Immunodeficiencies

Question 1

Chronic granulomatous disease underlying defect

Answer 1

Lack of NADPH oxidase

Reduced ability of phagocytes to produce reactive oxygen species

Question 2

Chronic granulomatous disease features

Answer 2

Recurrent pneumonia’s and abscesses
ESP catalase positive bacteria (SA) and fungi
Negative nitro blue tetrazolium test
Abnormal dihydrorhodamine flow cytometry test

Question 3

Chediak Higashi syndrome underlying defect

Answer 3

Microtubule polymerisation defect-> decrease in phagocytosis

Question 4

Chediak Higashi features

Answer 4

Partial albinism
Peripheral neuropathy
Recurrent bacterial infections
Giant granules in neutrophils and plts

Question 5

Leukocyte adhesion deficiency defect

Answer 5

LFA1 integrin (CD18) protein on Nphils

Question 6

Leukocyte adhesion deficiency features

Answer 6

Recurrent bacterial infections
Delay in umbilical cord sloughing
Absence of Nphils/pus at sites of infection

Question 7

Common variable immunodeficiency defect

Answer 7

Low IgG, many causes

May predispose to Lymphoma and AI disorders

Question 8

Brutons (X linked) congenital agammaglobulinaemia defect

Answer 8

Defect in Brutons tyrosine kinase (BTK) gene -> severe block in B cell development

Question 9

Brutons (X linked congenital agammaglobulinaemia features

Answer 9

XLR
Recurrent bacterial infections
Absence of B cellswith reduced Igs of all classes

Question 10

Selective IgA deficiency defect

Answer 10

Maturation defect in B cells

Question 11

Selective IgA deficiency

Answer 11

Most common primary Ab deficiency
Recurrent sinus and Resp infections
A/W coeliac, May cause false neg coeliac AB screen
Can get severe reactions to blood transfusions (anti-IgA abs -> anaphylaxis)

Question 12

DiGeorge Syndrome features

Answer 12

CATCH 22
Cardiac abnormalities - tetralogy of fallot
Abnormal facies
Thymic hypoplasia 
Cleft palate 
HypoCa
22q11 deletions 

Also failure to develop 3rd and 4th pharyngeal pouches, LD

Question 13

Severe combined immunodeficiency defect

Answer 13

Most common XL due to defect in gamma chain protein - used in IL2 receptors and other interleukins

Also adenosine deaminiase deficiency

Question 14

SCID feature

Answer 14

Recurrent infections due to viruses p, bacteria and fungi
Reduced T cell receptor excision circles
Stem cell transplant may work

Question 15

Ataxia telangectasia defect

Answer 15

Defect in DNAS repair enzymes

Question 16

Ataxia telangectasia features

Answer 16

AR inheritance
Cerebellar ataxia 
Telangectasia 
Recurrent chest infections
10% risk of malignancy, Lymphoma or leukaemia

Question 17

Wiskott Aldrich Syndrome defect

Answer 17

Defect in WAS gene

Question 18

Wiskott Aldrich Syndrome features

Answer 18

XLR
Recurrent bacterial infections 
Eczema 
Thrombocytopenia 
Low IgM
Inc risk of AI disorders and Malignancy