טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentGuttman-Yassky Emma
SubjectThe Epidemiology of Classic Kaposi's Sarcoma in Israel
Kaposi`s Sarcoma among the Jewish Population in
Israel
DepartmentDepartment of Medicine
Supervisors Professor Emeritus Michael Silbermann
Mr. Shai Linn
Clinical Professor B. Friedman
Dr. Micha Bar-Chana


Abstract

Classic Kaposi's sarcoma (CKS) is a rare complex multifocal disease, primarily affecting the skin, that predominantly occurs in elderly men of Mediterranean or Eastern European descent. In all CKS cases the human herpesvirus-8 (HHV-8) can be identified. The incidence rates of CKS in the Jewish population in Israel are considered among the highest in the world. In the present study we aimed to study the epidemiology of CKS in Israeli Jewish patients between 1960 and 1998, to analyze HHV-8 infection rates in Jewish CKS patients in comparison with a control population, to identify risk factors for CKS development, and to search for sequences of HHV-8 in biopsies from concomitant malignancies of CKS patients. CKS Jewish patients (n= 64), and a randomly selected control group (n-191) were included in the study. Collected sera were tested for HHV-8 antibodies using two immunofluorescence assays (IFA) (latent and lytic IFA) while a third test (ORF65 Western blot) was applied for disconcordant samples. Two different questionnaires were formulated for the patients and for the control population. In the present population-based study, 2107 cases of CKS (1475 men, 632 women) were identified, yielding world standardized incidence rates of 20.7 and 7.5 per million among men and women, respectively (RR=2.76, 95% CI 1.57-3.95). Highest incidence rate for men was demonstrated by Jews originating from Africa, and for women by Asian-born Jews. Using our approach for defining HHV-8 seropositivity, we found a high prevalence of HHV-8 antibodies among CKS patients (63/64, 98.4%) with a high concordance between the assays. We detected an overall HHV-8 seroprevalence of 13% (25/191) among the controls, also with a high concordance between the assays. We did not identified HHV-8 sequences in biopsies taken from concomitant malignancies.

Our study confirms, in one of the largest groups of CKS patients ever described, that HHV-8 infection is a prerequisite for CKS development. The fact that HHV-8, although in much lower rates, can also be found in the general healthy population, supports the notion that HHV-8 is obligatory for CKS development, but other genetical and environmental factors are probably involved in CKS development.