Oligo‐monoclonal immunoglobulins frequently develop during concurrent cytomegalovirus (CMV) and Epstein–Barr virus (EBV) infections in patients after renal transplantation

In the present study we report that the appearance of oligo‐monoclonal immunoglobulins (oligoM‐Igs) in the sera of transplanted individuals is concurrent with the detection of coincident active CMV infection and EBV replication. Eighty‐four renal allograft patients were monitored with respect to CMV isolation, to CMV conventional serology and humoral response against the EBV trans‐activator ZEBRA (an immediate‐early antigen also called BZLF1). Titration of anti‐ZEBRA antibodies (IgG and IgM) and amount of EBV DNA in serum were evaluated. Using the combination of four techniques (agarose gel electrophoresis, analytical isoelectric focusing, high resolution immunoelectrophoresis, immunofixation electrophoresis), oligoM‐Igs were found in 25% of patients after allografting and significantly associated with rejection episodes (P