Haematology and Blood Transfusion Flashcards
what different considerations to adults do we need to be aware of in the management of paediatric haemtological cancers?
blood sampling-more difficult to do
?normal reference ranges-going to change with age of the child
‘newer organs’-can tolerate more intense treatment dosing
different disease biology and evolution hence management
requirement of anaesthetic-consideration of GA for BM aspiration important when considering investigations for pt*
what investigation is necessary before doing a BM aspiration in a child in which leukaemia is suspected?
CXR-as may be a mediastinal mass due to the leukaemia which is causing the child no symptoms but will cause airway compromise when the child receives a GA for BM aspiration.
what proportion of childhood leukaemias is ALL responsible for?
80%
remaining 15-20%=AML
treatment of AML in children?
chemotherapy for 6-8 mnths with or without a transplant
overall survival=60-70%
when must transfusion of red cells be completed by after leaving temperature controlled storage?
within 4 hours
how is a pt receiving a blood transfusion monitored?
observations for every unit transfused
pre-transfusion: pulse, BP, temp and RR measured not more than 60mins prior to transfusion
during: pulse, BP and temp taken at 20 mins after start of each transfusion component, if changed from baseline then measure RR.
also at 1hr into the transfusion
post transfusion pulse, BP and temp should be taken not more than 60mins after end of component.
all observations to be taken and recorded.
what currently carries the highest blood transfusion risk?
incorrect blood component transfused
what is a massive haemorrhage defined as, and what is the role of blood transfusion here?
50% of TBV loss in 3hrs or TBV loss in less than 24 hrs or rate of blood loss at 150mls/min
give O negative emergency blood, whilst urgent X match sent
when is the massive haemorrhage protocol activated?
when 4 or more units of red cells have been transfused within an hr and similar further need is anticipated.
what tests and processing are required on donated blood?
testing: HIV, Hep B, Hep C, HTLV-human T-cell lymphotropic virus, syphilis
leucodepletion
centrifugation
importance of red cell storage in temperature controlled fridge (between 2 and 6 degrees C)?
if temp falls below this, cells may haemolyse
if temp goes above this, can lead to higher risk of bacteria proliferation and cause metabolic activity that may lead to deterioration in function.
when are PLT transfusions not indicated in treatment or prevention of haemorrhage in pts with low PLTs or PLT defects?
thrombotic thrombocytopenic purpura-may use FFP
heparin induced thrombocytopenia
1st sign of neutropenia?
sore throat (mucositis) *neutrophils required for maintaining integrity of mucosal surfaces, and prevent overwhelming bactierial infection and fever
causes of neutropenia?
drugs-cytotoxics, radiotherapy, Abx-chloramphenicol, phenytoin, clozapine, carbimazole, carbamazepine
infection-espec. viral-interferon prod.-causes BM suppression
immune mediated-SLE, felty’s syndrome-splenomegaly, RA, neutropenia
BM failure-pancytopenia
physiological-afro-caribbean ancestry
hypothyrodism, hypopituitarism
causes of neutrophilia?
- demargination-WBCs normally stick to b.vessel walls, can be made to mobilise-e.g. steroid treatment, post fall.
- early efflux from BM-infection-espec. pyogenic bacteria
- increased production-smoking, chronic myeloproliferative disorders-CML,polycythaemia vera, myelofibrosis
acute inflammation NOT caused by infection-surgery, infarcts e.g. MI, burns, crush injuries, RA, vasculitis
other drugs-adrenaline, G-CSF
acute haemorrhage and acute haemolysis
metabolic-DKA, gout, acute thyrotoxicosis
Ca not of haem origin e.g. carcinoma, melanoma
lymphoma
post splenectomy
lymphopenia causes?
transient low count in severe infection AIDS radiotherapy chemotherapy steroid therapy
most common cause of a reactive lymphocytosis?
