b cell differentiation activity assayed on b cells preactivated by staphylococcus aureus cowan i was found in synovial fluids ( sf ) of patients with rheumatoid arthritis ( ra ) ( n = 14 ) , while little , if any , activity was found in sf of patients without ra ( n = 13 ) including patients with osteoarthritis and traumatic arthritis .
C1511002
b cell differentiation
C0004561
b cells