Immune related conditions

Question 1

How fast do babies present with a neutrophil defect

Answer 1

Within first 2h of life

Can live 2 months before presenting to doctor with no lymphocytes

Question 2

What sort of recurrent infections are seen in patients in defects in complement proteins

Answer 2

Neisseria meningitis
Meningococcal infx

(often killed off through lysis and MAC formation where holes are punched in them)

Question 3

Specifically, what type of infections do C3 defects cause

Answer 3

Pyogenic infections e.g. Strep pneumonia

Question 4

Which complement deficiency is associated with Lupus (SLE)

Answer 4

Early classical complement deficiency (C2, C4)

Leads to inefficient clearance of immune complexes and apoptopic cells

Inappropriate immune complex deposition and tissue damage leading to glomerulonephritis

Question 5

Which complement deficiency is associated with Hereditary angioedema

Answer 5

C1 inhibitor deficiency

Swelling due to excess bradykinin.
Attacks triggered by trauma, infx, pregnancy.

No urticaria

Question 6

Which complement deficiency is associated with Paroxysmal nocturnal haemoglobinuria

Answer 6

Lack of CD55 (DAF), CD59 (protectin)

RBC susceptible to complement lysis

Tx: eculizumab: anti-C5 monoclonal Ab

Question 7

Which complement deficiency is associated with Atypical haemolytic uraemic syndrome

Answer 7

Uncontrolled activation of complement causing tissue damage. Mutations in factor H, I, MCP

Tx: eculizumab: anti-C5 monoclonal Ab

Question 8

What happens in Chronic Granulomatous Disease

Answer 8

Defect in NADPH oxidase which forms superoxidase in neutrophil burst

Question 9

What happens during AIDS

Answer 9

Decreased CD4 levels

Question 10

Differentiate Tuberculoid vs Lepromatous Leprosy

• infectivity
• IgG levels
• Th1/Th2 response ideal

Answer 10

TB:

• low infectivity, normal Ig
• normal T cell responsiveness
• Clinically do better if Th1 response (IL-2, IFN-gamma, TNF-beta)

Lepromatous:

• high infectivity, high IgG
• low/absent T cell responsiveness
• Clinically do better if Th2 response (IL-4, 5, 10)

Question 11

What pathogens are seen in humoral deficiencies

Answer 11

BACTERIAL: encapsulated, pyogenic

• S aureus
• S pneumoniae
• H influenzae

VIRAL
-Enterovirus
-Echovirus
(usually won’t get norovirus)

PROTOZOA
-Giarda

Question 12

What pathogens are seen in combined T and B cell deficiencies

Answer 12

BACTERIAL: intracellular
-Salmonella

VIRAL:

• RSV, parainfluenzae
• Rotavirus, norovirus
• CMV
• Adenovirus

FUNGAL:
Candida, aspergillus, cryptocossus

PROTOZOA
-pneumocytis, toxoplasma, cryptosporidia

Question 13

What pathogens are seen in phagocytic defects

Answer 13

BACTERIAL:

• staph
• pseudomonas

FUNGAL:

• candida
• aspergillus

Question 14

What is seen in classical pathway deficiency

Answer 14

SLE: inability to clear circulating immune complexes

C2 deficiency associated with recurrent bacterial infection and increased risk of CVD.

Question 15

What is seen in MBL pathway/alternate pathway deficiency

Answer 15

• Pyogenic infection

- Pneumococcal/neisserial infection

Question 16

What is seen in MAC (C5-9) deficiency

Answer 16

-Pneumococcal/Neisserial infection

Question 17

What is seen in complement regulatory pathway deficiency (C1 inhibitor deficiency)

Answer 17

• Angiooedema (may be hereditary or acquired)

- Paroxysmal nocturnal haemoglobinuria