Kaposi sarcoma of th e penis in anHIV-negative patient / Sarcoma de Kaposi de pênis em paciente HIV negativo

ABSTRACT Kaposi sarcoma is an angioproliferative disorder that ranges from a single indolent skin lesion to respiratory and gastrointestinal/visceral involvement. Kaposi sarcoma is rare in non-immunosuppressed patients. Nineteen cases of penile Kaposi sarcoma in HIV-negative patients were reported in 2012. We present the case report of a 48-year-old male patient with no previous medical history, who came to our urology clinic presenting a purple-color papule on the penis glans. Lab tests revealed negative serology for HIV, but tissue PCR was positive for human herpesvirus 8. Histopathology examination after lesion excision was compatible with Kaposi sarcoma. No other cutaneous or mucosal lesions were present. Primary Kaposi sarcoma of the penis is rare, but may occur in non-immunosuppressed patients.

RESUMO O sarcoma de Kaposi é uma doença angioproliferativa que varia de uma lesão cutânea indolente isolada ao envolvimento visceral respiratório e gastrintestinal. É raro em pacientes não imunossuprimidos. Dezenove casos de sarcoma de Kaposi de pênis em pacientes HIV negativos foram relatados em 2012. Descrevemos o caso de um paciente do sexo masculino, 48 anos, sem história pregressa, que se apresentou em nossa clínica urológica com pápula violeta na glande. Os testes de laboratório revelaram sorologia negativa para HIV, mas o PCR em tecido foi positivo para o herpesvírus humano 8. A histopatologia após a excisão da lesão foi compatível com sarcoma de Kaposi. Não existia outra lesão cutânea ou de mucosa. O sarcoma de Kaposi primário de pênis é raro, mas pode ocorrer em pacientes não imunossuprimidos.

Multi-transmembrane protein K15 of Kaposi's sarcoma-associated herpesvirus targets Lyn kinase in the membrane raft and induces NFAT/AP1 activities

Viral proteins of gamma-2 herpesviruses, such as LMP2A of Epstein Barr virus (EBV) and Tip of herpesvirus saimiri (HVS) dysregulate lymphocyte signaling by interacting with Src family kinases. K15 open reading frame of Kaposi's sarcoma associated herpesvirus (KSHV), located at the right end of the viral genome, encodes several splicing variants differing in numbers of transmembrane domains. Previously, we demonstrated that the cytoplasmic tail of the K15 protein interfered with B cell receptor signal transduction to cellular tyrosine phosphorylation and calcium mobilization. However, the detailed mechanism underlying this phenomenon was not understood. In the C-terminal cytoplasmic region of K15, putative binding domains for Src-SH2 and -SH3 were identified. In this study, we attempted to characterize these modular elements and cellular binding protein(s) by GST pull down and co-immunoprecipitation assays. These studies revealed that K15 interacted with the major B cell tyrosine kinase Lyn. In vitro kinase and transient co-expression assays showed that the expression of K15 protein resulted in activation of Lyn kinase activity. In addition, GST pull down assay suggested that the SH2 domain of Lyn alone was necessary for interaction with the C-terminal SH2B (YEEV) of K15, but the addition of Lyn SH3 to the SH2 domain increases the binding affinity to K15 protein. The data from luciferase assays indicate that K15 expression in BJAB cells induced NFAT and AP1 activities. The tyrosine residue in the C-terminal end of K15 required for the Lyn interaction appeared to be essential for NFAT/AP1 activation, highlighting the significance of the C-terminal SH2B of K15 as a modular element in interfering with B lymphocyte signaling through interaction with Lyn kinase.

