The paper presents literature data and results of own studies on the Kaposi's sarcoma herpesvirus (KSHV) and its association with Kaposi's sarcoma (KS), the primary effusion lymphoma (PEL) and multicentric Kastleman disease (MCD). The obtained data show that all 3 main clinical forms of KS, diagnosed in Russia, are significantly associated with KSHV, though not always in 100% of cases. Distinct groups of persons with high prevalence of virus infection have been detected among patients with other forms of cancer and non-cancer diseases that may represent a risk factor for development of KS. It was found that the prostate, especially in patients with carcinoma of the prostate and KS could be an important localization of virus and intimate contact with these patients should be limited. For the first time in Russia HIV-negative case of PEL associated with KSHV had been diagnosed and studied in details. It was also demonstrated that isolates of KSHV, circulating in the country, belong to the two major genetic subgroups of the virus (A and C), a widely represented in the European countries and in the United States, which indicates a common origin of the virus in these countries. The current methodologies of KS' treatment are also presented.

Summarized in the paper are study results of human herpesvirus type 8 (HHV-8) and of its association with Kaposi's sarcoma (KS). The data obtained denotes that the share of individuals producing the antibodies to HHV-8 in a majority of studied patients was low and ranged form 0 to 5.5%, which is indicative of a low degree of the virus spread in population. At the same time, a high share of persons with antibodies to HHV-8 was detected among HIV-infected homosexuals (71.4%), kidney recipients (26.0%) and among AIDS-KS patients (78.6%). It was also unexpectedly high among patients with T- and B-cell lymphomas (50%), encephalopathy (27.3%) and with stomach cancer (41.8%): the appropriate parameters were 7-12-fold higher versus healthy subjects. The HHV-8 markers, i.e. virus specific antibodies and/or nucleotide sequences of the virus, were detected in blood serum and ejaculate of a significant number of patients with different pathologies of the prostate. Such detection of viral markers in the above categories of patients is suggestive of that sexual contacts with such patients are decisive for the HHV-8 spread in population.

The purpose of the present study was to investigate the HH-8 seroprevalence among patients with Kaposi's sarcoma (KS), melanoma and gastric carcinoma (GC) as well as among renal recipients and blood donors. The obtained data revealed a high percentage of seropositive KS patients, which ranged from 83.6% in the classical disease type to 68.8% and to 71.4% in the immunosuppressive and AIDS-associated disease types, respectively. On the whole, the positive humoral response to HHV-8 reliably correlated with the positive findings if the viral genetic information in tumor tissue samplings. An unexpectedly high percentage of seropositive persons was found among the GC patients (41.8%) and among the renal recipients (26%), which is apparently predetermined by the immunosuppressive condition of such patients. Seroprevalence was found only in 4% of blood donors. Thus, the obtained data make it possible to conclude that KS cases, as diagnosed in Russia, are tensely associated with HHV-8 in spite of a low virus spread among the healthy population. Patients with pathology concomitant with a pronounced immunosuppression are characterized by a high prevalence of HHV-8 and belong to the category of persons with a KS risk.

Associations of a new human herpesvirus type 8 (HHV-8) with different forms of Kaposi's sarcoma (KS) in Russia have been studied. Search for this virus genetic information has been carried out in biopsy specimens of benign and malignant tumors other than KS, and probable sites of HHV-8 latency in human body have been checked. HHV-8 sequences were detected by polymerase chain reaction (PCR). HHV-8 sequences were most often detected in idiopathic (80.6%), AIDS-associated (80%), and immunosuppressive (100%) KS. The results indicate a selective association of HHV-8 with KS. No probable sites of the virus latency were detected in peripheral blood cells of patients with KS and in the prostate of patients with chronic prostatitis. The only exception was the husband of a patient with KS: HHV-8 sequences were detected in his prostatic secretion by nested PCR.