glandular fever (infectious mononucelosis) in EBV infectious mononucleosis, the 'reactive' or atypical lymphocytes are mainly CD8+ cytotoxic T cells activated following B lymphocyte infection and their subsequent proliferation. (T cell activation to control B cell proliferation.)
causes of lymphocytosis?
infection-viral-transient lymphocytosis, e.g. EBV, CMV, hepatitis, HIV in early stages. also whooping cough.
stress-MI, sickle cell crisis
trauma
adrenaline-reaction only in 1st few hrs
RA
leukaemias-CLL-mature lymphocytes, lymphomas
causes of eosinophilia?*
allergy-allergic asthma, allergic rhinitis, eczema ABPA parasitic infections churg-strauss syndrome sarcoidosis SLE lymphoma drug sensitivity-penicillin idiopathic hypereosinophilic syndrome
complications of eosinophilia?
restrictive cardiomyopathy and valve damage
liver disease
how can the antigens expressed by cells be determined, and hence how can benign and malignant causes of persistent lymphocytosis, and differentiation between B and T cell subtypes be made?
process of flow cytometry (immunophenotyping)
can characterise cells in peripheral blood or in BM aspirate samples
fluorescence and light scatter of cells is measured, and fluorescence generated due to cell prelabelling with fluorochrome conjugated to antigen-binding Ab allows detection of specific cell surface antigens.
fluorochrome excited by argon laser.
what condition are patients receiving immunosuppressive therapy following transplantation susceptible to as a result of loss of T cell control of EBV-infected B cells (remain infected for life)?
post-transplant lymphoproliferative disorder (PTLD)-B cell lymphoproliferation that may involve LNs or extranodal sites.
importance of CMV infection in immunocompromised patients?
especially in post-transplant setting, is important as absence of controlling T cells can cause life threatening complications e.g. CMV pneumonitis.
what is lymphoblastic lymphoma?
a malignant proliferation of lymphocyte precursors (usually T cell)
classified as a type of Non-hodkin’s lymphoma
lymphomatous equivalent of ALL, in that there is lymph node disease with little peripheral blood or bone marrow involvement.
commoner in adolescent males
frequent px with mediastinal mass
less than 20% blasts in BM (or would be ALL)
same tx protocols as ALL
what is CLL?
chronic lymphocytic leukaemia-malignant proliferation of B lymphocytes, characterised by accumulation of small mature lymphocytes in the blood, BM and lymphoid tissues.
blood film findings in CLL?
smear cells (disintegrated cells)-lymphocytes whose cell membrane has ruptured during slide preparation increased numbers of small lymphocytes
name given to the transformation of CLL to a high grade large B cell lymphoma (occurs in about 3% of cases)?
Richter’s transformation
most common presentation of CLL?
asymptomatic in 90% of cases with diagnosis following incidental finding on routine blood tests-minimum clonal B cell lymphocytosis-more than 5x10^9 lymphocytes/L
may be normochromic normocytic anaemia in advanced disease with marrow infiltration or hypersplenism.
clinical features of CLL?
often asymptomatic-incidental finding of lymphocytosis on routine bloods
most patients over 60 years
may be symptoms result of anaemia-fatigue, SOB
bruising and mucocutaneous bleeding/petechiae secondary to thrombocytopenia
sinusitis, bacterial pneumonia, secondary to hypogammaglobulinaemia
night sweats, fever and weight loss (B symptoms) uncommon-if severe B symptoms ?Richter’s transformation to high grade diffuse large B cell lymphoma
early satiety due to mechanical obstruction by splenomegaly
o/e: lymphadenopathy, hepatosplenomegaly
results of investigations in CLL?
incidental finding on routine bloods-monoclonal lymphocytosis greater than 5
may be anaemia and thrombocytopenia with BM infiltration and failure
direct antiglobulin test (DAT)/Coombs test may be +ve-CLL asooc. with AI haemolytic anaemia, and also ITP
BM aspirate and trephine biopsy-extent of BM infiltration, biopsy only if intent to treat immediately
hypogammaglobulinaemia, may be monoclonal band on immunoelectrophoresis
flow cytometry-malignant lymphocyte immunophenotyping shows expression of CD5, CD19, CD20, CD23, CD79a and surface IgM, CD10 negative.
complications of CLL?
