HHV-6 and EBV elevated in the GI tract of HIV+ patients
A group from Sapienza University in Rome has found a significantly higher prevalence for HHV-6 and an elevated viral load for EBV in the stomach and duodenum biopsies of patients with HIV compared to controls, suggesting that these viruses may contribute to the development of gastric cancer in immunocompromised patients.
The analysis included 41 stomach antrum biopsies, 15 duodenum samples and 11 colorectal biopsies. Findings revealed a significantly higher detection rate of EBV and HHV-6 in the gastrointestinal (GI) tract of HIV-infected individuals than that in uninfected patients (88.5 vs 63 %; p = 0.03). Interestingly, while 36 % of GI biopsy specimens collected from HIV-infected patients showed both EBV and HHV-6 DNA, co-infection was never observed in samples from HIV-negative subjects (p = 0.02). Also, although CMV is a frequent cause of disease in the GI tract of transplant patients, no CMV DNA was detectable in any specimen analyzed.
Distinct differences in the region of GI tract infected were also observed between HHV-6 and EBV. A significantly higher detection rate of HHV-6 DNA was found in the stomach mucosa samples of HIV-positive individuals vs. controls (50% vs 17 %; p = 0.03). Regarding EBV, although the prevalence in stomach biopsies did not significantly differ between the HIV+ and control groups, EBV viral load was significantly elevated in HIV+ patients (median of 5 vs 0 copies per microgram of DNA). In addition, 5 of 8 (62%) colorectal biopsies from HIV positive samples showed EBV DNA, while no EBV DNA was detected in HIV-negative subjects (p = 0.07). HHV-6 was found at a comparable rate in colorectal biopsies from both patients and controls.
Several groups have hypothesized the role of HHV-6 in the development of gastric cancer. A group from Finland’s Helsinki University Hospital has recently published evidence to suggest HHV-6B may be involved in the development of adenomatous gastrointestinal polyps (Halme 2013). Furthermore, it is known that HHV-6B antigens are commonly found in the intestinal mucosa of patients with immunosuppression, and a study published earlier this year reported that the activation of HHV-6B and HHV-7 in patients with gastrointestinal cancer may lead to a marked decrease in lymphocytes and worsening of immunosuppression (Sultanova 2013).
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