3) Immunodeficiency and Bone Marrow Failure Flashcards
Give examples of causes of acquired immunodeficiencies:
Chronic lymphatic leukaemia Myeloma HIV Chemotherapy Radiotherapy
Which acquired immunodeficiencies affect B cells?
CLL
Lymphoproliferative disorders
Myeloma
Nephrotic syndrome
Which acquired immunodeficiencies affect T cells?
HIV
Chemo
Immunosuppression e.g. Transplantation
Hodgkin’s disease
Which acquired immunodeficiencies affect both B and T cells?
Radiotherapy
CLL
Malnutrition
Which acquired immunodeficiencies affect neutrophils?
Neutropenia
Myelodysplasia
What fungal infections can occur in HIV disease?
Pneumocystis jirovecii
Candida albicans
Aspergillosis fumigated
Cryptococcus neoformans
What mycobacterial infections can occur in HIV disease?
Tuberculosis
Mycobacterium avium-intracellulare
What parasitic infections can occur in HIV disease?
Cryptosporidia
Toxoplasma gondii
What viral infections can occur in HIV disease?
Cytomegalovirus
Herpes zoster
Herpes simplex
How can pneumocystis pneumonia be diagnosed?
Direct microscopy of broncho-alveolar lovage
How is pneumocystis pneumonia treated?
Cotrimoxazole
How is candidiasis diagnosed and treated?
Clinically by visualisation of white plaques
Fluconazole
What infections can cytomegalovirus cause and how is it treated?
Pneumonitis, oesophagitis, colitis, hepatitis
Acyclovir/gancyclovir
What are the sites of haemopoiesis in the fetus? (3 stages)
0-2 months - yolk sac
2-5 months - liver and spleen
5-9 months - bone marrow
What are the sites of haemopoiesis in infants?
Bone marrow in most bones
What are the sites of haemopoiesis in adults?
Bone marrow: vertebrae, ribs, sternum, sacrum, pelvis, proximal femur
What is the difference between red and yellow marrow?
Red - contains haematopoietic tissue
Yellow - mainly fatty tissue
How does the composition of marrow change as we age?
All marrow at birth is red
Half of marrow is red in adults, rest converted to yellow
How can bone marrow be examined?
Trephine biopsy
Bone marrow aspiration
Describe the development of a myeloblast into a neutrophil:
Myeloblast -> promyelocyte -> myelocyte -> metamyelocyte -> band cell -> neutrophil
Describe the development of a proerythroblast into a red cell:
Proerythroblast -> early normoblast -> intermediate normoblast -> late normoblast -> reticulocyte -> RBC
What is the red pulp of the spleen?
Sinuses lined by endothelial macrophage and cords
What is the white pulp of the spleen?
Similar structure to lymphoid follicles
What are the functions of the spleen?
Sequestration and phagocytosis
Blood pooling
Extramedullary haemopoiesis
Immunological function
What are the causes of a massive splenomegaly?
Chronic myeloid leukaemia
Myelofibrosis
Chronic malaria
Schistosomiasis
What are the causes of a moderate splenomegaly?
Lymphoproliferative disorders
Myeloproliferative disease
Portal hypertension
Glandular fever
What are the causes of a mild splenomegaly?
Infectious hepatitis
Endocarditis
Sarcoidosis
Autoimmune diseases - SLE, ITP
What can cause hyposplenism?
What will be seen on blood film?
Splenectomy
Sickle cell disease
Coeliac disease
Can see Howell Jolly bodies
What are some causes of thrombocytopenia?
Reduced production - B12/folate def, bone marrow cancer, aplastic anemia, chemo, HIV
Increased removal or use - immune destruction (ITP), DIC, TTP, splenic pooling
What is immune thrombocytopenic purpura and how is it treated?
Autoantibodies against glycoproteins on platelets
Treated with immunosuppression
What are the consequences of severe thrombocytopenia?
Easy bruising Purpura Mucosal bleeding Severe bleeding after trauma or procedures Intracranial haemorrhage
What are the causes of neutropenia?
Reduced production: B12/folate def, cancer of bone marrow, aplastic anemia, radiation, drugs, viruses, congenital
Immune destruction, sepsis, splenic pooling
What are the consequences of neutropenia?
Severe life threatening bacterial and fungal infections
Mucosal ulceration
What are the causes of pancytopenia?
Reduced production: B12/folate def, cancer of bone marrow, aplastic anemia, radiation, drugs, viruses, congenital
Immune destruction, splenic pooling
What is aplastic anaemia?
Pancytopenia with a hypocellular bone marrow in the absence of an abnormal infiltrate and with no fibrosis
What malignancies can cause pancytopenia?
Acute and chronic leukaemia Lymphoma Myeloma Myelofibrosis Prostate, breast and lung cancer
What are some symptoms of pancytopenia?
Anaemic - fatigue, dizziness, shortness of breath
Bleeding and bruising
Infection, ulcers, fevers
