For definition of Groups, see Preamble Evaluation . It contains blocks of conserved herpesvirus genes that encode mainly structural proteins.
Lytic replication occurs in a subpopulation of infected spindle and haematopoietic cells.
Serological methods have been developed for the detection of antibodies to a latent nuclear protein and to defined and undefined structural antigens, including immunofluorescence assays, enzyme-linked immunosorbent assays and western blotting. The load of viral DNA is higher in tissue from Kaposi's sarcomas than in unaffected tissues from the same patients. Despite differences in sensitivity, in specificity and in the antigens examined, all of the available serological studies are consistent in showing high rates of antibody-positivity in Kaposi's sarcoma patients and lower rates of seropositivity among various controls. Thus, the strength of association between infection with this virus and Kaposi's sarcoma is high, as measured by PCR, Southern blotting and serology, with odds ratio greater than 10 being found in most studies involving large numbers of cases and well-defined controls. This association is found in studies with various designs and for all epidemiological types of Kaposi's sarcoma.