Haematology conditions Flashcards
What are the normal values for an MCV (mean corpuscular volume) blood test?
3 types of microcytic anaemia
normocytic
macrocytic
Female = 80-98.1 Male = 81.8-96.3 Micro: Fe deficiency Chronic disease Thalassaemia Normo: Acute blood loss Chronic disease Combined haematinic: B12+Folate+Fe deficiency Macro: B12/Folate deficiency Alcoho excessl/liver disease Haematological: chemo, haemolysis, bone marrow failure Hypothyroid(rare - neonate heel prick)
Why is the reticulocyte count useful in diagnosing anaemia?
Bone marrow responds to anaemia by producing and releasing reticulocytes, if the count is LOW it signifies a problem with production (bone marrow) and HIGH signifies a problem with removal (spleen, liver, blood loss, bone marrow)
what is meant by megaloblastic anaemia?
Type of macrocytic anaemia that results from inhibition of DNA synthesis during red blood cell production - B12 or folate deficiency anaemia. Erythroblasts = immature red blood cells, larger than normal.
Iron deficiency anaemia: cause symptoms diagnose treat
Low intake, blood loss, malabsorption.
Pale, fatigue, dizzy, SOB, palpitations.
FBC: low ferritin, low MCV, low reticulocytes
Treat with oral or IV iron supplementation, treat underlying cause
Anaemia of chronic disease - commonly associated with?
TB, SLE, Crohn’s, RA, malignancy
Thalassaemia - types, symptoms, treatment
alpha and beta chains can be affected. alpha thalassaemia 1 deletion = mormal blood picture 2 deletions = carrier 3 = moderate anaemia 4 = stillborn beta thalassaemia major = transfusion dependent from birth, abnormal bone growth/delayed puberty, iron chelation therapy to remove excess iron depositions intermedia = less severe anaemia, not dependent on transfusions minor = carrier, asymptomatic
B12/folate deficiency anaemia
cause, symptoms, treatment
B12:
autoimmune condition pernicious anaemia (body attacks parietal cells) is most common cause, also vegan diet/poor diet/maabsorption- ileal resection/medication
folate:
lack broccoli/green leafy veg, greater demands due to pregnancy
symptoms:
fatigue, pale, palpitations, dizzy, SOB (general anaemia)
B12 specific: parasthesia, mood changes, mouth ulcers, red tongue, yellow skin
Treat:
B12: if caused by pernicious anaemia, injection of hydroxocobalamin every three months for life. If dietary, supplements/advice. Folate = diet change/supplements
Haemolytic anaemia
what is it?
diagnosis?
common causes?
Early haemolysis of red blood cells. Shortened survival leads to increased production in bone marrow, large reticulocytes are released prematurely.
TESTS: increased reticulocyte count, serum unconjugated bilirubin, urinary urobilinogen, faecal stercobilinogen.
Splenomegaly, jaundice.
Cause: autoimmune - hereditary spherocytosis, enzyme defects, thalassaemias, sickle cell
what is hereditary spherocytosis?
sickle cell anaemia?
most common autoimmune anaemia, haemolytic, macrocytic.
Defect in rbc membrane makes cell spherical, unable to pass through splenic microcirculation so become trapped and are haemolysed = shortened lifespan.
Sickle cell: autosomal recessive, abnormal beta globin chains = rigid, sickel shaped cells give up O2 more readily. Haemolysed early. Heterozygous is protective against malaria.
Malaria
Different types
which have long incubation? which is most common/deadly?
Plasmodium... falciparum (75%, worst infections) vivax (long incubation - formation of hypnozoites) malariae ovale (hypnozoites) knowlesi
briefly describe the general lifecycle of malaria-causing plasmodium
- live as immature sporozoites in salivary glands of female anopheles mosquito
- mosquito bites, transfered to bloodstread where sporozoites go straight to liver
- vivax and ovale go dormant as hypnozoites, rest reproduce to form merozoites and invade RBCs where they further reproduce and develop into gametocytes.
- haemolysis of these cells occurs and gametocytes released into blood stream
- mosquito may pick them up and sexual reproduction occurs to form zygote in mosquito, –> new sporozoites
who is at risk of malaria?
protective factors?
symptoms of malaria (remember incubation period = time lag infection and symptoms)diagnosis of malaria
People in tropics/sub tropics 2yr history of travel pregnant young children immunosupppressed
Sickle cell anaemia, thalassaemia and G6PD deficiency are protective, infected cells die easily from oxidative stress
- cyclical fever, pattern depends on species of plasmodium
- haemolytic fever: fatigue, jaundice, splenomegaly, headache
complicated -> haemolysis of non-infected cells, black water urine
history: recent travel + cyclical fever
- blood film: thick and thin
- FBC shows thrombocytopenia, normocytic anaemia, increased lactate dehydrogenase from haemolysis
Describe the process by which plasmodium falciparum may result in complicated malaria
treatment?
Produces sticky coating around infected RBCs, which clump together and can’t flow to spleen for destruction, also blood flow to organs blocked –> haemolytic anaemia + ischaemic damage = organ failure.
Cerebral malaria: seizure, confusion, coma, altered mental state
Bilious malaria: (liver) jaundice, diarrhoea, vomiting, liver failure
+ sepsis-like picture, ARDS, renal impairment, haemaglobinuria, parasite infected cells = >2%
Treat: IV artesunate (or quinine)
Treat:
- non-falciparum malaria
- uncomplicated falciparum malaria
- complicated
- vivax / ovale
- Chloroquinine
- oral riamet (or quinine)
- artesunate (or quinine)
- add primaquinine to clear hypnozoites
chronic leukaemia
- what is it?
- cause?
- types: how do they differ?
- symptoms?
Chromosomal abnormality causes partial maturation of blast cells (precursor to WBCs), impairing their function.
Chronic myeloid leukaemia: ‘philadelphia chromosome’ translocation affects granulocytes, they divide too quickly
Chronic lymphocytic leukaemia: lymphocytes affected, especially B lymphocytes - they avoid apoptosis and accumulate.
Both –> accumulation of immature cells in the bone marrow, which spill out into the blood and crowd out healthy cells/settle in organs.
Crowding out = thrombocytopenia (easy bleeding), anaemia(fatigue), leukopenia(increased infections)
Settle in organs = CML: hepatosplenomegaly. CLL: lymphadenopathy
