GEOGRAPHICALLY DISTINCT HHV-8 DNA-SEQUENCES IN SAUDI-ARABIAN IATROGENIC KAPOSIS-SARCOMA LESIONS

A new member of the gamma-herpesvirus family, HHV-8 (also known as Kap osi's sarcoma (KS)-associated herpesvirus), has been Linked to KS and body cavity-based lymphoma, Other members of this family, eg, Epstein- Barr virus, were originally thought to have only one strain, but subse quent analysis revealed different strains correlating to cellular patt erns of infectivity and geographical location, To determine whether mu ltiple strains of HHV-8 exist, we compared DNA sequences among KS and body cavity-based lymphoma-derived HHV-8 and examined differences in H HV-8 subgroups between American and Saudi Arabian iatrogenic KS patien ts, Samples were analyzed by polymerase chain reaction using multiple primer sets to five different open reading frames from HHV-8, and DNA sequencing was performed. HHV-8 DNA was present in all of our KS and b ody cavity-based lymphoma samples by polymerase chain reaction. HHV-8 DNA was detected in each body cavity-based lymphoma sample using a maj ority of the primers, whereas only two primer sets consistently amplif ied HHV-8 DNA derived from KS lesions. DNA sequencing within open read ing frames 26 and 27 indicate the existence of at least three variants of HHV-8, with the majority of iatrogenic KS patients in Saudi Arabia containing unique nucleotide changes that may define a distinct, prev iously unidentified subgroup we term SA, whereas those from America we re of Group A or B. Thus, although the sequencing data within open rea ding frames 26 and 27 did not permit discrimination between patients w ith lymphoma versus KS disease processes, HHV-8 derived from Saudi Ara bian KS lesions were shown to have a distinct nucleotide sequence not seen in any of the other clinical samples examined.