"Rheumatoid factor (RF) is an immunoglobulin initially described in association with rheumatoid arthritis. It is an IgM antibody against the FC portion of the IgG antibodies. Ongoing research has identified a group of related immunoglobulins, classed as rheumatoid factors (RFs) and despite extensive investigation, the exact mechanisms of action, role in normal physiology and pathological effects are still largely unknown."
"EBV"
"Chlamydia pneumoniae"
"Klebsiella pneumoniae"
"Chlamydia pneumoniae"
"Klebsiella pneumoniae"
"Hepatitis A"
"Hepatitis B"
"Coxsackie B virus"
"Dengue virus"