Frequency distribution of cytomegalovirus envelope glycoprotein genotypes in bone marrow transplant recipients

Using restriction analysis of polymerase chain reaction (PCR)-amplified DNA, the cytomegalovirus (CMV) envelope glycoprotein (gB and gH) genotypes were determined for virus isolates from 128 bone marrow transplant recipients with fatal or nonfatal CMV. All isolates could be assigned to one of four gB and gH genotypes previously identified by DNA sequencing studies. Isolates of gB type 1 were more commonly found to be of gH type 2, whereas gB types 2-4 were more commonly linked to gH type 1. A small frequency of recombination with gB was detected by restriction analysis of DNA from variable regions of the gp55 and gp116 domains. Multiple isolates from various sites of 29 patients were typed and, with three exceptions, the gB genotype remained constant in all isolates from a single patient. Patients who survived CMV infection more commonly shed virus of gB type 1 than those who died (P =.003). This significant difference of gB types among patient subsets is unexplained but raises the possibility that gB genotypes may serve as a marker for pathogenicity of CMV strains in marrow transplant patients.