Richter’s transformation to high grade lymphoma
B symptoms
ITP-bleeding, AI haemolytic anaemia-SOB, fatigue
BM failure-also cause of low PLTs and Hb
hepatomegaly and splenomegaly-early satiety, worseneing of anaemia
hypogammaglobulinaemia-capsulated organism infections of RT e.g. strep pneumoniae, H.influenzae, also recurrent infections e.g. HSV, VZV
secondary malignancies e.g. lung Ca, bowel Ca, ?due to immunoparesis resulting in reduction in normal tumour sureveillence by IS.
management of CLL?
if asymptomatic, often simple monitoring in clinic required (watchful waiting)
tment indicated if systemic symps-w.loss, sweats, fever, cytopenias. use chemotherapy regimens to prolong survival in these symptomatic patients but note not curative (cure possible exception with stem cell transplants).
what is the monospot test?
test for EBV infection which uses an agglutination reaction (red cell clumping to form aggregates) as EBV causes Ab development capable of agglutinating red cells of other species. test: horse rbc agglutinate on exposure to the Abs.
define B symptoms
these were developed for lymphoma:
weight loss more than 10% in 6 months
unexplained pyrexia spikes
night sweats
causes of a pancytopenia?**
acute leukaemia
aplastic anaemia
megaloblastic anaemia-severe vit B12 deficiency
investigations performed on a BM biopsy in investigating leukaemia?
flow cytometry genetic studies (cytogenetics) immunohistochemistry-staining
examples of myeloproliferative disorders?
polycythaemia rubra vera
CML
myelofibrosis
essential thrombocythaemia
characterised by increased proliferative activity with fairly normal maturation
define CML
a myeloproliferatie disorder of pluripotent haemopoietic stem cells affecting 1 or all cell lines-myeloid, erythroid and PLT.
what genetic abnormality do 90% of patients with CML have?
the Philadelphia chromosome:
reciprocal translocation between the long arms of chromosomes 9 and 22, with part of chromosome 9 containing ABL gene breaking off and sticking to BCR gene on chromosome 22 producing the fusion gene BCR-ABL-transcribed into an oncoprotein with tyrosine kinase activity-causes increased cell cycling and failure of apoptosis.
which chromosomes are involved to form the Philadelphia chromosome?
9 (ABL gene) and 22 (BCR gene)
complications of leukostasis in CML?
this occurs due to very high WCC: priapsim-persistent and painful penile erection lung infiltrates amaurosis fugax renal impairment tinnitus stupor
what 3 stages does CML typically progress through?
chronic phase
accelerated phase
blast crisis/blastic phase
describe the chronic phase of CML
this is the 1st phase in which the immune system is competent and many pts are asymptomatic for long periods
mature cells in the periphery
normal blood counts achieved with therapy
what is the accelerated phase of CML?
blood counts become difficult to control, increasing numbers of blast cells, 15-29% blasts in BM or blood, more than 20% basophils in blood, thromobcytosis, thrombocytopenia unrelated to therapy or clonal chromosome abnormalities in the Ph+ clone.
epidemiology of CML
can occur at any age but rare in children
represents 15% of all adult leukaemias
median age at diagnosis=60-65yrs
describe the blastic phase of CML
30% or more blasts in the peripheral blood or BM or extramedullary blastic infiltration
aggressive acute leukaemia which is usually rapidly fatal
severe constitutional symptoms due to tumour burden-weight loss, night sweats, fever, bone pain, and due to infection and bleeding and EM blastic foci.
how can BCR-ABL be detected in investigating CML?
can enhance with PCR then FISH
this is quicker than testing for the Philadelphia chromosome (Ph)-shortened chromosome 22
lab features of CML?
