Search

Abstract: Background:: Kaposi''s sarcoma (KS) is caused by Kaposi''s sarcoma associated herpesvirus (KSHV/HHV-8), the eighth Herpesvirus found to infect humans. The molecular epidemiology of KSHV is related closely to ethnicity and geographical location of studied populations. There is little epidemiological and molecular information about KSHV strains circulating in Brazil. Objectives:: To characterize KSHV strains isolated from AIDS patients with Kaposi''s sarcoma (AIDS-KS) in São Paulo, Brazil, and to examine associations between KSHV subtypes, ethnicity and HIV risk categories. Methods:: AIDS-KS patients were recruited consecutively at the largest AIDS reference hospital in São Paulo. Fragments (420bp) of the VR1 and VR2 regions of KSHV open reading frame (ORF) K1 were amplified by nested PCR and sequenced directly. Results:: We analysed 37 samples from 33 patients, and found subtypes A–C in 48%, 21% and 30% of patients respectively, including two patients infected with subtype A5, a first report from Brazil. Sexual orientation was associated with subtype: 12/14 (86%) patients with subtype A were male homo/bisexual, compared with 3/8 (38%) among patients infected with subtype C (P=0.05). A higher proportion of male patients with subtype C were of Caucasian origin (7/8 (87%)), compared with 7/16 (44%) among male patients with subtype A (P=0.08). Conclusions:: This first detailed report of KSHV subtypes among AIDS-KS patients in Brazil reports the first isolation of KSHV subtype A5 in this country, and suggests KSHV strain transmission between different ethnic groups, and association of specific strains with sexual orientation. [Copyright &y& Elsevier]

The article presents information on a case study which determines three cases of classic Kaposi's sarcoma. Kaposi's sarcoma associated human herpesvirus or herpesvirus was detected for the first time in AIDS-associated Kaposi's sarcoma lesions in 1994. The incidence of classic Kaposi's sarcoma in a given population is difficult to establish and to discriminate from its prevalence because of slow disease progression. The diagnosis of Kaposi's sarcoma was confirmed in 2001 by a histopathological examination.

Kaposi's sarcoma-associated herpesvirus (KSHV) is the infectious cause of Kaposi's sarcoma (KS) and certain lymphoproliferations particularly in the context of human immunodeficiency virus (HIV) type 1-induced immunosuppression. The introduction of effective therapies to treat HIV has led to a decline in the incidence of KS, suggesting that immune responses may play a role in controlling KSHV infection and pathogenesis. Cytotoxic-T-lymphocyte (CTL) activity against KSHV proteins has been demonstrated; however, the identification of KSHV CTL epitopes remains elusive and problematic. Although the herpesvirus genomic layout is generally conserved, KSHV encodes a unique hypervariable protein, K1, with intense biological selection pressure at specific amino acid sites. To investigate whether this variability is partly driven by cellular immunity, we designed K1 peptides that match only the unique viral sequence for every individual studied here (autologous peptides). We identified functional CTL epitopes within K1's most variable areas, and we show that a given individual responds only to autologous peptides and not to peptides from other individuals. Furthermore, these epitopes are highly conserved sequences within KSHV isolates from a specific strain but are not conserved between different strains. We conclude that CTL recognition contributes to K1, and therefore to KSHV, evolution. [ABSTRACT FROM AUTHOR]