3) Immunodeficiency and Bone Marrow Failure

Question 1

Give examples of causes of acquired immunodeficiencies:

Answer 1

Chronic lymphatic leukaemia
Myeloma
HIV
Chemotherapy 
Radiotherapy

Question 2

Which acquired immunodeficiencies affect B cells?

Answer 2

CLL
Lymphoproliferative disorders
Myeloma
Nephrotic syndrome

Question 3

Which acquired immunodeficiencies affect T cells?

Answer 3

HIV
Chemo
Immunosuppression e.g. Transplantation
Hodgkin’s disease

Question 4

Which acquired immunodeficiencies affect both B and T cells?

Answer 4

Radiotherapy
CLL
Malnutrition

Question 5

Which acquired immunodeficiencies affect neutrophils?

Answer 5

Neutropenia

Myelodysplasia

Question 6

What fungal infections can occur in HIV disease?

Answer 6

Pneumocystis jirovecii
Candida albicans
Aspergillosis fumigated
Cryptococcus neoformans

Question 7

What mycobacterial infections can occur in HIV disease?

Answer 7

Tuberculosis

Mycobacterium avium-intracellulare

Question 8

What parasitic infections can occur in HIV disease?

Answer 8

Cryptosporidia

Toxoplasma gondii

Question 9

What viral infections can occur in HIV disease?

Answer 9

Cytomegalovirus
Herpes zoster
Herpes simplex

Question 10

How can pneumocystis pneumonia be diagnosed?

Answer 10

Direct microscopy of broncho-alveolar lovage

Question 11

How is pneumocystis pneumonia treated?

Answer 11

Cotrimoxazole

Question 12

How is candidiasis diagnosed and treated?

Answer 12

Clinically by visualisation of white plaques

Fluconazole

Question 13

What infections can cytomegalovirus cause and how is it treated?

Answer 13

Pneumonitis, oesophagitis, colitis, hepatitis

Acyclovir/gancyclovir

Question 14

What are the sites of haemopoiesis in the fetus? (3 stages)

Answer 14

0-2 months - yolk sac
2-5 months - liver and spleen
5-9 months - bone marrow

Question 15

What are the sites of haemopoiesis in infants?

Answer 15

Bone marrow in most bones

Question 16

What are the sites of haemopoiesis in adults?

Answer 16

Bone marrow: vertebrae, ribs, sternum, sacrum, pelvis, proximal femur

Question 17

What is the difference between red and yellow marrow?

Answer 17

Red - contains haematopoietic tissue

Yellow - mainly fatty tissue

Question 18

How does the composition of marrow change as we age?

Answer 18

All marrow at birth is red

Half of marrow is red in adults, rest converted to yellow

Question 19

How can bone marrow be examined?

Answer 19

Trephine biopsy

Bone marrow aspiration

Question 20

Describe the development of a myeloblast into a neutrophil:

Answer 20

Myeloblast -> promyelocyte -> myelocyte -> metamyelocyte -> band cell -> neutrophil

Question 21

Describe the development of a proerythroblast into a red cell:

Answer 21

Proerythroblast -> early normoblast -> intermediate normoblast -> late normoblast -> reticulocyte -> RBC

Question 22

What is the red pulp of the spleen?

Answer 22

Sinuses lined by endothelial macrophage and cords

Question 23

What is the white pulp of the spleen?

Answer 23

Similar structure to lymphoid follicles

Question 24

What are the functions of the spleen?

Answer 24

Sequestration and phagocytosis
Blood pooling
Extramedullary haemopoiesis
Immunological function

Question 25

What are the causes of a massive splenomegaly?

Answer 25

Chronic myeloid leukaemia Myelofibrosis Chronic malaria Schistosomiasis

Question 26

What are the causes of a moderate splenomegaly?

Answer 26

Lymphoproliferative disorders Myeloproliferative disease Portal hypertension Glandular fever

Question 27

What are the causes of a mild splenomegaly?

Answer 27

Infectious hepatitis Endocarditis Sarcoidosis Autoimmune diseases - SLE, ITP

Question 28

What can cause hyposplenism? | What will be seen on blood film?

Answer 28

Splenectomy Sickle cell disease Coeliac disease Can see Howell Jolly bodies

Question 29

What are some causes of thrombocytopenia?

Answer 29

Reduced production - B12/folate def, bone marrow cancer, aplastic anemia, chemo, HIV Increased removal or use - immune destruction (ITP), DIC, TTP, splenic pooling

Question 30

What is immune thrombocytopenic purpura and how is it treated?

Answer 30

Autoantibodies against glycoproteins on platelets | Treated with immunosuppression

Question 31

What are the consequences of severe thrombocytopenia?

Answer 31

``` Easy bruising Purpura Mucosal bleeding Severe bleeding after trauma or procedures Intracranial haemorrhage ```

Question 32

What are the causes of neutropenia?

Answer 32

Reduced production: B12/folate def, cancer of bone marrow, aplastic anemia, radiation, drugs, viruses, congenital Immune destruction, sepsis, splenic pooling

Question 33

What are the consequences of neutropenia?

Answer 33

Severe life threatening bacterial and fungal infections | Mucosal ulceration

Question 34

What are the causes of pancytopenia?

Answer 34

Reduced production: B12/folate def, cancer of bone marrow, aplastic anemia, radiation, drugs, viruses, congenital Immune destruction, splenic pooling

Question 35

What is aplastic anaemia?

Answer 35

Pancytopenia with a hypocellular bone marrow in the absence of an abnormal infiltrate and with no fibrosis

Question 36

What malignancies can cause pancytopenia?

Answer 36

``` Acute and chronic leukaemia Lymphoma Myeloma Myelofibrosis Prostate, breast and lung cancer ```

Question 37

What are some symptoms of pancytopenia?

Answer 37

Anaemic - fatigue, dizziness, shortness of breath Bleeding and bruising Infection, ulcers, fevers