immuno q7 - jcbc

[ArchivalUser]

A 54-year-old man presents with complaints of shortness of breath, a sore tongue, and a pins-and-needles
sensation in his feet. Laboratory examination reveals macrocytosis, anemia, and hypersegmented neutrophils.
Antibodies to intrinsic factor are detected in the patient's serum. Which of the following class II antigens would be
most likely to play a contributing role in the etiology of this patient's disease?
A. DR2
B. DR3
C. DR4
D. DR5
E. DR7

[ArchivalUser]

ddd

[ArchivalUser]

D. DR5

[ArchivalUser]

dd

[ArchivalUser]

The correct answer is D. The disease with autoantibodies to intrinsic factor is pernicious anemia (atrophic
gastritis and megaloblastic anemia secondary to vitamin B12 deficiency). Pernicious anemia is associated with
the DR5 class II antigen (relative risk 5); DR5 is also associated with juvenile rheumatoid arthritis.