Background: Worldwide, Kaposi's sarcoma (KS) occurs in immunocompetent elderly adults, especially men. Elderly Jews have relatively high KS risk, but it is unclear whether this indicates heightened prevalence of KS-associated herpesvirus (KSHV), the KS agent. We studied Jewish and non-Jewish patients at a New York City geriatrics clinic.
Methods: We measured plasma antibodies against K8.1 (a KSHV glycoprotein) by enzyme immunoassay and against viral latency antigens by immunofluorescence assay. Individuals positive by either were considered KSHV-seropositive. Titres were performed for positive subjects. We used polymerase chain reaction to quantify circulating KSHV DNA.
Results: Of 467 subjects (median age 80 years), 40 were KSHV-seropositive (8.6%). Seroprevalence was 8.8% among Jews (18 of 204), similar to other religious groups, and did not differ by sex or region of birth. However, K8.1 antibody titres were higher in men than women (geometric mean titre 177 versus 35, P = 0.03) and increased with age (P = 0.02). The K8.1 titres were higher in three people from Central/Eastern Europe (1,280, 1,280, 320), all of whom were Jewish, than in others (geometric mean titre 39, P = 0.006). The single person with detectable circulating KSHV (457 copies/million cells) had the highest titre (5,120).
Conclusions: The KSHV seroprevalence was not elevated among elderly Jews, despite their known high risk for KS. However, among KSHV-seropositive individuals, K8.1 titres were highest in subgroups at greatest risk for KS (men, older individuals, people from Central/Eastern Europe) and may identify individuals with poor immune control of KSHV replication during asymptomatic infection.