Kaposi’s sarcoma: evaluation of the role of human papillomaviruses: A study using the high sensitivity hot-start polymerase chain reaction detection method and a review of the literature

Opportunistic AIDS-associated malignancies in HIV-infected patients

Three major neoplasms are associated with AIDS definition in the course of HIV infection due to their increased incidence. The relationship between the immune system and the epidemiology of these virus-induced tumors is of importance in order to identify new therapeutic approaches for treating or preventing these neoplasms. Major improvements in the understanding of the pathogenesis have already been performed. The impact of highly active antiretroviral therapy (HAART) on their incidence likely confirms the concept of 'opportunistic malignancies'. Other neoplasms are likely more prevalent in HIV-infected individuals, but their relative importance requires further prospective case-control cohort studies.

Penile intraepithelial neoplasia overlying Kaposi's sarcoma lesions: role of viral synergy?

Several viral agents have been detected in the lesional tissue of Kaposi's sarcoma (KS). Their precise oncogenic role remains to be determined. A 32-year-old heterosexual man with acquired immunodeficiency syndrome (AIDS) who had penile lesions of KS with overlying epithelial changes characteristic of intraepithelial neoplasia associated with concurrent infection by human papillomavirus (HPV) and human herpesvirus 8 (HHV-8) is reported. The absence of viral DNA from uninvolved skin suggests that this coinfection is more than coincidental and may involve synergy between these viruses, as has already been suggested for HPV and herpes simplex 2 virus.

Differential expression of p53 and Ki-67 proteins in classic and iatrogenic Kaposi's sarcoma

In many neoplasms, the finding p53 immunoreactivity correlates with striking cytologic atypia, a high tumor cell proliferation rate, and poor prognosis. The literature regarding p53 and Ki-67 (a nuclear proliferation-associated antigen) immunoreactivity in Kaposi's sarcoma is limited. We aimed to: (1) evaluate the role of p53 in the development of Kaposi's sarcoma; (2) determine whether there is a correlation between p53 and Ki-67 protein expression; and (3) determine possible differences between classical Kaposi's sarcoma, known usually to have a benign course, and iatrogenic Kaposi's sarcoma, the course of which is unpredictable, by studying the differential expression of p53 and Ki-67. Among 26 cases of classic KS and 19 of iatrogenic KS, 12 were classified histopathologically as early type and 33 as mixed or spindle-cell type. P53 and Ki-67 immunoreactivity correlated significantly with the histopathologic stage of KS (r=0.63, p=0.0001; r=0.42, p=0.0084, respectively). P53 was not detected in any of the cases in an early histopathologic stage but was present in 55% of the cases in a more advanced stage. The spindle cells increased in proportion with the histopathologic progression and were more often positive (p=0.019) and displayed more extensive staining than the endothelial cells (p=0.0001). There was a strong positive correlation between p53 and Ki-67 protein expression (r=0.43, p=0.0087). There was no correlation between the expression of either p53 or Ki-67 and the extent of the eruption. The expression of p53 and Ki-67 was significantly lower in iatrogenic cases than in the classic cases (p=0.009, p=0.0014, respectively), although no statistical difference was found between the histopathologic stages in the two clinical forms of KS. P53 immunoreactivity was detected in 79% of the cases of classic Kaposi's sarcoma in the mixed or spindle cell stage but in only 21.5% of the iatrogenic cases showing the same histopathologic stage (p=0.001), and the percentage of spindle cells as well as the endothelial cells expressing p53 was higher in the classic cases than in the iatrogenic cases (p=0.0032, p=0.0142, respectively). We conclude that p53 immunoexpression is a marker of tumor progression in classic Kaposi's sarcoma but not in most cases of iatrogenic Kaposi's sarcoma. The proliferative activity of the tumor cells in classic Kaposi's sarcoma is much higher than in iatrogenic Kaposi's sarcoma. Our work implies that the molecular steps involved in classic and iatrogenic Kaposi's sarcoma differ.

Epidemiology, etiology and pathogenesis, clinical presentations and therapeutic approaches in Kaposi's sarcoma: 15-year lessons from AIDS

Kaposi's sarcoma (KS) is a leading cause of morbidity among 25-30% of AIDS patients and is by far the most common AIDS-associated malignancy. Since the beginning of the 1990s the incidence of KS continuously declined, but it was the introduction of protease inhibitors that markedly reinforced this phenomenon. In our experience, the annual incidence was 59/1,000 patient-years in 1984 vs 21.2/1,000 patient-years in 1990, 12.5/1,000 patient-years in 1996, with a drop to 3.2/1,000 patient-years in 1997. One of the peculiar characteristic of this tumor is the sexual susceptibility, which could be the consequence of a hormonal protection in females. The in vitro models of KS-like cell culture promoted and sustained in vitro with a conditioned medium containing several pro-inflammatory cytokines, the characterization of human herpes virus-8 (HHV-8) in almost all the cases of AIDS-KS as the putative KS-agent and the determination of a putative role of hCG-associated factors in the control of KS growth are among the leading discoveries of this last decade in this field.