FBC: anaemia, elevated WCC-often between 50 and 400, with excess neutrophils, myelocytes, basophils and metamyelocytes, blast cells in small numbers, granulocytes at all stages of development, PLT may be elevated, decreased or at normal levels
blood film-all stages of maturation seen
raised LDH, often raised uric acid
BM very hypercellular-BM aspiration and biopsy
what small molecule inhibitors can be used to treat CML?
imatinib-1st TK inhibitor developed for the treatment of CML, oral agent taken daily which binds to the BCR-ABL and inhibits the phosphorylation of tyrosine in protein so stops it’s leukaemogenic effects of increased cell cycling and apoptosis failure.
dasatanib
nilotinib
overall treatment of CML?
most will respond to imatinib therapy (small molecule inhibitor of inactive conformation of tyrosine kinase, binds to BCR-ABL)
hydroxycarbamide often used in 1st few days to reduce very high WCCs
can use 2nd line TK inhibitors if pt resistant to imatinib treatment
imatinib usually provides disease control, but cannot cure the disease
allogeneic BM transplant=only known curative therapy, best carried out in chronic phase-not available to pts over 45-50yrs of age, and must find matched tissue donor-sibling or unrelated matched donor-HLA typing.
what important diagnostic test is used for polycythaemia rubra vera?
JAK2 mutational analysis-mutation in erythropoietin signalling pathway
what is polycythaemia rubra vera?
chronic clonal disorder which features excesssive proliferation of a multipotent haemopoietic stem cell causing increased rcc, markedly elevated Hb and haematocrit, and often increased WCC and PLTs.
as high Fe demand for high rcc production, MCV is low.
clinical features of polycythaemia vera?
insidious onset, usually px late in life
features relate to high blood viscosity due to considerable increase in rcc: dizziness, headache, can be stroke.
pruritus, part. after a hot bath
marked thrombosis tendency-mesenteric, portal, splenic vein
may also be increased likelihood of bleeding
signs: florid dusky red face-plethora
splenomegaly
hepatomegaly
erythromelalgia-increased skin temp, burning sensation and erythema, may occur in extremities.
Low Fe
differentials for polycythaemia vera?
secondary polycythaemia-long standing hypoxia-COPD, plus along with raised WCC-COPD infective exacerbation
raised EPO-renal cell carcinoma, PKD
apparent polycythaemia when reduction in plasma volume causes raised haematocrit e.g. diuretic tment, dehydration.
treatment of polycythaemia vera?
venesection
aspirin to minimise stroke risk
ruxolitunib-against jak 2
antihistamines for pruritus
30% go into myelofibrosis
10% go into AML
how do myeloid cells mature?
all arise from a singe multipotent common stem cell
granulocytes: myeloblast to a promyelocyte-azurophilic granules, to myelocytes, eosinophil myelocytes, neutrophil myelocytes and basophil myelocytes. neutrophil myelocytes to metamyelocytes and then neutrophils. promonocytes to monocytes.
proerythroblast to normoblast to reticulocyte to rbc
megakaryoblasts-cyctoplasmic sheddng to give megakaryocytes-to PLT.
most common form of acute leukaemia in adults?
AML
what is AML?
a malignant clonal proliferation of myeloid progenitor cells, causing BM infiltration with immature cells resulting in impaired neutrophil, rbc and PLT prod.
classification of malignant cell types in AML?
FAB classification: undifferentiated blasts-M0 lightly granulated blasts-M1 granulated blasts often with Auer rods-M2 promyelocytic leukaemia-M3 myelomonocytic leukaemia-M4 monocytic leukaemia-M5 erythroleukaemia-M6 megakaryocytic leukaemia-M7
what genetic syndrome is assoc. with a much higher incidence of acute megakaryocytic leukaemia (M7) compared with unaffected children?
