Common causes of anaemia and thrombocytopenia Flashcards Preview

Clinical Pathology > Common causes of anaemia and thrombocytopenia > Flashcards

Flashcards in Common causes of anaemia and thrombocytopenia Deck (36):
1

What are the main causes of anaemia (other than blood loss)?

- B12/folate def
- Chronic disease-
Haemolysis
- Alcohol, drugs, toxins
- Renal impairement - EPO
- Haematological/marrow disorders e.g. malignant, haemoglopathies, aplasia, congenita

2

What conditions are associated with macrocytic, normocytic and microcytic RBC?

Macro - B12/folate def, marrow damage (alcohol/toxin, marrow disease), haemolysis (new ones are bigger than old ones)

Normo - chronic disease/inflammatiojn

Micro - Hb-opathies, iron def

3

Why is iron deficiency so common?

Iron is not absorbed easily (at duodenum) - mostly recycled

4

How is iron stored in in the body?

In ferritin

5

How is iron deficiency diagnosed?

LOW FERRITIN LEVELS
- low MCV, hypochromic (small, pale)

6

What causes iron deficiency?

Blood loss e.g. menstrual loss/periods, cancer, ulcer, GI etc

Increased demand e.g. growth/pregnancy

Malabsorption - diet/malabsorption

7

How is iron deficiency treated (best way!)?

IV iron

8

What is the cause of macrocytic RBCs?

Impaired DNA synthesis

9

Why does folate/B12 deficiency cause macrocytic RBCs?

Folate involved in purine/pyridamine synthesis

B12 required for folate synthesis

therefore, deficiency causes DNA synthesis impairment

10

How is B12 absorbed? What is the cause of B12 deficiency?

Parietal cells in stomach produce intrinsic factor which binds to B12

B12-intrinsic factor - absorbed in terminal ileum by specific factors

NOT cause by malnutrition, deficiency somewhere in this pathway

11

What are the main causes of B12 deficiency?

Stomach - pernicious anaemia , gastrectomy

Terminal ileum - churns disease, terminal ileum resection

12

How is folate deficiency caused?

-Malnutrition
-Increased demand e.g. pregnancy, haemolysis
-Malabsorption/small bowel disease
- Alcohol/toxins/ITU

13

What are the common features of B12/folate deficiency?

-Megablastic anaemia
-Pancytopenia (low RBCs, WBCs, platelets)
- mild jaundice
- anorexia/weight loss
- sterility

14

What are lab features of B12 and folate deficiency?

- Blood count and film
- Bilirubin and LDH - haemolysis (do not last as long!)
- Antibodies - pernicious anaemia

15

What is pernicious anaemia?

Autoimmune condition where body produces antibodies against parietal cells.

Intrinsic factor not produced so doesn't bind to B12.

B12 not absorbed by terminal ileum - therefore, B12 deficiency

16

What is the over condition associated with severe B12 deficiency?

Subacute combined degeneration of the cord

Demyelination of dorsal and lateral columns

Peripheral nerve damage

Reversible cause of demenetion

17

What is the treatment of B12 and folate deficiency?

B12 and folate infused (muscularly) until B12 deficiency excluded

DO NOT GIVE folate individually - can exacerbate B12 induced neuropathy

18

What are the main causes of haemolysis?

-Things wrong inside RBC
- Things wrong with RBC membrane
- Things wrong external to RBC

19

What intrinsic RBC factors could cause haemolysis?

Sickle cell disease
Enzyme deficiency (G6PD)

20

What RBC membrane factors could cause haemolytic disease?

Hereditary sphereocytosis

21

What external RBC factors could cause haemolysis?

-Antibodies (autoimmune -haemolytic anaemia - COOMB'S TEST)
-Vasculitis
-Heart valves (mechanical)
-Toxins/drugs

22

What are the diagnostic markers for haemolysis?

-Anaemia (?)
-Macrocytic RBCs (increased reticulocytes)
-RBC film - fragments, spherocytes
- Raised Bilirubin/LDH

23

What is the normally MCV for chronic disease?

Normocytic

24

How is anaemia in chronic disease usually caused?

Inflammatory diseases reduces iron absorption and iron metabolism

Poor erthropoetin response

Blunted marrow response

25

What inflammatory cytokine regulates iron absorption and release from macrophages?

Hepcidin

26

What are the presentations of people with chronic diseases (in relation to anaemia?)

Normocytic; mild anaemia

No other cause for anaemia other than condition

27

How do you treat anaemia in people with chronic disease?

Treat underlying cause

- EPO/iron (IV)

- Blood transfusion if severe

28

What are the common causes of thrombocytopenia?

-Alcohol
-Immune thrombocytopenia (ITP)
-Other autoimmune diseases
-Pregnancy
-DIC
-Coagulation disorders
- haematological/bone marrow disorders

29

What is the difference between adult and childhood immune thrombocytopenia purport?

Child - viral prodrome, platelets go down to very low levels but self limiting - will fully recover after a few weeks

Adult - no viral prodrome - chronic and remitting

30

What type of disorder is immune thrombocytopenia? What conditions is it associated with?

Immune disorder
- HIV
- other autoimmune conditions
Lymphomas

31

What is the presentation of immune thrombocytopenia?

Bruising or petechiae or bleeding (depending on platelet count)

32

How do you treat immune thrombocytopenia?

Steroids

IV immunoglobulin

Immunosuppressants/splenectomy- prevents spleen removal of platelets (by its removal or through saturation)

Thrombopoetins - make more platelets

33

What are the clinical symptoms of thrombotic thrombocytopenia perpura? (TTP)

F ever
A anaemia
T hrombocytopenia
R renal disease
N urological symptoms

34

What is TTP caused by?

Autoimmune condition - specifically against protease ADAMTS13

35

What is TTP characterised by?

Clotting in small blood vessels of the body (thromboses), resulting in a low platelet count

36

How is TTP treated

steroids

Decks in Clinical Pathology Class (50):