Detection of DNA of human lymphotropic herpesviruses in patients with HIV-1 infection, classic Kaposi sarcoma and healthy volunteers: prevalence and clinical significance

Human Lymphotropic herpesviruses (CMV, EBV, HHV6, HHV7, HHV8) are ubiquitous viruses, which after primary infection persist in the host in a latent form. The aim of our study was to evaluate the frequency of detection of lymphotropic herpesvirus DNA in the plasma, PBMC and saliva of HIV infected patients, Classic Kaposi Sarcoma patients and healthy volunteers. We analyzed plasma, PBMC and saliva from 36 patients with HIV infection without herpesvirus related diseases (HIV As), 9 patients with classic Kaposi Sarcoma (Cl KS) and 10 healthy volunteers (HV). All samples were previously treated for DNA extraction with a commercial kit and then a multiplex nested PCR was performed for the simultaneous detection of HHV6-, HHV7- and HHV8-DNA. Real time PCR was performed in order to detect EBV- and CMV-DNA, only in plasma samples. For each patient 300 μl of whole blood were incubated 1:1 with RPMI and stimulated with PHA (10μg/mL) for 24 hours at 37°C and 5% CO2. At the end of incubation supernatants (SN) were collected and stored at -20°C. IL1β, IL6, IFNγ, TNFα concentrations were measured by Enzyme-Linked Immunosorbent Assays (ELISA) according to manufacturer instructions. Statistical analysis was performed with SPSS software. The rate of detection of HHV6-DNA was very low in the samples drawn from the three groups of patients (HIV As:3%; Cl KS:22%, HV: 0%). HHV7 was the most commonly detected virus in plasma, PBMC and saliva of HIV AS group and HV. The rate of HHV7 DNA detection was lower in both plasma and PBMC of HIV AS group (31% and 22% respectively) than in HV (50%; p= 0,283 and 70%; p=0,008 respectively). No difference in the rate of detection of HHV7 DNA was found in saliva from HIV AS group and HV (58% and 60% respectively; p=0,6). As expected, the rate of HHV 8 DNA detection was higher in plasma, PBMC and saliva of Cl KS group (33%, 56% and 56% respectively) than in controls (0%, p=0,087; 0%, p=0,011; 0%, p=0,011 respectively). HHV8 DNA was detected in plasma and PBMC of 2 patients and in saliva of 6 patients of the HIV As group. EBV DNA was detected only in plasma of 8 patients from the HIV As group, while CMV DNA was detected only in 1 patient belonging to the Cl KS group. HHV6 and HHV7 were the only two viruses detected in the samples drawn from healthy blood donors. Concerning cytokine production after in vitro stimulation of whole blood, in the HIV AS group those subjects with plasma detection of HHV7 DNA had lower levels of TNFα, IL6, IFNγ, IL1β in SN, in comparison with subjects of the HIV AS and HV groups without plasma detection of HHV7 DNA (see table 1). Among human limphotropic herpesvirus HHV7 is the most commonly detected virus in HIV positive and negative subjects, although it is less frequent in seropositive individuals. HHV7 may provide an inhibitory effect on host inflammation interfering with HIV-1. 1