UKMLA PLAB AMC USMLE Prometric MCQ

Question Number 0809

Question:
A 54 year old female has had morning stiffness and pain her joints since her early thirties. The joint pain is symmetrical. Her hands are most severely affected, although she also has complaints in her feet. Over the years, a deformity has developed and now two of her fingers have a 'swan neck' deformity. Her lab work shows that she is positive for rheumatoid factor. What is rheumatoid factor?

a) antibody directed against immunoglobulin G
b) antibodies directed against platelets
c) C reactive protein
d) antibodies directed against histone proteins
e) free kappa light chains