The authors report a case of a patient suffering from acute polyarthritis with a high rheumatoid factor titre, associated with a Klebsiella pneumonitis. A polyclonal B lymphocyte activation or a possible cross reaction between rheumatoid factor and an antigen related to Klebsiella may explain the elevated production of rheumatoid factor observed.
Key words Klebsiella Pneumoniae - Rheumatoid Factor