Rituximab

Question 1

Rituximab is directed against the CD20 antigen expressed on T cells

Answer 1

False

B cells

Question 2

Rituximab causes B cells to deplete within 6-8 weeks

Answer 2

F

2-3 weeks

Question 3

Half life of rituximab is dependent on individual m’s available CD20

Answer 3

T

Question 4

Rituximab

Three mechanisms of B cell depletion

Answer 4

1.Antibody dependent cellular cytotoxicity
(NK cells recognize Rituximab Coated B cells via FCy receptor)

2. Complement mediated cytolysis (Rituximab bound to CD20 allows for activation of complement pathway , resulting in insertion of MAC into B cell membrane)
3. Inhibition of signaling and apoptosis (induction of p38 MAP kinase pathway)

Question 5

History of hypotension, bronchospasm and angioedema is a relative CI of Rituximab

Answer 5

T

Question 6

Rituximab may cause late onset neutropenia

Answer 6

T

Question 7

Rituximab can be given to patients with active infections

Answer 7

F

Question 8

Any non live vaccines should be given 4/52 prior to Rituximab tx

Answer 8

T

Question 9

Formation of anti drug antibodies in Rituximab?

Answer 9

1-30%

Question 10

Injection site reactions in Rituximab

Answer 10

17% in RA

USUALLY MINOR

Question 11

Rituximab may cause renal toxicity when used in conjunction with cisplatin

Answer 11

T

Question 12

Clearance of rituximab is through renal excretion

Answer 12

F

Phagocytosis

Question 13

Rituximab may decrease co stimulatory molecules on CD4+ T cells and numbers of memory t cels

Answer 13

T

Studies note this

Question 14

CD20- plasma cells in bone marrow are spared by rituximab and continue making Ig

Answer 14

T
Long lived Cd- plasma cells in bone marrow vs short lived CD+ B cells in periphery

This could explain why rituximab leads to decline in circulating disease-causing autoantibodies