Detection of human herpesvirus 8 DNA in pemphigus and chronic blistering skin diseases

Increased incidences of Kaposi's sarcoma and lymphoid malignancies have been observed in patients with pemphigus, and the human herpesvirus 8 (HHV-8) is very strongly associated with these tumors. Because the virus may be one of the triggering factors of pemphigus, we undertook this study to screen for the presence of HHV-8 in chronic blistering skin diseases including pemphigus. A total of 45 paraffin-embedded specimens were studied using nested polymerase chain reaction (PCR) with primers to amplify a 160-base pair HHV-8 fragment. HHV-8 DNA could be detected in 7 of 9 patients with pemphigus vulagris, and 1 of 2 with pemphigus foliaceus. All specimens of other blistering skin diseases were negative for HHV-8. On sequencing PCR products, the sequences were almost identical with the prototypic sequence for HHV-8, and a few base- pair substitutions at 1086C-T and 1139A-C were detected. The results of our study suggests that HHV-8 might have trophism for pemphigus lesions. Further studies including comparison of HHV-8 DNA load in both lesional and normal skin in the same patient, serological and animal studies would be helpful to study the relationship between HHV-8 and pemphigus.

Detection of human herpesvirus 8 DNA in pemphigus and chronic blistering skin diseases

Increased incidences of Kaposi's sarcoma and lymphoid malignancies have been observed in patients with pemphigus, and the human herpesvirus 8 (HHV-8) is very strongly associated with these tumors. Because the virus may be one of the triggering factors of pemphigus, we undertook this study to screen for the presence of HHV-8 in chronic blistering skin diseases including pemphigus. A total of 45 paraffin-embedded specimens were studied using nested polymerase chain reaction (PCR) with primers to amplify a 160-base pair HHV-8 fragment. HHV-8 DNA could be detected in 7 of 9 patients with pemphigus vulagris, and 1 of 2 with pemphigus foliaceus. All specimens of other blistering skin diseases were negative for HHV-8. On sequencing PCR products, the sequences were almost identical with the prototypic sequence for HHV-8, and a few base- pair substitutions at 1086C-T and 1139A-C were detected. The results of our study suggests that HHV-8 might have trophism for pemphigus lesions. Further studies including comparison of HHV-8 DNA load in both lesional and normal skin in the same patient, serological and animal studies would be helpful to study the relationship between HHV-8 and pemphigus.

Human herpes virus 8 and kaposi's sarcoma: A review

Kaposi's Sarcoma (KS) was first described one century ago as a disease occurring in elderly men manifested as an indolent cutaneous form. After the onset of human immunodeficiency virus type I (HIV-1) infection, KS became epidemic which, in association with HIV, presented as an aggressive, systemic disease. Recently, the recognition that a novel human herpes virus-8 (HHV-8) was highly prevalent among KS patients provided strong evidence to indicate that HHV-8 was the etiology of KS. The pathogenesis of KS in AIDS patients is still controversial, but there is evidence suggesting that KS is a cytokine-mediated disease, and that increased levels of inflammatory cytokines in AIDS patients were responsible for the aggressive pattern of disease seen in such patients. The recently developed serological assays for detection of HHV-8 antibodies have made possible a better understanding of the prevalence of HHV-8 in different populations, and this has allowed a deeper understanding of HIV-8 epidemiology.

Detection of herpes virus (KSHV) DNA sequences in Brazilian patients with AIDS-associated Kaposi's sarcoma

To explore the possible involvement of herpes viris (KSHV) in AIDS-associated Kaposi's sarcoma (KS) in 7 patients in Brazil, we analyzed 7 AIDS-KS lesions. Using PCR, we found KSHV specific sequences in 3 cases and by using nested PCR, we identified sequences in each of 7 cases. Direct sequencing on nested-PCR products showed a certain degree of variability in relation to classic KSHV sequences, and identified alterations similar to those described in some endemic cases from Africa and in AIDS-associated KS specimens from North America. This mixed pattern of KSHV sequences observed in AIDS-associated KS from Brazil may reflect the geographic origin of the samples, consistent with the environmental and epidemiological backgrounds of people in this country. It is apparent that, just as in other countries in the world, Kaposi's sarcoma in HIV patients is related to herpes virus infection.