Down’s syndrome-400 times higher incidence
what inherited mutations can predispose to AML?
those of critical haemopoietic transcription factors e.g. AML-1
how can AML be classified in relation to underlying molecular abnormalities?
WHO 2001 classification: 4 categories-
acute myeloblastic leukaemia with recurrent cytogenetic changes-with t(8;21), usually young pts, t(8;21) and t(15;17) assoc. with more favourable prognosis
AML with multilineage dysplasia-evolving from myelodysplastic disorder, usually older pts
AML and MDS, therapy related-alkylating agents e.g. cyclophosphamide, mitomycin C-given intravesical in pts with high risk non invasive bladder Ca, and topoisomerase II inhibitor related-anthracyclines e.g. doxorubicin. recurring abnormality of chromosome 5 and/or 7.
AML not otherwise categorised-morphologically categorised M0-M7.
clinical features of AML?
reflect BM failure: anaemia infections bleeding, bruising, purpura blast cell infiltration of other organs e.g. skin and gums-part. in monocytic leuakemia (M5), and can invade CNS lymphadenopathy splenomegaly
lab findings in AML?
FBC: anaemia, thrombocytopenia-BM failure, WCC-may be very high due to high numbers of circulating blasts, in over half of cases is low, in almost all pts total no. of normal circulating neutrophils is reduced.
blood film: large blast cells, may show azurophilic rod-shaped cytoplasmic inclusions (Auer rods-formed by granule fusion), espec. M2 and M3, azurophilic granules-M3-promyelocytic leukaemia.
flow cytometry-distinguish AML from ALL as treatment differs, look for expression of typical antigen profile-AML-CD13, 15, 33, stem cell marker 34. stem cell factor receptor c-kit-CD117, ALL-blast expression of B or T cell markers. note some rare leukaemias-biphenotypic, express myeloid and lymphoid antigens.
BM-aspiration and trephine biospy-BM always contains blast cells. cytogenetics-APML-translocation 15;17, blocks maturation at promyelocyte stage of development.
characteristics of acute promyelocytic leukaemia (M3)?
malignant cells=promyelocytes-contain abundant azurophilic granules and Auer rods. granule release may occur spontaneously or at start of cytotoxic chemo, and leads to uncontrolled activation of fibrinolytic system, causing DIC and potentially life threatening bleeding.
characterised by translocation between chromosomes 15 and 17
now most curable subtype of AML-treated with all-trans-retinoic acid (ATRA)-non chemo differentiating agent, specific for the translocation, limits DIC threat. can combine with conventional chemo e.g. anthracyclines, or with the poison arsenic trioxide.
AML treatment overview?
intensive chemotherapy-anthracyclines e.g. doxorubicin and cytosine arabinoside
supportive care-high risk of neutropenic sepsis following intensive chemo, often due to damaged gut mucosal surfaces allowing gram -ve bacteria to cross bowel wall into the blood, prolonged periods of neutropenia assoc. with fungal infection-aspergillus and candida.
BM transplantation-if features indicating poor risk disease or pts who have relapsed, allogeneic-myeloablative therapy to destroy patient’s BM, and immunosuppression with HLA-matched donor BM to allow engrafting, procedure restricted to younger pts due to severe toxicity assoc. with the treatment, but recently the graft versus leukaemia effect of the transplant that allows eradication of chemoresistant disease can be used in older pts with reduced intensity treatment-non-myeloablative.
how do myelodysplastic syndromes lead to BM failure?
syndromes characterised by a clone of abnormal dysplastic haemopoietic cells that are unable to mature normally, and this block to maturation tends to worsen overtime leading to blast cell accumulation and ultimately BM failure either due to transformation to acute leukaemia or due to stem cell failure.
most common presentation of myelodysplastic syndromes?
symptoms of anaemia in patients over the age of 50 years.
what characterises Hodgkin’s lymphoma?
