chronic myeloid leukemia occurs at which level?
pluripotent hematopoeitic stem cells
Acute myeloid leukemia AML
stats?
pathology?
increases with age
40% in adults
many have abberations in chromosome count or structure eg t(8,21) -> RUNX1/RUNX1T1 fusion
t(15,17) -> acute promyelocytic lueukemia!!
inv(16) -> may see eosinophilia
two hits
type 1 - promote proliferation and survival
type 2 - block differentiation
t(15,17) translocation occurs in?
Clinical effect?
most important diagnostic test?
acute promyelocytic leukemia - must be treated quickly.
can cause massive hemorrhage eg cerebral hemorrhage
accumulation of promyelocytes NOT blast cells
causes DIC!
hypergranular, multiple auer rods!!!
may habve bilobed nuclei (variant apl)
cytogenetic analysis/molecular/fish -> looking for translocation
what chromosomal duplications are common in AML?
+8
+21 (downs)
in a patient with AML with normal chromosomes, what molecular abnormality could have occured?
point mutation NPM1, CEBPA
partial duplication FLT3
loss of tumour suppressor genes
AML vs ALL?
Which is Mpo +ve?
What are the different cell markers expressed by these?
AML has fine granules in cytoplasm - you probably cant see them. has aueur rods (pathoneumonic of myeloid neoplasm)
cytochemical staining:
Myeloperoxidase -> stains for Myeloid cells (tell from name) -> brown stain
sudan black stain -> +ve myeloid cells
non-specific esterase -> +ve myeloid cells
Immunophenotyping -> identify cell type based surface or cytoplasmic antigen only expressed on lymphoid vs myeloid cells. xamples include
- immunocytochemistry/immunohistochemistry = using antibodies + florescent enzyme
- flow cytometry - will tell you markers eg CD13!! AND CD33!! expressed by myeloid cells -> AML
(ALL is Tdt +ve -> T cells express CD3!, B cells CD19!, CD10!)
AML features?
bone marrow failure ->anemia, neutropenia (infections - can be as serious as septic shock), thrombocytopenia (bleeding)
inflitration of tissues by leukemic cells -> spleenomegaly, hepatomegaly, gum infiltration if monocytic, lymphadenopathy occasionally
Skin/CNS disease eg cranial nerve palsy
DIC -> vascular obstruction, gangrene
hyper viscosity of wbc = retinal hemorrhage
AML diagnosis
blood film!
- blasts and auer rods
- if no auer rods, immunophotyping to distinguish AML from ALL
- if aleukemic lukemia suspected = bone marrow aspirate
once diagnosed, do cytogenetic studies to guide treatment
AML treatment
Red cells, platelets, FFP/Cryoprecipitate if DIC, antibiotics if infection, allopurinol if uric acid release from chemo
combination chemo
all trans retinoic acid for acute promyelocytic leukemia
ALL stats?
features?
diagnosis?
occurs in children
most common childhood malignancy!. AML rare in child
bone marrow failure: anemia (pallor), neutropenia, thrombocytopenia (bruising)
local infiltration: lymphadenopathy (more prominent than AML), thymic inflitration (mediastinal mass!! - this does not occur in AML) if T lineage may occur, spleenomegaly, hepatomegaly
bone pain!
CNS, testes, kidneys
blood film
immunophenotype - important as T-ALL and B-ALL are treated differently. best technique to diagnose
where does ALL start?
which patients have better prognosis?
treatment
B-ALL in bone marrow
T-ALL can start in thymus -> thymic enlargement -> mediastinal mass
patients with hyperdiploidy eg t(12,21) t(1,19)
patients with t(9,22) due to tyrosine kinase inhibitors/ imatinib that inhibit BCR-ABL-> which is philadelphia cchromosome also seen in CML
chemo
CNS directed therapy as lymphoblasts can enter CSF
supportive care: blood products, antibiotics
how are childrens FBCs different from adults?
how are newborn babies different from adults?
how is sthe experience of illness different for kids?
children have higher lymphocyte counts and MCVs
have LOWER hemoglobin concs
newborns have higher lymphoctytes and MCVs
HIGHER hemoglobin conc
kids more likely to respond with lymphocytosis
disease or treatment can cause delayed puberty and growth retardation may happen in kids
neonate reference range for FBC different from a child and adult
causes of anemia in fetus
parvovirus infection in mother
shared twin placenta
fetal to maternal transmission
causes of polycythemia in fetus or neonate
placental insufficiency
itrauterine hypoxia
twin to twin transfusion
Why does sickle cell anemia not manifest at birth?
it is a Beta chain defect not alpha chain
clinical features manifest as hemoglobin F synthesis decreases and BetaS and hemoglobin S production increase
why is sickle cell anemia different in child vs adult?
What conditions occur only in child?
in child, red marrow extends throughout skeleton and is susceptible to infarction
in adult, it is confined to axial skeleton
thus hand-foot syndrome only seen in children, typically in fist 2 years
infant still has a functioning spleen so splenic sequestration can occur -> severe anemia, shock
in adults, spleen undergoes multiple infarctions and thus no longer succeptible to splenic sequestration but hypospleenism can occur
red cell aplasia more common in children due to highr liklihood of coming across parvovirus as a child
stroke more common in children - smaller cerebral arteries
seen in children:
- hand foot syndrome
- splenic sequestration
-
sickle cell anemia management in child?
vaccinate
educate important to give penicillin and folic acid to children
if siblings with sickle cell anemia present simultaneously with severe anaemia and low reticulocyte count, what is the likely diagnosis?
Parvovirus B19
how does blood film in sickle cell anemia and sickle cell trait differ?
sickle cells wont be seen in blood film for sickle cell trait
what is beta thalasemia?
how does heterozygous and homozygous present?
reduced synthesis of Beta globin chain and therefore hemoglobin A
heterozygous = harmless
homozygous = severe anemia, fatal without blood transfusion in first few years
homozygous
anemia -> heart failure, growth retardation
erothropoeitic drive -> bone expansion, hepatomegaly, spleenomegaly (extramedullary hematopoeisis)
iron overload -> heart failure, gonadal failure
beta thalesemmia major treatment?
blood transfusion to maintain Hb
Will cause iron overload -> desfeiroxamine for chelation