Elevated rheumatoid factor titer as a consequence of immunization?

A forty year old healthy adult man was admitted to our outpatient departmen t because of a highly elevanted rheumatoid factor. Since the person was pla nning an extended stay in Africa, we performed an extensive history, clinic al and laboratory examination to rule our oligosymptomatic inflammatory dis eases. We further analyzed if the person presented genetic risk factors to develop rheumatic diseases in the future or if the presence of the rheumato id factor could be a reaction to multiple immunizations. Possible explanati ons for an elevated rheumatoid factor including the genetic risk factors ar e discussed.