Complement Deficiencies

Question 1

Complement Deficiencies & Abnormalities - C1q, C1r, C1s Deficiency

Answer 1

• Defective classical pathway activation
• Systemic Lupus Erythematosus
• Pyogenic infections
• Immune complex disease

Question 2

Complement Deficiencies & Abnormalities - C4, C2 Deficiency

Answer 2

• Defective classical & lectin pathway activation
• Systemic Lupus Erythematosus
• Pyogenic infections
• Immune complex disease

Question 3

Complement Deficiencies & Abnormalities - C3 Deficiency

Answer 3

• Defective activation of all pathways
• Glomerulonephritis
• Pyogenic Infections
• Respiratory Infections
• Immune complex disease

Question 4

Complement Deficiencies & Abnormalities - C5, C6, C7, C8 Deficiencies

Answer 4

• Defective MAC formation
• Disseminated Neisserial infections

Question 5

Abnormalities/Deficiencies of Complement Regulation - C1 Inhibitor

Answer 5

• Deregulated classical pathway activation, consumption of C3
• Acute intermittent attacks of skin and mucosal edema
• Hereditary angioedema (HAE)
• Acquired angioedema (AAE)
• Systemic Lupus Erythematosus (SLE)
• B cell lymphoproliferative diseases

Question 6

Abnormalities/Deficiencies of Complement Regulation - Factor I Deficiency

Answer 6

• Deregulated classical, lectin and alternative pathway activation, rapid consumption of C3
• Pyogenic infections Immune complex diseases

Question 7

Abnormalities/Deficiencies of Complement Regulation - Factor H Deficiency

Answer 7

• Deregulated alternative pathway activation, rapid consumption of C3
• Pyogenic infections
• Glomerulonephritis
• Atypical Hemolytic Uremic Syndrome (aHUS)
• Dense Deposit Disease (DDD)

Question 8

Abnormalities/Deficiencies of Complement Regulation - Decay Accelrating Factor (DAF) Deficiency

Answer 8

• Deregulated C3 convertase activity
• Complement-mediated intravascular hemolysis

-Paroxysmal nocturnal hemoglobinuria (PNH)

Question 9

Abnormalities/Deficiencies of Complement Regulation - Homologous restriction factor (HRF), CD59

Answer 9

• Increased susceptibility of erythrocytes to MAC-mediated lysis
• Complement-mediated intravascular hemolysis

-Paroxysmal nocturnal hemoglobinuria (PNH)

Question 10

Complement Receptor Deficiencies/Abnormalities - CR1

Answer 10

• Deregulated C3 convertase activity
• Poor immune complex clearance

-? Systemic Lupus Erythematosus

Question 11

Complement Receptor Deficiencies/Abnormalities - CR3

Answer 11

• Pyogenic infections
• Leukocyte adhesion deficiency