Haem - general Flashcards
Anaemia in men + women
Men Hb <130 g/lWomen Hb <120 g/l
Men: 135-180 g/l (180-135=45)
Women: 115-160 g/l (160-115=45)
Alpha defect in thalassaemia on chromosome
Chr 16
Beta defect in thalassaemia on chromosome
Chr 11
Sickle cell anaemia inheritance
AR
point mutation β globin gene on Chr 11
What kind of anaemia does hypothyroidism cause?
Macrocytic anaemia which is non-megaloblastic
Causes of macrocytic anaemia
B12 deficiency deficiency
- Alcohol
- IBD + Coeliac
- Bariatric surgery
- Malnutrition (meat is the predominant source of vit B12)
- Pernicious anaemia (AI loss of parietal cells +/or IF )
Folate deficiency
- Alcohol
- IBD + Coeliac
- Anti-folate drugs
- Pregnancy
Myelodysplasia, hypothyroidism, liver disease, haemolysis, alcohol, B12 deficiency, folate deficiency
Causes of HUS
- E coli strain EO157:H7
Organisms proliferate in undercooked red meat, unpasteurized milk or milk products, water, fruits, and vegetables.
Rarely - shigella, strep. pneumoniae, genetics
Which Von Willebrand Factor cleaving protein (VWFCP) is mutated in thrombotic thrombocytic purpura?
ADAMTS-13
Deficiency of VWF cleaving enzyme (ADAMTS-13) –> unusually large VW multimers –> platelet aggregation –> thrombocytopenia + thrombi
ITP definition
Primary ITP Immune thrombocytopenic purpura
• Autoimmune haematological disorder
• Isolated thrombocytopenia (<100x10^9/L) in the absence of an identifiable cause
• Antibody-mediated destruction of peripheral platelets, antibody-mediated inhibition of platelet production
ITP in children
Happens following a viral infection or following immunisation (CMV, VZ, HCV, HIV)
What is Hodgkin’s Lymphoma?
- Uncommon haematological malignancy arsing from mature B cells
- Malignant tumour of the lymphatic system
- Characterised by the presence of Hodgkin’s cells + multinucleated giant cells (Reed-Sternberg cells)*
Happens following an infection
RF • Epstein-Barr virus infection - implicated in around 50% of cases • HIV • Immunosuppression • Smoking • FHx
*Reed strenberg cells = giant cells derived from B lymphocytes containing >2 oval nuclei with eosinophilic nuclei resembling “owl eyes”
Hodgkin’s lymphoma epidemiology
- Young adults
* Peak in 20-34, second peak in >70
Non-Hodgkin’s lymphoma epidemiology
- > 50
- M>F
- More common than Hodgkin’s lymphoma
- The 2 most common types of NHL are diffuse large B cell lymphoma and follicular lymphomas
Which species causes the most severe malaria?
How is it transmitted?
When do patients present?
Plasmodium falciparum
o Transmitted to humans through a bite by an infected female Anopheles mosquito
o Patients present within the 1st month or within the first 6 months of infection
What is the myelodysplastic sydrome?
- Dysplastic changes in one or more cell lineages
- Ineffective + dysplastic haematopoiesis resulting in 1 or more cytopenias
- Blasts <20%
- Variable predilection to development of acute myeloid leukaemia (AML if blasts >20% (incl 20%))
• The bone marrow
Becomes hypercellular
With disordered growth
Maturation of a clonal proliferation of abnormal cells
Extrinsic pathway of the clotting cascade
How is it measured
Normal value
Affected by
PT
14s
Warfarin, Liver disease
Intrinsic pathway of the clotting cascade
How is it measured
Normal value
Affected by
APTT
34s
Heparin, Haemophilias, von Willebrand disease
Platelet deficiency causes
petechial haemorrhages
Ecchymoses
Clotting factor deficiency produces
haematomas + hemarthroses
Which clotting factor is deficient in haemophilia A?
F VIII
Which clotting factor is deficient in haemophilia B?
F IX
How is haemophilia inherited?
X-linked recessive disorder
therefore it affects MALES born to carrier mothers
Which is the most common haemophilia?Which is the most severe haemophilia?
Haemophilia A
Pathophysiology of haemochromatosis
Deficiency of hepcidin
HFE gene mutations on the short arm of Chr 6
Known mutations of the HFE gene are C282Y and H63D (must be homozygous)
Increased intestnal absorption of iron causes accumulation in tissues , esp liver
This can lead to organ damage
normally hepcidin prevents enterocytes from allowing iron into the hepatic portal system, thereby reducing dietary iron absorption
RF for ALL
- Insulation from common infections in early life may predispose children to abnormal immune responses when they encounter them later, placing them at higher risk of developing ALL
RF for AML
Radiation
Benzene
Chemo
Constitutional karyotype abnormalities (T21, XXY, T13 (Patau’s syndrome)T8:21, inverted 16)
RF for CLL
What conditions is it assosicated with?
What can it transform to?
FHx
- Can be associated with AI thrombocytopenia + anaemia
- Can transform to aggressive NHL – Richter’s syndrome
RF for CML
T9:22 transolcation –> shortened Chr22 –> Philadelphia chromosome (encodes for a protein with tyrosine kinase activity)
Transolaction places an oncogene (abl) from the long arm of Chr 9 to the long arm of Chr 22 in the BCR region
BCR-ABL - causes an abnormal expansion of the myeloid cells in the BM + peripheral blood
Most common leukaemia in children
ALL
Acute lymphoblastic leukaemia
Multiple myeloma definition
Plasma cell disorder
Infiltration of the bone marrow by plasma cells
Presence of a monoclonal immunoglobulin in the serum +/or urine
Classified by the type of ab they produce
IgG myeloma is the most common type
Malignant proliferation of plasma cells that secrete monoclonal antibodies + light immunoglobulin chains