Reed-Sternberg cells-bi or multinucleate cells with each nucleus containing 1 prominent nucleolus. type of B lymphocyte that has become malignant.
why is it important to do a coagulation screen in investigation of acute leukaemia?
to investigate for DIC which may be present- if acute DIC then low PLTs, prolonged PT and APTT, decrease fibrinogen, increase D-dimer and FDPs
what options are available for ALL treatment after achievement of remission following chemotherapy?
if complete remission achieved after induction chemo, more chemo may then be given, or may have an autologous stem cell transplant
if more than 1 induction chemo course needed for remission, a donor transplant (allogeneic) may be considered
what may be given alongside induction chemotherapy for ALL treatment if Ph chromosome present?
imatinib-monoclonal Ab that inhibits binds to BCR-ABL fusion protein to inhibit its tyrosine kinase activity
features of remission induction in ALL?
this involves chemotherapy treatment, and usually steroids, and patient has to stay in hospital for about 1 month.
which subtype of classical Hodgkin lymphoma has the best prognosis?
lymphocyte rich: more lymphocytes so less Reed-Sternberg tumour cells, infiltrate largely small lymphocytes, few eosinophils, reed-sternberg cells and mononuclear hodgkin’s cells
most common subtype of classical Hodkin lymphoma?
nodular sclerosing: node divided by broad bands of CT into nodules containing mixture of reed-sternberg cells, mononuclear hodgkin’s cells, lymphocytes, plasma cells, macrophages and eosinophils.
who is at risk of Hodkin lymphoma?
men more commonly than women
in the UK, more common in men between 20 and 24, and 75-79, and in women between 20 and 24, and 70 and 74.
suppressed IS e.g. post transplant-immunosuppressive medication, HIV, AI condition e.g. RA, SLE
EBV infection
FH of hodkin, non hodkin or CLL in 1st degree relative
smokers
obese
what triad of features raises the suspicion of multiple myeloma?
back pain
anaemia
raised ESR
most common presentation of Hodkin lymphoma?
lymphadenopathy, usually cervical and mediastinal LN enlargement
clinical features of Hodkin lymphoma?
cervical and mediastinal lymphadenopathy, cervical-compressive symptoms?-dyspnoea, dysphonia, dysphagia, o/e-rubbery LNs
weight loss
unexplained fever
night sweats
pruritus-cytokine mediated, often sign of relapse
alcohol induced pain in affected LNs
cough, SOB or chest pain due to extensive intrathoracic disease
how is definitive Hodkin lymphoma diagnosis made?
excision LN biospy (note that an excision LN biopsy is ONLY to be performed by a surgeon, so if cervical lymphadenopathy will require ENT r/f.)
why does LN involvement tend to be contiguous in Hodkin lymphoma?
as spread is mainly along the lymph vessels
how are lymphomas staged?
via the Ann-Arbor staging system using CT scanning (+BM biopsy)
poor prognostic factors in Hodkin lymphoma?
male older patients advanced disease low serum albumin anaemia leucocytosis
treatment of early stage Hodkin lymphoma (stage IA-IIA)?
chemotherapy (2-4 cycles of ABVD therapy-adriamycin (doxorubicin), bleomycin, vinblastine, dacarbazine) and localised radiotherapy (NEVER to the mediastinum in young female)
if relapse, can often salvage with comb chemo or high dose chemo with peripheral blood stem-cell rescue (autologous BM transplant)
treatment of advanced Hodkin lymphoma?
6 to 8 courses of combination chemo (ABVD, also other combinations), reserve radiotherapy for residual masses or after chemo completion to areas previously involved by bulky disease.
complications of treatment for Hodkin lymphoma?
secondary malignancies e.g. breast Ca with radiotherapy to peripubertal breast tissue, AML with chemo e.g. alkylating agents
infertility
bleomycin-severe pulm toxicity
anthracyclines (doxorubicin)-cardiomyopathy
