Clinicopathologic study of Kaposi's sarcoma and strain analysis of human herpesvirus 8 (HHV-8)DNA in the Hua-Lien area of eastern Taiwan

Background and purpose: Kaposi's sarcoma (KS) is a spindle cell malignancy of endothelial cell origin. The tumor has been demonstrated to be associate d with human herpesvirus 8 (HHV-8) or Kaposi's sarcoma-associated herpesvir us-like virus (KSHV). Previous studies have revealed the distribution of un ique viral strains in different ethnic populations. Eastern Taiwan has an e thnically mixed population with a relatively high incidence of KS. This stu dy was designed to characterize the clinicopathologic features of KS and to evaluate the HHV-8 strain distribution in the Hua-Lien area of Eastern Tai wan. Methods: Clinical records and laboratory data were collected from 15 cases of KS diagnosed and treated between 1993 and 1999 in Tzu-Chi General Hospit al. For nine cases, paraffin blocks were available for the molecular study of HHV-8. HHV-8 genomic variation was analyzed using polymerase chain react ion nucleotide sequencing of ORF26 and ORF75 of HHV-8 genomes derived from different subgroups of KS. Results: Among the 15 patients with KS, two had AIDS-associated disease, fo ur had gouty arthritis and psoriasis and were receiving corticosteroid ther apy (iatrogenic type), and nine had classical KS. Nine of the 15 cases occu rred in aborigines, including one with AIDS-associated disease, four with i atrogenic disease, and four with classical disease. Among the nine cases fo r which tissue was available for DNA analysis, eight were positive for HHV- 8 DNA. Sequence analysis revealed that the C strain occurred in three Han C hinese KS patients, whereas a hitherto rarely described strain (strain D) o ccurred in all four aborigines tested (including one with AIDS-associated K S) and one Han Chinese with AIDS from Burma. Conclusion: This study found a high proportion of iatrogenic KS and the fin ding of a rarely described strain D virus in Eastern Taiwan aborigines. Our studies further confirm the distribution of different types of KS and viru s strains in different ethnic populations.