Blood disorders Flashcards
Causes of macrocytic
B12 Folate Alcoholic Thyroid High reticulocytes / haemolysis
Development of spherocytes
Systemic sclerosis > autoantibodies specific for RBCs > antibodies stick to RBCs > spleen will detect antibodies and spleen will bite off bits with antibodies on > no more biconcave, now like footballs = spherocytes
RBC with antibodies stuck on, a DAT test is where you add an antibody to the antibody (on the RBCs bad), causing RBCs to ?
Agglutinate
If DAT is positive then its likely to be autoimmune haemolysis
If DAT is negative then hemolysis is due to heart valve etc
Hodgkins Lymphoma vs Non-Hodgkins Lymphoma Age/Sex Sx Dx Extra
HL is usually younger male patients
HL features progressive lymph node enlargement that causes a mediastinal mass SVC/airway obstruction = cough
Extra-nodal involvement is more common in NHL - thus wider range of potential presentation - also more associated with autoimmune conditions
HL features mirror-image nuclei + Reed-Sternberg cells + raised ESR. Most common type is nodular sclerosing
NHL is more often B cell than T cell and can be Diffuse large B cell or Follicular
‘B’ symptoms in lymphoma and in which are they more common?
Fever, weight loss and night sweats
More common in HL
In NHL they signify disseminated disease (remember extranodal more common in NHL)
Diagnosis of Lymphoma
- Excision node biopsy
- Immunohistochemistry/ FISH to subtype
- Staging via CT
Blood film is useful for reed-sternberg cells
Bone marrow biopsy often needed in NHL (extranodal)
LDH is raised = poor prognosis + increased risk of tumour lysis
Which lymphoma is associated with HIV and is given Rituximab to target CD20 cells
Most aggressive NHL?
Diffuse large B-cell
Burkitt’s
Histopathological examination of an enlarged lymph node demonstrated prominent, well-defined para-cortical follicles with germinal centres, diagnosis?
Normal!
Ann Arbor staging
I: Single LN region
II: One side of diaphragm
III: Both sides of diaphragm
IV: Disseminated
A: No systemic symptoms
B: Fever, night sweats, weight loss
E: Extralymphatic site
S: Splenic disease
Tumour lysis syndrome Pathophysiology Adverse effects Risk factors Prevention Mx
Death and breakdown of a large number of tumour cells into toxic components which induce renal AKI
Hyperuricemia (nucleic acid breakdown)
Hyperkalemia (K from dead cells)
Hyperphosphatemia (dead cells)
Hypocalcemia (opposite to phosphate and renal failure)
AKI due to urate/uric acid
Arrhythmias due to metabolites
High LDH or chemo sensitive tumours - BURKITTS, leukemia, small cell, germ cell
Hydrate, correct elctrolytes and ALLOPURINOL / Rasburicase
Virchow’s triad
Stasis of blood flow
Endothelial injury
Hypercoagulability
Factor V Leiden Pathophysiology Sx Ix Mx
Mutated Factor V lacks cleavage site with natural anticoagulant Protein C thus no anticoagulation of Factor V takes place
DVT, PE, risk of miscarriage
Normal PT/apTT
Activated protein C resistance Test
If positive, confirm with DNA testing
DVT
Wells score
Ix
Any unprovoked VTE do cancer screen
Tender swollen Calf >3cm one side Pitting oedema Collateral superficial veins Previous DVT Cancer Immobile/surgery - if alternative Dx more likely
- Wells score
- D dimer
- Venous duplex USS (skip to here if wells score is >2)
- CT/MRI contrast venography is too invasive really
PE
Wells score
Ix
Any unprovoked VTE do cancer screen
Haemoptysis HR >100 Raised RR Clinical signs of DVT Previous DVT/PE Surgery or immobilisation Active cancer Pleuritic chest pain SoB Collapse
Raised JVP
ECG - S1Q3T3
Respiratory alkalosis as hyperventilation
- ECG/CXR/ABG
- Wells score + D dimer
- CPTA - diagnostic
DIC Pathology Cause Sx Ix Mx
TF excess causes lots of clotting but then runs out and you get lots of bleeding
Sepsis, malignancy, trauma, liver disease
Prolonged PT + apTT
Low fibrinogen
Low platelet
High D-dimer
Tx underlying cause
Resus + blood transfusion
Test and clotting factors that assess intrinsic pathway?
Test and clotting factors that assess extrinsic pathway?
Vitamin K dependent clotting factors?
Correction/mixing study to prolonged apTT?
Bleeding time?
apTT
8,9,11
Hemophilia, vWB, Heparin or Lupus anticoagulant (actually prothrombotic in vivo, but prolongs aptt time when tested in vitro)
PT
7
Warfarin, Vit K def
2,7,9,10
If apTT is prolonged then add mixing study if it corrects then it was a clotting factor deficiency BUT if its still incorrect then it’ll be due to Lupus anticoagulant
Platelets/thrombocytopenia
Haemophilia A Pathophysiology Sx Ix Mx
X-linked thus often missed in families if females affected. Can be acquired. Factor 8 (aaaight)
Young, bleeds after venepuncture or surgery, joint pain/swelling
apTT prolonged but then NORMAL after mixing study
Factor 8 assay determines severity
Replace with recombinant factor 8
Haemophilia B
Pathophysiology
Sx
Ix
X-linked Factor 9 deficiency
Presents similar to Haemophilia A but is far less common
Prolonged apTT
Factor 9 def
Acquired Haemophilia
Cause
Sx
Ix
Autoimmune Hx, Liver/renal disease (reduce platelets), Vit K def, drugs
Presents later in life
The APTT is not correctable because the patient has antibodies to the factors and therefore will continue to destroy the factors in a mix, unlike haemophillia A/B
If the question features a female, no specific factor deficiency just prolonged apTT AND asks for most common/likely bleeding disorder?
Von Willebrands
Von Willebrands Pathophysiology Sx Ix Mx
Autosomal dominant
VWF binds platelets and stabilises factor 8
Platelet type picture - brusiing, epistaxis, prolonged bleeding
As it stabilises factor VIII it can mimic a factor VIII deficiency in blood results, so it is important to request a vWF study too
Desmopressin (DDAVP) stimulates VWF production
A 57 year old woman presents with an acute 2 day history of a swollen and painful right knee. The joint is red and extremely tender on examination.
Which is the most important initial Investigation?
Septic arthritis
Joint aspiration!
Trauma - most appropriate replacement fluid?
Whole blood
Febrile neutropenia
Criteria
Ix
Mx
Neutrophil <1.0 + FEVER
FBC, U&Es, cultures, CXR - search for source
IVT + broad spectrum antibiotics - Tazocin/Gentamycin
Thrombocytosis Cause Ix DDx Complication
More likely to have blood clot/stroke
Splenomegaly
Associated with JAK2 but if that is negative then do bone marrow biopsy to look for MEGAKARYOCYTES as may be serious cause > aspirin
DDx: Polycythaemia rubra has raised haematocrit
Can progress to myelofibrosis
Haptoglobin during hemolysis?
Low as all used up to mop up RBCs
High LDH High reticulocytes High bilirubin DAT scan for antibodies if its autoimmune Blood film for spherocytes
To know whether high platelets is due to reactive/infection or myeloproliferative disorder, do ?
CRP
Hx
Trend of patlets is it in keeping with onset of illness?
Low platelets, what do next?
Redo test as often platelet clumping can cause this!
