Clinical evaluation of patients with infectious mononucleosis and development of antibodies to the R component of the Epstein-Barr virus-induced early antigen complex.

Previous reports have emphasized that the transitory antibody responses to Epstein-Barr virus (EBV)-induced early antigens (EA) in the course of infectious mononucleosis are usually directed against the D (diffuse) component of the EA complex. In this report clinical and serologic data have been presented on 14 patients with infectious mononucleosis who responded either solely with antibodies to the R (restricted) component of the EA complex or revealed anti-R after the initial anti-D responses had subsided weeks or months after onset of the disease. Anti-R persisted usually for many months , as many as 39, but in some patients it was no longer detectable in late follow-up serum spectimens. Although many patients had an unremarkable course of illness, others, mostly those with late anti-R responses, showed unusual or protracted clinical manifestations and several complained over periods of 4 to 28 months of recurrent symptoms resembling those experienced during the acute stage of disease. The presence of anti-R and the relatively high continuous titers of antibodies to EB viral capsid antigens (VCA) may reflect a more than usual, persistent EBV activity which, in turn, may account for the recurrent symptoms.